Google Challenge Results In Astoundingly Efficient Inverters

AmiMoJo writes: A few summers ago, Google and IEEE announced a one million dollar prize to build the most efficient and compact DC to AC inverter. It was called the Little Box Challenge, with the goal of a 2kW inverter with a power density greater than 50 Watts per cubic inch. Typical solar inverters have a density of about 5 W/cubic inch. Now the results are in, with the winners hitting 143 W/cubic inch using GaN transistors, and two other teams meeting Google's goal.

Comments

10 ways to make your microsoft clojure app more $x

[Anonymous Coward]

Learn to master microsoft clojure app development from the experts!

Hooray for science

[gatkinso]

The world is a slightly better place.

Re:Hooray for science

[Anonymous Coward]

GaN has been know about for many years. I first heard about its usage in the 1990s, and I doubt I was cutting edge. The problem is fabrication and cooling issues. GaN was supposed to be the great thing to replace silicon ICs, and bring on the next iteration of miniaturisation. Perhaps this is it (nah, it won't).

Who participated?

[Anonymous Coward]

Did Google adequately encourage women and minorities to enter the challenge? We need to ensure that opportunities like this are accessible to women and minorities to encourage their participation in STEM fields.

Re:Who participated?

[Anonymous Coward]

We need to ensure that opportunities like this are accessible to women and minorities to encourage their participation in STEM fields.

No. We don't. Women and minorities need to study the same shit everyone else does and participate under the same opportunities / challenges everyone else does.

Now take your angsty SJW baggage and get the hell off my lawn.

Re:Who participated?

[Anonymous Coward]

Did Google adequately encourage women and minorities to enter the challenge? We need to ensure that opportunities like this are accessible to women and minorities to encourage their participation in STEM fields.

Glad to say the token nigger provided an "inverter" which was a box that could be turned upside down. Glad to say that he was happy with the consolation prize, which was a bunch of bananas

Re:Who participated?

[GLMDesigns]

I think he forgot the /sarc at the end of his post.

Re:Who participated?

[Anonymous Coward]

Did Google adequately encourage women and minorities to enter the challenge? We need to ensure that opportunities like this are accessible to women and minorities to encourage their participation in STEM fields.

Glad to say the token nigger provided an "inverter" which was a box that could be turned upside down. Glad to say that he was happy with the consolation prize, which was a bunch of bananas

And the Indian and Chinese teams were duly informed that they did not count as minorities, because they are generally competent and law abiding. The Indian team was particularly disappointed because they thought the "banana" prize was even more work.

Re:Who participated?

[cc1984_]

I think he forgot the /sarc at the end of his post.

You are assuming GP male. This kind of sexist assumption is exactly the type of thing that needs to be stamped out in the industry.

Now if you need me, I'll be in my safe space. /sarc

Re: Who participated?

[Anonymous Coward]

Spoken like a true white male middle class virgin...

Re: Who participated?

[Anonymous Coward]

Chinese and Indiands as law abiding? Their whole fucking countries are full of corruption, bribery, and uncivilized behavior like spitting all over the streets and even just taking a dump in the middle of the road.

Re: Who participated?

[Anonymous Coward]

Yeah, but that's sexism. Making poor women and minorities actually have to put in effort rather than just threatening a racism lawsuit/sleeping with the boss to get something accomplished. All at the expense of the WHITE MAN.

Re: Who participated?

[Anonymous Coward]

Fortunately there is this awesome song which should put and end to public defecation: https://www.youtube.com/watch?...

Re:Who participated?

[suutar]

I think that's the point - to remove some of the challenges not everyone else has so they have the opportunities everyone else does.

Whether any given program actually achieves that is of course debatable.

Re: Who participated?

[Coeurderoy]

Thanks to all the AC for clarifying why Trump might become you president....

As a side note: positively discrimination on a goal oriented challenge would be beside the point, after all you want the maximum of "what ever" from the winner...
But not going through a phase of positive discrimination has two drawbacks, you get less talented people from the discriminated group, and you give the illusion to a whole bunch of idiots in the advantaged group that they are actually worth something in their chosen activity, instead of letting them either try harder, or change business.
So as defined in the Hacker's Dictionary Loose Loose !

Re:Who participated?

[Anonymous Coward]

We're using non-gender specific pronouns now to avoid this problem.

"I think ze forgot the /sarc at the end of zer post.

Re:Who participated?

[silas_moeckel]

Because registering a team is somehow hard for minorities or women? The fact they had to use the internet or english? Please describe a change faced by these groups that a white male from Appalachia would not also face?

Re:Who participated?

[U2xhc2hkb3QgU3Vja3M]

The original parent was obviously speaking with tongue-in-cheek to mock the whole concept and your reply while being modded as a troll was completely genuine.

You want the truth? People can't handle the truth!

Re:Who participated?

[kimvette]

I think someone is trying to be too politically correct. For ages it's been assumed that "he" and "man"/"mankind" may be used in a generic sense to refer to everyone, because English is already cumbersome enough as it is without having to write out "he or she" just to satisfy the hypersensitive knee-jerk reactionists out there.

Re:Who participated?

[Anonymous Coward]

You are assuming GP male

This is /., he is statically likely to be correct.

Re:Who participated?

[HiThere]

And when AIs start objecting we'd need to write she/he/it.

Re:Who participated?

[Anonymous Coward]

i don't think they like being called "it" i believe they prefer "overlord"

Re:Who participated?

[Anonymous Coward]

Which will promptly be portmanteaud to "shit."

Re:Who participated?

[Maxo-Texas]

As far as I know they didn't. They didn't correct for creepy fellow male students mobbing them nor for creepy professors hitting on them or for creepy co workers mobbing them and hitting on them once they graduate either.

Of course, they do face significant challenges
http://gos.sbc.edu/b/baum.html

A scary finding of the questionnaire was that women reported their high school guidance counselors were very non-supportive of their decision to study engineering. Non-supportive is a nice word, because I got long letters that talked about how they were actually discouraged by people in their high schools. There seem to be many high schools in our country which discourage women from taking advanced math and physics courses, and, in fact, there seem to be very few women who were physics teachers in high school.

Two-thirds of the women who are married say they make more money then their husbands, and in many of those families, that really is a source of tension for women engineers as well as for other women.

They were expected to take care of household duties any way.

And having a child is a challenge - especially since men don't get maternity leave.

--

However, creepy bad behavior and biased doesn't stop all female engineers.

1. Emily Roebling (1803-1903)

Emily Roebling stepped in as the first woman field engineer and technical leader of the Brooklyn Bridge when her husband, Washington Roebling, became paralyzed and could no longer work without the help of his wife. Emily became responsible for much of the chief engineerâ(TM)s duties, including day-to-day supervision and project management. The Brooklyn Bridge was completed in 1883 and holds a plaque honoring Emily and her husband.

Emily_Warren_Roebling

2. Beulah Louise Henry (1187-1973)

Beulah Henry was known as âoethe lady Edisonâ in the 1920s and 1930s for the many inventions she patented, including a bobbin-free lockstitch sewing machine, a doll with flexible arms, a vacuum ice cream freezer, a doll with a radio inside and a typewriter that made multiple copies without carbon paper. Henry made a large fortune during her career by capitalizing on her inventions through manufacturing companies to produce her creations.

Beulahlouisehenry
3. Hedy Lamarr (1913-2000)

Hedy Lamarr might be recalled as a sexy movie star of the 1930s and 1940s, however, few know that she invented a remote-controlled communications system for the U.S military during World War II. Lamarrâ(TM)s frequency hopping theory now serves as a basis for modern communication technology, such as Bluetooth and Wi-Fi network connections.

hedy_lamarr
4. Stephanie Louise Kwolek (born 1923)

While working for DuPont, Stephanie Louise Kwolek discovered liquid crystalline polymers, which resulted in the product Kevlar. Containing fibers that are stronger than steel, Kevlar is used to make bulletproof vests, radial tires, airplane fuselages and fiber optic cables. For her accomplishments as a research scientist she received the National Medal of Technology in 1996 and was named to the National Womenâ(TM)s Hall of Fame in 2003. The American Chemical Society awarded her the Perkin Medal in 1997.

Kwolek famous female engineer
5. Martha J. Coston (1826-1904)

Another famous female engineer in history, Martha Coston is credited with developing a signaling flare system thatâ(TM)s used by the U.S. military and known as Coston flares. Coston needed a way to support herself and her children after the death of her husband and discovered a design he had left behind in a notebook. She worked for nearly 10 years revising the designs to include pyrotechnic components to create a long-lasting and multicolored system of flares.

martha coston
6. Lillian Gilbreth (1878-1972)

Lillian Gilbreth contributed to industrial engineering by studying workplace patterns and ergonomics. She became the first female member of the American Soci

Re:Who participated?

[erapert]

We need some kind of automatic bounds checking for sarcasm so that these kind of comment overflow attacks can't happen.

Re: Who participated?

[Anonymous Coward]

Thank you for furthering that ALL unwanted behavior or attention by any make is "creepy". Such nuance!

Re: Who participated?

[Anonymous Coward]

You found all 8 female engineers!! Well done!!!

Re: Who participated?

[Maxo-Texas]

When there's 1 of you and 17 others hitting or eeriely friendly towards you- it's creepy.
When you travel with your advisor and they want to go out and get drunk with you, it's creepy.

But I think you pretty much set the standard so I'll just use your words.

ALL UNWANTED behavior or UNWANTED attention is creepy.

I duped the unwanted to make it clearer.

Cheers.

Re:Who participated?

[dave420]

I think this discussion is pretty good evidence of the challenges facing minorities in tech. It's not about registering, it's about getting to the point in one's career when one can register. That is the part more difficult for under-represented groups. This has nothing to do with blame or vengeance, just fixing something obviously wrong.

Re:Who participated?

[silas_moeckel]

I do not see that as much different than a white male who grew up in the poorest parts of the US. In many ways a member of a minority or female in the suburbs has a lot more access and opportunity. To often we make the bad leap from correlation that some group has statistically less representation in a field to that they are somehow excluded from that field. Asians/pacific islanders hold nearly twice their percentage in the overall population in new STEM degree's. American Indians/Alaskan Natives only about a third. In any event you have to look as why people are not choosing that field of work, poor education, societal values that do not value those sorts of fields, lack of role models, etc.

In any event thats far far out of scope for a contest to deal with, you can not fix not having enough minorities or women with the appropriate skills as part of a less than two year competitive event. If anything you realy should not give anybody special treatment in a competitive event only the results matter. Initial outreach is probably as far as you can go without biasing towards those minorities or women. Longer term unbiased outreach to younger populations could even things out in the long run and remain fair.

Re:Who participated?

[Coren22]

As far as I know they didn't. They didn't correct for creepy fellow male students mobbing them nor for creepy professors hitting on them or for creepy co workers mobbing them and hitting on them once they graduate either.

Yeah, the same guys that can't get a date to save their lives. They come across as creepy because they don't know how to talk to women, but I guess it is more fun to make fun of the kids with handicaps than to understand that very likely you are talking about people with autism.

A scary finding of the questionnaire was that women reported their high school guidance counselors were very non-supportive of their decision to study engineering. Non-supportive is a nice word, because I got long letters that talked about how they were actually discouraged by people in their high schools. There seem to be many high schools in our country which discourage women from taking advanced math and physics courses, and, in fact, there seem to be very few women who were physics teachers in high school.

When I was in Calc and Physics (ap and regular), the class was half women. My Calc teacher was a woman, my physics teacher was a man, so what? Women far outnumber men in teaching positions, should we start correcting for that next? I'll bet that those same guidance councilors would discourage men from teaching or going into nursing, where is all the outrage? Considering my office (systems engineering) is half women, I don't see an issue, if you personally run against sexism, you should move around it or deal with it, not complain on an internet forum where there will be no effect on the problem.

They were expected to take care of household duties any way.

That is an issue in the household, it sounds like she chose the wrong husband. There are guys that would love to stay home and take care of the house and kids, those guys are considered creepy by woman like you because they are more sensitive instead of being alpha males.

And having a child is a challenge - especially since men don't get maternity leave.

It depends. When men work in white collar employment, many companies offer paternity leave, but I would be seriously surprised if anyone offered maternity leave to a man, as that would be the wrong type of leave.

http://dictionary.reference.co...

Re:Who participated?

[Maxo-Texas]

Amazing. I was quoting from responses to a survey of 4,000 female engineers.

The response- all from males- allege there is no problem for female engineers.

Those silly female engineers just don't understand apparently.

Keep kidding yourself.

Re:Who participated?

[slashdotwannabe]

Pregnancy. Rape. Institutional racism/discrimination. The complete obliviousness of the average white male to their privilege relative to lesser privileged groups to the point where they have to ask such a question as this.

Re:Who participated?

[silas_moeckel]

So pregnancy is somehow a hurdle? It's a choice at least in the modern world. Rape has something to do with people ability to enter an engineering competition? With their ability to get an education?

What institutional level racism or discrimination would a person of color have to deal with that a white male from appalachia would not have? The "justice" system comes to mind but not a lot else. Comparatively they have a lot of programs in their favor.

Sorry your just a SJW with your check your privilege this or that. I'll give you a hint to check privilege in effect means to pull somebody down from there perceived unfair advantages, to say they have no right to the circumstances they were born and/or raised with. Want equality thats enabling people to rise as equals, additive vs subtractive. That's also a much harder sell, to say they are free to earn it that yes their parents are responsible for not giving them a specific advantage etc.

Re:Who participated?

[slashdotwannabe]

So pregnancy is somehow a hurdle?

Get pregnant and see. Oops. You can't. I'm shocked, shocked that you are therefore unaware that pregnancy can be an impediment to career advancement.

It's a choice at least in the modern world.

Leaving aside the obvious retort that many women don't live in the modern world, it's a choice that men never have to make. Go ahead. Tell me about that time you had to delay your career for 9-30 months because your wife wanted to have a family.

Rape has something to do with people ability to enter an engineering competition? With their ability to get an education?

Obviously you have never been raped. When you're afraid to leave your home, it's rather hard to get to your local institution of higher learning. When you are sexually coerced by your Chemistry professor, it's somewhat difficult to trust your other teachers. I don't expect you to understand; your tone deafness speaks volumes about your ability to empathize, but you might at least try to research the things you say before you allow your biases to blithely dismiss them.

What institutional level racism or discrimination would a person of color have to deal with that a white male from appalachia would not have?

Obviously you aren't a person of color. Lower pay. Fewer employment opportunities. Fewer educational opportunities. Grading biases. Selection biases.

The "justice" system comes to mind but not a lot else.

Well! I guess the biases in Justice system can't really do much!

Comparatively they have a lot of programs in their favor.

This is where citations would come in really handy!

Sorry your just a SJW with your check your privilege this or that.

*You're. As in "You're just a privileged while male attempting to mansplain his way through why the world owes him his privilege because everyone else also has access to it. They're just too lazy/stupid/{state character defect of your choice here} to claim it."

I'll give you a hint to check privilege in effect means to pull somebody down from there perceived unfair advantages

*Their. For example, "White people like to lecture socially oppressed people on their problems without understanding what those problems are". Pro Tip: people are far less likely to dismiss you as an uneducated dolt when you use proper spelling and grammar.

Want equality thats enabling people to rise as equals, additive vs subtractive. That's also a much harder sell, to say they are free to earn it that yes their parents are responsible for not giving them a specific advantage etc.

“The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.”

-- Stephen Hawking

Re: Who participated?

[Anonymous Coward]

There it is. Privilege. Was wondering how long it would take.

Re:Who participated?

[RockDoctor]

For ages it's been assumed that "he" and "man"/"mankind" may be used in a generic sense to refer to everyone

The operative word in that is, of course, "may". At other times, it may NOT be assumed that (etc). In other words, you don't know.

So I assume that I don't know, whereas if I see someone who writes "he/ she/ it/ they" then I do know that it's someone who does think that it's a significant point they're making.

Part of the point is that it does take an effort.

Re:Who participated?

[RockDoctor]

Not just the AIs. I don't know how restricted your social circles are, but I've known at least one person who has been through male-to female gender re-assignment surgery, and may know more (how would one know without asking, and what possible grounds would one have for asking?). I also know people who consider their anatomical and identity genders unimportant, and would really prefer to have a neuter grammatical gender.

There is, of course, "one", but that's a bit contrived for some uses.

Re:Who participated?

[RockDoctor]

And having a child is a challenge - especially since men don't get maternity leave.

Who the fuck are you kidding? All countries in the civilised world have maternity leave for fathers as well as mothers.

Or do you not live in the civilised world? You poor, unprivileged bastard.

Efficiency

[fyngyrz]

Astoundingly Efficient Inverters

This doesn't seem to be about efficiency at all, but rather about power density (how much power can be converted in a particular cubic volume.)

Not that small isn't a worthy goal, but efficiency is important in any application where available power isn't both free and copiously oversupplied.

Re:Efficiency

[guruevi]

Don't they go hand-in-hand though? You can only dissipate so much (waste) energy in a particular cubic volume. Decreasing the amount of waste energy increases the amount you can pack together. It wouldn't be a challenge if you're just looking for miniaturization.

Re:Efficiency

[Anonymous Coward]

Being efficient with space is still being efficient. But of course, the summary could have done more to clarify.

Re:Efficiency

[Stewie241]

Yeah... from the website:

INTRODUCING THE LITTLE BOX CHALLENGE

An open competition to build a (much) smaller power inverter, with a $1,000,000 prize.

Design and build a kW-scale inverter with the highest power density (at least 50 Watts per cubic inch).

Efficiency is not mentioned anywhere. I see somebody arguing that efficient with space is still being efficient. This is true, but is not what is commonly meant when referring to the efficient of an inverter, and misusing the word in this context is confusing.

Re:Efficiency

[PIBM]

If you had read the challenge when it was proposed (or went to read the rules), the efficiency was required to be > 95%

. Produce a DCAC conversion efficiency of > 95%

From https://www.littleboxchallenge...

Re:Efficiency

[slashkitty]

95.4% efficient in the conversion per the Datasheet http://littleboxchallengecetpo...

Re:Efficiency

[DeathToBill]

Maybe, though Hack-a-Day say it involves an "incredible thermal management solution," which doesn't sound like they've actually bumped the energy efficiency up that much.

Why were Google so keen to have an inverter that maximises power density? Why not maximise energy efficiency?

Ideally you'd like to minimise cost of energy. But I guess it's fairly difficult to construct a competition around this: It depends too much on production scale and the prevailing cost of electricity. But why power density as a substitute?

Re:Efficiency

[Anonymous Coward]

From the website https://www.littleboxchallenge.com/:

In brief, the other specifications are :

* Must be able to handle up to 2 kVA loads
* Must achieve a power density of equal to or greater than 50 W/in3
* Must be able to handle loads with power factors from 0.7–1, leading and lagging in an islanded mode
* Must be in a rectangular metal enclosure of no more than 40 in3
* Will be taking in 450 V DC power in series with a 10 O resistor
* Must output 240 V, 60 Hz AC single phase power
* Must have a total harmonic distortion + noise on both voltage and current of 5%
* Must have an input ripple current of 20%
* Must have an input ripple voltage of 3%
* Must have a DC-AC efficiency of greater than 95%
* Must maintain a temperature of no more than 60C during operation everywhere on the outside of the device that can be touched.
* Must conform to Electromagnetic Compliance standards as set out in FCC Part 15 B
* Can not use any external source of cooling (e.g. water) other than air
* Does not require galvanic isolation

Re:Efficiency

[Stewie241]

Ah, I didn't look that closely to see that. On the other hand, I still wouldn't consider them 'astoundingly efficient' as the headline claims. This article discusses a design for a 97.09% efficient inverter. (I admit at this point I'm beginning to be argumentative, but I still think the headline should have been astoundingly dense inverters, though my theory is that slashdot injects in intentional errors to drive comments and traffics from those who like to nitpick submissions).

Re:Efficiency

[fyngyrz]

They can go hand in hand; they don't have to go hand in hand. Generally speaking, efficiency of power conversion is fairly high, 95% isn't all that uncommon for a design that tries hard. Some of the problems are that when you're doing conversion at the KW level, 5% is 50 watts, which tends to be RFI (both direct and indirect) and heat - that's efficient in one sense, and a serious problem in another. Going from 95% to 97.5% cuts that to 25 watts; and that's not space saved once per installation, that's money saved and more energy for other things and less crap in the air every moment the conversion is ongoing.

In the case of houses and cars, where KW is the order of the day, space is a minor problem; efficiency is the major problem. I'd take a 97.5% efficient box at 10x the volume over at 95% converter any time. But it isn't even 10x the volume, generally speaking.

That's why the first thing I looked for was competition for conversion efficiency, and why I was a little put off by it not even being there.

Re:Efficiency

[Anonymous Coward]

(I admit at this point I'm beginning to be argumentative).

You should talk to a professional about why you tend to do that. Awareness is the first step toward change.

Re:Efficiency

[Anonymous Coward]

Per the challenge design spec, DC-AC efficiency had to be better than 95% for any entry. Look at the requirements at littleboxchallenge.com and the winner's data sheet at http://littleboxchallengecetpower.com/cetpower-littleboxchallenge-datasheet.pdf

Re:Efficiency

[bytesex]

They want to put it in your mobile phone! Have a solar panel on the one side, your house fuse box on the other, and your phone in the middle! That's why they wanted the highest energy density per volume!

Re:Efficiency

[Ol Olsoc]

Ah, I didn't look that closely to see that. On the other hand, I still wouldn't consider them 'astoundingly efficient' as the headline claims. This article discusses a design for a 97.09% efficient inverter. (I admit at this point I'm beginning to be argumentative, but I still think the headline should have been astoundingly dense inverters, though my theory is that slashdot injects in intentional errors to drive comments and traffics from those who like to nitpick submissions).

I disagree that you're being argumentive. While efficiency can mean a lot of things, it's a dead lock given that in a story about electric inverters, that efficiency would mean conversion efficiency.

Because the "efficiency" they were actually referring to was efficiency in th enature of efficiency apartments.

I certainly don't want to disparage what they did, because it was very impressive. This was more an issue with the person who wrote the original article.

Re:Efficiency

[Anonymous Coward]

What does it mater? Most people don't know the difference or care. For all the promotion done by the science! people and countless inspirational television programs, I've noted a marked decline in fundamental understanding of how practical things work (as opposed to something like quantum dots).

Re:Efficiency

[Anonymous Coward]

Commercially available, 93% efficient inverter.

What they really should be interested in at this stage is cost.

Re:Efficiency

[Anonymous Coward]

You can be efficient in terms of materials cost, construction cost, energy consumption, space utilization, or any other number of physical characteristics.

If space is the most valuable resource in a particular design, then you focus on using it efficiently.

Re:Efficiency

[Anonymous Coward]

I have some kind of micro-hemorrhage in my right index finger, dating to a warehouse incident. I crushed the tip, the nail soon fell off then regrew.

I can see a tiny speck of dried bleeding beneath the nail, every few months. If I press really hard during those, it almost stings a tiny bit.

I could consult a physician, here in healthcare USA where it'd cost me a day's work to ask. Or maybe I don't need to >talk to a professional about something less relevant than the annoying tiny pebble bouncing around in my shoe's heel.

So GP is mildly sperging or something, who cares. I hope you were being flippant and saying whatever came to mind for the sake of filling a post. Sometimes phrases like that (I can't even be assed to check carefully) are deliberately placed as pacifiers, since modern social conduct is a fucking waltz of platitudes and wasted steps interspersed with actual communication when permission is briefly granted for it. Forget to announce your devil's advocacy during a contradiction and you might shatter a fragile ego, setting someone off. Subtly, or sometimes plainly.

Re:Efficiency

[Anonymous Coward]

I disagree that you're being argumentative.

That's priceless, thanks for that!

Re:Efficiency

[DeathToBill]

According to [1], the winner achieves 95.4% efficiency - not actually that impressive as inverter efficiencies go.

[1] http://littleboxchallengecetpo...

Re:Efficiency

[Anonymous Coward]

Given that the challenge was specifically to come up with *space* efficient inverter designs, it's dead certain that the 'astoundingly efficient' comment refers to *that*, not conversion efficiency. (Given that the designs are required to be 95%+ efficient on the conversion metric, and that isn't atypical for less space-efficient designs, that's a further indicator that 'astoundingly efficient' refers to space requirements.)

Re:Efficiency

[Anonymous Coward]

I'm a little puzzled about this competition too.

I currently have micro-inverters, i.e. small inverters attached to each solar panel on the roof. Each one is rated for 225W. Size is not an issue--they are already small and thin enough to put under the panel.

And according to specs they are 96.5% efficient--better than what the "winner" achieved.

I'm not sure what the "breakthrough" is here.

Re:Efficiency

[arth1]

According to [1], the winner achieves 95.4% efficiency - not actually that impressive as inverter efficiencies go.

So, in the space saved, they can fit a small stirling engine? :)

Re:Efficiency

[AmiMoJo]

Batteries. Current inverters are rather large compared the batteries that can provide their maximum output power.

Electric vehicle charging would benefit from this. You want to be pushing 120kW+ DC into the battery. You can also go back the other way and run your house from the car battery to save money when your solar panels are not producing anything.

Re:Efficiency

[Anonymous Coward]

A lot is left unsaid in this announcement.
One extremely obvious way to have a box with a set conversion factor smaller, is to allow it to get hotter. A lot hotter.
Say you make a box that is designed to run reliably at 200C instead of limited to 80C. (In The Vacuum Tube era, some transmitting tubes were designed to have the Plates glow Red Hot, and instead of glass, Ceramics were used as housings... did they get hot!)
So, no Epoxy PCBs, no Film Resistors, no Polyester Caps. Note that the bits already exist- Point-to-point wiring using Silver solder, Nichrome Resistors, Mica Caps.

But a more interesting question, why the need for such a small controller in the first place? Unless of course, it's built into something else, like a "Car" Battery... 12.6VDC from the normal posts, plus a place to plug in a Tea Kettle.

Captcha: industry

Re:Efficiency

[Anonymous Coward]

so they can use them in their data centers.

Re:Efficiency

[Anonymous Coward]

Oh, slashdot does not have to do anything to drive nitpickers and ridiculous comments. This is slashdot, after all.

Re:Efficiency

[Ol Olsoc]

Given that the challenge was specifically to come up with *space* efficient inverter designs, it's dead certain that the 'astoundingly efficient' comment refers to *that*, not conversion efficiency. (Given that the designs are required to be 95%+ efficient on the conversion metric, and that isn't atypical for less space-efficient designs, that's a further indicator that 'astoundingly efficient' refers to space requirements.)

Go ask an EE what they think of when dealing with efficiency in inverter circuitry. Given that I'm not the only one noticing the headline was misleading, I'm not alone at all in my response.

Re:Efficiency

[CauseBy]

I don't understand your attempt at pedantry. Density is spacial efficiency. If you make something smaller, you make it more efficient in the dimension of size.

Re:Efficiency

[cheater512]

Space efficiency is technically a type of efficiency as well as all the other points above. :)

Re:Efficiency

[castionsosa]

There is always liquid cooling. A data center usually has a decent water chilling system present, so if inverters could be cooled by that (likely via a heat exchanger, so a leak wouldn't be a major disaster), it would be more efficient than ones that are air cooled. Liquid cooling is maturing slowly, but surely, the main advance are better closed loop systems which make it easier to go this route.

Re:Efficiency

[Anonymous Coward]

Is Google doing work for DARPA? Are we going to see this thing inside some killer bot or some laser weapon?

Re:Efficiency

[KGIII]

> If I press really hard during those, it almost stings a tiny bit.

Err... I can save you the expense of a doctor's visit! It's stinging because, you know, you're pressing really hard. Just a guess. Don't do that and the problem will go away.

"Doctor, it hurts when I hit myself with a hammer."
"Don't hit yourself with a hammer."

That'll be $50 and schedule a follow-up in six months with the secretary out front.

Disclaimer: I am, technically, a doctor. I am not a medical doctor. Consult a qualified medical professional before deciding to stop pressing on an old injury really hard to see if it stings. My daughter is a real medical doctor. She is not my doctor. She probably is not your doctor unless you're a child in a trauma/intensive care unit.

Re:Efficiency

[JimSadler]

Consumption of space is an efficiency in itself. For example, suppose your car engine could be made the size of a pack of cigarettes with the same power output. Even if that small engine was made of pure gold it would have less weight and therefore, your car would use less fuel. You could also reduce the frontal area and wind drag on the vehicle. Bulk almost always means less efficiency.

Re:Efficiency

[JimSadler]

Wouldn't it be wonderful to do that energy conversion outside the home with a tiny box. Keep in mind that the more equipment inside a home the more power the home will consume. In hot weather a big box inside the home would add to the cooling energy load on the home. If installed outside the home a duct could, in cold weather, direct that excess heat from the converter to keep pipes warm or pumps from freezing up. Most people fail to realize that once power is sent down the power line to the home or industry that that power will be converted to heat again. Whether it is an air conditioner, a TV set, a computer or an electric motor or water heater all of that electricity is converted to heat. To really fight global warming we must control heat generation at both ends of the power line. One way is to reuse the heat emitted from every device to be used by other devices. For example, heat radiated by your hot water heater could be used to heat your home a bit. Heat generated from an air conditioner is already used to heat some hot water tanks. I wonder how many people have even considered this sort of thing.

Re:Efficiency

[JimSadler]

Consider a mobile installation of such an inverter. Electric cars might be far cheaper if AC power to the wheels was used instead of the DC from the battery packs. Higher powered DC brushless motors seem to be very expensive. Higher powered AC motors seem to be much cheaper but I can't comment on what industrial, bulk buying, prices might be. The weight of AC motors seems to be less as well. So being able to carry a tiny DC to AC converter might be far more efficient in an electric car or truck. Apparently an AC to Dc converter is also called for in regenerative braking systems. Again a tiny box might make that far more efficient as the car must carry the device. I feel that the competition was quite meaningful.

Re:Efficiency

[dpidcoe]

Whoosh!

Re:Efficiency

[torkus]

Electrical Efficiency is loosely coupled to volumetric efficiency. We're talking about an inverter roughly the size of a fist that's outputting 2kW. Without very high efficiency your cooling solution would be larger than your inverter. A moderate size CPU cooler (sinking ~65w) is the size of this whole inverter.

The rules require efficiency >95% which is typical for high efficiency inverter systems. At that, the primary benefit to higher efficiency is lowered cooling requirements (i.e. size) which is the primary goal of the competition.

So the rules basically *do* set teams out to maximize efficiency. Having small, highly efficient inverters is useful is many applications (solar, vehicular, UPS, etc.)

As for Google's exact benefit? I could see them running these in datacenters: deliver 450VDC rails to all your racks and power them off a hockey puck inverter or two. Simple to scale - add more battery, more racks with inverters as needed. Everything becomes modular.

Beyond that, solar and larger UPS systems typically run at 450VDC - so this means you can also scale your UPS and solar installation in conjunction with your datacenter. Basically combine all the technologies together without requiring large monolithic components. Ok, TLDR my own post.

Re:Efficiency

[penguinoid]

Space efficient :-p

Also, smaller may additionally imply cheaper, or lighter.

Re:Efficiency

[Anonymous Coward]

95.4% efficiency during optimal conditions isn't that impressive no. 95% efficiency over the entire range from 300V to 450V is pretty OK.
Unfortunately that isn't specified in the "datasheet"

Re:Efficiency

[Anonymous Coward]

Liquid cooling has matured already. I once worked at a Facility that used Freon to cool most of the critical Electronics. If it leaked, which it did, 45KV Power Supplies underneath wouldn't explode. This stuff was put in in 1972, and accounts, in part, for the Ozone Hole above Berkeley.
We also tried using Propylene-Glycol, until we discovered that the damn stuff polymerizes at relatively low Standoff Voltages, and the polymers are corrosive to Copper.
We tried a lot of things- Deionized Water, Liquid Nitrogen and Helium, supercooled N2 and He gasses, Propane, SF6, Silicone Oils, Fomblin... the end result always came to the same; the less heat that needs to be carried away, the less cooling needed.
One of my last tasks was to design a Goniometer that would go down to 12Kelvin; the bulky Commercial versions had difficulties making 25K.
My design actually made 8K, using half of the Liquid Helium of previous designs. One of my tricks was the use of very thin annealed Gold foil as heat gaskets, which is common enough, but my Foils were powder coated with 10 Micron Diamonds.

The design of the Inverters is worthless for Data Center applications: 400VDC to 60Hz sine-wave 240VAC is the Spec. There are few modern applications that require pure sine wave in the Kilowatts region, except Air Conditioners.
(On my boat, I have a stepped-sine Inverter. The compressor in my ice maker is definitely noisier when running off the Inverter rather than Shore Power, but it's worked fine for 2 years.)

Re:Efficiency

[viperidaenz]

They are dissipating 92 (2kW @ 95.4%) watts in a 13.77 cubic inch enclosure and it's only heating 19 degrees above ambient.

Re:Efficiency

[viperidaenz]

The winner runs at 48 degrees in a 29 degree environment.
A laptop PSU runs hotter than that at full load, and it's only transferring 60W, not 2000.

Re:Efficiency

[Anonymous Coward]

(I admit at this point I'm beginning to be argumentative).

You should talk to a professional about why you tend to do that. Awareness is the first step toward change.

So is impulse control.

Re:Efficiency

[Guspaz]

The inverters used for 120 kW+ charging isn't in the car, it's in the charging stations. The only charging stations hitting 120 kW+ are Tesla's superchargers, which are pure DC as far as the car is concerned.

Re: Efficiency

[Anonymous Coward]

It is also about efficiency. One of the requirements is for efficiency > 95%. There was also a max thermal requirement which gets very difficult to meet when your enclosure size gets very small. High efficency is a must.

Re: Efficiency

[Anonymous Coward]

But how does this apply to the size of Trump's fingers?

Re:Efficiency

[Coren22]

As for Google's exact benefit? I could see them running these in datacenters: deliver 450VDC rails to all your racks and power them off a hockey puck inverter or two. Simple to scale - add more battery, more racks with inverters as needed. Everything becomes modular.

Let me guess, you don't have an electrical engineering background?

Computers run on DC, why oh why would you convert DC - AC, then AC - DC inside the case? It is far better to convert that 450 VDC to 12 VDC, 5 VDC, and 3.3 VDC and run the whole computer off that. Also, in a datacenter, the DC line losses could be pretty extreme, there may be a tradeoff in the increased efficiency in not converting DC to AC in the UPS system, but it depends on voltage and distance from the source.

Re:Efficiency

[werepants]

Waste heat is low-grade, and hard to employ in a way that makes it worth it. What do you do with that bit of extra heat from the water heater that is leaking into the utility closet that will be cheap enough to have a payoff time within decades, controllable so you don't heat your home up when you don't want to and make a significantly larger impact than just letting that heat disperse through the house naturally? There probably isn't anything viable.

The thing is, power plants aren't using heat to produce energy, they are using a heat differential. You need to have a very high temp heat reservoir and a low temp exhaust to efficiently extract energy from heat, and the larger the difference in temp the more efficient you can be. So, in the case of a water heater being a few degrees warmer than the surrounding air, there's very little that you can do that will be worth it.

What I've found from researching energy improvements is that the most effective savings to be found is also the most low-tech and boring: insulation. The other thing that's a real bear about optimizing energy use is that every improvement you make reduces the impact and increases the payoff time of future improvements. My house is insulated well enough that my gas bill is only ~$300 a year, so at this point anything exotic (read: expensive) isn't close to worth it... an air-source heat pump, radiant floor heating, solar powered heating, etc - even if they reduced my heating bill to zero it still would take over a decade to pay itself off and I'll probably move by that time.

Re:Efficiency

[angel'o'sphere]

Why not maximise energy efficiency?
Because AC/DC converters are already extremely efficient.

Re:Efficiency

[Anonymous Coward]

Guspaz Fucks ass. You are a piece of dog shit you motherfucker. You are a dirt pig and a low life piece of shit. You know nothing and for YEARS youve sat here you FAT FUCK and lied and brought fascism in.

Please pardon the flagitious overtones that will be found throughout this letter, but since their emergence on the stage of history, sanguinary headcases have been a parasitic growth on the stem of true citizens. You see, I unquestionably believe that thanks to Guspaz The Assfuck, self-righteous, jaded election-year also-rans can now freely condemn children to a life of drugs, gangs, drinking, rape, incest, verbal abuse, physical abuse, and a number of other horrors. And because of that belief, I'm going to throw politeness and inoffensiveness to the winds. In this letter, I'm going to be as rude and crude as I know how, to reinforce the point that I support the way of willing exchange, of common consent, of self-responsibility, of open opportunity. Guspaz The Assfuck, in contrast, supports leaving behind a legacy of perpetual indebtedness in developing countries. This difference in what we each support indicates that his crime syndicate is an army of evil. From this anecdotal evidence I would argue that I am flummoxed as to why Guspaz The Assfuck would want to degrade, divide, and destroy our nation. No mystery, however, veils the causes or consequences of Guspaz The Assfuck's most beer-guzzling deeds. Specifically, this is preeminently the time to speak the truth, the whole truth, frankly and boldly. Let me therefore state that Guspaz The Assfuck's fantasy is to glorify insane pests. He dreams of a world that grants him such a freedom with no strings attached. Welcome to the world of Fabianism! In that nightmare world it has long since been forgotten that due to Guspaz The Assfuck's repeated insistence that he's morally obligated to take advantage of human fallibility to base racial definitions on lineage, phrenological characteristics, skin hue, and religion, many wretched simps have come to accept such asininity as undisputed truth. What should remain arguable settles into surety. Having lost their faculty for critical thinking, such people cannot comprehend that there are two challenges we must face if we wish to repair the incoherent world we have inherited from Guspaz The Assfuck. The first challenge is to scrap the entire constellation of saturnine ideas that brought us to our present point. This is only slightly less difficult than the second challenge, which is to convey to people the knowledge that whenever Guspaz The Assfuck is blamed for conspiring to create a beachhead for organized fetishism, he blames his cultists. Doing so reinforces their passivity and obedience and increases their guilt, shame, terror, and conformity, thereby making them far more willing to help Guspaz The Assfuck corral his foes into mini-Bantustans to prevent them from preaching a message of community and brotherly love.

Guspaz The Assfuck's wicked writings can be quite educational. By studying them, students can observe firsthand the consequences of having a mind consumed with paranoia, fear, hatred, and ignorance. This is hardly an ersatz sideshow. It is instead a matter of Guspaz The Assfuck not bothering to listen, not taking seriously the foundational work being done to dispel ignorance. If Guspaz The Assfuck were listening, he would find that he maintains that the most valuable skill one can have is the ability to lie convincingly. Sorry, but I have to call foul on that one.

Guspaz The Assfuck alleges that he acts in the public interest. Naturally, this is a tale told by an idiot, full of sound and fury, signifying nothing. Adoption of his pea-brained fibs begets the insanity of interventionism, and if you don't believe me then you should provide a trenchant analysis of his rodomontades. His homilies are not our only concern. To state the matter in a few words, he once said that five-crystal orgone generators can eliminate mind-control energies that are being radiated from secret, underground, government f

AC is by its very nature inefficient

[Anonymous Coward]

We should not be generating AC power in the first place. DC is much more efficient.

Re:AC is by its very nature inefficient

[dlleigh]

Is that you Thomas Edison?

Stop electrocuting elephants!

Re:AC is by its very nature inefficient

[Anonymous Coward]

Ya, down with AC! There is no reason at all to have AC!

Re:AC is by its very nature inefficient

[DeathToBill]

If you don't understand why this isn't going to happen, you need to be kept away from grid design.

Replacing the AC network with a DC network would mean either replacing or substantially modifying the entire fleet of existing generation plant, all distribution and conversion equipment, all industrial equipment powered by electricity and most appliances. You might well be right that you can achieve better efficiency in a new network with DC than with AC; when you have to replace the entire electricity system, from spinning turbine to phone charger, it just ain't gunna happen.

Re:AC is by its very nature inefficient

[cc1984_]

We should not be generating AC power in the first place. DC is much more efficient.

Perhaps not now, but way back when, AC was required because transformers could only work on AC, and people wanted high voltage, low current to minimize power wasted in the pylons' cables.

Re: AC is by its very nature inefficient

[Anonymous Coward]

Suck my cock AC faggot.

Re:AC is by its very nature inefficient

[Anonymous Coward]

You can't "generate" DC power in the first place... Unless you want to build giant batteries that are powered by seawater.

Re:AC is by its very nature inefficient

[Anonymous Coward]

For low power applications (clocks, Flat screen TVs, phone chargers, LED lighting, etc) you've got a point. A whole house inverter with some standardized outlets would definitely help with efficiency/cost. However with high power applications (electric water heaters, fridges, washing machines, etc) DC is wholly impractical. Draws of that nature over DC would require heavy gauge cable (think car/truck jumper cables) to be ran throughout the house.

Re:AC is by its very nature inefficient

[Anonymous Coward]

I would assume that the parent is talking about on a residential basis (Excerpt from Little Box Challenge Website "The problem is household inverters are too big") not on a utility scale. If that is the case there is some reasoning to keep the power DC where it is reasonable (TV's, LED lights, etc), A KW scale DC-AC inverter is still however necessary for high draw appliances which are unlikely to run off of DC anytime soon. Homes in the future will likely run a mixed AC/DC system, using power from the grid (AC) and from residential solar/wind (DC) to feed AC & DC wiring throughout the house.

Re:AC is by its very nature inefficient

[Anonymous Coward]

If you don't understand why this isn't going to happen, you need to be kept away from grid design.

If you don't understand when you're being trolled, you need to be kept away from /.

Re:AC is by its very nature inefficient

[mrclevesque]

As you did too, taking an opportunity to make a point is fine

Re:AC is by its very nature inefficient

[slashping]

We should not be generating AC power in the first place. DC is much more efficient.

I look forward to your design that can convert generator output to 300kV DC for long distance transmission.

Re:AC is by its very nature inefficient

[Bengie]

AC is very efficient for transitions without using exotic equipment. Barrier to entry is much much lower. And efficiently transmitting DC requires very dangerous voltages.

Re:AC is by its very nature inefficient

[IcyHando'Death]

You know the same thing could have been (and was) said about the switch from an analog phone system to digital. Every phone, every piece of switching equipment, every repairman's kit had to change -- all at enormous expense. It paid for itself though, by increasing profits (companies could charge for the new services that were made possible). All it would take is for some upstart startup to begin hooking up DC power in some new neighborhoods to get the game going. I don't even know if that would be legal now in most places though. The entrenched power monopolies would be a big obstacle to overcome.

Re: AC is by its very nature inefficient

[KGIII]

Cock, alternating, cycles... I'm pretty sure there's a retort about how your dick hertz in there somewhere.

Re:AC is by its very nature inefficient

[Anonymous Coward]

>Every phone
Same old copper runs in millions of residences and the analog phones work just fine.
I'm not countering your point that it was a large, expensive change, but the customers didn't have to rewire their homes or buy digital phones just because the phone companies switched to digital.

Re:AC is by its very nature inefficient

[Anonymous Coward]

The original poster posted a gross oversimplification of the matter and likely doesn't know what he's talking about.
But HVDC is a real thing.
https://en.wikipedia.org/wiki/High-voltage_direct_current

Re:AC is by its very nature inefficient

[Anonymous Coward]

You do realise DC power systemshave all sorts of problems with electromigration that AC systems do not have. These problems are overcome by careful design, and making sure the entire electrical environment is dry.

If you're just stringing power lines up on poles, running DC through them is a terrible idea.

If you were going to redesign the power network today from scratch, the thing to do would not be DC, but high frequency AC like the 400Hz AC used on aircraft. You get to keep your cheap transformers, but at the same time you get to make them smaller and more efficient. All the transformers in all your devices get smaller and more efficient too.

The only place where this would be a major downside would be in the long distance transmission department, and this is one place where you really do want to use DC, and they often do now.

Re:AC is by its very nature inefficient

[Anonymous Coward]

It won't happen overnight but DC is and will continue to make inroads. DC is being used currently for things like grid-interconnects (it's much easier and more reliable to convert to AC-DC-AC than to try to sync two or more very large AC grids) and long-distance high-power transmission. I could be wrong, but I suspect that it will continue to filter down through the system.

You could start by phasing in DC for high-voltage lines (convert at substation level), then convert other bits as the old ones get to end of life. Eventually you reach a situation where only your local to-customer transmission is AC. Then you could start looking at installing DC-AC converters at customers residences (bonus for people who have solar systems). Finally you might even start looking at DC power in the home. Not a fast process, but I would actually be surprised if large parts of the grid don't end up moving to DC in the medium/long term.

Re:AC is by its very nature inefficient

[ChrisMaple]

There are numerous devices for making DC directly from mechanical motion. Tesla invented a low voltage device ("Unipolar Dynamo") which is unfortunately very inefficient. There are also very high voltage DC generators like the Wimshurst machine that induces an accumulation of charge and the Van de Graff generator which uses the simple technique of transporting charges on an insulating belt.

Re:AC is by its very nature inefficient

[ChrisMaple]

100,000 3 volt power supplies wired in series.
Ten 30kV DC CRT power supplies wired in series, from discarded televisions. Recycle!

Re:AC is by its very nature inefficient

[ChrisMaple]

For a given amount of power, DC can use lower voltage and/or lower current than AC. That means less aluminum or copper, or towers that aren't quite as big. DC doesn't suffer from skin effect. (Skin depth for aluminum and copper is about 10 mm at 50/60 Hz.) One disadvantage of DC is that arcs aren't self-quenching.

Re:AC is by its very nature inefficient

[Anonymous Coward]

The problem with high tension DC transmission is electrolysis. Essentially it rusts anything and everything resembling metals, not just iron. This is a well-known problem with 3000V DC based legacy railway electrification and can affect anything within app. 100 meters from the tracks. Italy knows the most of the topic or at least has the biggest basis for comparison, since they use 3kV DC as well as 25kV /50Hz AC monophase and formely used 3,6KV / 15Hz AC tri-phase for railway traction.

Re:AC is by its very nature inefficient

[Anonymous Coward]

Except for that little thing called solar.

Re:AC is by its very nature inefficient

[angel'o'sphere]

We should not be generating AC power in the first place.
And how exactly do you propose to that? (*facepalm*)

Fucking hell, people are dumb.

[Anonymous Coward]

You want to exploit a bunch of nerds, you turn anything into a competition and sit back while they strive to display their massive egos.

Ka-ching.

Re:Fucking hell, people are dumb.

[Dr. Spork]

It's not like it's a secret who won the competition, and you know the winners are about to seriously upgrade their jobs. There's also prize money, but arguably, the fact that you can get a job pretty much anywhere with this on your resume is the bigger reward. There are lots of incredibly competent people in the world whose competence is underutilized by their employers. If contests like this bring out their A game, everybody comes away better off.

Watts per cubic inch?

[Anonymous Coward]

Are guys fucking serious?!?

If you really want to use your old units, why not horse power per cubic inch?

Re:Watts per cubic inch?

[Anonymous Coward]

British, German (Pferdestaerke), boiler, electric, or (another) one of the tax horsepowers? (This list is not exhaustive.)

This is a common problem with unsystematic measurements (SI is a system, anything "customary" is jumble), though since google is American[tm] they'll stick to inches because IT'S THE LAW there in backwardia. Yes indeed, they legislated the inch to be 2.54 cm. So that one isn't all that confusing; they're talking about just about 0.016387064 litre. That makes 50W/0.016387064L = 3051.187205 W/L or more usually 3.051187205 W/m^3 volume power density.*

Notice how litres to cubic metres is a comparatively easy conversion: Since a litre is 10cm^3, there's 1000 litres to the cubic metre. That's one of the things a measurements system does for you. Compare: How many cubic inches to the gallon? Your answer should begin with "which gallon?" followed by at least three conversions.

* Overlong number left that way to make a point. Strictly speaking it should conclude with "3.1 W/m^3" because the original had only two digits.

Re: Watts per cubic inch?

[Anonymous Coward]

Fail.

3.1 MW/m^3

Re:Watts per cubic inch?

[suutar]

Wouldn't that be 3.05MW/m^3?

Re:Watts per cubic inch?

[Anonymous Coward]

Seriously? An Anonymous Coward (guess I can't use AC in this discussion) got a +3 insightful for simply bitching about the US being non-metric? That's a pretty low bar the mods have set there.

Re:Watts per cubic inch?

[Anonymous Coward]

That makes 50W/0.016387064L = 3051.187205 W/L or more usually 3.051187205 W/m^3 volume power density.*

Notice how litres to cubic metres is a comparatively easy conversion: Since a litre is 10cm^3, there's 1000 litres to the cubic metre. That's one of the things a measurements system does for you. Compare: How many cubic inches to the gallon? Your answer should begin with "which gallon?" followed by at least three conversions.

* Overlong number left that way to make a point. Strictly speaking it should conclude with "3.1 W/m^3" because the original had only two digits.

I wouldn't call liters to m^3 a 'comparatively easy conversion', I'd call it a trivial conversion.

However, a liter isn't 10 cm^3 - you probably mean (10cm)^3, i.e. 10 centimeters cubed or 1 dm^3 (which is 1000 cm^3, 10 cm x10 cm x10 cm) , but yes, 1m^3 is 1000 liters

But if you start with 3051.187205 W/L I find it real hard to end up at 3.1 W/m^3. To get there you need to be shifting the decimal point the wrong way...
Starting with 3.1kW/L, 1m^3 being 1000 liters, you end up with 3100 kW/m^3 or 3.1 MW/m^3

A basic sanity check should have told you that when you have a fixed power per volume and you up the volume unit , the power should go up as well, not drop...

Re:Watts per cubic inch?

[Anonymous Coward]

I think the post is bitching about mixing watts (kg*m^2/s^3) and inches.

Re:Watts per cubic inch?

[Actually, I do RTFA]

Electricity post-dates the metric system, so the US uses SI units for electricity.

Re:Watts per cubic inch?

[serviscope_minor]

If you really want to use your old units, why not horse power per cubic inch?

Or BTU per hour per inch squared. The great thing about imperial is that there's no shortage of choice.

Re:Watts per cubic inch?

[Anonymous Coward]

Ayup, had a brain fart, didn't double check and so there's egg on my face now.

The silver lining is that no less than three people spotted it (and commented on it) immediately and that the fix is easy: Shift the decimal (for double the digits) the other way. Thus SI still wins, for how many people would've spotted having used the wrong conversion factor, like picking the wrong gallon or ton or pounds to a bushel? What it it was not 1000 but (makes up wild numbers) a factor 4.54 off, or say 4.54*32?

And yes, (10 cm)^3 isn't the same thing as 10 cm^3, good catch. This is a bit of a pitfall with compound units in general (and shows how rusty I am), though SI indeed has the dm^3 that I should have used. All in all the egg only strengthens the point, though leaving me with a messy face.

Re:Watts per cubic inch?

[Anonymous Coward]

* Overlong number left that way to make a point. Strictly speaking it should conclude with "3.1 W/m^3" because the original had only two digits.

This is a limit, not a measurement. It would be unfair to let someone submit a design that is 50.49 W/in when someone else may have rejected a 50.4 W/in design because it exceeded the limit. So the limit is exactly 50 W/in, to whatever accuracy Google is able to measure.

Also, if we were to accept "significant digits" as a suitable means of specifying accuracy (which it isn't, it's just some shit that textbook manufacturers made up to avoid having to teach real accuracy calculations), then we'd have to note that there is only one significant digit in 50 W/m, and so the actual number you'd be looking for is 3 W/cm.

As for why significant digits don't work:

1.0 covers everything from 0.95 to 1.05, so it is accurate to about 5%.
9.0 covers everything from 8.95 to 9.05, so it is accurate to about 0.5%.

So say you perform some calculations on your two significant digit value, and after starting with 1.0 in one set of units you finally end up with a value of 9.08174 in another set of units, which you turn into 9.0 according to the rules of significant digits. By using two significant digits for the second value, you're indicating that it's 10x as accurate as the value you started with. It would be more accurate to say that that result has only one significant digit. Similarly, if your calculation went the other way, you'd be throwing away a significant digit, as it would make more sense to state the result of turning 9.0 into 1.08174 as being 1.08 so that it has a similar accuracy of about 0.5%.

The only thing significant digits are good for is to avoid writing out twenty random digits at the end of your results. So the concept should be taught as being just a crude form of specifying accuracy, and it should be taught that you always include one insignificant digit in your measurements, so that when the rules lead to you discarding one too many digits, the one you've discarded was irrelevant anyway, and when interpreting results, one should be aware that it simply isn't known whether the last digit is or is not accurate.

(Of course, I expect much opposition to this, but then I was the only student in my chemistry class who ever (and always) failed to get the correct result in every experiment. I always just noted in the summary that the mass scales we were using were flimsy as all hell and nowhere near as accurate as we were told to assume they were with our significant digits, which when combined with tiny sample sizes that the scales couldn't even get one significant digit on meant that the result was a virtually random number. The rest of the class always conferred with each other to see the numerous different results they came up with, used a combination of what results seemed to be most frequent combined with whatever knowledge anyone could come up with as to what the correct result should be (as even an average of ten experiments didn't offer much of an improvement on the accuracy), and then faked their numbers so that they'd come up with the correct answer. So, what can I say, other than that I've learned not to give a fuck what anyone else thinks, as they're probably not thinking for themselves anyway, but rather, just looking at what everyone else is saying and repeating that so that it looks like they know what they're doing.)

Re:Watts per cubic inch?

[Anonymous Coward]

Because different individual horses have different power outputs, it gets kind of cumbersome to figure out the right combination of horses and then list them by name when you talk about high power levels.

So instead we switch to Watts (American phonetic spelling of "What?"), with a Kill-O-Watt defined as the muzzle energy of a 10mm handgun round times 1 second so that we don't have to do any further maths. But hey, we used a 10mm round so look, metric!

Re:Watts per cubic inch?

[Anonymous Coward]

And machining tolerances in Royal Cunt Hairs.

Does any one know : HVDC inverters

[Chrisq]

Does any one know what power density the inverters for HVDC transmission lines achieve? I know that this is not a comparable use case, i'm just interested.

Re:Does any one know : HVDC inverters

[aaarrrgggh]

The first iteration was around 80% conversion efficiency, but I understand they are in the low 90% range now. The challenge is the IGBTs need to be chained for the voltage, which increases switching losses.

Re:Does any one know : HVDC inverters

[Anonymous Coward]

GP asked about power density, I.E. W/m^3, not efficiency...

Re:Does any one know : HVDC inverters

[aaarrrgggh]

Doh. Looks like the new yards are about 500' square by (say) 30' operating height, at 3.2GW that gives you about 4W/cubic inch. But the satellite images are kind of old and poor quality so it is hard to tell for sure where the separation between the AC substation and DC equipment really is.

Re:Does any one know : HVDC inverters

[Chrisq]

Doh. Looks like the new yards are about 500' square by (say) 30' operating height, at 3.2GW that gives you about 4W/cubic inch. But the satellite images are kind of old and poor quality so it is hard to tell for sure where the separation between the AC substation and DC equipment really is.

I thought it might be low, because of the heat dissipation. Even at 90%+ efficiency there must be a lot of heat produced

GaN Transistors are the future

[stevel]

Gallium Nitride transistors have a lot of nice characteristics, but low yields and high costs have slowed their introduction. Two tiny laptop chargers, the FinSix Dart and Avogy Zolt, were said to use GaN transistors. The Dart still hasn't shipped, a year past its claimed release date. The Zolt has but is apparently using older Silicon Carbide-substrate transistors instead (Also see here.) (I received my Zolt recently and it is working well.)

It won't be a surprise to anyone following this technology that it can make inverters more efficient - that's what FinSix and Avogy have been claiming/demonstrating for two years at least.

Re:GaN Transistors are the future

[Anonymous Coward]

SiC actually has a lot better properties, but even worse yields.

Re:GaN Transistors are the future

[Anonymous Coward]

I work in RF, Ku band stuff, we use GaN parts like candy. One day I noticed that these things always come straight from Japan in hand-written and hand-packed little boxes... I asked what the BOM cost was and it was very high!

These things are so cutting-edge that you can't even google for the part number they ship you; it's not even on the manufacturer's page! You need to ask for the datasheet and often it's just screen printouts from the VNA...

I've also noticed that they smell different when the top explodes because of a mismatched load.

Re:GaN Transistors are the future

[rahvin112]

GaN isn't cutting edge. It's just super expensive. The only real use for GaN, due to the cost, is in radio transmitters and a few other niches where they need the ability of GaN to run at faster MHZ than silicon can support and can afford to pay the ridiculous process costs. GaN will remain a niche in process tech until they can find a way to make chips cheaper and they've been trying for a very long time. A lot of companies have come and gone trying to improve GaN because of the promise.

I can remember in the 90's is was the big fad that GaN was going to replace silicon. You can hopefully see how well that worked out.

Re:GaN Transistors are the future

[MattskEE]

RF GaN parts are certainly expensive - the GaN is grown on silicon carbide substrates which is incredibly expensive by itself, and high-speed RF stuff has much more demanding fabrication needs like very small T-shaped gates, better contact resistances, and so on.

GaN for power electronics is much cheaper, grown on 6 inch silicon substrates, and produced in much higher volumes. You can buy GaN parts from EPC on Digikey for a couple of dollars each, the other GaN power device manufacturers aren't selling publicly that I know of (just to partners, or nobody) but the cost per unit is not tremendous - a bit more than the same voltage and current rating silicon device but the GaN part can switch faster.

Re:GaN Transistors are the future

[Anonymous Coward]

What are you babbling about? GaN replaced GaAs and is the latest in power amplifiers. I assume that by your reference to "faster MHz" you are not getting that I'm talking about 12GHz 100 watt power amplifiers here.

Re:GaN Transistors are the future

[Anonymous Coward]

The Zolt has but is apparently using older Silicon Carbide-substrate transistors instead

Silicon Carbide is newer than GaN. GaN has been around in various forms since the 1970s, but SiC IGFETs have only started appearing in the last 10 years.

Re:GaN Transistors are the future

[Anonymous Coward]

> GaN isn't cutting edge.

The next iteration of the miniature swedish jetfighter, the SAAB Gripen-E uses GaN in its electronic warfare suite. It is said to be a first in that regard.

Re:GaN Transistors are the future

[vandamme]

Yeah, but that's RF. The promise of GaN was that it would be used everywhere in power circuits. To replace SiC.

Maybe someday it will. Or something better will come along.

Why is this important?

[Kohath]

Genuine question. The web site talks about inverters being 1-2 cubic feet in size, and it wants them smaller. I understand that smaller is better. What's the application that requires a 2kW inverter smaller than that?

Re:Why is this important?

[swb]

Marine or other mobile applications?

2-5kw is a sweet spot for these applications. Most marine generators in recreational applications are about 5kw -- and most of that is usually to drive air conditioning or similar high voltage applications.

2kw or so, though, is pretty decent for off-battery use of lower powered items and might even provide enough power (if you can use all 2k) for a small microwave.

Re:Why is this important?

[mykepredko]

An obvious one for me is for solar cells. As small/flat as possible to minimize the size/mass of an array.

When I've looked at home arrays, the inverter is a large box that fits off to the side in its own enclosure. I can see that having a small inverter that is part of the array would be an advantage in terms of cost and installation workload.

Re:Why is this important?

[Kohath]

Yeah, but solar cells to generate 2 kW are large. The size of the inverter doesn't seem like a limiting factor in that kind of installation.

Re:Why is this important?

[afidel]

Heck a 10,000 BTU AC unit in a small travel trailer only needs 700W once running so a 2kW setup would net you almost 3:1 runtime:collection (or about 2:1 once all inefficiencies are accounted for). The big problem is that 2kW of panels takes a lot more room than you have on a travel trailer (at least the ones that only need one 10k A/C!)

Re:Why is this important?

[Tx]

You don't need to use the solar cells directly, you charge up your batteries from your solar panels, or from cheap off-peak grid power, and you then need an inverter so you can run all your AC appliances from the batteries. The basic Tesla Powerwall model is 3.3kW, so that should give you a pretty strong hint of at least one application.

Re:Why is this important?

[Kohath]

That helps. I don't foresee a lot of applications that have room for those batteries but not for the inverter though. I can definitely see the merit of the complaint that the inverter is too large compared to the batteries. I'd still like to know what makes it very important rather than just something that's nice to have. Maybe nice to have is an adequate motivation for Google ...?

Re:Why is this important?

[Anonymous Coward]

Then your mom better do more swallowing this weekend if you're going to afford a doublewide.

Re:Why is this important?

[Anonymous Coward]

That problem is already solved. https://enphase.com/en-us/products-and-services/microinverters

Microinverters also have the advantage of the wiring on your roof being higher voltage, which means lower amperage for the same power, which means much thinner wires on the roof. My entire 6 KW array can feed into a single 10/3 wire that goes into my grid tie box. If everything was DC on the roof, the wire feeding to the inverter would need to be much larger, 0 gauge if not 00 gauge.

Re:Why is this important?

[Anonymous Coward]

As an aside, note that one US household electrical outlet can provide about 2Kw, so this would be an inverter you can plug one "generic anything" into.
One of those in a car to run a few high-end laptop chargers or other things... weight and size would be an issue.

Re:Why is this important?

[Anonymous Coward]

"Marine or other mobile applications?"

The design goal for the DC Input is 400VDC, and Sine Wave 240VAC out.
We're not going to see that on Boats anytime soon...

"Most marine generators in recreational applications are about 5kw"
That's on the high end, for fixed diesel installations; most of the boaters that I know use much smaller portable generators. (I don't; too noisy.)

There might be Aeronautical applications; cover the Wings/Blimp with seriesed Solar Cells, and run an AC Motor. High Voltage/Low Current in and out makes sense here, because copper wiring is damned heavy, and a small lightweight inverter would be ideal. Sine wave is also telling; motors don't like pulsed or pseudo-sine approximations.

Re:Why is this important?

[aaarrrgggh]

Matching inverters to an appliance would be my guess.

Re:Why is this important?

[Anonymous Coward]

Google is doing work for military-industrial-complex?

Re:Why is this important?

[MrNiceguy_KS]

Google is doing work for military-industrial-complex?

It's actually the other way around. Once Google has their killer robot army, they can finally force everyone to use Google+

Re:Why is this important?

[swb]

Didn't know about the design goal wanting 400V DC input. That clearly cements it in some kind of fixed installation mode, but it would be interesting to know if the input voltage can be scaled down.

There are some interesting variable speed DC generators which seem to provide better overall efficiency than fixed-speed AC generators because they can run at lower RPMs when power demand is lower, but they mostly seem to make sense when integrated into a larger battery bank. And usually they have some kind of programmable range of run speeds tied to various use cases -- like deep charging battery, topping off the battery or maximum load output.

"Most marine generators in recreational applications are about 5kw"
That's on the high end, for fixed diesel installations; most of the boaters that I know use much smaller portable generators. (I don't; too noisy.)

I guess it depends on what you're looking at. Most recreational boats I've looked at that come with generators seem to start at 5 kw, which seems to fit the typical maximum power usage (stereo/TV, microwave, air conditioning, lighting). Kohler's smallest is 4kw @ 50 hz and 5 kw @ 60 hz. Boats over 40 ft tend towards even larger, like 9+ kw.

There are a lot of people who seem to want to use a Honda suitcase generator on 30 ft. boats. I think this is a nutty fire risk, and the 2kw models probably can't start the air conditioning, either.

Of course I've only ever looked at power boats, too. I don't know how it works on sailboats -- most larger ones with inboard engines may use the propulsion power plant with the prop disengaged and tied to a heavy duty alternator for battery bank charging. Although I would kind of expect more dedicated power generation on larger boats that may have bigger power consumption (fridges, lighting, marine electronics).

My own interest was mainly to see how practical a solar/battery bank would be on a recreational boat, or how much generator run time it might reduce when not running air conditioning.

Re:Why is this important?

[istartedi]

That's the right question. I think you'll eventually reach the inevitable conclusion that we must hack their inverters, with the end result of filling the Google data center with freshly popped popcorn.

Re:Why is this important?

[Anonymous Coward]

"Of course I've only ever looked at power boats, too. "
Interesting. There are four marinas within easy walking distance of where I keep my boat, and it's around 90% Sail. Admittedly, the shortest slip where I keep my 29' boat is 30', but the marina next door has 20' slips, and there are about 400 boats "dry sailed" there as well.
It might be a geographical thing also; the Ocean is right next door. As one goes up the Sacramento Delta, there are many more power boats.

"I don't know how it works on sailboats -- most larger ones with inboard engines may use the propulsion power plant with the prop disengaged and tied to a heavy duty alternator for battery bank charging."
That's exactly how it works, even on the smallest diesels. Disregarding efficiencies, it takes about one hp to drive a 60A alternator at full output; that leaves me with about 17 hp to go chase wind.
Where problems come in is with outboards; very few of them for the Sail market have charging worth a damn.
5KW is a lot of kilowatts. My Stereo runs about 0.1A, LED TV 0.8A, LED Lighting ~0.2A, Ice Maker making 1Lb Ice/Hr ~4A, Macbook ~0.3A, Instruments ~1A, VHF ~0.2A. All told with everything on, (They never are...), maybe ~6.5A/hr. I have ~150AH of capacity; more than enough. And it doesn't take much of a Solar Panel to keep the engine off. (These are measured values, not taken off of brochures. I, by nature, measure things. The Ice Maker draws the most, but it's only on ~2hr/day.)

What I don't have is a washer/dryer, microwave, AC, Plasma TV, or Coffeemaker. Cooking is done with stove alcohol and/or Propane. Washing is done with a bucket and two feet. Hey, it's SF Bay, who needs Air Conditioning?
I do have a 300W Inverter for running the Ice Maker, and for charging the Macbook. (The Inverter is about the size of a 2Lb block of cheese; making it smaller is silly.) The $90 20" LED TV isn't the best, but I was looking for one that runs off 12V. The same goes for the $25 Mechless Stereo. The portable Ice Maker was $100 on sale at Home Depot. (Marvelous invention, and a couple of grand cheaper than Marine Refrigeration.)

The funny thing is, among the Sailors that I hang out with, there are people who are far more extreme. Wind Generators. Pedal-powered Generators. Washing in salt water. Homemade Bio-Diesel. IcyBall Refrigeration. It's an entirely different mindset from those that turn keys and crank up a pair of 200HP Gas engines, and burn fuel at a rate of 10-20GPH. (At 6KN, I'm using ~0.4GPH. I'm getting ~15NMPG when the wind isn't cooperating.)

"My own interest was mainly to see how practical a solar/battery bank would be on a recreational boat..."
Many Sailboats are already so equipped. A 50 Watt panel for a couple of hours a day is good for me. But Big Powerboats with all the Mod Cons will need a _lot_ more. You really have to figure out, or better yet measure, your daily Energy budget. An AC running 12 hours a day at 1KW is 12KWH. At ~12W/sqft, that's 1,000 square feet of panels divided by the number of hours they are lit up. Assuming half of the time, the AC is on when it's dark, that's 6KW/hr drawn from the Batteries- 500AH. And that's just for the AC. So Solar/Batteries aren't replacing Generators any time soon on Powerboats.

Hooray for economics?

[Anonymous Coward]

I wonder how much science vs. engineering (vs. economics) went into this.

Supersonic Flow

[Anonymous Coward]

We've got supersonic flow to meet the cooling requirements. We win.

Astoundlingly dense

[Anonymous Coward]

There's probably a joke to be made at your expense, here.

E-nuf

[Anonymous Coward]

Teh G for to-day.

Trifecta

[PopeRatzo]

We may have just hit peak Google. Three stories in a row.

Re:Trifecta

[houghi]

As the postings are all about different subjects, it just shows how big Google is.

Ironic heading to the comment

[mykepredko]

Personally, I read it as "Anonymous Coward by its very nature inefficient".

Three Google slashvertisements in a row!

[Anonymous Coward]

Google must have gotten Timmay a new wheelchair.

Split phase

[shawn2772]

Another nice improvement the winners made above the requirements was that Google asked for 230 or 240 VAC output, but the winning device provides 240 VAC split phase, which means it can also be used to provide two legs of 120 VAC. Not that it's terribly hard to add a 240 VAC -> 120 VAC transformer, but with this design there's no need.

Cubic inches?

[HammerToe]

Cubic inches?! So this isn't a project intended to be looking beyond the borders of one country?

-Matt

Re:Cubic inches?

[fibonacci8]

And in English no less, the third most commonly spoken first language in the world. Could we please get these summaries in Mandarin and Spanish? If we're going to base things in the US on what more people are doing elsewhere, why stop at measurements?

Re:Cubic inches?

[Anonymous Coward]

Your mom swallowed 0.5 liters of cum last weekend. Happy now?

Re:Cubic inches?

[Anonymous Coward]

English is the language most likely to be a common language for two people from different countries. Even if more people understood Mandarin, they would almost all be in one country, so Mandarin is not be a good choice for international communication. When Germans and Finns talk to each other, they speak English, not because they hate their own languages or because English is such a beautiful language, but because English is the language both understand and speak. The concept is known as a "lingua franca". That name should teach you that your position on that high horse is not as secure as you think it is. Watt per cubic inch is indeed an affront to educated people.

Re:Cubic inches?

[Anonymous Coward]

> Watt per cubic inch is indeed an affront to educated people.

So, I guess it didn't bother you then.

Re:Cubic inches?

[Anonymous Coward]

Clearly it bothered me so little that I wrote a comment, correct.

Re:Cubic inches?

[cyborg_monkey]

Hi there,

STFU.

FOAD.

Thx,

CM

Re:Cubic inches?

[CauseBy]

First of all, you mean two countries, right?

Second of all, by "one country" you mean "the most important and powerful country that has ever existed through all of history, including Rome". So, yeah, okay fine, not intended to be looked at beyond that country.

Also, if we are going to keep pretending that Europe is more than one country, then I insist that Europeans recognize the USA as fifty countries. Then, any time they complain that Americans don't know the King of whichever European theocracy, they can prove they aren't hypocrites by naming the governors of all fifty of our States from memory. When they fail, we will mock them as stupid and unworldly.

Finally, I challenge your unstated major premise that most people in the world don't know what an inch is. Unlike you, I doubt people are so poorly informed. Maybe they are -- presumably you are, or you wouldn't be carping -- but I doubt everyone else is.

Re:Cubic inches?

[Anonymous Coward]

Ignorant and proud, a true American.

Re:Cubic inches?

[Anonymous Coward]

Bad analogy - for a start, English may have the third highest number of native speakers, but it is easily the second most understood language once you include second language speakers, and it is the de-facto standard language for international trade, scientific and technical collaboration; just like metric.

There are precisely three countries that still use imperial measurements - the USA, Burma and Liberia. And of those, Burma and Liberia are in the process of adopting metric. It's simply a better unit system - more internally consistent, easier maths and based on measurable physical quantities.

Try the following in your head: If I run a mile, and my stride is 32 inches, how many strides have I taken? If I run 1.6km, and my stride length is 80cm, how many strides is that? That simple example just uses length, but if I wanted to know the approximate pressure exerted by a cubic yard of water, vs a cubic meter of water, metric really comes into it's own:

Metric: P = force / area = mass * acceleration / area = 1000kg * 10 m/s^2 / 1m^2 = 10kPa
Imperial: P = force / area = mass * acceleration / area = (62*27) / (36*36) = ???

Here in the UK, we are largely metric, only using Imperial units for road distance, speed and some fluid measurements (beer and milk in pints, everything else in liters). Older people still use stone, pounds and ounces sometimes (especially for weights of people), but Fahrenheit has been largely banished even from weather reports, and nobody working in a technical sphere would dream of using imperial units. The really weird thing is timber, which is often sold in inches for cross section, and meters for length ("three meters of two by four"), but even this is now usually sold in millimeters.

At this point, the US using Imperial units at all is just being different for the sake of being different, to the detriment of your own people, industry and commerce. A technology company such as Google (and a tech-focused website such as /.) should be trying to drag the rest of the country out of the dark ages, not perpetuate a backwards and harmful tradition.

Re:Cubic inches?

[Anonymous Coward]

Three countries actually: United States, Liberia and Myanmar.

All others are metric.

Re:Cubic inches?

[rsborg]

Cubic inches?! So this isn't a project intended to be looking beyond the borders of one country?

-Matt

It's a secret ploy to force all those millions of non-imperial-units-aware challengers to use Google:
https://www.google.com/search?...

Someone call the antitrust department!

Re:Cubic inches?

[Anonymous Coward]

Finally, I challenge your unstated major premise that most people in the world don't know what an inch is. Unlike you, I doubt people are so poorly informed. Maybe they are -- presumably you are, or you wouldn't be carping -- but I doubt everyone else is.

Yea. Inches are kind of THE STANDARD for doing PCB layout worldwide. Well, I don't know about Germany, but in Australia and New Zealand, we do PCB design in mils (thousandth of an inch), because lo and behold, that's what all the component sizes from the US and China are specified in.

And as everyone ought to know, a standard inch is exactly 25.4mm, so a mil is just a conveniently sized unit equal to 25.4um. The people who are constantly ragging on the US system, obviously never do any engineering work, as mixing inches and mm in a design is quite routine; it doesn't cause any difficulties.

Re:Cubic inches?

[Anonymous Coward]

Mils are a technological legacy which has some inertia because of breadboards and through-hole perfboard. With through-hole parts going out of fashion, mils are becoming less relevant. Lots of new parts come with mm specs, and not converted from mils. Just one example that hobbyists may be familiar with: The ESP8266 chip has 0.5mm pin pitch, not 0.508mm. Even many of the modules that it's sold on have mm pitch (2.0mm instead of 2.54mm).

Re:Cubic inches?

[Anonymous Coward]

the most important and powerful country that has ever existed through all of history

Keep telling yourself that, all the way to the Trump rally

Re:Cubic inches?

[stooo]

>> A technology company such as Google (and a tech-focused website such as /.) should be trying to drag the rest of the country out of the dark ages, not perpetuate a backwards and harmful tradition.
Yep ! interesting fact is, NASA was working largely in metric at apollo times, and reverted to more imperial as far as i know....

Re:Cubic inches?

[stooo]

>> Yea. Inches are kind of THE STANDARD for doing PCB layout worldwide.
Not any more.
Today, 80-90% of components are SMD, and SMD is metric.
The odd 2,54 component is just destroying the harmony of the grid, but that's OK, the modern CAD packages handle this well.
Yeah, sometimes I use 2,00mm headers instead of 2,54mm -> more compact, but a bit more exotic.

Farewell, imperial.....

Re:Cubic inches?

[Anonymous Coward]

SMD is metric.

There are imperial and metric names for SMD components, and it is a mess since the names overlap and conflict. And when you're working in mils or 0.1 mils, it doesn't matter that the original size for both name systems is a round number of millimeters, when it converts exactly to an imperial unit anyway.

Re:Cubic inches?

[Anonymous Coward]

You know most people on this site have enough sense not to copy their first name into the body of each and every one of their posts. But not you. You're special.

-Matt

Re:Cubic inches?

[angel'o'sphere]

The states of the US are only a little bit more than the federal states of gGermany, the Kantons of Switzerland, or the regions of Spain.

So be careful what you ask for, as Europe most certainly has more "governors" and parliaments than the USA have.

Also your "King of whichever European theocracy" sounds a bit fishy :D I believe the only theocracy is the Vatikan ... but I could be wrong ;D

Re:Cubic inches?

[vandamme]

And weight spec in stones...

Re:Cubic inches?

[petermgreen]

It depends on what level you are doing PCB design at.

At the hobbyist level imperial-based packages like DIL and SOIC dominate but most smaller packages (TQFPs , BGAs, QFNs etc) tend to be metric based. If you have a mixture of components it's usually better to work in metric because a dimension designed in inches can be converted exactly to a terminating decimal fraction in mm while converting the other way can result in a recurring decimal.

Anoyingly some common PCB packages work internally in inch-based measurements regardless of what units they are using for display/entry which leads to strange DRC violations due to rounding errors.

Re:Cubic inches?

[petermgreen]

Passives aren't really an issue, with only two pins the difference is negliable.

With ICs one sees a fairly distinct line between the large old packages which use imperial pitches (2.54mm 1.27mm) and the small modern packages which use metric pitches (1mm 0.65mm 0.5mm 0.4mm ).

Re:Cubic inches?

[CauseBy]

Denmark has an official state religion; that's a theocracy. Iceland's constitution reads "The Evangelical Lutheran Church shall be the State Church in Iceland and, as such, it shall be supported and protected by the State"; that's a theocracy.

But the worse offender is the UK. Britain's official state religion is Anglicanism, the Church receives tax money, and the head of the church is the ruling Monarch. Church leaders have reserved seats in the legislature. That's absolutely a theocracy.

Now, let me be super duper clear because some people just can't hear me say this without retorting how Americans are so religious and blah blah blah whatever, or how other theocracies are so terrible because yadda yadda.

Yeah, that's all true, but at least America doesn't have an official religion, doesn't give tax dollars to an official church, doesn't give church leaders legislative powers, and doesn't make the President of the USA the head of any church (how crazy would that be?). Furthermore, no, I'm not equating the UK to, say, Iran; all I'm saying is that they are both theocracies, and theocracy is bad, not that they are all equally bad.

(Furthermore, my insult was not only about theocracies but monarchies, and there are a bunch of monarchies still hanging on all across Europe.)

Re:Cubic inches?

[angel'o'sphere]

Just because a religion is tied to the state, it is not a theocracy. So your examples of Denmark and Iceland's are simply wrong. I'm not sure if one could consider Iran a theocracy either.

The states you mention are still constitutional republics. Especially if you consider that the head of Anglicanism, which is the Monarch, has no power at all.

But perhaps I'm nitpicking :D

and there are a bunch of monarchies still hanging on all across Europe
Yes, basically every country is a monarchy. The exceptions I count from my mind are: Italy, Germany, Switzerland, France ... and then it starts with the question what you count as "Europe." If the border is Ural, then all of east Europe (Poland, Letland, Estland, Luitania, ex Yugoslavia etc.) are non monarchies, but most of the west is.

Re:Cubic inches?

[CauseBy]

If the leaders of the government are the leaders of the official state religion, then that's theocracy, and that describes Denmark and Iceland, where the legislatures control the religion. For instance, in America you can't pass a law requiring a church to perform same-sex marriages, but in Denmark you can, as this American pastor was aghast to find out

http://www.addictinginfo.org/2...

That's because in Denmark they have civilian control over the state Church. That's a theocracy.

I should have added this to the list of retorts I hear every single time:

"Especially if you consider that the head of Anglicanism, which is the Monarch, has no power at all."

This is plain nonsense. If the Queen has no power at all, then she isn't the Queen. Can just any old person live in her tax-supported house and do her official state duties? Yes? No, of course not. She's the queen, nobody else is the queen. She is the head of state and the head of the religion, and nobody else is. She has the power and nobody else has that power.

And no, not all European countries are monarchies. It's substantially less than half, but the quantity doesn't change how ridiculous it is to have a monarchy:

https://en.wikipedia.org/wiki/...

Anyway, that's what I meant: theocracy is stupid, monarchy is stupid, America is neither, and that is two big ways that America is better than some other countries. And all of that is just a tangential insult to my original point, which is that saying "only one country" in reference to America is a silly way to talk about the world's and history's most important country.

Re:Cubic inches?

[angel'o'sphere]

If the leaders of the government are the leaders of the official state religion, then that's theocracy
And all this is not the case in the examples of Denmark, Icelands etc.

The government is elected ... perhaps you should check that once.
And it is not leading the religion. So what is your point?

Your are simply wrong, sorry.

in reference to America is a silly way to talk about the world's and history's most important country.
What retarded statement is that?

Basically every nation of the world cam make the same claim, at a certain time.

Right now the US migt be 'important' in 20 years theybare history, like Germany, the roman empire or the persian empire.

Sorry, thinking that the US are important in any way besides winning the two world wars is just retarded.

Re:Cubic inches?

[CauseBy]

"And all this is not the case in the examples of Denmark, Icelands etc."

In Denmark, the legislature passed a law compelling the state religion to grant same-sex marraiges. That is "leaders of government being leaders of the state religion." That is theocracy. Whether the government leaders are elected isn't relevant.

Every nation can make what claim at a certain time? that they were the greatest nation in all of history? When did New Zealand lead the world? India? Papua? Cuba? Brazil? Argentina? South Africa? Only Rome, China, UK, and America have any plausible claim like that.

Winning the second world war is in the top ten things America did in the last century, but not in the top three. "Pax Americana" is number one: our might is so awesome that the world has seen unprecedented peace. And we did all that without the metric system.

Re:Cubic inches?

[angel'o'sphere]

A theocracy is a government form where the priests are ruling. In one of your examples that is the case.
Which as a first thing implies: they are not elected.

In Denmark, the legislature passed a law compelling the state religion to grant same-sex marraiges.
1) That is "leaders of government being leaders of the state religion."
2) That is theocracy.

Your idea is simply wrong. 1) the government makes laws. If they tell "a religion" to conduct same sex marriages, 2) that does not make the government a theocracy.

In a theocracy, the priests had forces the government to either do it, or don't do it, at their leisure. It is exactly the opposite around as you think it is.

Regarding when which country was a world might: you for fuck sake should read some history if you not even grant India or Persia that title. E.g. Africa was governed by nations as great as rome, India or Persia, just because you don't know that makes that fact not vanishing. The only point where you might be right is New Zealand ... and even for that I would not bet as we simply don't know enough about human history.

"Pax Americana" is number one: our might is so awesome that the world has seen unprecedented peace.

Pax americana ... that does not exist. It was a nice word when america was openly imperialistic and the rest of the world called it mockingly "pax americana".

The correct word would be "bellum americana" as since the US are "the declining leading country" we had more wars than the centuries before, and if you count all the death: more death than World War II (which is estimated about to be 50 millions including the death by Stalin in the aftermath)

Summary:
As long as not priests are making the politics, elected or unelected, a ruling system is not a theocracy.
Secondly: having a state religion, does not make a country a theocracy. Iceland are for all matters a typical western democracy. The church has no say in anything that is relevant for ruling the country.

Hint: "Section VI (of the constitution) contains articles 62-64, and sets the Evangelical Lutheran Church as the State Church and establishes freedom of religion."
Freedom of Religion ... you can pray to/for what ever you want in Iceland.

But is it sign wave invertor?

[Anonymous Coward]

Sign wave has pure wave's that's more better than sguare wave's one's. Also they cost's more.

Economics of those challenges?

[sshir]

I'm still puzzled by the economics of these prize driven challenges. Look at the winning design: (pdf) . R&D costs of it (including expertise, etc) well exceed $1mil. And having a lot of teams working on their designs... Assuming that there are at least 3 other good teams means then expected payout is laughable $250k...

As a professional, I expect to be paid for the work I do for hire. Sure, some things are done for fun, but building entire product is rarely is... Like, look at the open source software, for example: many parts of Linux OS are interesting and fun, others are not - so if you need them to be done, you better be ready to pay.

Another angle: even if you don't need money, there are plenty of engineers who do - google can afford paying for these things full sticker.

Re:Economics of those challenges?

[chrysrobyn]

Another angle: even if you don't need money, there are plenty of engineers who do - google can afford paying for these things full sticker.

Google is not avoiding paying one team, but several. Not only are they avoiding dealing with exclusively a firm at random, who, lacking financial competition, is likely to build in a decent profit margin, but they're soliciting from several teams who understand the nature of the competition. Regardless, they're catching a price break. Successful companies often get that way by avoiding paying money they don't have to. In this way, they're not ending up with an "average" design, and not only are they getting the "best" design, but they're getting a whole pile of designs. Any chance they see to pick design elements from a few of the "almost best" ones to make the "best" even better, that's something they can leverage.

I'm still puzzled by the economics of these prize driven challenges. Look at the winning design: (pdf) [littleboxchallenge.com]. R&D costs of it (including expertise, etc) well exceed $1mil. And having a lot of teams working on their designs... Assuming that there are at least 3 other good teams means then expected payout is laughable $250k...

The $250k is only a small part of the payment. Look at the biographies at the back of that PDF. This team isn't doing it for the cash, they're doing it for the publicity. They might want to get Google to conduct business with them more regularly, perhaps even manufacturing these boxes for them, but they really want the wider engineering market to see what they're doing as innovative. This isn't some cheapskate bully firm screwing an individual graphic artist by offering only publicity for their hard earned work (and nobody cares about it), this is GOOGLE. This publicity is worth something. In their portfolio, they can now put "Winner of the Google Little Box Challenge" and they'll shove that in any prospective client's faces. I don't know if this is going to help them seal any deals or get higher profit margins, but I'd expect it's one of those two.

Re:Economics of those challenges?

[sshir]

That publicity is great for the people, not for the firm that paid the bills. You can bet your ass that most of folks, whose names were printed, will be gone from CE+T by the end of the year.

Re:Economics of those challenges?

[Khashishi]

I suppose the publicity of winning is worth something, though maybe not as much as $1 million.

One inverter for my whole house now

[Anonymous Coward]

And charge my EV great at 1 buck a watt for panels all I need now is for inverters to cost about 50.00 instead of 2000.00.

How $1 million cost, for an inverter company?

[raymorris]

If you started with nothing and had to buy all of the tooling and equipment, recruit people, etc., I could see this easily costing $1 million, but the winner is an inverter company. They already have all of the tooling, equipment, expertise, etc.

They "just" needed to optimize one of their existing designs for size. Also, they only needed a working prototype, not a full production model. How do you figure that costs a million dollars?

Re:How $1 million cost, for an inverter company?

[sshir]

What you described is essentially a marginal cost of R&D. Which indeed is well below $1mil. But just to put a better contrast on what I've said before: try to go to Intel and ask them to design and produce for you "only a prototype" custom (non fpga) CPU for $1mil., for 10mil... They will laugh you out of the building.

Re:How $1 million cost, for an inverter company?

[Anonymous Coward]

Guys, this is just publicity to them (and good publicity, at that).

Google could have paid, sure. They did not. Good for them. Game theory well played IMHO.

The point is: as a professionnal, what is the value of having your name associated to this? As a consultant, how much would you have to shell outto get that attention on Slashdot? ;-)

Re:How $1 million cost, for an inverter company?

[pchimp]

The point is: as a professionnal, what is the value of having your name associated to this? As a consultant, how much would you have to shell outto get that attention on Slashdot? ;-)

Absolutely. Also, as a consultant, do you have any downtime that's not being charged? This sort of competition is worthwhile and (if you like your job) fun.

Also, gamifying these problems gets lots of minds thinking about the problem that wouldn't otherwise. And the "competition" is a cost-free way of separating the wheat from the chaff.

Re:How $1 million cost, for an inverter company?

[Anonymous Coward]

Additionally, the PR value of winning the challenge far exceeds 1 million dollars.

Re:How $1 million cost, for an inverter company?

[sshir]

Ok, publicity argument makes sense. Advertisement plus google's good will. Hopefully the firm that won is ready to lose all those engineers to google and such...

Re:How $1 million cost, for an inverter company?

[Anonymous Coward]

Yea, but a circuit board has much less NRE than a 10 (7?) nm CPU.

I have built many 1-of circuit boards for clients, of the same level of complexity as an inverter, for less than $5k. Now, I can easily see this costing much more, since it isn't a 1-of, but a bunch of invention and experimentation to hit world-beating metrics of efficiency and size. If someone comes to me for an ASIC, they are talking $100k and up, and that's just for schematics/RTL and mask artwork; add another $10k-$10M for mask processing and an initial shuttle run.

If you asked me to build a mature processor in a mature process (> 150nm) with some "off the shelf" peripherals, I could easily quote it under $1M. Intel probably could too, if they wanted to, I doubt they would, because they are not in that line of work.

Re:How $1 million cost, for an inverter company?

[Anonymous Coward]

How is that relevant? You might as well talk about how expensive it is to ask for a custom car from scratch, or for someone to make a new movie, etc., which are all very different processes than making an inverter. A previous company I worked at would make custom power supplies, and prototypes for one-off design studies would be done for a little under $10k quite regularly, as it was about $1k in parts (quick turn around boards and assembly mostly) and a day total split between a lower pay grade EE, pcb layout person, and enclosure designer.

Google suckered everyone

[ArchieBunker]

Sounds like Google had very specific design requirements and didn't want to spend the money in house doing development. So they dream up a contest and offer a cash prize. Meanwhile Google saves way more than the $1 million they paid out.

Re:Google suckered everyone

[asylumx]

Welcome to the 'gig economy' -- in this gig, many people do the work but only one gets paid!

Re:Google suckered everyone

[Anonymous Coward]

That is the the point of all "contests" like this. In the end big business profits as usual.

Re:Google suckered everyone

[tsqr]

Sounds like Google had very specific design requirements and didn't want to spend the money in house doing development. So they dream up a contest and offer a cash prize. Meanwhile Google saves way more than the $1 million they paid out.

Are you implying that Google somehow assumed ownership of the designs? TFA didn't say that the submitted designs ended up belonging to anyone aside from the submitters; it was, in fact, mute on the subject of ownership. Do you have a source to cite that says Google ended up owning any of the designs?

Re:Google suckered everyone

[Eivind Eklund]

The FAQ on the website says this:

Does Google own the intellectual property created during the competition?

No. Google is not requiring any IP or licenses be granted except a non-exclusive license to be used only for the purpose of testing the inverter and publicizing the prize. We want entrants to benefit themselves through the advancements they make in order to help grow an advanced power electronics ecosystem.

It also links to the detailed terms and conditions, which I've not read.

Re:Google suckered everyone

[tsqr]

Thanks for that. Too bad the mod points seem to be in the hands of people who would rather believe it's not true.

Does it?

[Maury Markowitz]

"Google Challenge Results In Astoundingly Efficient Inverters"

Sooo, what is that number? I can't find it anywhere.

Commercial PV inverters are about 97% peak, 93% average. Not a lot of room for movement there.

Japan

[DarthVain]

Hell if I remember correctly half of Japan runs at 60Hz and the other have at 50Hz due to a standards change years ago, and they've never been able to convert even that due to the monumental effort required, and that is AC to AC!

Though I expect the use of things things would be for Cars and Homes, not entire network conversions...

Re:Japan

[Anonymous Coward]

That was one of the reasons for the Fukishima cooling failure, i.e. the inability to get the appropriate large generators on site quickly.

Re:Japan

[Gramie2]

That's right, the east (Tokyo) part of the country is 50Hz and the west is 60Hz. The only thing I remember it affecting was a timing dial on some kitchen appliance (rice cooker?) that had one scale for east and another for west.

Re:Japan

[cstdenis]

It's due to half the countries power plants using generators from US (GE), and the other half generators bought from Germany (AGE), originating back in the early power grid days when each city had it's own individual separate grid.

There are connections between the grid with frequency converters, but they don't have much capacity.

Re:Japan

[Anonymous Coward]

Well, there are two ways to shift a frequency. One is to mix it with another frequency and the other is to convert it to DC and back.
The latter is a lot easier and doesn't give you a mirror frequency.

AC to AC is a lot harder than AC to DC and back.

Re:Japan

[stooo]

Yeah it's hard. Hard as a rock :)
https://www.youtube.com/watch?...

on a more related side, the solution the winner used is very innovative. switching a filtering capacitor with full power swing for minimizing the size is quite novel.
I love the MLCC bricking from team Augustin Reibel also

Efficiency?

[PPH]

Watts per cubic inch (cm or whatever) is just one measure. It's a fine target for aerospace and automotive applications. But it is of secondary importance for fixed installations like solar. Here, the efficiency I'd be interested in is power conversion efficiency. Particularly across a wide range of loads. And I'd like that efficiency to come at a reasonable price as well. Where I can evaluate the dollars spent to save a Watt of inverter loss vs the dollars per Watt that a larger solar panel will cost me.

The size of inverters used in solar installations has already come down to the point where small single inverters per panel are available. Once these units have come down to the size of a paperback book, their physical volume is no longer much of a factor compared to the panel size.

I'll believe it when ...

[fahrbot-bot]

... the Mythbusters test it - oh, wait ... damn (sigh).

Open Spec

[phorm]

Are the results open for everyone? If so, then they're also paying for something which everyone can (potentially) benefit from

Re:Open Spec

[Anonymous Coward]

Try paying your mortgage with someone else's potential benefits. It's amazing to me that people are defending the loss of their own income and stability, to the benefit of the billionaire beggar class.

Re:Open Spec

[Eivind Eklund]

From the FAQ:

Does Google own the intellectual property created during the competition?

No. Google is not requiring any IP or licenses be granted except a non-exclusive license to be used only for the purpose of testing the inverter and publicizing the prize. We want entrants to benefit themselves through the advancements they make in order to help grow an advanced power electronics ecosystem.

phrasing...

[Anonymous Coward]

Did anyone else read the title thinking that Google was challenging the results of the contest, like they thought they were faked?

Re:10 ways to make your microsoft clojure app more

[U2xhc2hkb3QgU3Vja3M]

Learn how to run your #C apps on Linux with Xcode!

astounding posting stimulus

[Anomalyst]

Google must have gotten Timmay a new wheelchair.

or wired the current one to give 240VAC shocks to the occupant.

Pardon my ignorance but

[Anonymous Coward]

what would you be able to do with SINGLE phase 240V AC then?

or are we talking about buying this in bundles-of-3 for the home?
I suppose I missed something, but my memory about this subject can be jogged only so much.

thank,
-ac

Re: Pardon my ignorance but

[Anonymous Coward]

Homes use three phases because they have them, but nothing in a typical home actually needs 3 phases 120Â out of sync.
But if you do need that for some load then yes, you can do it by syncing three inverters.

Designs are public

[Anonymous Coward]

The top 18 finalists' designs are available here: https://www.littleboxchallenge.com/

The winner's design is here: https://www.littleboxchallenge.com/pdf/finalists/56568-Tech.pdf

"GaN transistors have many very interesting electrical characteristics (low Rds_on, low
Qgate and Cds, ultra low Qrr); these create technological advantages over current MOSFET and
IGBT devices (small size and low production costs). Unfortunately, they also have serious
drawbacks due to their very fast switching characteristics: they are challenging to drive and
require sensitive electromagnetic noise management. Another pitfall is the high voltage drop due
to the reverse current when the GaN is turned off. The solution selected to overcome these
difficulties is to control all the GaN transistors using soft switching for the entire operation
range"

google's bullshit claims - metric mistake?

[Anonymous Coward]

Google's claims in that are bullshit! "which is more than 10 times more compact than commercially available inverters" - uh, no, not at all.

Link or it didn't happen? OK, these are CURRENTLY for sale, not vapourware: http://www.ebikes.ca/product-i...

The power density of those is 0.5W / cm3. The competition was for 50W / inch3 = 3W / cm3. That's a 6x increase, not a greater than 10x increase.

Those are also 95% efficiency.

Conclusion: google's claims on this are bullshit. Do they really not know the field, despite a million dollar prize? That seems awfully stupid of them.

Re:google's bullshit claims - metric mistake?

[PIBM]

The only problem with this specific item, is that it's doing exactly the opposite work of what google was looking for. This is an AC -> DC converter, which have been improving a lot in the last years, and they wanted to improve the DC -> AC path.

Re:google's bullshit claims - metric mistake?

[koreanbabykilla]

What you linked to is a battery charger that takes 120-240V AC and outputs 24-60V DC, not an inverter that accepts 300-450V DC input and outputs 240V split phase AC. These are very different things.

Re:google's bullshit claims - metric mistake?

[Anonymous Coward]

Conclusion: you are a moron who shouldn't be allowed to tie his own shoelaces.

Slobodan Cuk is not convinced.

[ferespo]

Slobodan Cuk of "Cuk's converter" fame (https://en.wikipedia.org/wiki/%C4%86uk_converter) is not very convinced. From the commentaries:

I could not find anywhere in a number of public announcements the efficiency achieved for any of the top three designs! It appears then that efficiency was NOT a criterion at all in Google's Little Box challenge, but only Power Density and resulting total volume!
I spent 42 years in Power Electronics with the main goal of improving efficiency and reducing magnetics size tenfold without increasing switching frequency! Both are the prime factors enabling smaller size and weight! Without the efficiency objective and novel systems solutions, the glorification of the power density alone sends absolutely wrong signals to Power Electronics industry and misleads young engineers as to what is really important! This is one man’s opinion, I invite yours!
Dr. Slobodan Cuk

Re:Slobodan Cuk is not convinced.

[stooo]

That's true, the extreme power density at the expense of cost and efficiency is kind of a niche thing, especially more with active air cooling, and grid connection, there's no point in that strange combination, really....
But this is to be considered research! The advances in this field can be applied to more common segments....

and you can run them HOT

[Anonymous Coward]

No candy ass 150C limit on junction temps for GaN.. When you're trying to reject the heat to something else, either by conduction or radiation, bigger delta T always helps

(of course, the littlebox challenge says 60C max package temp)

Not that promptly

[Anonymous Coward]

It has to go a few years as s/h/it.