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The Last DC Power Grid Shut Down in NYC
cell-block-9 writes "Today the last section of the old Edison DC power grid will be shut down in Manhattan. 'The last snip of Con Ed's direct current system will take place at 10 East 40th Street, near the Mid-Manhattan Library. That building, like the thousands of other direct current users that have been transitioned over the last several years, now has a converter installed on the premises that can take alternating electricity from the Con Ed power grid and adapt it on premises.' I guess Tesla finally won the argument."
most people don't even know who Tesla was or that he pushed for the system that we now use to distribute electricity.
Are there any advantages to DC current?
But Edison electrocuted an elephant, which quite frankly is just an awesome smear campaign.
How long until a significant proportion of local users have a hybrid AC/DC system to manage power distribution from power generated on site? Tesla certainly won the medium power, wide area power distribution battle, but there are a lot of developments taking place that will increase the visibility of DC power generation.
Less is more.
Frankly, I'm shocked that there was still a DC power system in use in the US.
Can anyone tell me how to set my sig on Slashdot?
Okay, so if the building was running DC, what did the electronics and appliances inside plug into?
Laughter is the Spackle of the Soul.
the new yorker hotel is on 34th and 8th. the final dc site near the midtown library is on 40th and 5th
unfortunately, business acumen and scientific genius do not necessarily go hand in hand
sad
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
When I lived in Cambridge, I sometimes visited friends in Boston who had 600VDC elevators using power from the city.
Later elevators still used 600VDC but used a dynamotor; that whine you used to hear when you pressed an elevator button elsewhere was the dynamotor starting, to convert to 600VDC from the 120VAC line current. Eventually, elevator manufacturers stopped using it, but when you hear that whine in a medium-old elevator, you know what is is.
AC's advantage of high voltage transmission doesn't apply to subways as 1200V seems to be the limit for third rail. 2400VDC was tried in 1915 on the Michigan Railways (an electric interurban in central Michigan) with abysmal results - the voltage was changed to 1200V within a year of the initial installation.
do you have a superior system than capitalism in mind?
people are fond of pointing out democracy's many failures too
but the real overriding realization with democracy and capitalism is that however much you think they suck, and they do suck in many ways, they are still better than any other system we can think of and have tried
so please, criticize capitalism. but unless you can enunciate a superior alternative, your criticism means absolutely nothing
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Thomas Edison is a hack. He didn't invent anything, he just used work-for-hire technicians and inventors then slapped the Edison label on them before marching off to the patent office. Had there been a Steamdot back in the late 19th century and early 20th century I'm certain nerds back then would be decrying Edison's ethics and business practices. Of course old Tommy would've been literally and figureatively deaf to their criticisms.
The most charitable description of Edison's oeuvre is improving something that's already been invented. How can anyone consider Edison to be a legitimate scientist if he actually pursued technology that communicates with the dead?
Nikola Tesla may be considered obscure to Joe Sixpack and the mythical GNU/Linux-using Grandma but every generation will learn that efficient alternating current, those ubiquitous fluorescent lights and wireless broadcasting which form the backbone of Earth society and culture were the brainchild of a humble yet eccentric Serbo-Croatian. Someday soon Edison will become a footnote in history while Tesla will stand as an example of creativity and inspiration tempered with a rational mind seeking to contribute to humanity rather than to one's personal savings account.
First of all, let me tell you that Tesla is one of my role models. He is one of the reasons I studied electrical engineering - with a passion. And AC, if you want, is the "winner" for all intents and purposes. The future really validated Tesla's AC system. There have been other folks that helped the adoption of the AC system, like Proteus, another role model for me.
Said all that however, high-voltage DC, a transport technology that starts to make sense nowadays, thanks to high-power solid-state switching elements, has many advantages over AC in terms of losses and cable utilization. You can transport more energy via DC than AC, across the same thickness cable. And you have practically no losses due to parasitic capacitances and inductances. The corona effect is much easier to control, too.
So, if I was forced at gunpoint to make a prediction for the electricity transportation in 150 years from now, I'd say hihg-voltage DC.
"The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
No, it's Con Ed for Consolidated Edison.
Idiot.
Without Tesla there's be nothing to watch the Super Bowl on. I'm pretty sure I could live without the Bengals or the 49ers (some might disagree with me).
Quack, quack.
That would be the 49ers. The start of their dynasty that lasted nearly 20 years, but is now in ruins.
General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
I know an excellent surgeon who can remove that foot from your mouth.
DC has become feasible and possibly advantageous for long-distance transmission lines now, thanks to better technology. The trouble was that there wasn't a good way to alter DC voltage, something trivial with AC using transformers. Now that DC can be pumped up to high voltages like AC, it's easier to transmit due to fewer losses and less stress on the lines.
It still may not be economical beyond transmission lines though.
"No one likes working in a hamster wheel, and your shop smells of cedar shavings from here." - TaleSpinner
What's this "electrocuted" you're talking about? He was westinghoused!
So... the capital city of the U.S. is now Washington, A.C.?
He was too busy DISCOVERING how these things worked to be able to "read" them all laid out nicely in some book. Yes, some of his inventions were a bit crazy, but we owe a lot of progress to the man. If it weren't for him, we'd be stuck with Edison's crappy DC systems and the modern electrical systems we have today would not exist. Edison helped ruin the poor man just to sell his crap and he did it via evil fearmongering, doing things like electrocuting an elephant with AC.
Also, the wireless power transfer IS possible. Too dangerous to actually use, but possible. And he left behind plenty of shocked people to prove it (literally...).
Kinda sad to me but it was in the way of progress. Lots and lots of buildings still use the old DC elevators here in New York City. Just yesterday I loaded in to Bayard's in downtown Manhattan into a 4x4 foot elevator that I swear Otis himself must have installed. I love how you have to hold the lever to go up and down and manually align the elevator to the floor. The elevator lights are powered by the DC current as well. At Pratt Institute they used to have those old DC elevators that were powered by an ancient motor generator set that was dated back to the 30's. Hell up until 1999 the MTA still had an old DC substation that had Rotary converters for the subway. ConEd also kept the 25 cycle plants running to feed those substations until the early 90's.
If you want a feel of old DC equipment from the days when if you wanted power you had to make your own, head down to Pratt Institute (located in Brooklyn on Willoughby ave. and Hall st.). They still have 3 steam driven reciprocating piston dynamos built by Ames Iron Works. They work but are only for show. And to top it off they also have a steam turbine dynamo all of which is hooked to a large open marble panel board with knife switches, carbon arc circuit breakers and blade fuses. The panel is still live on the AC side. The Motor generator I mentioned is still there. You can go down to the Pratt engine room and get a tour from Conrad Milster, the Chief engineer who keeps the place running. The large 1930's brick steam boiler still heats the campus and the surrounding neighborhood. The site is an IEEE land mark and walking down there is like going back in time, a real treat.
Not quite yet. While AC has an advantage over DC transmitting long distance at low voltages, at high voltages DC has the advantage. There are discussions in Europe to use high voltage CD current long distances. By stringing up all of Europe with these power lines it would make it easier for Europe to develop alternative energy sources. For instance while it may not always be windy in Spain it may be in Germany or Poland, and Turkey could provide solar power part of the tyme. Some months back I think IEEE's "Spectrum" had an article of this, here's one from the "Economist", "Where the wind blows".
FalconShould there be a Law?
Seems like a DC grid would be a lot easier to have people feed surplus power into from solar cells.
One could easily apply this to economic systems as well. The only thing I could think of that would be better would be some Deus Ex-type computer-AI directing or at least regulating human activities. Self regulation seems to be one of our biggest difficulties.
sig sig sig siggy sig
no one needs anyone to tell them that shit smells like shit
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
But not the war. In the end DC will win
DC is far more useful then AC especially now with the drive for efficieny
When efficieny/cost wasn't an issue then Direct-on-line AC machines (a.k.a Induction machine) were best (and their construction is easy). HOWEVER they are very inneficient and the drive to variable-speed drives using sync-machine has been going on for the last decade and they all need a DC-link to operate.
TV? run on DC. phone chargers? DC, vacuum some run on DC... infact there is hardly anything that actually requires AC to work now that electronics is everywhere, it exists for practicality
Power demands are going up and central Power stations just can't cut it. More and more homes are getting local generation (The full war of current was: AC & few,large central plants vs DC and many,small community plants) and such generation generates DC (which needs to be inverted to AC just cause the house is AC). Not only that but power needs to be moved around and to move vast quantities of it requires HVDC. China are building the highest voltage/power link from N->S atm (they are also builting the highest voltage AC as well in parallel) to shift vast quantiites of power. Europe will soon be inter-connected by a grid of HVDC networks under the sea linking all the wind-farms and networks together.
IF houses had a 42Vdc ring as well as the 230Vac ring it would make more sense from electronics and efficiency POF (no rectifier or low-freq transformer). Keep the AC for the high-power stuff (space-heating,oven...) and had the low-voltage DC for the entertainment stuff. This will cutdown on all the bulky power-bricks and small bricks can exist.
Tesla won the battle back then due to practical reasons, but the war will be won by Edison
Who the hell modded this "insightful"? Oh hell, I'm off to meta-moderate, get these fools the heck out of MY slashdot.
sig sig sig siggy sig
But it uses AC electric motors. The best tech for the best uses. We don't have AC batteries yet!
DC is actually used extensively in modern power grids, the main advantage being that there is no need to synchronize the phase from different generating stations or subgrids. For example, the Pacific Intertie transmits three gigawatts of direct current between Los Angeles and eastern Washington state. (Power is sent from LA to Washington in the winter, covering the demand of electric heating in the pacific northwest; and from Washington to LA in the summer to power our air conditioners.)
all you did is enunciate standard real world checks and balances on the ideas
no one expects pure capitalism or pure democracy to ever be able to exist
i'm taking umbrage with radical fundamental departures from the core concepts: communism instead of capitalism, for example, or theocracy versus democracy
not capitalism, tweaked, or democracy, tweaked
the core ideas are always tweaked in one way or another to fit in the real world
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Without Tesla there's be nothing to watch the Super Bowl on. I'm pretty sure I could live without the Bengals or the 49ers (some might disagree with me).
I'm pretty sure most if not all TVs the Super Bowl plays on convert the AC power they receive to DC. Most home and office appliances have to convert the AC power they're fed to DC before using it. This conversion introduces inefficiencies. Now is it more efficient to transmit high voltage DC then step down the voltage when it reaches the point of use, or convert at the transmission point?
FalconShould there be a Law?
No it really isn't. There's a time to get off your ass and do something, but if it's not that time yet it is one of few ways to express such an idea. If shit gets rolling and you just sit there and complain, that's useless. Right now many could do with such an insight.
He sure did, and Edison's company clearly lost and has faded into historical obscurity. What was that company called again? Electric... General... General... something...
-Arthur
Cave ne ante ullas catapultas ambules
but I didn't realise that anything was still being served anything other then AC out of the wall. I guess in the New york area was some of the original electrical installations. It is a shame that Tesla's lab was destroyed because I would bet that he could have come up with some more stuff that even today would make peoples jaws drop.
that Tesla's band is already beginning to disappear from the history books too.
Don't De-Rock ME!
Or that he died broke and alone because people like Edison stole his ideas and robbed him blind. Tesla was a genius and could have done so much more for the world if only things weren't controlled by rich people with no vision further than how much money they can make, right away, off an idea. Tesla's failure is a perfect example of capitalism at work.
No, that's an example of the Corporate Aristocracy Thomas Jefferson warned against.
FalconShould there be a Law?
So, are you like, waiting for "the revolution" or something?
actually no, that means 80+ years ago that was true but now a high voltage dc transmission system is in fact more efficient, uses less condutors, eliminates need for sychnonization between different systems. HVDC also preferred for undersea long distance transmission because of less capacitive losses.
a populace decided to vote to ban all religious minorities
oe how about a populace that votes a very popular ruler in as dictator for life
both are extremely bad, and both could happen from pure democracy
no, democracy, like capitalism, must be tweaked to fit into the real world
a republic, for example, has checks and balances so that the a popular leader cnanot become a dictator or fundamental rights are not restricted, due to popular fickle whims
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
It keeps being repeated, even in this article which says "it can be transmitted long distances far more economically than direct current", that AC is more efficient. This is not really true. The advantage (and pretty much the only advantage) that AC has over DC is that it is relatively simple to change voltages.
Over the short-haul, this is good since losses are primarily resistive and losses are related to the amount of current flowing in the conductors. Power in my neighborhood is delivered at 12,000V and down-converted to 120/240 by transformers located every few houses. Delivering power at 120V would require 100 times the current and massively larger conductors. Once it gets to my house, with the exception of some motors and some lights, everything from TV to stereo to computer ends up having to take that power and reconvert it to DC.
But AC has far higher losses through capacitance and inductance which become severe over long distances. This is why some current and other planned long-haul transmission routes use DC. A good example of this is the 800-kilovolt DC line that connects into the Sylmar Terminal Station near Los Angeles.
Apparently, the use of Extra High Voltage DC is being proposed for a number of new long-haul transmission systems and it is the high losses incurred by AC over long distances that is driving the use of DC.
~~~~~~~
"You are not remembered for doing what is expected of you." - Atul Chitnis
Score: -1, Turd ?? :^P
Capitalism rewards manipulative wheeler-dealers far more than creativity. It rewards those who can best exploit creative ideas, not make them.
And that's why we have patents!
Oh...wait...nevermind....
capitalism should be tweaked with some socialism: universal healthcare, for instance
and democracy should have some checks and balances on unfettered popular rule too: a republic, as you insist, or otherwise, in a pure democracy, the rights of racial or religious minorities can be trampled on, or, perhaps, the democracy can vote itself out of existence (voting a very popular leader to be dictator for life, for example). such pure unbridled democracy is not possible in a republic, and that's a good thing
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
"um the fact that we use AC for long distances means that it is in fact better..."
Ah, yes, the old "I've been doing it this way for twenty years" reasoning. I can't think of a more dumb way to prove something than to say the reason is because "we've been doing it this way".
Second, re-design corporations - make directors accountable personally, make ceos accountable personally.
Ah but Corporate charters can be revoked. Corporations were originally granted charters if it served the public good and when a corporation no longer did the charter could be revoked. Unfortunately charters haven't been revoked in a long tyme. I agree though officers and directors of corporations should be held accountable.
ut you want solutions to capitalism? Sure, close the borders with any other country that doesn't implement capitalism the same way we do, so that we can compete under a fair system.
Oh you mean Mexico can and should give Mexican farmers billions of dollars, er pesos, in subsidies like the US gives to US agribusinesses? The US even gives farmers subsidies for NOT growing a crop.
Should there be a Law?
the notions of democracy and capitalism are more complicated and nuanced than the propagandistic ways in which you describe them
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Still active in New York City:
- A utility network that delivers steam. No kidding!
- A service that delivers seltzer siphons to elderly European immigrants. They pick up the empty bottles and charge them up with fresh seltzer. No kidding!
- A pneumatic tube delivery system linking major law firms with City Hall, various court houses, and a dwindling number of restaurants. The restaurants send out menus and accept orders by New Amsterdam Pneumo-Tube; lunches are delivered in special cylindrical lunchboxes. One of the thermos cylinders used to deliver hot soup recently fetched several thousand dollars on eBay. No kidding!*
- A guy in a goat cart who delivers jugs of whale oil to five historic buildings in lower Manhattan. They're working from "old stock" bottled over a hundred years ago. No kidding!**
Stefan
* Well, OK, I'm kidding.
** Yeah, that's fake too.
Except that your long post goes on about an entity that currently does not exist. The free industrialized world nations that you know today are representative republics. Democracy is where everyone votes and power and law are decided based on the outcome directly. A republic is where everyone votes but the power and law are implemented by representatives.
Excuse me but a "republic" is "any form of government other than a monarchy", that includes democracies as well as dictatorships.
FalconShould there be a Law?
In Chicago it's ComEd, for Commonwealth Edison. In New York, it's Con Ed for Consolidated Edison. I think Massachusetts used to have a ComEd, though not sure if that was the same company as in Chicago, it stood for Commonwealth Edison (but these days it's called NSTAR in Mass).
There are some advantages (source: http://en.wikipedia.org/wiki/HVDC#Advantages_of_HVDC_over_AC_transmission):
- Undersea cables, where high capacitance causes additional AC losses. (e.g. 250 km Baltic Cable between Sweden and Germany[9]).
- Endpoint-to-endpoint long-haul bulk power transmission without intermediate 'taps', for example, in remote areas.
- Increasing the capacity of an existing power grid in situations where additional wires are difficult or expensive to install.
- Allowing power transmission between unsynchronised AC distribution systems.
- Reducing the profile of wiring and pylons for a given power transmission capacity.
- Connecting remote generating plant to the distribution grid, for example Nelson River Bipole.
- Stabilizing a predominantly AC power-grid, without increasing maximum prospective short circuit current.
- Reducing line cost since HVDC transmission requires fewer conductors (i.e. 2 conductors; one is positive another is negative)
Shoot, it's used in the US and UK (in the "Chunnel").Here's a list of notable places that use it:
http://en.wikipedia.org/wiki/List_of_HVDC_projects
The sheer amount of High Voltage left the audience Thunderstruck, ready to Shoot to Thrill.
My grandmother used anecdotal evidence all the time, and she lived to be 120 years old.
Put it this way, the computer you typed that on runs on DC. If you print this out, the printer will use dc power as well. Almost every electrical or electronic equipment in the home and office converts the AC power they are fed into DC power. Inefficiencies are introduced during the conversion. Because of these inefficiencies people who build their homes Off the Grid wire the home mostly for 12V, 24V, or 48V DC then they furnish it with DC appliances where they can.
FalconShould there be a Law?
Tesla Man out of Time Which is a excellent book on what was going on then.
Amazing.
DC is still far more of a pain to convert than AC at least if you want high efficiancy and high reliability. While HVDC is certainly more efficiant for very long or undersea transmission lines it would be extremely difficult to build a power distribution grid based on it.
note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
The difference is, you can actually not care about that Super Bowl -- it had pretty much zero impact outside of its fandom. Even videogames have a more broad impact, by continuing to drive Moore's Law. (Modern Superbowls might have more of an impact on our advertising, though.)
To say that Tesla winning has historical significance would be an understatement. Call me Captain Obvious, but electricity, including the invention of AC, is much more fundamental to society than either the Superbowl or Portal.
And everyone cares about that, even if only abstractly. Even if the only thing you care about is the Superbowl, it would be nothing without TV, which would be nothing without AC.
Don't thank God, thank a doctor!
We had Mass Electric and Boston Edison... Boston Edison is nstar now and mass electric is part of National Grid now.
BOO!!
Capitalism isn't the problem; thievery is.
If you're point had been that Tesla would be the rich, fat cat and that would be bad, then your moral compass would be off but at least your logic would be sound.
I know the parent was probably meant as a joke, but it is also insightful. Don't take karma away from the poster by modding it funny. Even after seeing a whole special on PBS a couple years ago about the early battle between Edison/DC and Tesla/AC, I had no idea there was even a single installation of DC power distribution still operational in this country. My impression was that while DC had started out strong, AC was so much more efficient over long distances that DC distribution died off very rapidly, and very early. Like, prior to WWII.
If you'd asked me to guess when the last remaining DC grid was shut down, I would have said sometime between 1955 and 1975 at the latest. Certainly not any time during the last quarter of the 20th century. It's absolutely bizarre to me that there was still a DC grid in operation until this very day, in the 21st century. The whole concept of having a DC grid makes little sense in a world were every household electric device is made to run from AC power. What have they been doing for the last several decades, distributing DC and converting it to AC at the building?
I don't know about the rest of you, but for me this is a really weird story to be reading on Friday, November 16, 2007. It's amazing how long old stuff is kept in use sometimes.
Is cheering from the grave.
OK. So let's say you invent a better widget. Your widget solves all my personal problems, mitigates global warming, whitens my teeth, and provides a better gaming experience than a Wii. But, just as you sit there condescendingly proclaiming in absolutes how capitalism operates to opress creative geniuses in favor of useless wheeler-dealers, I also realise your arguments don't convince me.
See that's because you seem to me like another of a long string of self-proclaimed scions of "creativity" - and therefore I discount you and your claims, and don't buy your product.
But one of these wheeler-dealers come along - someone who knows how to connect to me emotionally and in practical terms - and convinces me to buy your product - you know, someone who can talk to us simple cavemen who don't understand your creative vision. Are you thus saying you have a problem with this?
I don't. The very fact that success in a economic system depends on convincing others to embrace a particular creation shows there is choice, and that a particular creation must earn its way.
Other economic systems mostly imply central planning that provides limited choices - and if you don't like the choices (or choice), tough. You can thus do without; and if you continue to protest your limited choices, eventually we have a gulag for you. Can't have you bucking our system set up by our annointed "creative" types, your own creativity be damned.
When I toured the plant in 1996, the tour guide (a maintenance employee that day) said that when the plant was first built, it transmitted DC power and still had a DC customer in Northern Missouri, a metal smelter.
It was a cool tour, and since I was the only one on it, I got to go all kinds of places they didnt normally take tours, include INSIDE a generating turbine.
He also showed me how they can HAND START the entire plant -- they had a gizmo that looked something like a bicycle that could be hand-cranked to generate enough power to get a single turbine running, and that turbine could then power the rest of the plant (I don't remember, but I assume it was to power the electromagnets used in the turbines). He said it hadn't been used for a long time as they had power from the grid, although during the flooding in the early 90s I seem to remember him saying they at least tested it in case the flood had damaged their grid power.
Well worth the stop in Keokuk, plus its a very interesting architectural presence on the river.
Having higher voltage DC available in automobiles opens up a LOT of possibilities for fuel savings, as the higher voltage (and consequent lower current/lower I^2R losses) allows all kinds of loads to be operated electrically, rather than directly off of the crankshaft.
The proposed 42 volt standard would allow the intake and exhaust valves to be operated by solenoids, rather than by traditional timing chains, camshafts, lifters, pushrods, and rocker arms, with all their frictional losses. Direct electrical operation of the valves would allow the valve timing to be adjusted "on the fly" to optimize for different load/speed/altitude/fuel, rather than being a fixed function of the camshaft pattern.
Higher voltages also make it possible to run many accessories from their own electric motors, allowing their speed to be controlled as needed, rather than being tied to engine speed. A/C compressors, power steering systems, etc. could all be driven electrically, for increased efficiency.
Remember "News for Nerds, Stuff that Matters"? Help make it a reality again! http://soylentnews.org
I remember hearing that the police station in Chinatown (NYC) was still using DC for its lighting. Can anybody confirm or deny this? Urban legend?
I remember now. you subscribe to elevator world:
http://slashdot.org/comments.pl?sid=335049&cid=21069343
>> ...except for the trolls and turds.
> Even trolls need electricity.
Turds don't.
This story explains what the original FA obscures; that some old buildings had elevators and pumps designed to run on DC. Sue me if the link doesn't work. http://query.nytimes.com/gst/fullpage.html?res=940CE7DF173DF93BA25750C0A9679C8B63&sec=&spon=&pagewanted=print
BSA: "Would you like a free Software Audit"? me: "No, thanks. My software is all Free".
Yeah, but it is a pain to make HVDC or step it down to lower levels for distribution. After all there is no such thing as a DC transformer (which of course wouldn't make sense). People build contraptions like motor-generators and big SCR controlled devices to convert HVDC to AC for distribution. They are not particularly efficient or cheap. Add in the fact that DC has the big grounding issue while 3 phase AC will work just fine with a single ground (and transformers can isolate grounds between sections). And note that most industrial electric motors are 3 phase AC motors. I don't think we are going to see a big future with HVDC distribution systems.
More and more industrial motors are being controlled by variable-frequency drives, which must internally convert incoming AC power to DC and then back to AC.
While there is no reason to replace a three phase AC motor with a DC motor, You might start powering variable-frequency drives directly from a DC distribution system.
You're on the highway to hell for dirty deeds, done dirt cheap.
He may have a mild point (certainly not worth +5) but really blows it on the second item. Completely wrong. Down you go.
One simple rule for its versus it's
60Htz AC in conjunction with the Earth's magnetic field sympathetically resonates with Lithium ions, causing Lithium ions to energize and move on a vector. This means that naturally occurring Lithium in your blood crosses the blood-brain-barrier more easily, and in fact has an impact upon brain chemistry. (Lithium drugs are also known as anti-depressants). You can read more about this principal here.
Ergo, everybody living within a society wired at 60 Htz AC is living in mind-dampening cage.
I always wondered how AC was adopted over DC. While I think Edison was a dick, and Tesla was rockin' cool, I still think that the wrong system won for the wrong reasons.
-FL
Warning: Serious Offtopicery Ahead.
Unfortunately, AIs aren't much better. Computers are literalists, and bugs in a massive codebase can stay dormant for incredible lengths of time - heck, nobody thought the perihelion of Mercury was a problem for centuries after the Principia hit the streets. And besides, a centralized AI running society is a Single Point of Failure - if the AI dies/breaks/goes rampant/what-have-you, society breaks along with it.
Yes, Computer Science has something to lend to the creation of an ideal governmental-societal system. But it's the techniques of CS - NOT the technology - that'll get us there. The fact that we've been doing systems and algorithms design on computers for the past few decades is that the computer industry was the first place that needed that level of formal design work; as I mentioned before, computers are literalists to a fault, and need to be handed a perfect system to work the way we want them to work. But now that we've got that groundwork of theory, how could we expect to build a system that is scalable (population boom), robust in the face of failure (the misinformed) and attacks (the powermongers), and highly-responsive (every single crisis in the history of ever) without taking advantage of it?
Send me an e-mail or something. Let's get on this.
(rot13) rpbzbab@tznvy.pbz
I hope that the current HD-DVD vs Blu-Ray debate is resolved a bit quicker
The whole concept of having a DC grid makes little sense in a world were every household electric device is made to run from AC power. What have they been doing for the last several decades, distributing DC and converting it to AC at the building?
Open up a lot of electric devices in the home and you will a lot of them converting the AC power they are fed into DC. The laptop I'm typing this on uses DC, otherwise I wouldn't be able to unplug and take it with me for use away from an outlet, the battery provides DC power. I bet my monitor, TV, DVD player, and stereo also convert the AC in DC power.
FalconShould there be a Law?
Washington State, or Washington DC?
Washington state, wind and DC hot air.
FalconShould there be a Law?
Why there are plenty of switch power supplies in your computer, some of which are outputting hundreds of amps on a mobo costing a modest amount seems like that could scale or even old fashioned motor-generators in the substations.
Apocalypse Cancelled, Sorry, No Ticket Refunds
What sort of electric devices even come with DC input? Most everything has a AC/DC converter built into it. Does that mean that every electronic device on the premises needs both a DC/AC converter and a AC/DC converter chained together? Wow...
San Francisco's trolleys use a moving cable under the ground! That's why they are more properly called "cable cars". The trolley just grabs the cable and lets the cable tow the car around. The cable motion is created by big turning wheels at the end points of the lines, and I don't know what motors they use to turn them. It has probably changed a few times over years, as old as they are it might not have even been electricity back in the beginning.
Thanks for the info.
FalconShould there be a Law?
Standard practice for DC substations in urban areas was to wire the M-G sets or rotary converters in parallel with a battery. The AC power could drop out for an hour or more, but the DC customers would still have power.
I think the most beautiful piece of old AC to DC conversion technology was the mercury arc rectifier...apparently these devices were still used on some branches of the NYC subway until late in the 20th century. A video of one in operation can be seen at http://www.youtube.com/watch?v=Rt-a8fxgtno
A center-tapped transformer was connected to two anodes to form a full-wave rectifier(some had more anodes and were used for 3 phase power), and a pool of liquid mercury was used as the cathode material which would form an arc only if the anode was positive. A keep-alive electrode kept the interior full of vaporized mercury to facilitate the discharge. I'd sure like to have my own. Unfortunately an average sized mercury arc rectifier contains around 2 pounds of liquid mercury, so if it ever broke, my neighborhood would have to be decontaminated, my home razed to the ground, and the rubble buried in a concrete encasement.
Toasters, irons, incandescant light bulbs and appliances with universal motors ran just fine off of DC - back in the 1930's it was possible to get appliances that ran off of 32VDC (standard voltage for wind-chargers). Appliances such as refrigerators would be more of a problem, bu I wouldn't be surprised if some were made to run off 110VDC. Phonographs required a DC-AC MG-set to provide '60' Hz.
It'd be nice of we actually had an economy that really did operate through a true capitalist system. No system that supports businesses through subsidies using money drawn from public money, "IP" protections and the various other quasi-monopolies and other breaks and benefits that the larger businesses enjoy globally these days can legitimately be characterized as a capitalist system. Some strange form of socialism perhaps, but not capitalism.
As far as democracy goes, Jefferson would weep.
------ The only greater hazard to your liberty than n politicians is n+1 politicians.
Tesla Wins??
Is this why many data centers are now piping DC directly to servers to avoid the power loss in the power supplies?
Better yet, is this why almost all computers have some kind of AC to DC converting power supply?
Most Telecom server rooms are 48 vdc
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I *am* the revolution. lol i dunno...
Yeah, except computers make sense in applications other than as a laboratory curiosity. Wireless power transmission doesn't.
Wireless power makes as much sense as WiFi, and is even more useful.
FalconShould there be a Law?
Why there are plenty of switch power supplies in your computer, some of which are outputting hundreds of amps on a mobo costing a modest amount seems like that could scale or even old fashioned motor-generators in the substations.
No, your regular computer power supply does not provide hundred of amps - tens, tops, and that is for a really power hungry system on a 110VAC line. Switching power supplies prices scale up rapidly with increasing power output.
And then again, how long does the average computer PSU runs before failure? Transformers are big, bulky, hard to build and expensive, but they're extremely rugged devices, with basically zero manteinance. 10-20 years life for an industrial transformer is common, and for household devices is even longer.
Next time you're browsing the website of one of the larger vendors (HP, IBM, Sun, etc.) you might take a look at the section containing their high end servers - you will find a link to a set of machines described as "carrier grade"
Carrier grade means that they are designed for use in a telco environment and implicitly expect DC power.
Grand Central Station had an extensive 120V DC system until an overdue rewiring in the 1990s. Grand Central had several independent power systems - 600VDC subway traction power, 25HZ 12KV Pennsylvania Railroad traction power, original 120VDC Edison utility power, 60HZ AC utility power at the usual voltages, and a sizable in-house steam plant, all fed from different sources. Old equipment was running off of one or another of these sources, and had to be replaced. After the rewiring, everything that didn't run on rails was powered from commercial 60Hz power.
Grand Central provided power and steam for several nearby buildings, and during the cutover, some businesses were discovered to be mooching off Grand Central's power.
I have a hard time believing that DC "feels better" than AC. In grade school, I had a 6-volt car coil from a Model A Ford that I would bring into class as a "shocking machine." Everybody would hold hands in a big circle, with the person starting the circle holding the coil wire, and the person at the end of the circle holding the coil casing.
People liked 6 volts of AC being applied to the primary side of the coil better than they liked a 6 volt battery. Perhaps it has to do with the way the magnetic field collapsed on DC vs. just being a transformer with AC (I never had any equipment to take secondary winding voltage measurements using different power sources).
I've never been shocked with 120 volts of DC; I don't know where I'd accidentally come into contact with that unless I hooked up a bridge rectifier directly to an AC outlet. I have gotten a couple of zings in the past, and I think people's discomfort with it is related to their skin's resistance.
For instance, my father witnessed an old guy he knew take the one of the plug wires off of a running tractor, and the tractor would run rough. He'd hold the wire in one hand, and touch the spark plug with the other hand, and the tractor would run smooth. I've never seen it done, but I've messed around with magnetos enough to know they hurt like a bitch.
http://en.wikipedia.org/wiki/Topsy_(elephant). Yucky.
Singularity stupid: stupid gotten so dense that no intellect can escape
There's just nothing cooler than a NOD Tesla coil frying your enemies.
Yes, DC wins when using cables with high capacitance and also between power grids of different frequency. About 5 mins walk from my house is the anchor point for the UK France cross-channel HVDC link. The converter station is at Sellinge, about 10 miles away, and can ship up to 2GW in either direction. However, due to higher capacity on the French side (they have more nuclear), I understand the UK are net consumers of energy.
Although the UK and France both operate at a nominal 50Hz, it is normal for actual grid frequency to vary slightly throughout the day. The way this was explained to me was fairly intuitive: when you load the grid, you load the generators and in turn they load the turbines, which slow down ever so slightly. Because turbines have very large inertia, their response time to step loads is rather long. In order to pump power into the grid, a generator has to have a phase lead to overcome its self inductance. A shift in the phase means a shift in the power being pumped.
France is 1 hour ahead of the UK and have different norms regarding hours of work, cooking etc, all of which mean they have a different load profile. Combining the UK and French grids would only be possible if the link were much greater than 2GW thus able to cope with the difference in power swing. The link was never intended to serve that purpose. Perhaps, like Concord[e] and the Chunnel, it was more a punctuation of the ongoing Entente Cordiale than a technical necessity.
http://en.wikipedia.org/wiki/Fermat's_last_theorem
Yeah, but it is a pain to make HVDC or step it down to lower levels for distribution. After all there is no such thing as a DC transformer (which of course wouldn't make sense).
High power electronics make it easy to "transform" DC. It's a solved problem.
And note that most industrial electric motors are 3 phase AC motors.
The are being phased out (no pun intended). They are inefficient and being replaced with variable frequency AC motors. It is even easier to get variable frequency AC from DC than it is to get it from 50 or 60 Hz AC.
Finally! A year of moderation! Ready for 2019?
Considering the nature of the +4 comment, I'd agree with you.
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How long does the average computer PSU need to run before failure? In most cases, a lot less time than it actually does. At that point it should be recycled (ha ha) and we should move on to the next more efficient model.
Given the rate of technological development, your transformers would never be around long enough to die - they would always be obsoleted first. And in the meantime it would require much more energy (and other costs) to produce them than the lighter-weight systems they replace.
Switching power supplies can be more efficient than most of them are today. Switching power supplies are not the enemy. Piecemeal, off-the-shelf construction and synchronous logic are the enemies. If we constructed whole machines of custom silicon then we'd have way more super-low-power designs and such, and we wouldn't need umpteen voltages, at least not at high power. We don't do that because it costs too much right now. And the synchronous logic thing makes it much harder to turn off parts of the logic that aren't in use and necessitates needless action when the logic is just NOPing.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
I didn't say anything about the "power supply", I was talking about the Motherboard, which feeds electricity to that power hungry CPU, taking in the 5VDC at 20 Amps and convert it to 1.33 VDC at 60 amps per unit
Now we have multi-CPU and multi-core CPU; that easily hundreds of amps on a MOBO; it mind boggling but your computer might be consuming as many amps at 1.33 volts as you4 entire house at 225/117VAC.
Apocalypse Cancelled, Sorry, No Ticket Refunds
I am afraid 42V automotive systems are about as far in the future as nuclear cars.
I have been waiting for automotive (=rugged, cheap, long term availability) 42V Power supply components for my applications for about 15 years now, and they have been "just about to be introduced" all that time.
The reason seems to be that automotive engineers seem to be a *very* cautious and conservative bunch - and, IMO, not without good reason.
I expect my car to run at least for 15 years without any major safety or reliability issues over more than a 100C/180F temperature range (temperatures on the dashboard or under the hood) and a 5..100% humidity range, with occasional saltwater-spray, fiendish vibrations and tampering by unskilled mechanics and owners.
Just imagine that all engines from one manufacturer broke after less than two years as happened with the faulty organic capacitors in cheap motherboards a few years ago.
Unless they are *really* forced to convert (gas in Germany is app. $8 per gallon right now), each car manufacturer will try to wait until the competition gets burned by the inevitable learning curve of introducing a wholly new system, and the high cost of being the first to do it.
I, the consumer, however, would like them to introduce 42V systems as soon as possible on the next car *You* buy!
My father's office was, for an half-century, in the Diamond District (W. 47th Street). At least through the mid-70's, he claimed trouble with building management over what appliances (particularly, an air conditioner) he could run because "they were on DC". I didn't know or understand the details, and it's possible that they were bulling him, but my guess is that they had a half-arsed inverter supplying some outlets with inadequate AC until they installed an adequate, building-wide, inverter c. 1974.
Switching power supplies can be more efficient than most of them are today. Switching power supplies are not the enemy.
:) that AC is used for a reason, and that is that it allows ease of voltage conversion, which is crucial when you talk about distributing power. Switching systems do this for DC, but with added complexity, costs and decreased reilabilty.
Much agreed, but my point is (or tried to be
No, those are peak current requirements - the PSU may deliver 120A but for brief high current draw periods. It's easy, if you take a 400W PSU (which is overkill for most systems), and use it to somehow power the 5VDC rail alone you get 80A maximum draw. In reality, available power is more or less balanced between the 12V and 5V, so it's really half that. That is, if the system actually gets to require full power.
Now we have multi-CPU and multi-core CPU; that easily hundreds of amps on a MOBO; it mind boggling but your computer might be consuming as many amps at 1.33 volts as you4 entire house at 225/117VAC.
Actually, modern multicore CPUs are well behaved (relatively - they still draw power like hell) in that sense; such systems usually draw about 200W under load (specs here).
Then again, it's not surprising that a motherboard is running as many amps as your house wiring, since the issue here is power draw, and for computers this is still relatively low - 200-500W isn't really much outside household usage. Like i said, building a switching system for a industrial applications is not easy, nor cheap, and prone to malfunction; there's a reason most power distribtution systems run on AC.
Yep. Muscles are like solenoids. Apply some current, and they contract. With AC, your muscles have 60 chances a second to flail you around and dislodge yourself from the electrical source (in the US, anyway). With DC, you kinda just lock on...
I recall these games in penny arcades years ago with two vertical handle a foot and a half maybe 2 feet apart about waist height. The idea was to push the two handles as close together as you could, however pushing them together caused current to run through them shocking you and the closer they were the more you'd be shocked.
FalconShould there be a Law?
COMmonwealth EDison.
COM ED.
Christ, does ANYONE know how to fucking read and write anymore?
He spent the last ten(?) years of his life by himself, penniless, in a filthy hotel, feeding pidgeons. Because he wouldn't drop his grand theory that he could power an ocean liner in Japan from a giant tower in New Jersey. Even at the time he was building it, there were dozens of electrical experimenters who could have told him it's not going to happen.
Ok so Tesla died penniless, that doesn't mean he died unhappy.
Look, I love Howard Hughes. Hell's Angels is one of my favorite movies, seriously. But the simple fact of the matter is that he went crazy, pure crazy. That doesn't diminish my respect of the man before he went crazy, but you gotta face reality.
Same with Howard Hughes, what matters is if he was glad for his life when he died. My greatest fear about death is that I will die without enjoying life, which looks more and more likely to happen as my life is more like living in hell to me. The one reason I prefer death now is to end suffering. Unlike what Buddhists teach, to end desire, I have no knowledge on how to do so without dying. I look at my life as a waste, however because of the disability I so called "survived", a Traumatic Brain Injury, TBI, I know of no way to change it. I went from a college student majoring in something I wanted to do, Computer Engineering, to not being able to do many things I loved doing. Maybe it's because of my experiences but what matters to me a lot is enjoying life not making a lot of money or having a successful career. My family was told by the docs while I was in a coma that more than likely I would not live, but the fact is is I wish I had died. AND THAT"S REALITY!!!
FalconShould there be a Law?
Just off the top of my head:
Hong Kong never had a 'empire' but thrived through capitalism while the socialists around them starved and killed each other fighting over scraps.
Likewise South Korea has thrived while their brothers to the north eat tree bark stew.
Likewise West Germany thrived while their brothers to the east enjoyed their 'workers paradise'.
Finally Russia's empire (Belarus, Ukraine, Estonia, Latvia etc etc) didn't produce a thriving economy. Just a bigger mess.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
Their value as social commentary is nothing.
They critiqued a system they didn't understand and came to nonsensical conclusions.
If you base your world view on them you are an even bigger idiot. They were just stupid dreamers, you are stupid and ignoring history.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
Until Americans are lining up to get back into Europe you are talking out of your ass.
In the modern world people vote with their feet as to what country has the best system.
Both the dollar and the Euro are going to have inflation issues as the baby boom retires and all countries involved print money to fund their socialist retirement systems.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
seriously, your brain cramping because the truth is extreme and its easy to just psychologically deny it, but do the math 200W under load / 1.33VDC core voltage = 150 Amps! Your house probably has a 200 Amp panel, the two are comparable current wise; emotively you'd expect the computer to turn into a china-syndrome pool of molten metal.
here figure a 375KVDC line running the same 80 Amps as your computer PSU does at 5 VDC means you're controlling 30 MW I know controlling 375KVDC at 80 Amps isn't trivial but neither is controlling the same in AC
Apocalypse Cancelled, Sorry, No Ticket Refunds
It's not "who threw the ball the most that day", it's who made humanity progress by leaps and bounds, and how.
You can't take the sky from me...
This just goes to show that our power grid is way too complicated and under maintained. How on earth could cutting a wire in New York City shutdown the power grid in our nations capitol? You would think this wire would have been guarded 24/7 by Homeland Security but no, they still seem to believe in "Security Through Obscurity". This makes you wonder what other vulnerable wires are hidden throughout the system. There is a wire that comes in one side of my basement and goes out the other side. Probes show that it is live but I have never investigated where it comes from or where it goes. Perhaps cutting it will cut off the NYC power grid...
And you missed mine.
FalconShould there be a Law?
Wish there was some useful information on these Web 2.0 pages, like what the last DC current building looks like, what appliances it uses, what the DC converter looks like, how much it costs to run it on DC. A few years ago they were writing pages on the resurgance of DC for server rooms. What happened to that?
We do not have pure capitalism (any more than we have pure democracy) in the US, and few other countries really approach a system where money is the only thing that makes things happen.
Just as we have a representative democracy, we have a regulated capitalist economy. That means you can't say, "fine, you don't like aspects of the brutality of capitalism, well tell us how to replace it entirely!!!"
We need to constantly adjust how our economy works so we have the right mix of regulation (too much is a planned economy that we know is a failure, and too little is a slave labor state with old ladies thrown out into the street, a popular culture owned by mega corporations, and a population of humans that have no social security or health care; both extremes are bad).
What the OP was likely bringing up is that "capitalism" is frequently extolled as a golden god that does no wrong and should never be questioned or reformed or regulated in any way. That is clearly not true, the the OP is giving a real example of the ills of a "Capital Is Everything" system.
The alternative to brutal capitalism is not "communism," just because the Rupert Murdoch channel wants you to think so. It is possible to have a capitalist state with controls and regulations that assist the weak in our society and provide social services for everyone without resorting to a planned economy and a communist revolution that turns labor into an all singing all dancing peasant class.
In particular, the US is in no danger of falling to communism, but is already teetering on the brink of a corporatist state where the government exists primarily to enforce copyright law and dole out corporate welfare. That's fascism, and it's just as scary as communism.
Anyone who defends pure capitalism as a perfect system devised by Jeebus and refers to anyone seeking reform as leftists and commies has fallen to the right wing propaganda machine. The US needs to purge those people out of control just as Germany did after the war.
Kevin Poulsen Attacks Ron Paul, iPhone, Mac Users In a Single Broad Brush of Wired Incompetence.
The CNN article has a much more informative article than the New York Times article cited in the Slashdot article.
I was just going for the short and sweet...the summary alone should've been clue enough it wasn't ComEd.
Your house probably has a 200 Amp panel, the two are comparable current wise; That's like saying two cars are comparable because they use the same amount of oil. Shut the fuck up already.
Migod, you have the memory of an elephant!
- Ecsad Essemal
The Hexadecimal TV-REMOTE!
Whoa!
HUNDREDS of amps?
Is this why some of those laptops burst spontaneously into flames?
Actually, with hundreds of amps, they'd probably be converting hydrogen to helium, and the battery would be only be a 'trigger'.
At last! The power of the Sun (the REAL Sun)in a laptop!
Hundreds...! My oh my!
- Ecsad Essemal
The Hexadecimal TV-REMOTE!
seriously, your brain cramping because the truth is extreme and its easy to just psychologically deny it, but do the math 200W under load / 1.33VDC core voltage = 150 Amps! Your house probably has a 200 Amp panel, the two are comparable current wise; emotively you'd expect the computer to turn into a china-syndrome pool of molten metal.
Yeah the current is quite surprising though you are probablly overestimating at least for normal systems (afaict the figures in the toms hardware article linked by the parent are whole system power consumption). Quad core chips probablly involve higher currents though.
Still current is not the only issue, a switched mode converter must rapidly switch the input voltage, easy enough at 5V or 12V and not too bad at 300V (about what you get from the input rectification/rough smoothing stage of a cheap and nasty PC power supply) but as the voltage climbs further it gets harder and harder.
I know controlling 375KVDC at 80 Amps isn't trivial but neither is controlling the same in AC
DC is much harder to break than AC because zero crossings tend to kill arcs.
But more important is that with AC you only need to switch it when you are reconfiguring the power routes or dealing with a fault, so switching can be mechanical and fairly slow (e.g. pull an arc and then kill the arc with a burst of gas). With DC you have to switch it many times per second to get a voltage conversion.
There are cases where DC makes sense.
* Backup power systems for elecronics dominated loads where DC lets you eliminate a conversion step and saves you from the issues of inverters driving rectifiers. Telcos have done it this way for years and finally other datacenters are catching up.
* Vehicles for similar reasons to above.
* Inside equipment where small transformers would require substantial circitry on the output anyway to get a power supply suitable for driving electronics.
* Specialist systems at the very high end of power transmission where other advantages of DC (no need to sync grids, no losses caused by capacitance and inductance, better peak-rms ratio) outweigh the cost and inefficiancy of the conversion stations. The main ones are when a very long or undersea run is involved or where two grids are not synced for political (syncing grids requires a LOT more trust and cooperation than merely exchanging power) or historical (different frequency) reasons.
but for general power transmission and distribution systems I still belive that DC would just increase cost and decrease reliability, efficiancy and safety. Utility transformers while initially fairly expensive have a long life even in outdoor conditions, and have very high reliability and efficiancy.
note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register