Domain: eevblog.com
Stories and comments across the archive that link to eevblog.com.
Comments · 68
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Re:The CHANNEL that got BANNED from Slashdot
why are you wearing an eevblog t-shirt when you have only one post
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Discussion over at eevblog.com
Snake oil as far as everyone there is concerned. https://www.eevblog.com/forum/...
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Re:Instruments
will be nice to view
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Re:SOLAR FREAKIN ROADWAYS
For those that have not followed EEVBlog over the years, here is a sample of the debunking Dave has done of solar roads:
- https://www.eevblog.com/2014/06/20/eevblog-632-solar-roadways-are-bullshit/
- https://www.eevblog.com/2014/11/07/eevblog-681-more-solar-roadways-bullshit/
- https://www.eevblog.com/2015/03/16/eevblog-724-home-solar-power-system-analysis-update/
- https://www.eevblog.com/2015/05/13/eevblog-743-solar-roadways-test-results/
- https://www.eevblog.com/2016/02/14/eevblog-850-french-wattway-solar-roadways-busted/
- https://www.eevblog.com/forum/blog/eevblog-1047-solar-roadways-finally-busted-colas-wattway/
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Re:SOLAR FREAKIN ROADWAYS
For those that have not followed EEVBlog over the years, here is a sample of the debunking Dave has done of solar roads:
- https://www.eevblog.com/2014/06/20/eevblog-632-solar-roadways-are-bullshit/
- https://www.eevblog.com/2014/11/07/eevblog-681-more-solar-roadways-bullshit/
- https://www.eevblog.com/2015/03/16/eevblog-724-home-solar-power-system-analysis-update/
- https://www.eevblog.com/2015/05/13/eevblog-743-solar-roadways-test-results/
- https://www.eevblog.com/2016/02/14/eevblog-850-french-wattway-solar-roadways-busted/
- https://www.eevblog.com/forum/blog/eevblog-1047-solar-roadways-finally-busted-colas-wattway/
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Re:SOLAR FREAKIN ROADWAYS
For those that have not followed EEVBlog over the years, here is a sample of the debunking Dave has done of solar roads:
- https://www.eevblog.com/2014/06/20/eevblog-632-solar-roadways-are-bullshit/
- https://www.eevblog.com/2014/11/07/eevblog-681-more-solar-roadways-bullshit/
- https://www.eevblog.com/2015/03/16/eevblog-724-home-solar-power-system-analysis-update/
- https://www.eevblog.com/2015/05/13/eevblog-743-solar-roadways-test-results/
- https://www.eevblog.com/2016/02/14/eevblog-850-french-wattway-solar-roadways-busted/
- https://www.eevblog.com/forum/blog/eevblog-1047-solar-roadways-finally-busted-colas-wattway/
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Re:SOLAR FREAKIN ROADWAYS
For those that have not followed EEVBlog over the years, here is a sample of the debunking Dave has done of solar roads:
- https://www.eevblog.com/2014/06/20/eevblog-632-solar-roadways-are-bullshit/
- https://www.eevblog.com/2014/11/07/eevblog-681-more-solar-roadways-bullshit/
- https://www.eevblog.com/2015/03/16/eevblog-724-home-solar-power-system-analysis-update/
- https://www.eevblog.com/2015/05/13/eevblog-743-solar-roadways-test-results/
- https://www.eevblog.com/2016/02/14/eevblog-850-french-wattway-solar-roadways-busted/
- https://www.eevblog.com/forum/blog/eevblog-1047-solar-roadways-finally-busted-colas-wattway/
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Re:SOLAR FREAKIN ROADWAYS
For those that have not followed EEVBlog over the years, here is a sample of the debunking Dave has done of solar roads:
- https://www.eevblog.com/2014/06/20/eevblog-632-solar-roadways-are-bullshit/
- https://www.eevblog.com/2014/11/07/eevblog-681-more-solar-roadways-bullshit/
- https://www.eevblog.com/2015/03/16/eevblog-724-home-solar-power-system-analysis-update/
- https://www.eevblog.com/2015/05/13/eevblog-743-solar-roadways-test-results/
- https://www.eevblog.com/2016/02/14/eevblog-850-french-wattway-solar-roadways-busted/
- https://www.eevblog.com/forum/blog/eevblog-1047-solar-roadways-finally-busted-colas-wattway/
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Re:SOLAR FREAKIN ROADWAYS
For those that have not followed EEVBlog over the years, here is a sample of the debunking Dave has done of solar roads:
- https://www.eevblog.com/2014/06/20/eevblog-632-solar-roadways-are-bullshit/
- https://www.eevblog.com/2014/11/07/eevblog-681-more-solar-roadways-bullshit/
- https://www.eevblog.com/2015/03/16/eevblog-724-home-solar-power-system-analysis-update/
- https://www.eevblog.com/2015/05/13/eevblog-743-solar-roadways-test-results/
- https://www.eevblog.com/2016/02/14/eevblog-850-french-wattway-solar-roadways-busted/
- https://www.eevblog.com/forum/blog/eevblog-1047-solar-roadways-finally-busted-colas-wattway/
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Re:What year is it?!
Tune in next week when we discover, again, that some 9-volt batteries have six AAAA-sized cells in them!
Turns out there's a non-destructive way to test for this, too. Though technically, the 9V batteries don't use AAAA sized batteries (they're slightly smaller than AAAA). But it's very close.
The other configuration is flat which is they're put in a plastic tube as a layer cake - a "pile" configuration.
If you have a high-resolution multimeter (6 1/2 digits), observing the terminal voltage and giving the 9V battery a squeeze can tell you the construction. If the voltage increases, it's a pile construction. If it decreases or the slope of the discharge (the multimeter has enough resolution that its input impedance can clearly discharge the battery)
EEV Blog #518 - https://www.eevblog.com/2013/0...
EEV B;pcl #515 - https://www.youtube.com/watch?... -
Re:Do the math...
There is more detail of the install on the forum. A user there went and got some details. Those include apparently insufficient gauge wiring, some 3000 W worth of power for heating, the fact that 2 of the "working" panels are actually broken and datasheets for various components. Few pages worth of just the new install here.
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Pros and cons of Big Physics
There was a pretty good thread on this recently on eevblog, with various arguments being made in both directions. As far as I'm concerned, the only valid arguments against LHC-scale projects are that they pull huge amounts of funding away from other research efforts. It's one thing to spend $10 billion a year on physics research, but how much of that should be dumped into a single project or facility? If a legitimate scientist complains about having to compete for funding with giant monolithic projects like the LHC, it's hard to say they're wrong.
The other arguments against large-scale research funding are just a bunch of monkeys thumping their chests on computers they wouldn't have if the politicians had listened to their chest-thumping parents, while connected to a network that wouldn't exist.
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Re:RF harvesting can work for power.
http://www.eevblog.com/forum/r... - I am unsure if this link will work. This shows a teardown of a tag.
On eevblog, under the title "weird "energy-harvesting" broadband (?) antenna ".This shows a 450mAh rechargable lithium-ion battery.
http://www.ti.com/ww/en/wirele... - this is a TI device which is designed for sensor tags, and sports a 1 year battery life reporting once a second over BLE with a 2032 battey. This is one half the capacity of the lithium battery used.
It also won't be sending data at one second intervals.
It seems entirely reasonable that the comparatively large battery will last five years without any wifi charging at all. -
Re:watIf you want to know what this is all about read EEVblog #284 – Braun Toothbrush Teardown There is also a youtube video worth watching. It talks about the microprocessor inside a toothbrush.
And you thought you were joking.
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Solar Roadway Bull$it
Do government ministers check their brains into deep storage when they are elected?
There are sooo many things wrong with this concept; the first being grip.
How do you make glass grip? You have severely roughen the surface which will make the light scatter severely reducing efficiency.
They are not angled correctly. They will get damaged. Very expensive because they have withstand trucks... any anyway, next time France gets invaded, the tank tracks will rip them to pieces.
Just go find a nice field to put them in,Dave at EEVblog has already covered the concept in depth.
http://www.eevblog.com/forum/b...
https://www.youtube.com/watch?...
http://www.eevblog.com/2015/05... -
Solar Roadway Bull$it
Do government ministers check their brains into deep storage when they are elected?
There are sooo many things wrong with this concept; the first being grip.
How do you make glass grip? You have severely roughen the surface which will make the light scatter severely reducing efficiency.
They are not angled correctly. They will get damaged. Very expensive because they have withstand trucks... any anyway, next time France gets invaded, the tank tracks will rip them to pieces.
Just go find a nice field to put them in,Dave at EEVblog has already covered the concept in depth.
http://www.eevblog.com/forum/b...
https://www.youtube.com/watch?...
http://www.eevblog.com/2015/05... -
Re:Supply chains
MCP2221, CH340G, etc. Just see:
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Keeping me happy for disabling auto-updates
I think I'll keep my Windows computers with updates disabled, as all the updates have been detrimental to the user, lately.
Checking the eevblog thread, though it seems it affects Windows 10, which I also elected not to touch. -
A solution in search of a problem & likely fr
Assuming the project isn't essentially fraudulent, and is technically feasible- why? It would have worse performance than inductive charging and would require a specific alignment of an extra peripheral towards the sound source.
Anyway, there's another link in the article to a take-down of the product that goes over basic physics and sound level safety requirements that suggest this project is fraudulent. One thing you do see in there, however, is talk about Ubeam's 25 year old CEO, Meredith Perry. A google search quickly reveals she's an attractive young lady.
Quite frankly I think she's a huckster, and is using her charisma, beauty, and the latest 'women in tech' craze to bilk a few investors who have money to blow. Sure, there might be a few engineers performing 'research'- fiddling with components and actually transmitting power with ultrasound in a carefully controlled and isolated environment. Their function is to provide Ms. Perry with legal cover. They'll do work obstinately in the relevant line of investigation, while knowing full well that the final finished product can never be delivered for a variety of reasons. They'll issue reports saying 'the next obstacle to overcome is....' knowing that obstacle is insurmountable. And the entire time, Ms. Perry will be collecting an excellent salary for a 25 year old, and may even get bought out by some fool.
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Re:BATTERISER SHILL!!!
He showed people making similar comments in reply to his story.
Those are probably people who watched the video (as opposed to you).
See, I don't dislike that he debunks the claims of the batterizer thing. I actually clicked the Play button because I too was finding the thing fishy. But after 2 minutes I just found it unbearable, so I clicked on the link he provided that says "Click here if you don't want to spend 40 minutes watching this crap" and this was a link to his blog or something.
The blog post starts with this:
Many people have asked for a much shorter explanation of the claims, so here we go, for those who can’t afford the 40 minutes
And guess what, even that blog post was awful and unreadable. I managed to read about 1/3 before scrolling to the Summary at the bottom (which is now about at 1/2 the page because he keeps adding stuff below), and his Summary is another 4 paragraphs that I summarized in 1 sentence ("The author doesn't disagree with the technology or the fact that it can extend battery life, he just loses his shit about the 8x claim and some other minor things").
See for yourself: http://www.eevblog.com/2015/06...
The guy may be a skilled engineer and such, but he's a terrible communicator, and his video deserves a lot of Dislikes because it sucks.
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Re:not just AMD
Nvidia is really starting to piss me off with their proprietary shit like this, Gsync and their 'nVidia hair' bollocks for games.
There's a lot more than just this stuff, too. Since they went from the 9x00 series to the three-digit GTX series, they've been making more and more proprietary and/or user-hostile decisions as time passes.
Sometime around the GTX switch, for example, they started crippling OpenGL calls not used by games to artificially slow down "gaming" GPUs vs. their more expensive workstation counterparts. There are other examples if you search, but in that one the guy that wrote it re-implemented the OpenGL call via shader and got a massive speed increase because the driver couldn't artificially cripple the shader the same way. He also noticed that, not only did performance drop going from a GTX 200 series card to a GTX 480 series, but that it dropped further going to a GTX 680.
Another example is related to PCI-e passthrough of graphics cards in virtualization. This used to be possible with NV cards, as demoed by Ubisoft in this YouTube video. They used GTX 460 cards, with one passed through to the guest OS to get near-native GPU performance in a VM. Fast forward a generation or two and you have to do shit like this to get the same functionality because nvidia started arbitrarily restricting it. (see also this).
There's also this shit where they removed features from the Linux driver for "feature parity" with Windows.
I've been an nvidia user since the late 90s (started with a Riva TNT card), but the GTX 660 in this aging system is going to be my last until nvidia cleans up its act, if it ever does. Based on what I knew about nvidia's support prior to the 600 series, I bought the 660 intending to do VGA passthrough from a Linux host -- use the GTX 260 as the host GPU, with the 660 on a Windows guest for reboot-free gaming -- and was pretty pissed to find out it got crippled for that purpose. Then I was even more pissed when, later, I found out about the OpenGL crippling and their removal of driver features for Linux users.
So, never again. I'll deal with whatever warts AMD's GPUs and drivers have because they, at least, don't artificially limit niche features to up-sell you to $2000+ GPUs. They don't even do it for their CPUs; even their bog-standard consumer CPUs can be used for niche things like VGA passthrough because AMD doesn't lock them away behind slightly different SKUs and a price hike.
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Not tested
That guy doesn't actually test the device, just tries to tell us why the claims are too optimistic.
http://www.eevblog.com/2015/06...
I'd rather see real, objective testing using all sorts of typical loads and battery types. -
Re:May be of some use
Ahhh... That makes sense. For the life of me, I couldn't imagine a use case where this would happen. Just shows my lack of imagination
;-) Thank you for the reply. This explains perfectly how you get a relatively long battery life with a higher than usual required voltage. -- low power except for transmission spikes, older design (likely pre-rechargeable era).The newer Slashdot post follows up on the debunking of the overblown claims of the joule thief:
http://www.eevblog.com/2015/06...It hits all my points far better than I noted -- the most important being that most devices today are designed with the rechargeables in mind and/or have their own internal regulator making this thing moot... and also point out the flaws in logic of how much this would actually extend the use of the batteries even for cases like yours where it really might help.
I hope you get the chance to try these out to see whether they can help you. Depending on your setup, it could be a cheaper alternative to switching out that equipment. Best of luck to you.
As an aside: I have cheap outdoor thermometers that run off of AAs and transmit to a unit inside (one for the back porch and another for the greenhouse) They're cheap recently purchased AcuRite devices; but my uncle has a sophisticated system for his farm. I was recently looking into arduino and raspberry pi alternatives - and there's some really nice advancements in that area that may become cheap alternatives in the near future.
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Re:Modern Technology
http://www.eevblog.com/forum/t...
nice old classic tek test gear. highly in demand by collectors and those who appreciate good old fashioned engineering and build quality. the last of the 'repairable' tek scopes, pretty much (and even this is borderline repairable, with many custom chips).
still, a few new caps, a new battery backed nvram module and you have another 20 or 30 yrs left on this scope.
search that same forum for other old test gear (power designs (brand) power supplies are also built like tanks and run forever. I have 4 of them at home in my lab and they date from the mid 50's to early 60's. still hold their precision and would cost $5k to $10k today if you could even buy them.
I have audio gear that I personally built in the 70's and 80's that still runs fine (hafler amps, etc).
today, its hard to find things built to last, but it USED to be the norm "before your mother was born", so to speak.
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Re:Computer Missues Act 1990
http://www.eevblog.com/forum/reviews/ftdi-driver-kills-fake-ftdi-ft232/msg535270/#msg535270
"Straight out of their driver. Function/variable naming and comments mine."
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Re:HIGHLY SKEPTICAL ALL CAPS YAY ALL CAPS DAY
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Re:Not "bricked"
http://www.eevblog.com/forum/r...
driver is "testing" eeprom, fake chips fail the test
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Re:Class action? How about criminal offence?
This isn't a bug. A poster on the EEVblog forums reverse engineered their driver and posted this.
The naming of the function and variables is their own, but they've written a function which is called unconditionally and has no purpose whatsoever with respect to their own chips. It is written such that it cannot affect their own chips. This is clearly not a bug, otherwise, you'd need to argue they intended to set the PID of their own chips to 0. The only logical explanation for this code is to overwrite the EEPROM of chips which were not manufactured by them. Pretty clear cut case of destruction of property (which coincidentally, under the law, includes unwanted alterations, not simply smashing with a hammer).
Combine that with their official statement and it's pretty slam dunk:
FTDI Chip is committed to taking appropriate measures to protect our customers from the adverse impacts caused by counterfeiting of FTDI Chip devices. Many of these devices resemble FTDI Chip markings which may lead the customer to believe they are genuine. FTDI Chip has established a proactive and global process aimed at detecting and deterring such counterfeit activity.
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Re:Is this legal?
Just how bad is this, really?
Forum thread states, "The workaround is to use a Windows XP or Linux system to change the PID back, and then don't use the new driver."
If this USB Product ID is a number that is supposed to represent who manufactured the device, then I'm rather surprised that this can be updated. (ROM would seem to be a sensible way to store such a thing.)
Apparently the USB VIDs (Vendor IDs) are centralized, meaning a central organization is keeping track of them. Also, there are some ways that someone can use a Vendor ID without needing to pay the central organization.
So if the driver is made by FTDI, and the driver only affects equipment that identifies itself as FTDI equipment, then shouldn't FTDI be able to determine what happens?
A quick lookup indicates that FTDI uses VID 0403, so I'll use that number as an example. (Note that I'm not saying that this is FTDI's only VID.)If FTDI makes a decision that all such equipment with VID 0403 should act a certain way, like using a Product ID according to guidelines that FTDI determines, then isn't FTDI simply enforcing rules that is within their authority (because they have the right to describe how equipment operates when that equipment is using VID 0403)? And if a competitor's device doesn't like what FTDI's driver does, when FTDI's driver is working with VID 0403, isn't that a problem with the device failing to properly act according to the behaviors that are legitimately expected of a device using VID 0403?
Finally, the term "brick" seems to be getting misapplied. If FTDI's driver sets my device's PID to 0 in one Windows 7 machine, and then I can no longer take that device to another Win7 computer and have it work, then I understand why someone might think that the device is bricked. But if I can take it to a computer (running XP) and use some software to change the PID to a non-zero value, then the device can work again. To me, the term "brick" refers to when a device is completely worthless, and cannot be fixed so simply (because, like a brick, it won't respond to any signals). But if the problem is just that Win7 doesn't contain the software routines that lets a user set a particular value, that doesn't mean the device is really bricked.
I'm not actually trying to suggest that FTDI is innocent in any of this. What I'm trying to do is to clarify that the accusations being made have a strong foundation so that I can feel more justified in joining the public outrage. Any clarification to these points would be appreciated.
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Re:Only 4 displays, sticking to AMD.
You can http://www.eevblog.com/forum/c... but you also need to hack to report of your machine as approved machine to run quadro in SLI.
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Re:Systemd? Not on my system...
Wow, thanks for answering my rant and especially the bit about hardware modding an nvidia card. How silly.
No problem, I always try to follow up on posts in case there are questions or anything else, even when I post anonymously here. Not much point with logging in since I comment rarely; usually everyone else covers any useful input I'd make before it even hits my RSS reader, so I just lurk and anon-post here. On SoylentNews I actually comment enough to bother being logged in (as Marand), because there aren't as many people contributing already, so I'm more likely to have something to say that won't be redundant.
This page on the Xen wiki has info about hardware that works, as well as some information on what cards need modification. It also has some references such as this one detailing the sort of work required. The actual modification doesn't seem too bad, but the fact that it's needed at all is bullshit. Hell, I'm not even sure what will happen if you try to use the cards for dom-0 (host) while using an AMD or older nvidia card on a guest.
Something else I learned while researching this is that nvidia seems to be deliberately crippling the hardware at the driver level if it thinks you're not using a quadro. I found where this guy went from a 200 series to a 400 series gtx and noticed a massive performance drop on certain operations. He even re-implemented the operations with shaders and the performance difference evaporated, which makes it sound like deliberately gimping of certain GL calls that are used more in non-gaming apps, to sell Quadros.
Also, it seems I was mistaken about the 400 series. I thought I saw before that the 400s would work fine, but the Xen page says they need modding as well. I know my gtx 260 should work on a guest OS, but that's a hell of a downgrade. If/when I try I'll just have to pick up an AMD card I guess.
I've been using nvidia GPUs since the '90s because their drvers always worked well, especially in Linux, but lately I've been finding a lot of reasons to look elsewhere. I hate that, but I'm not going to tie myself to a brand if they're going to go out of their way to make it harder for me to use. Same reason I tend to use AMD processors; it's far easier to find an AMD cpu+mobo that works with all the virt stuff you want.
On another note, H264 streaming of a game from Windows VM to display on the linux desktop would be a way to do the reverse. So you keep the linux desktop. The encoding is done real time by a dedicated unit on the GPU.. and that feature is especially supported on Geforce 600 and 700 series!, i.e. the generation past 400 series. So that's why it's disabled (though there's some level fo consumer support for this if you use a separate computer)
Good point; wasn't that supposed to be a selling point of that SHIELD thing nvidia was pushing? Plus Steam does something similar now and has a Linux client. It might actually be easier to run a second Windows machine with a kvm switch and then stream it to Steam running on Linux, now that the Linux client got support for it.
The pro is that it's likely easier to set up, the con is that you have to duplicate your hardware unless you don't do anything cpu/gpu intensive on the Linux side, in which case you could just have a trash-box for the regular desktop.
Thinking about it, I believe I'm still inclined to go for passthrough instead. I could set up a kvm switch and hook one monitor up to both displays, and just switch that monitor over when I want to play a game, or something like that.
As a side rant, years ago I thought the port of KDE to Windows meant we'd be able to run the KDE desktop on Windows but no it was
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Re:Tonka Tough
You'd have to be both racist and ignorant of the iPhone to think that Chinese workers can't produce quality goods; like anyone else, they build to the specs that are given to them and standards that are expected of them.
Indeed. I have a pair of Chinese made (English) Wharfedale loudspeakers I got about 9-10 years ago and they are beautiful. Interesting thing is that there is not any indication either on the boxes or the user leaflet saying where they are made. They appear to be made to Wharfedale's specs, and that's the point - if no particular quality is specified then often made-in-China stuff is rubbish. One notable exception is AFAIAC is a Rigol DS2072 oscilloscope that I bought. Very nice. http://www.rigolna.com/ Hackable too -> http://www.eevblog.com/forum/t... Review -> http://www.eevblog.com/2013/04...
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Re:Tonka Tough
You'd have to be both racist and ignorant of the iPhone to think that Chinese workers can't produce quality goods; like anyone else, they build to the specs that are given to them and standards that are expected of them.
Indeed. I have a pair of Chinese made (English) Wharfedale loudspeakers I got about 9-10 years ago and they are beautiful. Interesting thing is that there is not any indication either on the boxes or the user leaflet saying where they are made. They appear to be made to Wharfedale's specs, and that's the point - if no particular quality is specified then often made-in-China stuff is rubbish. One notable exception is AFAIAC is a Rigol DS2072 oscilloscope that I bought. Very nice. http://www.rigolna.com/ Hackable too -> http://www.eevblog.com/forum/t... Review -> http://www.eevblog.com/2013/04...
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Re:Pocket scopes!
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Re:The best advice is not by me but by
Yes, upon I reading the summary my immediate thought was to link to http://www.eevblog.com/2009/06....
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The best advice is not by me but by
Dave from eevblog he does a lot of reviews of this type of hardware
http://www.eevblog.com/2010/05...
or check this search to see a lot of reviews of specific ones old and new
https://www.youtube.com/user/E...no i'm not affiliated with EEVblog its not click bait its just the best reference material i know to help this in his decision
tl;dr
buy a used analog one they're often cheap or free -
OWON makes a line (VDS) that looks decent
They have ethernet and USB - amazon.com
Also, ask these questions on eevblog forums. Slashdot is not great at hardware.
small review/discussionie., over half of the nitwits posting so far are recommending logic analyzers. Please stop. There are also cheap JTAG programming solutions, power supplies, etc. Don't start recommending wrenches when someone asks you for a screwdriver.
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Re:It's sad what has happened to HP
and they are also reduced to producing shit for handheld dmm's:
http://www.eevblog.com/forum/t...
http://www.eevblog.com/forum/t...
agilent used to be good. for high end gear, they probably still are; but it seems they have fallen down quite a bit over the years.
HP - they are useless, now. when they were more than a printer-ink company, they were a force to be reckoned with. now, they are a printer-ink and pc whore.
how the mighty have fallen
;( -
Re:It's sad what has happened to HP
and they are also reduced to producing shit for handheld dmm's:
http://www.eevblog.com/forum/t...
http://www.eevblog.com/forum/t...
agilent used to be good. for high end gear, they probably still are; but it seems they have fallen down quite a bit over the years.
HP - they are useless, now. when they were more than a printer-ink company, they were a force to be reckoned with. now, they are a printer-ink and pc whore.
how the mighty have fallen
;( -
Re:I wrote anti-terrorist software for banks.
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Yes, crap meters can and do explode....
Compare what happens to multiple brands of cheap meters vs. a Fluke when intentionally whacked with high energy pulses:
http://www.eevblog.com/2010/05...
Notice that ALL the meters were damaged in this test. But the Fluke simply died gracefully, without exploding, catching fire, etc.
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Fused leads = major safety FAIL.
So if your probe fuse blows without you knowing it, and you go to check if that wire is live, you get a nice zero voltage reading, regardless of whether the circuit is dead or not. The potential consequences of this should be obvious.
Input protection for the voltage/resistance ranges of a properly designed DMM consists of gas discharge tubes, MOVs, PTC thermistors, transorbs, etc. The internal fuses are for the current ranges ONLY, and need to be the HRC type for safety.
Properly designed input protection is the FIRST place that the cheap DMM makers cut corners. The second is properly molded and sealed enclosures, to contain the shrapnel in case of a catastrophic failure. Both are required to achieve proper safety compliance for a Cat III or Cat IV meter, which is what you want for measuring mains voltage.
A good illustration of what happens to cheap meters under high energy fault conditions is here:
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Ship them to Australia
I'm sure Dave Jones would be happy to take receipt of them, have them painted, and returned to the US. For a nominal fee of course.
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Re:All I Have To Say Is
Dont forget Flir E4 thermal camera ($800 model unlocks to a full $8000 one)
http://www.eevblog.com/forum/t... -
Re:Dear Nvidia...
I doubt that. The firmware, maybe, but probably not drivers. Normally the difference between high-priced and low-priced models is that the low-priced models have some internal fuses blown, so that some of the cores are disabled. Sometimes those cores were defective, other times they disable cores just to meet the demand. It could be that they disable the cores with firmware instead of fuses, and somehow the drivers could reenable cores in the latter cases, but my guess is that the people who give the orders simply think of their precious architecture details as information that needs to be kept secret, in case the competition gets too many ideas from those details.
drivers and/or jumpers
http://www.eevblog.com/forum/chat/hacking-nvidia-cards-into-their-professional-counterparts/ -
Re:Elephant in the room
Dave Jones (EEVBlog) rants about the changes that affect content creators. These include changes to the commenting system such that it's practically impossible to do a proper reply, including notifications when new comments are posted. Even worse is that all the stuff you get notified about now only happens via G+.
Some of his complaints were fixed. It's possible to reply normally now. What still bugs is that to see the parent comment by clicking the "in reply to (name)", the whole video page reloads. In the past, it did not.
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Re:Elephant in the room
Google has been slowly making Youtube worse. First they get rid of channel customization, then they get rid of the ability to have a background image, then they start repeatedly asking for your real name and most recently they make it a requirement that you have a Google+ account to upload videos or to post comments.
Vimeo, Blip and Twitch are looking better every day.
It's even worse for content creators. Dave Jones (EEVBlog) rants about the changes that affect content creators. These include changes to the commenting system such that it's practically impossible to do a proper reply, including notifications when new comments are posted. Even worse is that all the stuff you get notified about now only happens via G+.
And Twitch is only good for gaming videos - as PS4 owners found out using the camera accessory. At one point Twitch had to ban uploads from PS4s for it, and now they've hidden those links until they're manually approved.
Vimeo might be the best alternative.
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Re:amd crippled R9 double presicion just like nvid
You can turn recent Nvidia Geforce cards into Quadros by removing and adding 1 or 2 resistors.
The resistors simply encode the PCI device ID.
http://www.eevblog.com/forum/chat/hacking-nvidia-cards-into-their-professional-counterparts/ -
Re:Why proprietary chargers?
Perhaps this is a stupid question, but why does Apple like to use proprietary chargers/connectors so much in the first place?
It may be that poor-quality third-party chargers could damage the device. But then I have to ask, why are iDevices so fragile in the first place? It seems most other smartphones have a standard USB port and can work with any old 5V power supply.
Because at the time, there was no standard for USB charging (this was way back in 2003). And since you wanted dumb chargers, you needed a way to signal how much current the charger was willing to give (USB devices are only allowed to draw 100mA prior to enumeration, and 500mA only if the host allows). Since that was relatively unacceptable, Apple came up with a way to do it.
First, the resistors pull D+ and D- to various states which signals 4 different charge currents - 100mA, 500mA, 1A, 2A. (the first and last were reserved until later on). This was because you didn't want to pull too much power out of an inadequate charger.
Second, the 30 pin connector was just standardized (back in 2003), because there were no standards for connecting up A/V equipment to a portable device, so Apple used the 30 pin to allow accessory makers to build accessories cheaply - a serial port for control, analog audio outputs so you didn't need a DAC, etc.
Sometime later, the USB guys made a USB charger spec which shorted D+ and D- together to signal a charger. Unfortunately, the USB charger spec is deficient in that it does not signal charge current - the official spec says youc an draw 800mA or so (and it relaxes the 100mA pre-enumeration requirements so you could boost charge your battery until you can boot far enough to detect chargers and such). Of course, without current signalling, things are confusing because your tablet might try to draw 2A out of a 500mA adapter (I've seen cheap adapters blow up because they overheat).
As for what happens here to cause Apple to do this - cheap adapters are cheap. There is often ZERO regard to safety, including things like basic creepage and clearance (how far must high voltage rails be separated), the use of substandard safety parts (snubber capacitors), etc. In some designs, the USB port is barely 1mm away from mains voltage - a particularly humid day can easily bridge the distance and put a rather significant amount of voltage on the USB port. Or a critical part can fail and due to bad isolation, you get line voltage on the USB port.
Here's what a real Apple adapter looks like inside. The green dot recall was because the pins could fall out, and you can see Apple molded them into the plastic so the only way to rip them out is to destroy the plastic cover.
A fake charger torn down. Note the general crappiness.
A dozen adapters tested. Apple is not the best - Samsung chargers are better! But the crappy chargers are clearly crap. In fact, you'll know them because your phone's touch screen stops working when you charge it. This happens on all phones - Apple, or Android. The noisiness of the power rails interferes with the analog touchscreen electronics.
Dave Jones (EEVBlog) tears down two fake chargers he got. He's not impressed and he's really shocked at the lousy nature of it. Taking them apart was the best thing you could do safety wise than using them.
There's nothing special to an Apple charger or any other charger. In fact, modern USB charger controller ICs now have autoswitch modes where they try all known charger methods to be the one universal charger. Youc an convert a standard USB charging charger to an Apple one with a few resistors, and an Apple one to a standard just as e
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Re:They don't use proprietary chargers.
Generally they can't. But they can be badly grounded and damage you (which actually happened recently).
The issue is not grounding, as all these chargers are double insulated, but rather creepage and dielectric isolation.
Creepage in electrical engineering terms is the safe distance between electrical conductors of a different potential.
There are tables we use depending on pollution level, voltage, and whether it is surface or air creepage.
Dielectric isolation is the method(s) used to prevent a direct connection between the high voltage input, and low voltage output.
Normally a transformer and opto couplers provide the isolation. Cheaping out, or poor design in this area, is the likely cause of the electrocution.Checkout this link for a teardown on a cheap chinese fake apple charger.
http://www.eevblog.com/2012/11/20/eevblog-388-apple-clone-usb-charger-teardown/