Talk:PC Power Supply

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AndrewBCN 20/10/2014 Much of the information on this page is very good but presented in a disorganized way, some information is obsolete, and imho it lacks a couple more warnings about safety. PC power supplies (which I prefer to call ATX PSUs, because that's the standard designation for these power supplies) are dangerous! Since I have converted three ATX PSUs for RepRap use and am right now documenting my 3rd conversion, I intend to contribute to this page and perhaps also work on a Spanish translation. Any help in doing so will be much appreciated!

Dangerous? I broke many many items as hobbyist, but these PS supplies are sturdy and as harmless as a 220V driven device can get. Toasters are definitely far more dangerous. I'd happily learn about what the danger of such an unopened PSU would be. Spilling a cup of coffee through the venting slits?
ABCN They are dangerous even when unopened and operating normally in the sense that they can supply very high currents, and a short circuit on a PCB will possibly result in smoke and flames. And yes, if you spill any liquid or drop any metallic object inside a live ATX PSU you can expect some problems, again possibly smoke and flames. When opened and if powered on, you have all the risks associated with a naked high voltage, high current device i.e. can be fatal in some circumstances. So for example a fair warning when opening any ATX PSU is to unplug its power cable and let it discharge for at least 10 minutes.
BTW., what are you "converting" there? I simply plug them in as-is. No need to open them at all. However, I do see many many people lamenting about how complicated a "conversion" would be. My usual answer: "don't convert, just use it".
ABCN That applies to users of Gen7 electronics and other ATX-ready RepRap boards. Unfortunately the almost universal RAMPS 1.4 was not designed with an ATX connector (a huge flaw imho) so when using an ATX PSU with a RAMPS 1.4 one is forced to cut a few cables. I intend to write a page with a detailed guide on how to do that safely.
Last not least, I entirely agree about this page being a bit disorganised/overfilled. For example, I don't see much value in explaining average RepRappers the difference between minimum load, base load and balancing load. Would you agree on keeping dead simple instructions near the top of the page and move more detailed descriptions below that?
ABCN I think you know as well as I do that there is no such thing as an average RepRapper. ;-) But I fully agree about keeping the simple stuff on top and the nitty-gritty at the bottom of wiki pages (and opinions/discussions in the discussion page)!
All this nasty stuff said, I'm very happy to see somebody writing not just advertisements into the wiki. Thanks! --Traumflug (talk) 16:45, 19 October 2014 (PDT)
ABCN You are welcome and I am the one to thank you for all your important contributions to the RepRap world!

Now better? --Traumflug (talk) 04:28, 20 October 2014 (PDT)

Please do not take any of the above as criticism! I personally think this entire wiki is a wonderful and essential resource for RepRap beginners such as myself. OTOH for example the section about modifying an ATX PSU for lab use (at the bottom of the page) is very much obsolete and slightly messy, imho.
Currently I can't decide wether it should be removed entirely or moved into another page ... :-) And I actually love discussing and criticising things. That's the way to find the best for everybody. Big thank you for your work, too!
I made the decision for you ;-) and removed all the paragraphs that had been copied from the ehow website, but left a link just in case people want to have a look at it.
One more point: we are in 2014. So any AT PSU or 20-pin ATX PSU has long passed its service lifespan and for safety reasons I would most definitely discourage their reuse for RepRap projects - again that's my personal opinion so it does not go into the page itself. But here it is! :-)
I have several of them, because I typically salvage them from old PCs. But more dangerous? For me they're just the ones without ATX12V connector, I see no reason to explicitely disencourage their use. BTW., the second right button in the row above this editing field inserts --~~~~, that's where these signatures come from. --Traumflug (talk) 03:17, 21 October 2014 (PDT)
There are two technical reasons to discourage the use of old PSUs:
First is the ageing of electrolytic capacitors. Specially the cheap electrolytic capacitors used in noname PSUs. They bulge, leak and eventually short. In the secondary circuit, they usually go out with a puff and some smoke, but the big bulk capacitors in the primary go out with a bang and a flame. In both cases they likely will kill the RepRap electronics, apart from possibly causing a more severe accident.
The second reason is the outdated design of the switching electronics in ATX PSUs older than 2~3 years. They are not only terribly inefficient compared to modern PSUs, they have less protections, have worse regulation, and have smaller/noisier fans. Of course if you have a high end Seasonic ATX PSUs from 3 years ago that you have only used for a couple of hours, all this does not apply!
imo, the savings achieved by reusing an old PSU are not worth the risks, the lower performance and the hassle. But again, that's my opinion. On the other hand, the technical reasons I just listed are facts, not opinion.
BTW thanks for the tip about the signature! I had seen it but was wondering whether to use it or not!--AndrewBCN (talk) 11:41, 23 October 2014 (PDT)