P.S.U.s Keep or toss?

narsbars

2[H]4U
Joined
Jan 18, 2006
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2,202
I have a few older P.S.U.s and a huge pile of PSU cables that might fit the PSUs or not. Any suggestions on anything useful I can do with one not knowing what cable is which or should I just toss them?
Ahead of time: Yes, I do have a VOM but I am very lazy and need the space.
 

Ready4Dis

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Nov 4, 2015
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If you happen to be in SC, I could help you solve your issue :). I have a DOM and kids that need to learn about PSU's ;). In seriousness though, PSU's cost so much to ship, it's almost not even worth giving them away for free. Either find someone local looking for a project or find a recycler and dump them. Not really many other options if you don't feel like going through them.
 

narsbars

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Jan 18, 2006
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Thanks, the last test they had was before storage, all pulled from my own working units. The shipping is a KILLER or I would put them in the freebies thread.
 

GotNoRice

[H]F Junkie
Joined
Jul 11, 2001
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10,097
Yeah... seen this 100 times with modular PSUs. Someone has a perfectly good older PSU but the modular cables are nowhere to be found, so the PSU gets junked. It's probably also the reason why manufacturers have not come up with any sort of standard for modular cables - that would make it too easy to replace cables. They are happy to have you keep buying a new PSU more often.

As far as whether to actually junk it or not - That depends on what cables you have to work with. I have one of these kinds of PSUs in my file server, a nice Seasonic 80+ gold unit. I got it for free because the previous owner lost some of the modular cables. But the cables that were missing were the PCIe power cables and some of the SATA power cables. I didn't need the PCIe power cables since I was putting it into a file server and there were enough SATA and Molex power cables still available that I was able to use a splitter or two and power all of my hard drives.
 

narsbars

2[H]4U
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Jan 18, 2006
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Yeah... seen this 100 times with modular PSUs. Someone has a perfectly good older PSU but the modular cables are nowhere to be found, so the PSU gets junked. It's probably also the reason why manufacturers have not come up with any sort of standard for modular cables - that would make it too easy to replace cables. They are happy to have you keep buying a new PSU more often.

As far as whether to actually junk it or not - That depends on what cables you have to work with. I have one of these kinds of PSUs in my file server, a nice Seasonic 80+ gold unit. I got it for free because the previous owner lost some of the modular cables. But the cables that were missing were the PCIe power cables and some of the SATA power cables. I didn't need the PCIe power cables since I was putting it into a file server and there were enough SATA and Molex power cables still available that I was able to use a splitter or two and power all of my hard drives.
The worst part is I probably have all the cables, and more, but due to lack of standards and a failure to mark cables to match PSUs I have a bunch of junk. I was hoping someone had a clever project for old PSUs. A world dominating PSU powered robot with laser eyes or maybe something simpler. They all have the MB power connection built in, some hare barely modular at all, everything 650 or up. Oh well, I guess I have to give up on world domination.
 
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is there a maker/hackerspace near you? they'd probably take the PSU's off your hands and put them (or their components) to use if the alternative is sending them to the recyclers. Maybe they'll even get in on the robot idea ;)
 

narsbars

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is there a maker/hackerspace near you? they'd probably take the PSU's off your hands and put them (or their components) to use if the alternative is sending them to the recyclers. Maybe they'll even get in on the robot idea ;)
I live in Maine, very rural Maine, if there is a raccoon that knows how to run a 3D printer I will buy it all the kibble it wants.
 

vick1000

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Sep 15, 2007
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Ever heard of a multi meter and a pin out diagram?
https://www.amazon.com/AstroAI-Digi...d=1&keywords=multimeter&qid=1611715715&sr=8-5
satapinout.jpg.01c22eb3335b850ddcc253b08f515374.jpg
PCIe_pinout.png
 

GiGaBiTe

[H]ard|Gawd
Joined
Apr 26, 2013
Messages
1,560
They're good to turn into bench power supplies, you can get a whole bunch of voltages off of them of varying capability.

-12v, -5v*, 3.3v, 5v, 12v (-5v only exists on really old or really shite modern PSUs based on old designs.)

Additionally you can get other voltages with less amperage capability.

7v (between 5v and 12v rails)
8.3v (between -5 and +3.3v rails)
10v (between -5 and +5v rails)
15.3v (between -12 and +3.3v rail)
17v (between -5 and +12v rails or -12v and +5v rails)
24v (between -12 and +12v rails)

All of these additional voltage sources are limited to the current limit of the negative rails, which is usually either 0.5A or 1A, except 7v which is limited by the amperage limits of usually the 5v rail since it's less on modern supplies.

Some supplies tolerate loading between the rails, while others may shut off in protection. Since the current is so low, it makes the voltages of limited usefulness, but they are available. Another option would be to use a buck/boost converter if you need a finer grain control of the voltage output.
 

narsbars

2[H]4U
Joined
Jan 18, 2006
Messages
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They're good to turn into bench power supplies, you can get a whole bunch of voltages off of them of varying capability.

-12v, -5v*, 3.3v, 5v, 12v (-5v only exists on really old or really shite modern PSUs based on old designs.)

Additionally you can get other voltages with less amperage capability.

7v (between 5v and 12v rails)
8.3v (between -5 and +3.3v rails)
10v (between -5 and +5v rails)
15.3v (between -12 and +3.3v rail)
17v (between -5 and +12v rails or -12v and +5v rails)
24v (between -12 and +12v rails)

All of these additional voltage sources are limited to the current limit of the negative rails, which is usually either 0.5A or 1A, except 7v which is limited by the amperage limits of usually the 5v rail since it's less on modern supplies.

Some supplies tolerate loading between the rails, while others may shut off in protection. Since the current is so low, it makes the voltages of limited usefulness, but they are available. Another option would be to use a buck/boost converter if you need a finer grain control of the voltage output.
Sounds like you could pull off a USB charger, maybe an 18V charger if you could use the 24V. Thanks, now all I have to do is figure out how to turn it into a spot welder for lithium ion batter packs(y)
 

GiGaBiTe

[H]ard|Gawd
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Computer power supplies aren't designed for any sort of welding. You'd have to do something like use it to charge a bank of supercapacitors through a current limiting choke. The capacitors would be used as a tank to take the peak welding draw and the power supply would top them off as they drained. Fully discharged supercapacitors look like a dead short to a power supply, so you'd need to make sure to use enough current limiting. There are readymade supercapacitor boards available on ebay but YMMV on how they hold up.
 

Epos7

Gawd
Joined
Aug 31, 2015
Messages
787
Any high school technology classes nearby? A school near me has a class teaching students about computers, including building them. I've dropped off some old gear with them a couple times.
 

narsbars

2[H]4U
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Jan 18, 2006
Messages
2,202
Any high school technology classes nearby? A school near me has a class teaching students about computers, including building them. I've dropped off some old gear with them a couple times.
I had not even thought about that. I have added even more old but functional parts to the pile and will call around.
 
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