Salvaging Computer PSU

[magatru]

Hi all,

From my computer workshop I have plenty of PSU ATX and Non-ATX, the condition is vary from the burn one to the goooood condition (still in their plastic wrap).

Usualy I used the broken unit to salvage the good component  ;D, so I can used it to another project or something else, yes it's my cheap solution than buying the new component to built a project.

Because they have variable output and look solid, can I make PSU for everyday user from it? Where the switch in the ATX form?

thanks in advance,

best regards

magatru

[EdwardM]

Hi again magatru

these PSU's are excellent and have huge current capability but I believe there is a minimum current that needs to be taken from them in order for them to work.  What that current is I don't know but I suspect it's fairly low, you'll need a web search on this one and for the on/off switch wiring unless someone on the board knows the answer already  ???

Best of Luck

Ed

[Guest Alun]

How about using some LEDs or even small incandesant lamps as the minimum load(s) then they could serve as power indicators as well.

[magatru]

@EdwardM,

Hi there, we meet again  ;D

Because they came in various model, so I take one example from branded HewletPackard (sorry, I forget the models, but it's from old computer - Pentium Classic series)
the PSU labels says:

-----------------------------------------------------------------
Model VL202-3515, ASTEC HP P/N:0950-2999
Max continuous output power is 160W
input  100-127V ~ 5A
          200-240V ~ 3A

output    DC  Voltage                    Max Current

              +12V                                  4,4A
              +5V                                    20A
              +3,3V                                  12A
                -5V                                    0,2A
                -12V                                  0,5A
                +5VSB

-----------------------------------------------------------------

I think for everyday user it's more than enough, for on/off ATX wire switch I'will post it here if I find some, thanks for your advice  ;D

@Alun,

I have open the PSU case, and the input go to the motherboard, like I said before there are many models of PSU and usualy the branded one have different wiring with common PSU, where I have to put the LED's (with resistor) to check the on/off switching wire? from the input to motherboard?

Because there only two wire from the on/off switch (the push-on switch type) in front of the computer case and it directly go to motherboard.

Just guessing, maybe the switch send a pulse to the PSU via motherboard (the software can do this also) to turn on and off the power, sorry for my lack of knowledge  ;D ;D ;D


thanks in advance,


best regards,

magatru

[GreekPIC]

You have to short pin 14 to pin 15 and it will turn on.
(source:http://www.laserlab.com/atx_ps_connector.php)

Nikolas

[ante]

Hi magatru,

You need a minimum load to get the output right as mentioned, a 4R7  >10W resistor on the 5 Volt output will do the trick. A couple of LEDs will probably not be enough as a load, but they form a good indicator though. 8)

[ZomBiE]

I just tested my old 350W ATX power supply made by Antec, and ifound that it needs load of 2A@3,3v, 1A@5v and 500mA@12v to regulate properly.

[ante]

Hi ZomBie,

Interesting! Was this done only by testing, no info on the label? Which where your criteria’s for deciding it was regulating correctly? Did the outputs need these loads simultaneously (for all outputs to regulate correctly) or just on each specific output?   
Just curious!  ;D