ATX power supply for use outside of computer case.

[Neil Jackson]

Micro P4ATX 200W (3 Screw SFX)
Switching Power Supply

AC INPUT: 115/230 Vac~ 8/4A
60/50Hz
DC OUTPUT :

COLOR : BROWN RED WHITE YELLOW BLUE PURPLE BLACK
GREEN ORANGE
DC : +3.3V +5V -5V +12V -12V
+5V-SB COM PS-ON PW-OK
OUTPUT : 11.5/18.7A 16/13A 0.3A 11A 0.3A
2.0A RETURN REMOTE P.G.

(3.3V and 5V Max Output 120W, Peak Surge Max Output 208W)

Hello all,
I'm having some trouble turning the above label power supply on. I.E. I'd
like it to run outside of the computer.
I'll be using this power supply to run a CNC engraver. The motors are
three(3) 6vdc unipolar.
I read elsewhere that I have to supply a small load across one of the red
and com leads.
Such as an old cdrom or 25ohm resistor. I really don't want to use the cdrom
drive as it will increase the weight of
my unit and I'm sure one of you guys are quite capable of creating a load
that would be necessary to make this work.

The site below and accompanying text is the controller unit that drives the
motors
http://www.stepper3.com/index.htm?31.htm&1
(S3ROC) Stepper3 Rev OC - 3 Axis 3 Amp Unipolar Stepper Motor Driver



I do have an older style AT box that will come on with the switch, but it
seems to power down as soon as my three motors are running in unison. The
fella at the site indicated below used 10ohm/10watt power resistors. How
exactly he set them up is beyond me. He called them power limiters. I was
assuming that the current draw from three motors running simultaneously
(6vdc unipolar) would cause the power supply to shut down???????

http://www.theworkshop.ca/metcastmach/FoamMill/foammill13/FoamMill13.htm

Any help or a crude schematic would be extremely helpful.

Peace
Neil

 

[JW]

Micro P4ATX 200W (3 Screw SFX)
Switching Power Supply

AC INPUT: 115/230 Vac~ 8/4A
60/50Hz
DC OUTPUT :

COLOR : BROWN RED WHITE YELLOW BLUE PURPLE BLACK
GREEN ORANGE
DC : +3.3V +5V -5V +12V -12V
+5V-SB COM PS-ON PW-OK
OUTPUT : 11.5/18.7A 16/13A 0.3A 11A 0.3A
2.0A RETURN REMOTE P.G.

(3.3V and 5V Max Output 120W, Peak Surge Max Output 208W)

Hello all,
I'm having some trouble turning the above label power supply on. I.E. I'd
like it to run outside of the computer.

You need to short the signal PS-ON to ground to turn it on. I recommend
having 2 to 3 amps of load on the +5 volt output for proper operation.
A 2 ohm 15 watt resistor would give you a 2.5A load, and should work just
fine.