ATX power supply for use outside of computer case

N

Neil Jackson

Guest
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
 
If I remember corectly you have to link two pins together before it will
turn on. Can't remember which two sorry.


"Neil Jackson" <njackso@cinci.rr.com> wrote in message
news:kct9b.6164$uJ2.866@fe3.columbus.rr.com...
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
Click to expand...
 
In article <kct9b.6164$uJ2.866@fe3.columbus.rr.com>,
njackso@cinci.rr.com says...
| ello 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.
|
|

I would first suggest you try to get it to work with an old CD ROM
drive or old hard disk. I think the way to turn the PSU on, is to
momentarily link PS-ON to ground or the common connection in you list.

Once you have got that working, then think about replacing the above
temporary load with a more permanent one in the form of resistors.
Connect two 10w 25 Ohm resistors, one between +5v and ground, the
second between +12v and ground. This should make the PSU hold up. You
might consider trying other higher values of resistor, which would
waste less current.

3 x 3amp stepper motors does seem rather a lot for a PC power supply,
if that is your intention. You might get away with adding 10 Ohm
resistors, one in series with each phase wire. This would restrict the
surge current a little and might enable it to work without tripping the
PSU.

--
Regards,
Harry (M1BYT)...

Remove the 'NOSPAM' in my email address to reply.

Free Amateur Radio Courses:-
http://www.ukradioamateur.org
 
"Harry Bloomfield" <harry.m1bytNOSPAM@tiscali.co.uk> wrote in message
news:MPG.19d13f45153fd0e89899b2@news.individual.net...
In article <kct9b.6164$uJ2.866@fe3.columbus.rr.com>,
njackso@cinci.rr.com says...
| ello 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.
|
|

I would first suggest you try to get it to work with an old CD ROM
drive or old hard disk. I think the way to turn the PSU on, is to
momentarily link PS-ON to ground or the common connection in you list.

Once you have got that working, then think about replacing the above
temporary load with a more permanent one in the form of resistors.
Connect two 10w 25 Ohm resistors, one between +5v and ground, the
second between +12v and ground. This should make the PSU hold up. You
might consider trying other higher values of resistor, which would
waste less current.
Click to expand...
In my experiance you don't need to force the 12 volt, only the 5, if you put
a load on of about 1 amp or just under on the five volt rail the PSU will
come on and stay on. I think they are designed this way because the 12 volt
rail is not regulated if the 5 volt is not drawing current.
 
Thank you for that bit of info, I was pretty darned sure about the resistors
inline with the phase lines.
As for the load on the 5v lines and 12v lines these would be shorted to
grind???
or a common?
Thank you very much
Neil
"Harry Bloomfield" <harry.m1bytNOSPAM@tiscali.co.uk> wrote in message
news:MPG.19d13f45153fd0e89899b2@news.individual.net...
In article <kct9b.6164$uJ2.866@fe3.columbus.rr.com>,
njackso@cinci.rr.com says...
| ello 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.
|
|

I would first suggest you try to get it to work with an old CD ROM
drive or old hard disk. I think the way to turn the PSU on, is to
momentarily link PS-ON to ground or the common connection in you list.

Once you have got that working, then think about replacing the above
temporary load with a more permanent one in the form of resistors.
Connect two 10w 25 Ohm resistors, one between +5v and ground, the
second between +12v and ground. This should make the PSU hold up. You
might consider trying other higher values of resistor, which would
waste less current.

3 x 3amp stepper motors does seem rather a lot for a PC power supply,
if that is your intention. You might get away with adding 10 Ohm
resistors, one in series with each phase wire. This would restrict the
surge current a little and might enable it to work without tripping the
PSU.

--
Regards,
Harry (M1BYT)...

Remove the 'NOSPAM' in my email address to reply.

Free Amateur Radio Courses:-
http://www.ukradioamateur.org
Click to expand...
 
"Neil Jackson" <njackso@cinci.rr.com> wrote in message
news:eek:9P9b.9580$uJ2.4901@fe3.columbus.rr.com...
Thank you for that bit of info, I was pretty darned sure about the
resistors
inline with the phase lines.
As for the load on the 5v lines and 12v lines these would be shorted to
grind???
or a common?
Click to expand...
On one of the disc drive power plugs put a resistor between the red wire and
the black wire next to it. Make it a 5 ohm to start with to prove that the
power supply stays on, don't touch the resistor when it is powered on, it
will burn you. Increase the resistor size until the power supply shuts down
then come back a little bit to make it stay on. It's best if you have the
biggest value resistor you can while maintaining the power supply's ability
to function. I guess it will be about 8 ohms that you end up with.
Make sure the resistor can handle the power dissipation ie minimum 5 watts.
If I were doing this I would probably use a bulb because the hot bit is
behind glass and it tells you the supply is on.
 
Thank you for all the input guys.
Now I have to figure out why the fella used current limiters on his motors
phase lines.

Thanks again.
 
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