Turning on ATX PSU with AT???

[TheGhengisKhan]

Does anyone know how I could go about connecting an ATX PSU to turn on with an AT PSU? I have 1 AT PSU & 2 ATX PSU's that I need to connect all together, and have them turn on at the same time. This is not for powering my PC, but for another project I'm working on, so none of them are going to be connected to a motherboard. I know that an AT PSU turns on when you flip the switch that's attached to it, and I've connected multiple ATX PSU's to each other before, so I don't need help with which wires turn them off and on, but what I really need to know is if there's a way to have the ATX PSU's come on when I flip the switch for the AT PSU.

 

[bchur83]

A 12v relay to switch the power on the ATX PS. When you turn on the AT PS, it flips the relay to close the connection on the right ATX Pins

EDIT: Here is a pic of the pins to connect here or here

Just put a relay in there to switch from the AT PS

 

[TheGhengisKhan]

Is there any other way (that wouldn't include spending money I don't have) to get it to work?

 

[CrashOveride]

I think the AT PSU's switch is just a 120v swtich that cuts the power to the actual PSU, so if you spliced the power cord for the ATX PSU into the AT one it should work. Personally I would try but you may want to wait until somone can confim that that is how AT PSUs work.

EDIT: Thats how it works I just opened up an old AT PSU to check.

If the triagle of the plug is facing up, when looking from the back of the plug (inside the PSU) the left prong is hte + and the right the a ground, the top one is another ground that goes to the PSU case. If you splice the ATX PSU wires into the AT wires AFTER the switch it should work the way you want. If you do this make sure you don't mess up as this is 120v wireing and it CAN KILL YOU or start a fire if you mess up in a bad way. Just just double check everything and I would use solder or secure screw thingys like on nice car amp fuse blocks (if you know what I mean). I was gonna get pictures but I can't find our camera ATM, I think my parents took it.

 

[bchur83]

the main switch on an AT PS is the 120v AC line. Like crash said, you could try to splice the main power, but that might be a little risky. I personally hate working with AC power (been shocked a few too many times).

 

[TheGhengisKhan]

Messing with 120V AC isn't really a big deal to me, since in my job I deal with some 440V 400Hz 200A power (US Navy weapons systems). So I'll give it a shot. Though for some reason one of the ATX PSU's that I've got isn't turning on when the green wire gets connected to ground. Yet another obsticle to overcome in the name of modding

 

[larrymoencurly]

The only reasons an ATX PSU won't turn on when the green is grounded are:

1. PSU needs a minimum load, probably on the +5V but sometimes also on the +3.3V. 10-20 ohm resistors should do the trick, but I have one PSU that needs to put out a few amps to regulate right (Integrated Intel i810 mobo w/ 466 MHz Celeron weren't enough -- HD wouldn't spin).

2. Case ground isn't signal ground. That troublesome PSU had its black wires not connected to its case.