Hello All,
I have a project for a friend that he wants to run a cluster of Raspberry Pi 4s from an ATX power supply in a computer case. He is working out the mounting by 3D printing parts. I have been tasked with power distribution.
Design is fairly simple. Either a group of buck converters to step voltage down to the 5 VDC from the power supplies 12 VDC rail. Or good old LDOs. Just concerned about heat dissipation inside the computer case for the second option. Still trying to decide on heat vs cost.
Using this because he wants 16 total of the Pis and at 4 amps each, that is 64 amps. Not many PC power supplies offer that on the 5 VDC rail. Now I know the 4 amps is max draw at full load, but might as well design for worst case.
Anyways, I was trying to come up with a circuit to latch the power supply on using the computer case original button. I came across an older video:
and thought that might be useful. But I know to turn on a PC power supply, you drive the PS_ON pin to ground. So I dug a bit further and found this:
https://www.edn.com/latching-power-switch-uses-momentary-pushbutton/ Specifically Figure 2 for the high side load.
My question to the forum is then: Would there be an issue using the EDN high side load circuit to directly drive the PS_On wire to ground? Or should I just play it safe and use either Dave's circuit or Figure 1 to drive a relay to drive the wire low?
Thanks for having a look.