Okay so, I have an ATX PSU that isn't connected to a motherboard, and I'm currently using the simple paper-clip trick to ground PS_On in order to trick the PSU into providing power when I need. However, doing this cleanly means wiring in a switch to do this, but my PSU already has its own switch on the back which I'd like to just use instead, rather than two separate switches. Now, I know that simply leaving PS_On grounded all the time isn't really safe to do if I have devices connected.
But then I found out about the PWR_OK signal, which is a +5V logical high signal that is triggered when the PSU considers itself ready (shortly after mains power is provided).
What I was thinking I could do is somehow wire up the PWR_OK, PS_On and a ground pin, such that when PWR_OK goes to high, PS_On is automatically grounded to activate the PSU automatically, but safely. I may still put a toggle switch in there for good measure, but I basically don't want to be able to ground PS_On without the PWR_OK signal.
I'd very much appreciate any help in describing how to do this. Please treat me as a relative novice for any answer; although I'm comfortable soldering things, mostly all I've done is things like creating my own splitter or adapter cables for computers and even then, only simple ones. It's been quite a while since I had to design a circuit, work out what resistors I need (and where) etc.
Answer
The way a PWR_OK works, or at least the ones I have worked with, is by signaling the stabilization of the power output with a certain tolerance. This is used for sequencing purposes (e.g. When 5V line is ready enable the 3.3V PS).
This means you won't be able to use PWR_OK unless PS_ON is high first.
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