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GigaFrog · 02-06-2002, 11:35 AM

The momentary power switch pulls to ground when you press it. It actually connects its to leads together, one of these leads being permanent ground, the other has a pull up resistor to 5VSB (I think).
I would guess it is the same 5V logic (form the same 5VSB, the only voltage active when the system is off).
The power switch does not provide any logic signal. It is closed or opened. Once closed, it triggers a flip-flop that will generate the PS-ON signal.

That's how I understand it.
Make a search on ATX motherboard, I am at work now and have no time to search.

Good luck.

02-06-2002, 11:35 AM	#4
GigaFrog Cooling Neophyte Join Date: Nov 2001 Location: NorthWest (French & US) Posts: 88	The momentary power switch pulls to ground when you press it. It actually connects its to leads together, one of these leads being permanent ground, the other has a pull up resistor to 5VSB (I think). I would guess it is the same 5V logic (form the same 5VSB, the only voltage active when the system is off). The power switch does not provide any logic signal. It is closed or opened. Once closed, it triggers a flip-flop that will generate the PS-ON signal. That's how I understand it. Make a search on ATX motherboard, I am at work now and have no time to search. Good luck. __________________ Got water? Water cooled for 3 years. Safe with thermal switch. Now silent with fan thermostat.