Circuit that emulate a push button

Hello Everyone!

I'd like to ask your help in making this circuit.

I want to make a simple circuit that emulates a push button switch:

When powered on, the circuit will trigger a switch. When powered off, it will trigger the switch again.

I'm thinking of using this for my home made coin operated PC.
There are various options for the coin operated PCs from shutting off the monitor or keyboard & mouse to software triggered.
But I'm thinking of using the stand-by or sleep option of the motherboard. My current setup is a coin slot that is connected to a timer circuit. When coin is inserted the timer is activated and a relay will turn on. I want to put the circuit to this relay output and connected to the pwr button of the PC.

Hoping for your assistance,

Jayefuu5 years ago
You want to turn the PC off after a certain amount of time? It might be better to lock it rather than just turning it off regardless of what the user's doing.
cvill (author)  Jayefuu5 years ago
not turn off, just stand by or sleep. It can be set thru bios.

what do you mean by locking though? please elaborate. ;-)