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NFG Forums => GameSX - The Site => Topic started by: brad on February 28, 2006, 07:59:10 AM

Title: pc power supply - jamma
Post by: brad on February 28, 2006, 07:59:10 AM
i read an article on here about using an atx power supply to kick on a jamma board. My question is, what wires do I send to a momentary switch to kick the supply on and off without a pc?  
Title: pc power supply - jamma
Post by: NFG on February 28, 2006, 04:15:14 PM
The ATX PSU pinout is easy to find.  

http://nfg.2y.net/nfg/x68repair/ (http://nfg.2y.net/nfg/x68repair/)

Use the green pin, PwrOn

Title: pc power supply - jamma
Post by: atom on February 28, 2006, 08:15:02 PM
QuoteThe ATX PSU pinout is easy to find. 

http://nfg.2y.net/nfg/x68repair/ (http://nfg.2y.net/nfg/x68repair/)

Use the green pin, PwrOn
Yeah, simply ground it and it will turn on. Disconnect the ground and its off. Not a momentary switch!
Title: pc power supply - jamma
Post by: NFG on February 28, 2006, 08:17:19 PM
Actually atom, it IS a momentary switch, it doesn't stay closed when the computer's on.  
Title: pc power supply - jamma
Post by: Aidan on February 28, 2006, 08:58:57 PM
As Lawrence points out, the switch to the PC is momentary.

However, the motherboard latches the signal to ground the "power on" line when it wants the PSU to provide the output power.

As Atom points out, simply connecting a momentary to the "power on" line will result in the PSU only powering up whilst that line is held low. Releasing a momentary button connected to the line would cause the PSU to shut itself down.

Thus, for the momentary switch to operate, either some extra circuitry is required, or a switch that isn't momentary!
Title: pc power supply - jamma
Post by: NFG on February 28, 2006, 10:13:10 PM
Ack, you're right, Aidan.  I was thinking of the switch to the mobo, not to the PSU.  Sorry atom!