When the PC is "switched off" by the button connected to the mobo the PSU goes into a quiescent state, yet must supply voltage to the mobo.
What voltages are active on the PSU, and what only comes up when the mobo powers up?
-- Dirk http://www.neopax.com/technomage/ - Magick and Technology
googles says; 5V standby, and then +12, +5, +3.3,-12 and optionally
-5V when it is on
-Lasse
Seems so - just been googling:
I need a PC to turn on mains to an amplifier, so just connecting a mains relay to the 12V of the PSU ought to do it. When the PC is up, so is the amp
-- Dirk http://www.neopax.com/technomage/ - Magick and Technology
AFAIK only the +5V standby rail is present, all the rest comes up after you press the power button on the computer.
-- Regards, Joerg http://www.analogconsultants.com/
That is correct. The +5V standby supply is on as long as the mains power is supplied. When the PC's power button is pressed, all the other supplies come up: +3.3V, +5V, +12V and -12V.
-- David dgminala at mediacombb dot net
standby 5VDC, pin 9.
I'd use a 5V relay connected to a USB port. Doesn't require tinkering inside the PC and it will work with any PC.
-- Failure does not prove something is impossible, failure simply indicates you are not using the right tools...
On a sunny day (Wed, 26 Oct 2011 10:39:21 -0700) it happened qrk wrote in :
That is the violet wire in ATX. The green wire on pin 14 is on/off switch to ground. The +12 V he could use is the yellow wire on pin 10.
To defuse cut any wire. :-)
googling:
you can get an extension cord with a relay controlled by the 5V in a USB connector for that exact purpose
-Lasse
-Lasse
Well, it is a little more complicated. Powering up is a BIOS function, and motherboards that have the BIOS option to always start when power is available or to start when power is available if the last state was powered-on, will always fully power up when the supply gets power, and then decide to stay on or power off depending on the BIOS selection. So, for instance, Dell desktops will pretty much all power on fully for about a half second, and then may turn off or stay on as selected.
Just thought you should know this. Maybe a 1-second time delay would be better in your application, or even have the software enable the device only after the software is running, if there is a safety or reliability issue with having the device power up too early.
Jon
Some PCs leave the USB 5V on in standby.
I think it is usually a bios/jumper setting on the motherboard
-Lasse
Yes, bomb makers always use international color coded wires. And bright red LED timers.
The EOD guy never thinks to simply remove the explosive from around the (single) detonator.
-- Dirk http://www.neopax.com/technomage/ - Magick and Technology
No, it's just an AV system based on a computer. So rather than have multiple power switches a mains relay actuated from the +12 should be sufficient to route power to the amps
-- Dirk http://www.neopax.com/technomage/ - Magick and Technology
OK, the original post said "PC" so I assumed an ATX power supply. If a short power-on whenever the power supply is plugged into the wall socket causes no harm, then everything is fine.
Jon
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