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PSU PC what voltages?

Started by Dirk Bruere at NeoPax October 26, 2011
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
On 26 Okt., 18:43, Dirk Bruere at NeoPax <dirk.bru...@gmail.com>
wrote:
> 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
On 26/10/2011 18:10, langwadt@fonz.dk wrote:
> On 26 Okt., 18:43, Dirk Bruere at NeoPax<dirk.bru...@gmail.com> > wrote: >> 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: http://www.pcguide.com/ref/power/sup/funcSoftPower-c.html 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
Dirk Bruere at NeoPax wrote:
> 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? >
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/
Joerg wrote:
> Dirk Bruere at NeoPax wrote: >> 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? >> > > AFAIK only the +5V standby rail is present, all the rest comes up > after you press the power button on the computer.
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
On Wed, 26 Oct 2011 17:43:58 +0100, Dirk Bruere at NeoPax
<dirk.bruere@gmail.com> wrote:

>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?
standby 5VDC, pin 9.
Dirk Bruere at NeoPax <dirk.bruere@gmail.com> wrote:

>On 26/10/2011 18:10, langwadt@fonz.dk wrote: >> On 26 Okt., 18:43, Dirk Bruere at NeoPax<dirk.bru...@gmail.com> >> wrote: >>> 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: >http://www.pcguide.com/ref/power/sup/funcSoftPower-c.html > >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
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... nico@nctdevpuntnl (punt=.) --------------------------------------------------------------
On a sunny day (Wed, 26 Oct 2011 10:39:21 -0700) it happened qrk
<SpamTrap@spam.net> wrote in <mbhga7lp1pi2p8rl45df46jdrikmmakg3p@4ax.com>:

>On Wed, 26 Oct 2011 17:43:58 +0100, Dirk Bruere at NeoPax ><dirk.bruere@gmail.com> wrote: > >>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? > >standby 5VDC, pin 9.
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. :-)
On 10/26/2011 11:43 AM, Dirk Bruere at NeoPax wrote:
> 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? >
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
On 26 Okt., 19:16, Dirk Bruere at NeoPax <dirk.bru...@gmail.com>
wrote:
> On 26/10/2011 18:10, langw...@fonz.dk wrote: > > > > > > > > > > > On 26 Okt., 18:43, Dirk Bruere at NeoPax<dirk.bru...@gmail.com> > > wrote: > >> 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:http://www.pcguide.com/ref/power/sup/funcSoftPower-c.html > > 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 >
you can get an extension cord with a relay controlled by the 5V in a USB connector for that exact purpose -Lasse -Lasse