Forums

PSU PC what voltages?

Started by Dirk Bruere at NeoPax October 26, 2011
"Nico Coesel" <nico@puntnl.niks> wrote in message 
news:4ea854c1.25649890@news.kpn.nl...
> 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.
Some PCs leave the USB 5V on in standby.
On 26 Okt., 22:30, "Ian Field" <gangprobing.al...@ntlworld.com> wrote:
> "Nico Coesel" <n...@puntnl.niks> wrote in message > > news:4ea854c1.25649890@news.kpn.nl... > > > > > > > > > > > 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 > > > 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. > > Some PCs leave the USB 5V on in standby.
I think it is usually a bios/jumper setting on the motherboard -Lasse
On 26/10/2011 19:48, Jan Panteltje wrote:
> 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. > :-) >
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
On 26/10/2011 19:52, Jon Elson wrote:
> 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
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
On 10/26/2011 03:45 PM, Dirk Bruere at NeoPax wrote:

>> 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
> 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 >
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