Forums

PC PSU driving relay

Started by Dirk Bruere at NeoPax July 28, 2012
I am using the +12VDC from a PC PSU to switch mains using a relay ie 
when the PC turns on mains power gets supplied to some amplifiers.

Do I need diode protection across the relay coil for when the PC PSU 
switches off, or do such PSUs have such protection built in?

-- 
Dirk

Full Spectrum Praxis : ZERO STATE : http://zerostate.net
On Sat, 28 Jul 2012 17:01:35 +0100, Dirk Bruere at NeoPax
<dirk.bruere@gmail.com> wrote:

>I am using the +12VDC from a PC PSU to switch mains using a relay ie >when the PC turns on mains power gets supplied to some amplifiers. > >Do I need diode protection across the relay coil for when the PC PSU >switches off, or do such PSUs have such protection built in?
If the relay coil is connected directly to the 12 volt supply, you don't need any other parts. There will be no flyback voltage. -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
"John Larkin"
> Dirk Bruere at NeoPax > >>I am using the +12VDC from a PC PSU to switch mains using a relay ie >>when the PC turns on mains power gets supplied to some amplifiers. >> >>Do I need diode protection across the relay coil for when the PC PSU >>switches off, or do such PSUs have such protection built in? > > If the relay coil is connected directly to the 12 volt supply, you > don't need any other parts. There will be no flyback voltage.
** So this Dirk dude imagines he is an engineer ?? ROTFL !! .... Phil
On 2012-07-28, Dirk Bruere at NeoPax <dirk.bruere@gmail.com> wrote:
> I am using the +12VDC from a PC PSU to switch mains using a relay ie > when the PC turns on mains power gets supplied to some amplifiers. > > Do I need diode protection across the relay coil for when the PC PSU > switches off, or do such PSUs have such protection built in?
The PC powersupply has a bridge rectifier and some large capacitors on the 12V output, if the capacitors don't suffice to provide a slow enough voltage drop the rectifier will clamp the flyback peak voltage to somthing smaller than -1V -- &#9858;&#9859; 100% natural --- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---
On 29/07/2012 03:28, Phil Allison wrote:
> "John Larkin" >> Dirk Bruere at NeoPax >> >>> I am using the +12VDC from a PC PSU to switch mains using a relay ie >>> when the PC turns on mains power gets supplied to some amplifiers. >>> >>> Do I need diode protection across the relay coil for when the PC PSU >>> switches off, or do such PSUs have such protection built in? >> >> If the relay coil is connected directly to the 12 volt supply, you >> don't need any other parts. There will be no flyback voltage. > > > ** So this Dirk dude imagines he is an engineer ?? > > ROTFL !!
Strangely enough, this is the first time I have ever used a mechanical relay. -- Dirk Full Spectrum Praxis : ZERO STATE : http://zerostate.net
"Dirk Bruere at NeoPax"
 Phil Allison wrote:
>> "John Larkin" >>> Dirk Bruere at NeoPax >>> >>>> I am using the +12VDC from a PC PSU to switch mains using a relay ie >>>> when the PC turns on mains power gets supplied to some amplifiers. >>>> >>>> Do I need diode protection across the relay coil for when the PC PSU >>>> switches off, or do such PSUs have such protection built in? >>> >>> If the relay coil is connected directly to the 12 volt supply, you >>> don't need any other parts. There will be no flyback voltage. >> >> >> ** So this Dirk dude imagines he is an engineer ?? >> >> ROTFL !! > > Strangely enough, this is the first time I have ever used a mechanical > relay.
** That supposed to be some kind of excuse ? It ain't.
On 30/07/2012 02:31, Phil Allison wrote:
> "Dirk Bruere at NeoPax" > Phil Allison wrote: >>> "John Larkin" >>>> Dirk Bruere at NeoPax >>>> >>>>> I am using the +12VDC from a PC PSU to switch mains using a relay ie >>>>> when the PC turns on mains power gets supplied to some amplifiers. >>>>> >>>>> Do I need diode protection across the relay coil for when the PC PSU >>>>> switches off, or do such PSUs have such protection built in? >>>> >>>> If the relay coil is connected directly to the 12 volt supply, you >>>> don't need any other parts. There will be no flyback voltage. >>> >>> >>> ** So this Dirk dude imagines he is an engineer ?? >>> >>> ROTFL !! >> >> Strangely enough, this is the first time I have ever used a mechanical >> relay. > > > ** That supposed to be some kind of excuse ? > > It ain't. > >
Based on your past record I assume your excuse is mental illness -- Dirk Full Spectrum Praxis : ZERO STATE : http://zerostate.net
 Dirk Bruere at NeoPax = Cunt

>> > Based on your past record I assume your excuse is mental illness > >
** Scum like you need a bullet in the head.
Phil Allison wrote:
> > Dirk Bruere at NeoPax = Cunt > > >> > > Based on your past record I assume your excuse is mental illness > > > > > > ** Scum like you need a bullet in the head.
Lost your inflatable sheep again? Buy some of these: http://www.wastesomecash.com/light-sheep-key-chain.html
Phil Allison wrote:

> Dirk Bruere at NeoPax = Cunt > > >>Based on your past record I assume your excuse is mental illness >> >> > > > ** Scum like you need a bullet in the head. > >
Didn't they take the guns away from you guys? I can see why. I understand you people only want to be good samaritans and clean up society but come on now, it appears to me, it may create empty streets with attitudes like yours. I mean, the worthless politicians won't have any brain dead voters to keep them in office so they can live free off our backs. Jamie