[sdiy] +-12V supply

[groovyshaman]

A very cool solution - definitely worth doing.  Since I have a bi-polar
supply, should I use a double pole relay and a resistor on each + and -
rail?

George

----- Original Message ----- 
From: "harrybissell" <harrybissell at prodigy.net>
To: "groovyshaman" <groovyshaman at snet.net>
Cc: <synth-diy at dropmix.xs4all.nl>
Sent: Saturday, January 15, 2005 3:40 AM
Subject: Re: [sdiy] +-12V supply


> That is exactly the point...and I might add that it is also a PowerOne
800mA
> supply that needed this treatment. :^P  I just added a series power
resistor (15
> ohms)
> in my case... with a one shot that delays a relay closure for two seconds.
When
> closed
> the relay shorts out the resistor.
>
> H^) harry
>
> groovyshaman wrote:
>
> > I am curious Harry - what is the advantage of a soft start mechanism?
Does
> > this in some way help alleviate the initial heavy current outrush that
> > occurs when turning on the power due to all of the decoupling caps on
all of
> > the modules in my system?
> >
> > I've noticed that from time to time when I power up the 800ma power one,
one
> > rail "goes flat" due to current limit circuitry I think - and I
immediately
> > shutdown when this occurs.  Hopefully this does not harm things.
(although
> > I think I remember someone mentioning that running certain ICs with one
dead
> > rail for any length of time will kill the part..)  I'm still running the
> > supply below the rated output once things power up ok.  It's the initial
> > current draw that's causing problems.
> >
> > George
> >
> > ----- Original Message -----
> > From: "harrybissell" <harrybissell at prodigy.net>
> > To: "Ken Stone" <sasami at hotkey.net.au>
> > Cc: <synth-diy at dropmix.xs4all.nl>
> > Sent: Friday, January 14, 2005 11:41 PM
> > Subject: Re: [sdiy] +-12V supply
> >
> > > I considered building a relay based "soft start" for my PowerOne
> > > supply as "building my own power supply".  The only time I would
> > > build my own is....
> > >
> > > 1) when I want cheap and dirty and don't care about performance
> > >
> > > 2) when it has to fit into a custom sized area
> > >
> > > 3) when I need an odd voltage not readily available
> > >
> > > H^) harry
> > >
> > <snip>
>
>