[sdiy] Power distribution board

[David G. Dixon]

This leads to my next question:  Presuming that most have only +/-15V
supplies in their modulars, what is the best way to handle digital power?
I've only breadboarded circuits with TTL chips powered by a 7805 reducing
+15V to +5, and was startled (and a little frightened) at how hot the
regulator ran.  I'm not sure I'd want anything that hot on any of my
lovingly hand-crafted boards!

I was thinking I would probably opt for just putting the +15V through a
simple voltage divider to get +5V and be done with it, but I'm wondering: is
this anathema?  Does one find oneself excommunicated from the fold for such
heresy?

> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
> bounces at dropmix.xs4all.nl] On Behalf Of Roy J. Tellason
> Sent: Saturday, April 04, 2009 10:14 AM
> To: synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] Power distribution board
> 
> On Saturday 04 April 2009 05:50:29 am Julian wrote:
> > Somthing ive wondered -
> >
> > Regulators are cheap - what about a power bus running over-voltage and
> then
> > a pair of dedicated regulators for each and every socket on that bus?
> >
> > Would that effectivly isolate every module?
> >
> > (im thinking back to my old doepfer lfos thatlld modulate the doepfer
> vcos
> > on the same bus...)
> 
> That was the approach taken for the real early S-100 bus computer systems,
> with the power buses being 8V, and +/-16V,  which were typically regulated
> down to 5V and 12V on each board.  Some boards had to have multiple
> regulators for the 5V,  and there were heat dissipation issues.  Later
> systems put jumpers in place of the regulators and used switching power
> supplies instead,  though I've not much experience with them.
> 
> But yeah,  I'd say this would provide a lot of isolation.