[sdiy] power supplies

[gregory zifcak]

wow, perfect! can you point me in the direction of some info on how to build 
that supply?
thanks a million,
greg


>From: Dave Magnuson <resfreq at hoohahrecords.com>
>To: "gregory zifcak" <zifcak at hotmail.com>, synth-diy at dropmix.xs4all.nl
>Subject: Re: [sdiy] power supplies
>Date: Wed, 25 Feb 2004 13:59:09 -0500
>
>At 10:46 AM 2/25/04 -0800, gregory zifcak wrote:
> >
> >hi all,
> >i have a tama techstar that runs on +/- 15v. i am only using one of the
> >modules and trying to figure out how to recase it into something smaller
> >than the 10"x16" case it's currently in. my problem is, the power supply 
>is
> >huge. i would love to be able to use a wall wart instead. how would i go
> >about converting unipolar (terminology?) dc to bipolar? would i need to
> >start with +30 volts dc in order to convert to +/-15?
>
>You could use an 18VAC wall wart and build a small bipolar regulated
>supply.  You should easily be able to squeeze that circuit into a 4" x 4" x
>1.5" space without much effort. (You could get it even smaller with careful
>selection of heat sink size and component layout).  Would that be small
>enough?
>
>alternatively, does
> >anyone know if there's such a thing as a bipolar wall wart?
>
>Yes, and that's an option.  Problem is that good (well regulated /
>filtered)  bipolar wallwarts are a bit hard to find, and they're usually
>pretty expensive.  But this would save the space of having to add the
>regulators that I mention above.
>
>
>  lastly, i am not
> >using any of the - volt functions of the synth parameters (- env, etc), 
>does
> >this mean i might be able to run just +15v? i wouldn't just disconnect 
>(or
> >ground) the board negative would i?
>
>I've never seen the schematics, but I'm pretty sure this won't work.  The
>negative rail probably connects to all of the opamps, etc.
>
>Dave
>
>
>
>Resonant Frequency:
>resfreq at hoohahrecords.com
>http://www.hoohahrecords.com/resfreq/index.html
>
>---
>Outgoing mail is certified Virus Free.
>Checked by AVG anti-virus system (http://www.grisoft.com).
>Version: 6.0.583 / Virus Database: 369 - Release Date: 2/10/04

_________________________________________________________________
Take off on a romantic weekend or a family adventure to these great U.S. 
locations. http://special.msn.com/local/hotdestinations.armx