[sdiy] power supplies

[gregory zifcak]

i found this one, which apparently takes 16 or 12vac: 
http://sound.westhost.com/project05.htm
would starting with 18vac give me higher output amperage? i'm not sure what 
my circuit needs. if i use 18vac, should i still use the 7815 and 7915? are 
there any other components that would have to be changed?
thanks,
greg

>From: "gregory zifcak" <zifcak at hotmail.com>
>To: resfreq at hoohahrecords.com, synth-diy at dropmix.xs4all.nl
>Subject: Re: [sdiy] power supplies
>Date: Wed, 25 Feb 2004 11:25:36 -0800
>
>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
>>
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