Positive voltage converter.

[Ken Stone]

Reverse the polarity of caps and diodes (and other components as needed) in
the charge pump. Consider the concept of the charge pump as distinct from
the specific circuit. There may be other odd changes needed.

OR 

Use a second bridge rectifier off the transformer, but connect it to the
transformer through some bipolar capacitors. The rest of the circuit would
be pretty much as per a standard regulator.

Of course I haven't looked in the synth in question, so there may be other
issues.

Ken

>Hi All...
>
>Some of you may remember me, I've been on the list for about 4 years but
>haven't been active for a while. Anyway, here's my problem....
>
>I'm doing some mods to a CS01 and have found that it uses a "psuedo
>negative" power supply. That is: the output of a 9V reg is used as ground
>(including the output socket) and gnd form the reg is used as V-. This is
>fine until you want to interface other stuff to it.
>
>I need to derive a positive voltage with repect to the CS01 gnd so I can
>power op amps to invert control voltages and such. All the charge pump IC's
>I've seen only do positive to negative conversion.  Any ideas???
>
>
>Thanks,
>
>Stewart.
>
>
>
_______________________________________________________________________
Ken Stone   sasami at blaze.net.au  
Catgirl Paradise <http://www.anime.net/~kens/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>