[sdiy] Re: LVM

[TIm Daugard]

From: "crystal" <crystals at sonic.net>


> i don't see what the big deal is:  make a 5V synthesizer or make a +/-12V
> synthesizer, whatever floats your boat. in my two (and a half) homebuilts i
> have used all kinds of different voltages IC chips. it's mostly +/-12V, but
> occasionally i have used 5V chips, and some other odd things. i use
> transistors (or quad opAmps) to level shift when needed. a little extra
> soldering.

I've done this. The problem with multiple supply voltages are:

1) Multiple power supplies are required or regulators in each module.
2) Power ups and downs have to be carefully timed - controlled
3) If everything is not right - the IC and the TO-92 regulator release the magic
smoke (I'm not sure which went first).

What I've done is redesigned modules that used 5 volt logic to use 15 volt CMOS.
I'm a believer in keeping things simple so that the design and build process
goes faster.

Back to the LVM - Analog sent me an e-mail on a nice IC. I went to the web site
to check it out and . . . supply voltage 5V max. . . curses foiled again.

Tim Daugard
AG4GZ 30.4078N 86.6227W
http://home.sprintmail.com/~daugard/synth.htm

with modules stacked in plastic shoe boxes because the wood work for the racks
takes longer and makes a bigger mess than building another module. Today's
project - a 25V power supply.