[sdiy] why +/- 15V

[Scott Gravenhorst]

"TIm Daugard" <daugard at sprintmail.com> wrote:
>I design for +15V and then end up using +12 for the supply. I can't get
>enough voltage out of a 18V transformer to regulate to 15V.  +15 volt allows
>integrating CMOS Logic chips without worrying about damage.
>
>This has worked for a few dozen modules.
>
>Tim

This is true unless you want to run the CMOS chips from a bipolar supply.  In
this case, +/- 7.5 volts is best (according to spec sheets), however, I've
had no problems using +/- 8 volts (absolute max ratings are usually 18 volts).

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