Right Transformer for 12v ?

[Tony Allgood]

Steven said:

A simple question: I am making a +/-12v PSU using halfwave rectifier / 1000u
/
7812 / 7912 regulators. Would it be better to use a 12v or 15v wall wart?
Also
would a 20v wall wart be usable?


Well it very much depends on:
a How much current you are drawing from the supply
b How much heatsinking you have on the the 78/79s
c The quality of the ac line supply
d The regulation of the ac wall wart.

My tip... use a 12V AC wallwart rated at 500mA (rms) and don't take any more
than 250mA (rms) from it. Oh and put a heatsink(s) on the regs. If you want
more than 250mA, then buy a ready made linear to do the job or build one
inside your unit using a good quality transformer and capacitors. And go
full wave as well.

Regards,

Tony Allgood, Cumbria, UK

e-mail: oakley at enterprise.net

Rack mounted Moog VCF module. Details to be found at...

http://aupe.phys.andrews.edu/diy_archive/schematics/effects/filter.html