MS20

[Tony Allgood]

Make sure you have separate grounds for the smoothing cap and the reg.
Take each one back to a common point near the transformer/rectifier.
The 78s are normally quite good at 50Hz/60Hz rejection, the 79s are
worse. However, there are many makers of these chips, and some are
better than others.

Just a thought, are you using half or full wave rectification. Full
wave should halve your ripple, but it will now be at 100Hz. And don't
forget to have separate RC filters on each chip or module. The more the
better. 47R and 10uF are nice.

Tony Allgood.

Cumbria, UK

'I may live in the middle of nowhere, but the ewes are nice'

----------
> From: Paul Perry <pfperry at melbpc.org.au>
> 
> BTW, I think i was wrong about those 7815 regs....cant get the last
bit of
> 50hz  (abt 5 mv) no matter what I do....
>