power supply

[Yoshiki Ohmura (Yoshi)]

On Sat, 5 Sep 1998, Maarten Halmans wrote:

> 1. Can I use 78xx and 79xx regulators or should  I use other (better?)
> regulators?

I used 78/79xx and it works fine, however's have better specs.

> 2. Because I can't find a transformer with 4 separate secondary
> windings,  I have to use each winding twice. When I use 78xx or 79xx
> regulators the whole thing oscillates. Any suggestions?

Do you have a filter capacitor?  If not this could be causing the
oscillation.  For a 0.8A PS you could use a 2.2uF Tantalum capacitor at
the input (conected to ground) and a 1.0uF at the output (make sure to get
the polarity right ;)

Hope this helps

Yoxhi