less hum: switching power supply?

[Ingo Debus]

Heiko van der Linden wrote:
> 
> Hi All,
> 
> When I had problems with 7805 or 7905 circuits and the voltage would be too
> high the problems were caused by oscillations.

Just hooked up the scope, no, there doesn't oscillate anything (or with
such a high frequency that my 20 Mhz Hameg doesn't catch it). The output
voltage of the 7905 is just too high when there's no load connected.

Ingo