power supply

[Oliver Scholz]

I used this setup (and it works for my microcontroller application,
although I am not completely confident...):

>   --R-D-----------[7805]----- +5V
>         |   |            |
>         S   C            C
>         |   |            |
>         -   -            -

The resistor is fairly small (4.7 Ohms) and depends on the max. current
of the circuit (voltage drop across R !). The Diode prevents negative spikes
from reaching the circuit. Use a fast diode here!
S is a Suppressor Diode (P6KE15) that clips fast positive spikes to about 15V.
The capacitor C is fairly large (1000 uF) and together with R forms
a low pass filter to suppress variations in the supply  line.

The 7805 also has two 100nF capacitors to suppress oscillation and to filter
fast spikes. The output C buffers the circuit.

Any improvements will be appreciated...

Best regards,

-Oliver