[sdiy] power-question

[Terry Michaels]

Message text written by harry
>My favorite way would be to put a Zener diode in series with the regulator
input...
maybe a 6.8V zener. Then 6.8V is dropped in the zener, leaving 6V for the
regulator... If the input voltage drops, the Zener will go out of avalanche
and the voltage drop will  be mostly in the regulator.

Many diodes in series would give the same effect...
<

Hi Harry:

That's not correct, if the input voltage drops, the zener will maintain a
6.8 volt drop until there is no headroom left on the regulator, and it will
then go out of regulation.

Terry Michaels