Steve, you can avoid the problem by wiring in the higher voltage zener
permanently and using your switch to connect the lower voltage zener in
parallel
with the higher voltage zener.
When both zeners are connected, the voltage will be set by the lower voltage
diode.
73,
Gerald K5GW
In a message dated 12/31/2008 1:26:03 A.M. Central Standard Time,
kk7uv@bresnan.net writes:
Considering the common zener bias circuit (with the 2n3055 and resistor),
what precautions should be taken if I wanted two different zeners (and
associated bias voltages) selected by a switch or relay? Is there a danger
in the
moment when the switch/relay throw is transferrring from one pole to the other
and neither zener is in the circuit? Likewise, if I used a
make-before-break setup, can the two zeners be in parallel for a moment
without causing
trouble?
Thanks,
Steve KK7UV
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