Use of diodes to prevent reverse flow

[Harold Lanfear]

Can someone give me some details on what I need to use to do the following. Specifically, can I use any small diode?

My -8 will have a SP3T switch that turns on LED lighting for LED1, or LED2 or 'Both'. The rear seat PAX will have a switch that actives LED2. I believe I can put a diode in line between LED2 and the 'Both' connection so the rear seat PAX doesn't active LED1 when the rear seat switch is turned on.

Before anyone says 'use two separate switches up front'; I know I can; but I don't want to . I'm "experimenting" - OK; playing if you want to be more accurate.

Thanks for indulging me.

[Rainier Lamers]

Yes,
should not be a problem.
Use something like a 1N4007 (1 amp) diode - make sure that is enough for you light (I assume it will be).
Wire the diode in forward direction between the "both" terminal and the switch for the pax lamp (and to the pax lamp).
This way, if the pax lamp is on, it cannot light the pilot lamp but the SP3T can still control the pax lamp as you desire.

Rainier
CEO MGL Avionics

Originally Posted by Harold Lanfear

Can someone give me some details on what I need to use to do the following. Specifically, can I use any small diode?

My -8 will have a SP3T switch that turns on LED lighting for LED1, or LED2 or 'Both'. The rear seat PAX will have a switch that actives LED2. I believe I can put a diode in line between LED2 and the 'Both' connection so the rear seat PAX doesn't active LED1 when the rear seat switch is turned on.

Before anyone says 'use two separate switches up front'; I know I can; but I don't want to . I'm "experimenting" - OK; playing if you want to be more accurate.

Thanks for indulging me.

[444TX]

A little more information about what you are trying to do
would help. If you want a map light in the front controlled
by the pilot and another one in the rear with a pilot override
just turn both on with one spst switch in the front and a
copilot switch in series that is normally off and only works
when the pilot switch is on.

You may have other ideas or concerns. Let us know exactly
how you want it to work and what exactly are these LED,s
for. There is a way to make it work, likely with no diodes.

George Meketa
RV8, 880+hours

[Harold Lanfear]

Rainer,
Thanks much, that's exactly what I needed.