[n86121]

You just have to realize these are flying dinosaurs. The voltage will drool up and down a bit, and so will your panel lights. If you have a digital voltage gauge somewhere you will see even cars do the same, as the battery and alternator and loads chase each other around.

Once way to fix that panel light issue is to voltage limit the supply side reference voltage of the dimmer circuit, the NPN TO3 transistor to a constant source. For example, a 20 volt zener diode to ground with a resistor to b+, then feed the totally stable 20V into the top of the reference for the dimer circuit. Now you have literally voltage regulated lighting.

Of course, I am not familiar with any FAA approval to do so.