This entry covers several days of testing I've been doing on the LED lights that will be part of the custom annunciator panel I'm building. I changed out the stock LEDs in the MPJA enclosures with higher-brightness ones. My concern was the range of brightness. I want these lights adjustable so they are really bright in the daytime, and can be dimmed significantly at night. So, with the help of a decade resistance box and a selection of various potentiometers, I figured out a combination of dropping resistors and a pot that will give a decent range. The dropping resistors are 150 ohm, and the pot is a 5K linear taper. I ops-tested the setup for 24 hours at 13.8V and "fulll-bright," just to make sure the LED would hold up, and the resistor would not get too hot. It seems fine.
