I received a baggie of engraved annunciator lamp diffusers from Aircraft Engravers. These are for EAO Series 31 lamps, which are available from the usual suppliers (as well as Aircraft Spruce, for a lot more money). The diffuser piece sits between the bulb – or LED, in my case – and an interchangeable colored lens.
The lamps are all controlled by the annunciator controller board I built years ago. I recently dusted it off and finished writing the software for it, so it's good to go now. It handles lighting the various lamps in response to external inputs, dimming, and the press-to-test function.
Across the top of the panel on the pilot's side is a row of lamps, showing an oil pressure warning (driven by a separate pressure switch), the master caution/warning annunciations from the G3X system, and a press-to-test button. The latter has a smoked lens on it so it presents as more or less plain black when not illuminated.
Next to the bus power switches there is a warning lamp for aux battery voltage, and a caution lamp showing that the bus 2 alternator is under load (i.e. the main alternator has failed).
At the bottom of the panel is an annunciator to remind me that the fuel pump switch is on. This has a blue LED but a smoked lens, so it appears dark when off.
Here's what they all look like when lit, although the camera struggles to make sense of the contrast with the LEDs illuminated:
As the controller software stands now, the press-to-test lamp is illuminated until you press it the first time per flight. That way I won't have an illuminated test button in my face all the time, but it will be lit up during startup, when "annunciator test" will be an item on the checklist.
Here's a closeup of the top row of lamps lit up. I'm pretty happy with the way these turned out.
