Interior Lighting System, Part 1

Hours Worked = 2.25

So, this is one area where I’m going way overboard. I’ve designed a custom interior lighting system. Here are the highlights:

2 PlaneAround LED Panel dome lights (one above the front seats, one above the rear seats)
2 AircraftSpruce 4-LED lights above baggage area
2 Aveo EveBeam Touches for Pilot/CoPilot
2 SteinAir eyeball LEDs for rear passengers
4 AircraftSpruce 4-LED lights in the footwells
2 AircraftSpruce 4-LED lights in the doors, for entry lighting when the gull wing doors are open

#1 – Dims the main overhead lights (the two PlaneAround LEDs and the baggage area LEDs)
#2 – Dims the footwell lights
#3 – Dims the rear passenger map lights. These lights are turned on/off with switches next to the lights, but I can override and turn them down/off from the front with this dimmer.
#4 – Dims the panel switches and displays

There are also going to be lever switches that are on each door pin and on the baggage door. These are normally closed switches, so when the door pin is pushing against it, the switch is “off”. When the door is opened, the switch turns on

If that isn’t complicated enough, I decided that I wanted this plane to work like a car. When you walk up to it and open a door, the dome lights come on. Planes are normally wired so that everything electrical is ran thru the master switch, so the light won’t be work until you open the door and reach in to flip the master.

Instead, I designed a system of relays and a timer that works directly off the battery. Here’s how it’s going to work (hopefully)

When a door is opened, the dome lights and the light in just the door that’s open will turn on to full power. This will happen whether the master switch is on or not. There is a timer circuit that will turn the overhead lights off if the door is opened for too long, and I’ll probably set this to something like 15 minutes. When the door closes, the lights turn off. The timer circuit also resets each time the doors are closed.

When the master is on, I can operate the lights with the dimmers as you would expect, but if a door is opened, the dome and that doors lights will turn on to full intensity regardless of the position of the dimmer knob.

If for some reason you want to have the door (or doors) open without the overhead lights on, there is an override button that will be next to the dimmer knobs. If you open a door, and then push this button, the overhead lights will stay off until the doors are all shut again, and then the override circuit will reset itself. The situation I see when this might be handy is if you want to taxi with the doors propped open on a hot night, and you don’t want to be blinded by the dome lights.

There is a master switch for the system that will be located in the baggage area. If the plane is going to be somewhere with the doors opened for a long period of time (say during an annual), I can flip this switch so that the system uses zero load. In normal operation, the system doesn’t draw on the battery at all, but if the doors are opened, and the lights have been turned off by the timer circuit, the system is still drawing a very small amount of current (in the millivolt range). Flipping the switch in the baggage area prevents that.

The system also provides “door ajar” annunciation to the G3X. Like I mentioned before, I have a pin switch on both door pins, on both doors, and on the baggage door. If any pin isn’t physically seated fully in the proper place, I will get the warning on the screen (and all the dome lights will be on!)

The relays and timer circuit will sit in a red project box that is going to be installed on the tailcone shelf. We’re calling this the LCU, for Lighting Control Unit.

All this might sound very complicated, and the circuitry that I came up with kind of is (at least for a newb circuit designer like myself), but the idea is that it will all just work in a very natural and expected way.

With all that said, tonight I began the construction of this system by building harnesses for the lights that sit in the overhead console inserts. I want the inserts to be fully removable, so the dimmer knobs, lights, and switches that install into these panels are wired up with molex connectors. Building these harnesses is what I got done tonight.

Here is a sample of the schematics that I came up with for the system. The first one is the wiring diagram for the lights and dimmers, including a plug that attaches to the LCU, and the second is the diagram for the LCU itself.

Lights Wiring Diagram

LCU Diagram

One thought on “Interior Lighting System, Part 1

  • March 15, 2015 at 12:31 PM

    My compliments on the quality of work you are doing on your project. you mentioned in another post you used a circuit design software in designing the light circuit. who makes or sells this software?

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