Feb 27 2011

Lighting Logic Controller

I finished installing the rotary switch circuit board into the panel and completed populating the parts onto the lighting logic controller circuit board I designed for the planes lighting system.  Overall, I am really pleased at how well it all turned out.  Exactly as I had envisioned the end product.

On the panel, LED’s shine into tiny light tubes embedded in the panel which directs the light to the front illuminating the switch position selection.  The switch position overall LED’s brightness is controlled by the panel dimmer.

The design purpose of this rotary switch is to reduce the overall number of switches on the panel.  I combined 8 toggles switches to 1 rotary selector.   The picture above indicates the “Start” position, which is the most dangerous to ground personnel, so when selected, the beeper, wig wag lights, strobes, belly strobe all turn on at once.    Maximum awareness… “Warning Will Robinson”

After the engine start up, the selection is, “Taxi” which would be the next expected action.  When selected the beeper and all strobes turn off,  the taxi/landing/wing belly beacon activate.  When you get to the end of the runway one selects “Day Landing”  (and takeoff) and so forth through the different regimes of flight such as  “Day” flight, “Night Landing” (and take), “Night Flight” and lastly flying in the “Clouds” (at night).    Each position activates the desired combination of lights.

A long time ago I was always amazed at how complex an aircraft instrument panel looked.  Lots of switches and breakers.  Why?   Now look at a fine car, there is none of that sh*t.   I think the modern car turn signal stalk is a work of design/engineering art.  Think about it it…. it turns you wipers of in all sorts of modes and speeds, has a button to wash the windshield, selects the Hi/Lo beams, flashes a car in the daytime  AND activates your turn signals.   So cool.

When I was a kid my dad was amazed when our VW came with a turn signal which had a little button button on the back side to FLASH the high beams.  I think it was a German thing for the Audubon to indicate you wanted to pass someone.  What a long way the simple turn signal switch has come.

Since the pilot ALWAYS activates (or should activate) a combination of light for best positional awareness for other planes, and for different types of flights, then why not build something which “automates” the process.   Why not simply the panel if I could?

The lighting logic controller is a simple relay board with diode isolators.  You can add/change the light combinations by changing diodes.  Sort of like programing a simple computer.   There are 8 relays each rated at 10 amp / circuit.  A 12 pin plug on the board mates into the plane’s lighting wiring.   I added a yellow LED light for each relay to show when it is activated to allow me to bench test the board.

If you would like to see how the circuit works, click on this link:  Logic board controller


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