On Sunday, June 9, 2013 10:11:54 AM UTC-6, wrote:
Some Venti (not all) featured an 8 position LED light-bar centered on the instrument panel hood which would identify flap position.



What "electronics" are used under the seat pan on the flap handle mechanism to "switch" the LEDs? Are there 8 individual reflective sensors reading the flap positions?

It's a simple switch-resistor-LED for each flap position. If you plan to use the gliders 12V bus, the LED's need the resistor. (FWIW, non-rechargeable lithium cells output 3.7V which is just right for an LED without resistor as millions of key-ring flashlights show.)

I know of three switch possibilities - Micro Switches, magnetic reed switches and Hall Effect devices. I really don't like Micro Switches since they need mechanical contact and so tend to wear out and get out of adjustment. Magnetic reeds and Hall devices don't require physical contact as they use magnetism instead. Reeds are typically glass so have to be installed carefully but if they are potted in epoxy, they work well. Some Hall Effect devices are inherently binary and very rugged. Both are cheap. I think Paul Remde sells suitable reeds.

The idea is to epoxy a tiny but strong NdFeB magnet to the flap push-rod in a convenient place with the reeds or Hall devices positioned to detect the magnet as it goes by. Each flap position gets it's own reed or Hall device.