Voltage regulator - part 2

I spent a couple hours testing the voltage regulator at 4 different input voltages (9v, 18v, 27v, and 36v). Using a spreadsheet, I recorded the output voltages generated using increasing values of resistance, as set by the potentiometer.

The most interesting thing to come out of this exercise was finding out how stable and precise this device is. As you’ll see in the video, the voltage is precisely controlled by the circuit regardless of the input voltage. 

Testing the stability of the prototype circuit board

On the heels of this successful test, I built a circuit board from a Radio Shack blank on which I soldered all the components, and a few connecting wires. This is a temporary arrangement designed to allow me to test the circuit with the actual load it will see in operation. 

The final version of this board will be chemically etched, and no extraneous connecting wires should be necessary. A proper enclosure will need to be found, including switches, lights, and other knick-knacks.

Testing the "pre-production" circuit board with a load

One additional idea that I am considering, is somehow tying the voltage regulator to the airspeed. 

This could be done via EFIS signal, or a simple airspeed switch, so that turning on the pitot heat on the ground would only bring about 150℉ (65℃) perhaps, using the 3.5v circuit, and once a certain airspeed is reached (flight mode), the 4.5v circuit could be automatically selected, generating 220℉ (104℃). 

Back on the ground after a flight, if the pilot accidentally forgot to turn the pitot heat off, the system would automatically return to low heat mode preventing any damage to the nose of the plane, or to anyone who might accidentally come in contact with the pitot tube.