This week Nicola Carpeggiani and I worked on a simple solar powered BEAM robot for out energy assignment. We started with a schematic for a BEAM project that stores up solar energy in a capacitor until it has enough voltage to pass through a voltage regulator and trigger a motor through a transistor.
We added a Potentiometer which combined with a capacitor seemed to create a RC timer with the smaller capacitor charging and releasing voltage at a relatively constant cycle. Ultimately we had some difficulty getting constant performance but we attribute this to some mechanical and fabrication issues as our testing on a breadboard suggested that the circuit was working as intended.
We were able to get it to work briefly out in the sun.
We used two 2200 microfarad capacitors and a smaller 47 microfarad capacitor for the RC timer. With each panel under well lit conditions we wear able to generate 6 Volts and 40 milliamps.
The original schematic came from (Solarbotics) as part of Jeff Feddersen’s Energy class at ITP.