I experimented with a number of power-smart head circuits on the breadboard, but none seemed as simple and reliable as the bare-bones photo head. However, I wanted to try one of the power-smart heads, so went ahead and built this one.
This is a solarized power-smart head. It’s based on a 74AC240, with two storage capacitors (the big silver cylinders), and photodiodes for “eyes”. The solar engine is free-formed to lie over the IC. The motor is a Nihon gear motor from a lens assembly (courtesy of Fair Radio Sales), epoxied into a base made from hard drive motor parts.
This head works pretty well, but looks a bit ugly. It’s harder to position the components around the cylindrical motor than the nice cuboidal Omron units.