Carbot 2

The creatively titled Carbot 2 is born! This bot uses the same Miller Solar Engine circuit as the previous Carbot, but some changes were made. I wired six 1V 30mA solar panels in series to produce 6V @ 30mA. A 2.2uF timing capacitor was used to give it adaquate spinning time, as the hefty spinner required it! It was constructed from brass rod and large plastic beads. The sun reflects off them quite nicely.

Originally I was planning on using three 4700uF storage capacitors in series to achieve 14,100 uF, but I only had two! I was worried that two would not be enough capacitance to spin this bulky spinner, so I opted to use what I had lying around: three .3F 2.7V supercapacitors in series, which equals .1F @ 8.1V. In this configuration, the bot takes about 30 seconds of charging in full sunlight before it begins to spin every few seconds.

The solar panels are held together with hot glue and jumbo paperclips, which is connected to the main chassis and motor by E6000 and tension. I would have preferred to build this bot with more toughness, but I ran out of time, as it was a Christmas gift. Also, as a stationary spinner, it will not see too much action!

As 131 triggers are hard to come by these days, i instead used the MCP112 equivalent drop-in IC (MCP112-450E) which triggers at 4.38V. The higher trigger voltage points gives the motor enough juice to get spinning.