2DOF Beam Solar Tracker

This 2 degree of freedom solar tracker is powered completely by the sun - no batteries here! A 6v 200mah solar cell charges a 10,000uF capacitor, and a driving circuit drives two gearmotors accordingly. Four infrared phototransistors serve as sensors. The frame was laser cut from hardboard. More info to come!

Background

For my first journey into BEAM robotics I thought I would make a solar tracker. I decided to use Wilf Ritger's schematic shown below.

Motors are probably one of the most important parts of a robot like this. Ungeared motors don't have enough torque to work reliably, so I chose some gearmotors from BG micro.

Next I designed a model of the robot in Solidworks. The hardest part of any kind of motored robot is the mounting of the motor shaft. My paticular motor had a 2mm shaft, so I came up with the idea of using a RC airplane propellor saver to screw on to the shaft, and having the robot parts attached through the screws. It worked great!


Dead bug construction of the circuit:

First prototype. Frame is laser cut from hardboard. The solar panel is rated for 5v 100ma, however it didn't have enough juice to move it like I wanted. Later I ordered and used a 6v 200ma panel which worked just great.

Here is a PCB of the circuit, not yet tested.