Solar tracker
Hi meyrickt,
I guess that tracker won't work well. I didn't spy sensors yet.
Here is a circuit with enough sensitivity even on hazy days. It uses 10mm red LEDs with a clear dome as sensors. With no direct sunlight the output voltage is about 25mV, good enough for an amplifier for a useful signal.
The circuit I suggest takes care of both, azimuth and elevation angle for the panel to track the sun.
Attached is a complete schematic and also a layout. The files were created using Eagle version 4.16, but can be importet to the latest version (5.0) without problems. The board size exceeds the restriction of the free version, but due to programmmer's error a ready made circuit can be loaded as is.
If there are any questions about how to adjust the circuit don't hesitate to PM me. The relays used fit into a modified DIL16 socket and that way they can easily be replaced in case the contacts burn off. Max. load is 2A at 24V.
Regards
Hans
P.S. I have also designed an automatic "homing circuit" which moves the panel towards the "sunrise position" after sunset. The time when to start moving depends on the twilight duration and that circuit takes care of that by programming the homing timer accordingly.