Greenwatts

Solar Tracker CDS Circuit(NEW)

This solar tracking circuit features a further simplified design and very accurate tracking. It provides fully automated solar tracking including morning reset to the east, automatic reset for cloudy periods and brightness tracking to optimize solar PV performance on cloudy days. We have also simplified the sun sensor array.

The circuit consist of clear green GaP LEDs for the sensor array which feed the positive and negative inputs to a operational amplifier (op-amp) voltage difference circuit. The output of the op-amp biases a PNP/NPN push/pull transistor curcuit which in turn drives the solar tracker DC motor either forward (west) or backwards (east). This latest circuit no longer uses a CDS cell in the feedback portion of the circuit. A zener diode on the PNP transistor dampens the east motor direction and prevents oscillation.

We are currently testing the circuit on our solar tracker #3. We will post a parts list and resistor values after we finish testing the circuit.