Solar Tracker Circuit

Low Cost DIY Solar Tracker Circuit

LM339 Solar Tracker Circuit Parts List

Many of the components in the following parts list can be substituted with equivalent components such as using a AN6912 comparator instead of a LM339. We use 5mm clear green super bright LEDs with a 40deg viewing angle but any clear lens LED should work for the sensor. 1/4 or 1/2 watt resistors are adequate, fuses should be placed on each rail and a DPDT switch can be used also.

solar tracker schematic LM339
  • U1/U2 - LM339 quad comarator
  • Q1 - TIP42C Power Transistor
  • Q2 - TIP41C Power Transistor
  • Q3 - 2N3906 Transistor
  • Q4 - 2N3904 Transistor
  • R1 - 1meg ohm
  • R2 - 1k ohm trim pot
  • R3 - 10k ohm
  • R4 - 10k ohm
  • R5 - 10k ohm
  • R6 - 4.7k ohm
  • R7 - 2.7k ohm
  • C1 - 10n ceramic capacitor
  • M - DC motor up to 1amp
  • LEDs - 5mm 563nm Hi Green Water Clear