WB0SMX

  Differential Temperature Controller Filed in homebrew on May.03, 2014 We had a need to control the temperature inside of our Solar Equipment Bay up at the Ranch. The Bay sits outside on our porch, and for some hours during the day, the sun shines directly on it. When this happens the interior acts like an oven, quickly heating up and subjecting the charge controller and inverter to temperatures that approach their maximum rating. We decided that part of the solution would be ventilation fans installed on the enclosure. We didn’t want the fans to run full time, since this is a solar system, and total power is limited by what we generate. Also, it didn’t make sense to allow the fans to turn on when outside temperatures were higher than inside temperatures. So I thought that a differential temperature controller would be ideal.   In Operation With this system, the fans would stay off as long as the temperature inside the box was below 80 degrees, or when the inside temper