Electronic temperature control

摘要

An electronic temperature control circuit is disclosed for use with swimming pool and spa heaters. The circuit employs a thermistor for sensing water temperature, and provides temperature control with a narrow differential. Safety circuits are also employed to prevent injury to the user or to the heater in the event of a component failure. The temperature control circuit is provided with means for presetting two desired temperature settings and for selecting one of the preset temperature settings for control. Remote control circuits are also disclosed for use with the temperature control circuit which permit temperature selection, temperature setting and a visual indication of heater status from a location remote from the heater.