Temp. control system for wall mounted gas burner - uses thermistor to sense temp. to control motor driving water thermostat for max. fuel economy

摘要

A thermistor acting as a temperature probe senses actual room temperature and provides a signal for a comparator. A programmer provides a control input for the comparator while an indicator signals the desired temperature. The comparator controls a changeover switch to provide a tri state signal for an electric motor. This causes the motor to operate in the forward, reverse or stop condition to control the setting of a water thermostat. This control ensures that the water temperature is not excessively high when the desired air temperature condition is achieved and thus reduces fuel input required. A potentiometer signals the motor position to the comparator while a safety circuit signals and of travel for the motor.