Patent ID: 7838803
Filing Date: 2010-11-23
Classification: H05B

Abstract:
1. Apparatus for controlling an electric heater having a heating elements capable of producing heat for heating a room when connected to a house a.c. power source, the apparatus comprising: a) a thermostat system including a temperature sensing device which produces a signal related to air temperature in the room, b) said thermostat system including temperature comparison circuitry providing a comparison of the air temperature in the room indicated by the temperature sensing device signal with a user set point temperature, c) processing circuitry operatively coupled to said thermostat producing an output corresponding to a power gating signal, d) a semiconductor power gating device for gating power from the house a.c. power source to the heating elements, the gating device receiving said power gating signal and conditionally gating the house a.c. power to the heating elements, e) said processing circuitry determining a percentage or fraction of maximum power from the house a.c. power source to be applied to the heating elements by controlling the application of the gating signal to the power gating device, the percentage or fraction of maximum power slowly being varied based upon the comparison of the temperature of the room with the set point temperature, f) said processing circuit changing the output gating signal to the power gating device at intervals of time less than a normal hysteresis time interval of the temperature comparison circuitry.