| 摘要 |
PURPOSE:To prevent an excessive inrush electric power when the switch of an electric space heater is turned ON by providing the electric space heater with a heater which has a positive resistance temperature coefficient, phase temperature control circuit, temperature sensor, and machine body sensor. CONSTITUTION:The main body 11 of a sunken electric foot warmer is provided with a PTC heater which has a positive resistance temperature coefficient and machine body temperature sensor 2 which lowers the continuity angle in a temperature control circuit when the temperature of the machine body rises. This electric space heater is also provided with a phase temperature control circuit and room temperature sensor 5 which lowers the continuity angle of the temperature control circuit when the room temperature drops. With an electric power switch 9 turned ON, the signal current flowing through the machine body temperature sensor 2, resistors 3 and 4, and room temperature sensor 5 charges a condenser 6 to raise the terminal voltage. When this voltages rises to the voltage of a pulse generating element 7 when the continuity is started, the charges stored in the condenser 6 is discharged and a pulse signal flows to the gate of a triac 8 to make the anode and cathode conductive so that electric current flows through a heater 1.
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