| 摘要 |
PURPOSE:To attain a temperature control with high accuracy and to prevent a fire from taking place, by detectig overheat of all parts of heater wires for attaining a suitable temperature control, in a device for warming seats of a car and a bed. CONSTITUTION:When the temperature of heater wires of a tubing heater is lower than a set value, the static capacitance of a dielectric 9 is small and when it is discriminated that the static capacitance between the heater wire 10 and electrode wires 8 is smaller than the set value, an output of a timer 35 is inverted for applying power to the heater wires to reach the set temperature. If the temperature of the heater wires exceeds the set value and a part of the heater wires is overheated, a capacitance value discriminating circuit 14 discriminates that the static capacitance between the heater wires 10 and the electrode wires 8 is larger than that of the set value, the inversion of the output of the timer 35 is stopped, the power applied to the heater wires 10 is stopped for lowering the temperature of the heater wires 10 to the set value. |
