| 摘要 |
PURPOSE:To prevent the malfunction of a heat-sensitive element which is caused by the switching of a switch for an electric heater carpet, etc., by providing a detecting electrode for temperature on the heater contact surface that is connected in common to the heaters connected in parallel to each other and a detecting electrode for temperature on the heater contactless surface to which a diode is connected. CONSTITUTION:Heat-sensitive elements 6 and 6' are provided in contact with heaters 2 and 2' via an insulated layer 7. The detecting electrodes 5b and 5'b for temperature on the heater contact surface of the elements 6 and 6' are connected to the heaters 2 and 2' via common line 13 as well as to the terminal C of one side of a temperature detecting circuit. At the same time, the detecting electrodes 5a and 5'a for temperature on the heater contactless surface are connected to a power supply via the voltage dividing capacitors C1 and C2 as well as to the terminals 10a and 10a of the other side of the temperature detecting circuit via the diodes D1 and D2. Thus the electrodes 5a and 5'a are set at the outflow side of the current. In such a way, a current i'2 caused by the induced voltage due to the switching action of a switch is flowed to the ground via the the line 13, and accordingly, no error is caused with respect to the conduction currents i1 and i2 of the elements 6 and 6'. Thus the detection of temperature is possible in a normal way. |
