| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce electric power using a circuit in an air conditioner, even if the insulation of a sensor is deteriorated while electric leakage cannot be detected, for example, when no earth leakage circuit breaker is installed on an indoor wiring system, when a temperature of a heat exchanger of the air conditioner including a control circuit constituted of a non-insulating power supply is detected by a contact temperature sensor with a metal case. <P>SOLUTION: In a temperature sensing device, a temperature sensor 12 having the metal case is equipped with a control power supply 14 non insulated from an AC voltage and provided in the vicinity of a discharge part of the heat exchanger or a compressor, one terminal of the temperature sensor is connected to the control power supply via a first resistor 29, the other terminal is connected to ground via a second resistor 30, and any one of the terminals of the temperature sensor is connected to a microcomputer 11 via a third resistor 31. The microcomputer performs A/D conversion to detect a temperature. An impedance of the ground as seen from each terminal of the temperature sensor is set to be equal to or more than a value obtained by dividing the square of a power supply voltage by 80. <P>COPYRIGHT: (C)2012,JPO&INPIT |
