| 摘要 |
PROBLEM TO BE SOLVED: To dispense dedicated power supply circuit or switch element by providing an exchange valve driver for switching the DC voltage of an inverter to the polarity corresponding to the operating mode of refrigeration cycle upon selection thereof and conducting the exciting coil of the exchange valve. SOLUTION: A refrigeration cycle is switched between cooling operation and heating operation through switching operation of a four-way valve and switching is driven through an exchange valve driver 21. The driver 21 uses a DC voltage from the rectifying section 51 of an inverter 23 as a DC voltage being applied to the exciting coil 49 of the four-way valve and it is arranged to control conduction polarity of the exciting coil 49 using switch elements 53U, 53V, 53W, 54X, 54Y, 54Z at the inverting section 52 of the inverter 23. An overcurrent detecting resistance 57 between the rectifying section 51 and the inverting section 52 is connected through an overcurrent detecting circuit 58 with a microprocessor 22 connected to a drive circuit 59. |
