| 摘要 |
PROBLEM TO BE SOLVED: To shorten a defrosting time by operating a motor with low efficiency. SOLUTION: An air conditioner comprises a motor 11 for driving a compressor, an inverter 20 for switching the pattern of voltage applied to armature coils 1a, 1b and 1c of the motor and a microcomputer 4 for controlling the output of the inverter 20. The microcomputer 4 outputs a switching signal to the inverter 20 so as to obtain a high efficiency or a low efficiency based on the input current or output current of the inverter 20. While the output of the inverter 20 is controlled so as to obtain the high efficiency during an ordinary operation, the output of the inverter 20 is controlled so as to obtain the low efficiency a during a defrosting operation. Accordingly, during the defrosting operation, a motor current is increased to heat the armature coils 1a, 1b and 1c and raise the temperature of the discharge refrigerant of the compressor, so that the defrosting time can be shortened. |
