| 摘要 |
PURPOSE:To reduce leakage current, by changing the capacity of earthing capacitors of a noise filter to one suitable for each conducting time such as the driving time of a compressor motor. CONSTITUTION:A compression cooling device loaded with an inverter device 9 is composed of a noise filter 2, a power factor reforming reactor 6, a voltage doubler rectification circuit 7, a smoothing capacitor 8, etc., by which a compressor motor 10 is driven. A switch 16 is provided to the noise filter 2 to turn ON and OFF the 1st-2nd connection capacitors 14-15 and the 2nd connection capacitor 15. The switch 16 is controlled by a control circuit 17 comprised of a microcomputer, etc. The compression cooling device thereby judges whether or not the compressor motor 10 stops driving. When it is driven, the switch 16 is turned ON and the charge and discharge current from a floating capacitance 11 is caused to return to the power supply side and to reduce the leakage current flowing through an earth wire E. |
