| 摘要 |
PROBLEM TO BE SOLVED: To perform frequency control of an inverter output to be supplied to an oscillatory compressor, by enabling a power unit to automatically cope with power voltage which changes widely, and enabling it to judge the drop of battery voltage regardless of wide input, and further more, enabling it to let one side of an oscillatory compressor go to the ground, and also detecting the waveform of the inverter current surely and accurately regardless of the fluctuations in the frequency. SOLUTION: As DC power source, a battery 2 and a power source, where commercial power is converted into DC are selectively switched and connected. An inverter 6 converters a DC into an AC by the alternate switching of two pieces of switching elements, and the controller 7 controls the AC output to be supplied from the inverter 6 to an oscillatory compressor 1. A DC/DC converter 17 controls the output voltage to a fixed value regardless of the change of input voltage, whereby it enables the supply of AC output at a fixed voltage value to the oscillatory compressor 1, with respect to any of plural kinds of commercial power sources which are different in voltage and plural kinds of batteries which are different in voltage. |
