| 摘要 |
<p>This invention aims at stabilizing the operating frequency of a compressor so as to prevent hunting in noise and improve the durability of the compressor. A means (41) for controlling the operating frequency of a compressor (1), and a resistor (R2) for detecting an electric current flowing in the compressor (1) are provided. A means (42) for reducing a frequency step (N) of a compressor motor (MC) at a predetermined speed when the supply current from the compressor motor (MC) has reached a predetermined level (Is), and a frequency holding means (43) for terminating the frequency step reducing operation of the frequency reducing means (42) when the supply current from the compressor motor (MC) has been reduced to the predetermined level (Is), and holding the current frequency step (N) until a predetermined period of time has elapsed are also provided. In addition to these means, a means for increasing the frequency step (N) at a speed lower than the above-mentioned predetermined speed until a predetermined period of time has elapsed when the frequency step holding operation of the frequency holding means (43) has finished, so that the supply current from the compressor motor (MC) reaches the predetermined level (Is) is provided.</p> |
