| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a direct current detecting device that can provide sufficient responsiveness and can reduce the cost. <P>SOLUTION: An amplifier 21 amplifies a detected current signal representing output current of an inverter. A filter 31 attenuates the frequency component of alternating-current power generated by the inverter in the detected current signal amplified by the amplifier 21. An amplification/bias circuit 32 amplifies the output of the filter 31 and further adds a bias to the amplified signal. A zero cross detector 24 detects timing when the alternating-current power generated by the inverter becomes zero. A CPU 33 converts the output of the amplification/bias circuit 32 into digital data, and integrates the digital data over one cycle period of the alternating-current power. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
