| 摘要 |
<p>PROBLEM TO BE SOLVED: To inform a user of a malfunction of a power circuit by providing a controlling means which inputs the output of an input voltage monitoring means and the output of an output voltage monitoring means, and stops control of a harmonic current suppressing circuit when the harmonic current suppressing circuit malfunctions. SOLUTION: A control circuit 8 inputs the output signal AC-LOW of an input voltage monitoring circuit 9 for monitoring the output of an AC input line and the output signal PF-LOW of an output voltage monitoring circuit 10 for monitoring the output voltage of a harmonic current suppressing circuit 4, and outputs ON/OFF signals for changing-over a battery input switch 7, and a PF-ON signal for controlling the controlling element 11 of the suppressing circuit 4. The control circuit 8 monitors the output voltage of the suppressing circuit 4 by the monitoring circuit 10, and judges by the PF-LOW signal whether it is an operable voltage for a direct-current-to-direct-current converter. Consequently, danger is prevented, and it is possible to inform a user of a malfunction of a power circuit.</p> |
