| 摘要 |
PROBLEM TO BE SOLVED: To provide a capacitor-charging apparatus of simple circuitry which does not require two independent circuits for detecting both the average current level and the peak current that flow to the primary side of a transformer. SOLUTION: A current is induced in the secondary winding of a transformer 7 by turning a DC current applied to the primary winding thereof on/off through a switching element 3, that current is smoothed and rectified and then supplied to a capacitor (not shown), thus charging the capacitor. In such a capacitor-charging apparatus, the DC current is generated by a power factor improving circuit 6, on/off control of the switching element 3 is performed at a PWM control section 11, and a current transformer, having the primary connected in series with the primary winding of the transformer 7 and the secondary connected with a CT circuit detection circuit section 1, is provided. The CT circuit detecting circuit section 1 extracts a voltage proportional to the average current flowing through the primary winding of the transformer 7, and a voltage proportional to the peak current flowing through the primary winding of the transformer 7. COPYRIGHT: (C)2008,JPO&INPIT |
