| 摘要 |
PURPOSE:To improve the power factor of a circuit to limit the flow-in of a reactive current, by providing plural capacitors for advancing the phase of an input current in parallel with a transformer for boosting of the input voltage and inserting or removing them selectively to or from the circuit. CONSTITUTION:For example, a commercial voltage is applied to input terminals 2 and 4, and a high voltage induced in a secondary coil 10 of a leakage transformer 8 is subjected to full-wave rectification in a circuit 12 and is applied to a capacitor (C) 16. A flash lamp 20 is discharged momentarily by electric charge charged to the C16 to perform fixing. An input current phase advancing means 36 and a controlling means 38 for the means 36 are provided in the input side of the transformer 8. The means 36 consists of Cs 24, 26, and 28 for advancing the phase of an input current and switch means 30, 32, and 34 which insert these Cs to the circuit selectively. The means 38 detects the change of the input current subjected to full-wave rectification in a circuit 40 and controls switching of means 30, 32, and 34 through a switching circuit 50. Since the advanced input current value is controlled in this manner, a delated input current is limited effectively. |
