| 摘要 |
PURPOSE:To improve the power factor by flowing an in-rush current through a parallel circuit of a choke coil and a surge voltage absorbing resistor, thereby suppressing a current peak value. CONSTITUTION:An AC voltage is applied from an AC power source 1 to input terminals A, B, a capacitor 4 is charged by a positive voltage by a circuit of an input terminal A, a parallel circuit of a choke coil 7 and a resistor 8, a terminal A', a diode 2, a terminal C', the capacitor 4, a terminal B' and an input terminal B, and a capacitor 5 is charged by the next negative voltage. Thus, a DC voltage of approx. double of the peak value of an AC voltage is supplied to a load 6. The impedance of the resistor 8 is sufficiently larger than the coil 7, and an in-rush current flows almost through the coil 7. Accordingly, the conducting angle increases, and its peak value is suppressed. The resistor 8 serves as a surge voltage absorber when the diodes 2, 3 are cut OFF. |
