Patent ID: 6239992
Filing Date: 2001-05-29
Classification: H02M,Y02B

Abstract:
An electric power unit for use with a load and for use in feeding electric power to the load, said electric power unit comprising:an alternating current power source;a bridge-type rectification circuit having an input from said alternating current power source and including diodes in bridge connection;a series circuit of a reactor and a diode connected to one output of said bridge-type rectification circuit and to be connected between said one output of said bridge-type rectification circuit and the load so as to flow a load current in a forward direction;a smoothing capacitor to be connected in parallel to the load; andan auxiliary capacitor connected in parallel to an output of said bridge-type rectification circuit, the capacity of said auxiliary capacitor being chosen to be small enough in comparison with the capacity of said smoothing capacitor, andwhereby charging to said auxiliary capacitor is started sufficiently earlier than charging to said smoothing capacitor in a cycle of said alternating current source.