CONVERTER CIRCUIT TO WHICH SINE WAVE IS INPUTTED

摘要

A converter includes a rectifier 1 of the diode bridge connected across the alternating current power supply via an input filter F; a circuit 2 having an reactor L1, switching element Tr1, and the reverse current flow blocking diode D1 connected across output terminals of the diode bridge; a smoothing capacitor Cd charged according to an energy stored in the reactor L1; and a controller 3 arranged having a comparator 36 for comparing a signal of circuits 31 through 34 which detects a difference between the direct current output voltage Vd and the set (reference) voltage Vs and amplifies thereof with a triangular carrier wave 36 so as to control the transistor Tr1, the transistor Tr1 being controlled to be turned on or off according to the carrier wave frequency. When the transistor Tr1 is turned to ON, the energy is stored in the reactor L1 via the rectifier of the diode bridge 1. When the transistor Tr1 is turned to OFF, the capacitor Cd is charged according to the energy stored in the reactor L1. The current in the element Tr1 flows therethrough when the input voltage is low irrespective of the voltage across the capacitor Cd so that the input current provides the sinusoidal wave. <IMAGE>