Abstract: An indirect and passive method for AC/DC converter power factor correction is disclosed. The correction is achieved by stabilizing the input impedance of the converter with keeping the inversely proportional dependence between the current iconv(t) and voltage uconv(t) of the output smoothing filter (3). The necessary dependence is achieved by natural characteristics of circuit with passive components. An uncontrolled converter (6) with alternation of parallel and series resonance is used as such circuit. To increase the operating frequency of this converter, a chopper or an inverter is used. The resonant converter decreases the commutation current of the switches. Output voltage is easy to control by pulse width modulation of chopper or inverter. Passive power factor correction results in the total harmonic distortion of main current THDi=10 to 40 per cent. All currents of the converter are limited naturally in all operating modes.

Abstract: An indirect and passive method for AC/DC( converter power factor correction is disclosed. The correction is achieved by stabilizing the input impedance of the converter with keeping the inversely proportional dependence between the current iconv(t) and voltage uconv(t) of the output smoothing filter (3). The necessary dependence is achieved by natural characteristics of circuit with passive components. An uncontrolled converter (6) with alternation of parallel and series resonance is used as such circuit. To increase the operating frequency of this converter, a chopper or an inverter is used. The resonant converter decreases the commutation current of the switches. Output voltage is easy to control by pulse width modulation of chopper or inverter. Passive power factor correction results in the total harmonic distortion of main current THDi=10 to 40 per cent. All currents of the converter are limited naturally in all operating modes.

Abstract: A controlled power supply in which an electric arc is used as a loading element. A single phase ac-to-dc invertor is provided with a matching transformer and a main rectifier and diodes which form the bridge and are connected to the matching transformer. The invertor has a controllable output. The bridge has a diagonal corresponding to an output of the rectifier and electrodes between which an electric arc can be initiated. a circuit for controlling the voltage across the electrodes includes a comparator to compare an actual rectified voltage with a reference value. The comparator provides for changing positions of the electrodes relative to each other. The single-phase ac-to-dc invertor is provided with two phase-shifting circuits that are connected in series and to the matching transformer. One of these phase-shifting circuits is a choke, whereas the other phase-shifting circuit is a capacitor. Each phase-shifting circuit is connected to a corresponding input of the main rectifier.