| 摘要 |
PURPOSE:To eliminate positive-negative asymmetry of AC output caused by voltage ripple, by a method wherein a switching element is controlled by logical processing of signals from a pulse-width modulator into which a DC source voltage feedback pulse is put and from a distributor which generates a current application mode signal. CONSTITUTION:A load 42 is connected between a DC source 34 and an invertor main circuit 40. Chemical capacitors 32a, 32b of the source 34 are connected to voltage frequency converters 44, 46. The output signals from the converters 44, 46 and from a distributor 52 which generates a current application mode signal in accordance with a frequency control signal are put into a pulse-width modulator 60 through gates 54, 56, 58 so that transistors 38a, 38b are controlled. Thus the DC source is divided into two source and each of them operates alternately in accordance with the polarity of the output and the average value of the output voltage is controlled at a constant value regardless of the ripple of the source by receiving a pulse-width modulating signal from a voltage feedback pulse so that asymmetry of the output is eliminated. |
