| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inverter circuit that maintains fundamental-wave components included in a full-bridge output waveform to be a fixed value, regardless of the variations in the input voltage. <P>SOLUTION: The output of a full-bridge circuit 2. connected to an input voltage source 1, is applied to a piezoelectric transformer 4 so as to make a load 5 operate by the output of the piezoelectric transformer 4. The duty of the full-bridge circuit 2 is controlled by a drive circuit 6. A DC voltage from the input voltage source 1 is divided into a prescribed ratio by a voltage divider 7. Voltage-divider output is introduced into a full-wave rectification generator 10, while a full-wave rectification waveform of a sine wave, based on the voltage-divider output, is generated so as to input it to a comparator 9. A reference voltage that is a minimum value of the voltage-divider output is generated by a reference voltage generator 11, and this input to the comparator 9. A rectangular wave is obtained by comparison between the reference voltage and the full-wave rectified waveform of a sine wave in the comparator 9, while the rectangular wave is input to the drive circuit 6, and duty control of the full-bridge circuit 2 is carried out.. <P>COPYRIGHT: (C)2008,JPO&INPIT |
