A drive circuit for driving a piezoelectric transformer capable of reducing heat generated from an electronic component constituting an inverter circuit

摘要

A boosting circuit for supplying first and second primary electrodes of a piezoelectric transformer having a main drive voltage, a frequency control circuit having a normal frequency sweep range, and a drive voltage for controlling input power of an input DC voltage supplied to the inverter circuit In a drive circuit for a piezoelectric transformer having a control circuit, an overvoltage protection circuit detects an overvoltage at the output AC voltage from the piezoelectric transformer. Upon detection of an overvoltage at the output AC voltage, the overvoltage protection circuit supplies a frequency control circuit having an additional reset signal and a switch signal, and switches the frequency control circuit switch from a normal frequency sweep range to a temporary Frequency sweep range. The switching signal may be supplied to a drive voltage control circuit to cause the drive voltage control circuit to reduce the input power of the input DC voltage.