SINGLE-INPUT PHASE LOCKING PIEZOELECTRIC TRANSFORMER DRIVING CIRCUIT

摘要

A circuit (10) for driving a piezoelectric transformer (12) in a phase locked mode without using an external reference signal. The circuit (10) utilizes a 555 timer circuit operated in a stable mode which is responsive to a feedback phase signal (18) coupled from an output signal (20) of the piezoelectric transformer (12). The feedback phase signal (18) overpowers the trigger circuit of the timer to phase lock the timer to an output of the piezoelectric transformer (12) at a resonant frequency of the piezoelectric transformer (12). The circuit (10) provides a simplified phase lock circuit without the need for a typical PLL configuration.