Patent ID: 7148633

Claim:
An DC/AC inverter for inverting a DC voltage source to an AC power source to drive a load, comprises: a half-bridge switch circuitry electrically connected to said DC voltage source and ground; a resonant tank electrically connected between said half-bridge switch circuitry and said load for filtering said AC signal to supply power to said load; and a controller, electrically connected to said half-bridge switch circuitry, feeding back an output of said load, and providing a pulse width modulation signal to turn on and off said half-bridge switch circuitry so as to allow said load to be operated close to said resonant frequency of said load, wherein said controller comprises: a driver circuit electrically connected to said half-bridge switch circuitry for providing two sets of driving signals to drive said half-bridge switch circuitry; a pulse width modulator electrically connected to said driver circuit for providing a pulse width modulation signal to said driver circuit so as to generate said two sets of driving signals; and a frequency generator electrically connected to said driver circuit and said pulse width modulator for generating a triangular wave signal and a pulse signal to said pulse width modulator and said driver circuit respectively such that said pulse width modulator generates said pulse width modulation signal based on said triangular wave signal, wherein both said triangular wave signal and said pulse signal have the same frequency.