INVERTER CIRCUIT OF MICROWAVE OVEN FOR SHORTENING INITIAL OSCILLATION TIME AND MONITORING OPERATING STATES THEREOF

摘要

PURPOSE: An inverter circuit of a microwave oven is provided to prevent a variation of outputs of an inverter and the noise of the inverter by shortening an initial oscillation time. CONSTITUTION: A microcomputer(20) outputs a PWM signal corresponding to a user setting voltage. A first comparator(30) is used for comparing a present voltage level with a predetermined reference voltage. An integrator(40) outputs a voltage having a predetermined level corresponding to a high signal of the first comparator. An initial oscillation controller(90) is used for consuming an output voltage of the integrator when the present voltage level is less than a level of the PWM signal of the microcomputer. A PWM controller(50) is used for outputting a driving signal of a magnetron by controlling a switching frequency of a switching element. A driver(70) is used for driving the magnetron according to the driving signal of the PWM controller.