Driving circuit for inverter microwave oven

• Main Authors: KODAMA; HIROKAZU, MINAMINO; KOUJI, OKAMOTO; MITSUO
• Format: Patent
• Language: English
• Published: 19.01.1993
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; BLASTING; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GENERATION; HEATING; LIGHTING; MECHANICAL ENGINEERING; OTHER DOMESTIC STOVES OR RANGES; RANGES; VENTILATING; WEAPONS

A driving circuit for an inverter microwave oven which includes a push-pull voltage type inverter circuit having two sets of switching element groups each provided with more than two switching elements connected in parallel to each other for switching the D.C. current supplied from a D.C. power source, a control device arranged to set a period for simultaneously turning OFF the two sets of switching element groups and to alternately turn ON the switching element groups by the same duty cycle, a step up transformer supplied, at its primary winding having a center tap, with A.C. current from the inverter circuit, and a voltage doubler rectifier circuit connected to a secondary winding of the step-up transformer for supplying electric power to a magnetron through a capacitor. The driving circuit is set so that one half period of a waveform of current flowing through the switching elements becomes equal to the duty cycle by adjusting the leakage inductance of the step-up transformer, the capacitance value of the capacitor and the circuit resistance of the voltage doubler rectifier circuit or the duty cycle of the switching elements.