HIGH-FREQUENCY HEATING POWER SUPPLY DEVICE

摘要

There is provided a high-frequency heating power supply device for driving a magnetron such as a microwave oven. It is possible to provide a frequency modulation method for suppressing high-frequency current generated by high-frequency switching operation. When supplying a DRIVE signal for driving a first semiconductor switching element (3) and a second semiconductor switching element (4), the inverter operation frequency for each commercial power supply phase is supplied with a frequency difference (inclination) of phase 0 to 90 degrees by a triangular wave generation circuit in an oscillation circuit (16). The modulation waveform for frequency modulation control is formed by setting the upper limit clamp, the lower limit clamp, and the lowest value equivalent to the lowest frequency by the frequency modulation generation circuit (15) according to the commercial power supply division waveform after rectification. By optimally combining these, generation of higher harmonic current is suppressed while forming a frequency modulation waveform capable of absorbing various irregularities such as an inverter main circuit parts constant and a power source (Vcc) of drive control IC unit (14).