JPH01104691U - - Google Patents

Description

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of this invention. FIG. 2 is a diagram showing the structure of the magnetron 400 shown in FIG. 1. FIG. 3 is a diagram showing voltage waveforms at various parts of the high-frequency heating device shown in FIG. 1. FIG. 4 is a circuit diagram showing an example of a conventional high frequency heating device. FIG. 5 is a circuit diagram showing another example of a conventional high-frequency heating device. In the figure, 1 is a commercial power supply, 3 is an output setting means, 100 is a rectifier and smoothing circuit, 200 is an inverter circuit, 201 is a switching element, 202 is a drive transformer, 203 is a resonant capacitor, 400 is a magnetron, 500 is a control circuit, 601, 602 and 603 are rectifying and smoothing diodes, coils and capacitors, respectively, and 604 is a magnetic field generating coil.

Claims (1)

[Claims for Utility Model Registration] A DC power supply, a transformer whose primary winding receives the output of the DC power supply, a switching element interposed between the primary winding and the DC power supply, and a switching element inserted between the primary winding and the DC power supply. a resonant element that cooperates with the primary winding to form a resonant circuit and generates a resonant voltage across the primary winding when the element is turned off; an inverter that induces a high-frequency voltage on the secondary side of the transformer by resonance; a magnetron that is driven by applying the secondary output of the transformer directly between the cathode and the anode; and a secondary output of the transformer. A high-frequency heating device comprising a control circuit that detects the operating cycle of the inverter based on the operating cycle and thereby controls on/off of the switching element in synchronization with the operating cycle, the magnetic field provided in the magnetron. a generating coil; and a secondary output of the transformer is rectified and smoothed and applied to the magnetic field generating coil, and the transformer is configured to rectify and smooth the secondary output of the transformer, and to apply the rectified and smoothed secondary output of the transformer to the magnetic field generating coil. A high-frequency heating device characterized by comprising circuit means for increasing or decreasing the energizing current of the magnetic field generating coil in accordance with fluctuations in the secondary output.