PURPOSE: To enhance heating efficiency by driving a matching element in a waveguide tube, and generating an optimally matched condition for each item of foods.
CONSTITUTION: A waveguide tube 5 is provided whose one side is connected with a magnetron 3 and other side is connected with a heating chamber 1, and a matching element 10 for adjusting the impedance matching of the magnetron with the heating chamber is installed at one of the walls of the waveguide tube 5 on its side with connecting part to the heating chamber. A directional coupler 6 is installed at one wall of the waveguide tube between the magnetron 3 and element 10, and a driver device 13 is provided which rotates the supporting shaft of the matching element of coupler and emits information about a plurality of predetermined drive positions during the driving process. A control device 14 first actuates the driver device after the start of the heating, takes in and stores the sensing signal of the coupler for each of a plurality of predetermined rotational positions, selects an appropriate one of the stored sensing signals which is used to determine the optimum stop position of the driver device, and drives the matching element supporting shaft to the driving position according to the selected signal.
ARAI TATSUSHI
TACHIKAWA TERUYUKI
ANAMI FUMIMASA
KIMOTO KAZUHIKO
KYUSHU ELECTRIC POWER