As the door is closed, the contact of MONITOR SWITCH opens. This switch creates the short circuit to blow monitor fuse during operation under abnormal condition. (ie, should the contacts of primary and secondary switch fail to open the circuit) The latches are secured by latch board. The oven light turns on while the oven is in operation.
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A high voltage of approximately 2100 volts AC, is generated in the secondary of the high voltage transformer which is increased by the action of the diode and charging of the high voltage capacitor. The negative DC voltage is then applied to the filament of the magnetron.
WHEN COOKING POWER LEVEL AND COOKING TIME ARE SET
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WHEN THE DOOR IS OPENED DURING COOKING
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The contacts of the timer switch changes to ON position. WHEN THE TIMER KNOB IS ROTATED. (While power control knob is set at "Full Power")
Both primary switch and secondary switch open to cut off the primary winding voltage to the high voltage transformer to stop microwave oscillation. Timer, turntable and fan motor stop. As the door is opened, if the contact of primary switch fail to open, the monitor fuse opens due to the large current surge caused by the monitor switch activation which in turn stops magnetron, oscillation.
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The contacts of the secondary switch close the circuit. Input Volts AC. is applied to the high voltage transformer through power control switch as shown by the solid line.
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POWER PRIMARY TIMER CONTROL SWITCH SWITCH SWITCH
RELAY H.V.T FUSE
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POWER PRIMARY TIMER CONTROL SWITCH SWITCH SWITCH
RELAY H.V.T
FUSE
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MONITOR FUSE MONITOR RESISTOR MONITOR SWITCH
MONITOR FUSE MONITOR RESISTOR MONITOR SWITCH
SECONDARY SWITCH
SECONDARY SWITCH
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Turntable rotates. The fan motor rotates and cools the magnetron by blowing the air (coming from the intake on the backplate) over the magnetron. The air is also directed into the oven to exhaust the vapor in the oven through the upper plate. Timer starts rotating. 3.2 volts AC. is generated from the filament winding of the high voltage transformer. This 3.2 volts is applied to the magnetron to heat the magnetron filament through two noise preventing choke coils.
