Safety circuit for microwave oven - has fuse in series with relay coil and resistor

摘要

The safety circuit has a monitoring switch monitoring the switch position of the door switch and connected in series with a resistor in parallel with a relay circuit. A fuse is connected in series with the relay circuit. The door switch opens when the oven door is opened and thereby disconnects the supply from the microwave oscillator. A second switch may also be incorporated and operated by the oven door. The relay circuit consists of a relay excitation coil in series with a resistor. The resistor is shunted by a capacitor. The relay contacts disconnect the supply and are accordingly connected to the microwave oscillator's h.v. transformer.