Microwave oven energization circuit and components therefor

Abstract

A fan motor sequencing switch assembly is employed to effect delayed full power energization of a magnetron in a microwave oven for protecting the magnetron and energization circuit therefor against high start-up current surge and for cooling the magnetron during oven operation. The sequencing switch is connected in parallel with a start circuit consisting of a start switch and serially connected current limiting resistor, and is operated by an actuator movable by the magnetic field induced in the fan motor upon energization, the motor being connected to the start switch and sequencing switch for energization through either switch. In the preferred embodiment, the actuator is the rotor of the motor which is mounted for rotation and limited axial movement with respect to the motor stator and normally biased to a position with its magnetic center axially displaced from that of the stator, whereby upon energization of the motor, the rotor is caused to move axially by the induced magnetic forces in the rotor and stator to effect delayed actuation of the sequencing switch.

Dependencies are inferred from the claim text.