WALL MOUNTED MICROWAVE OVEN

摘要

PURPOSE: A wall mounted microwave oven is provided to drive a hood motor upon turning-on of a hood thermostat even when the micro computer has problems. CONSTITUTION: A hood driving circuit comprises a power supply unit(5) for supplying power to a hood motor(10), the hood motor formed of an AC motor, and a switching unit(15) for switching the power supply to the hood motor. The switching unit includes a triac(18) installed at the power line between the power supply unit and the hood motor and which controls power supply, a voltage charging unit(19) for controlling the power supply to the triac, and a diac(17) for supplying a turn-on signal to the triac when the charged voltage of the voltage charging unit reaches a predetermined level. The voltage charging unit includes a capacitor(16) installed at a bypass power line(11) branched from the front end of the triac and connected to the rear end of the triac, and a variable resistance(12) connected to an external operational knob and which cooperates with the capacitor to control the time constant of current being supplied to the hood motor in accordance with the control of the operational knob. The power line connecting the front and rear ends of the variable resistance of the bypass power line, is provided with a resistance(14) and a hood thermostat(13) which is turned on/off by the result of sensing the heat or smoke within the hood duct.