| 摘要 |
9D-RG-16394 MAGNETRON WITH MICROPROCESSOR POWER CONTROL A microwave oven uses a full wave full bridge inverter for supplying energy to a cooking magnetron by way of a power transformer. The inverter is controlled by a microprocessor which acts upon a control circuit having an oscillator. The control circuit provides gating pulses which are used to switch on FET switches in the inverter. The microprocessor stops and starts the gating pulses. The microprocessor may adjust the power of the magnetron by turning the control circuit on and off for variable time intervals. Alternately, the microprocessor may control the power of the magnetron by changing the switching frequency of the inverter. The microprocessor is used in a filament standby mode to monitor the current in the magnetron's filament. In the filament standby mode, the inverter is operated at a lower than normal voltage such that the magnetron is not generating microwave power, but its filament is receiving sufficient current to warm it up, the current flowing through a filament winding of a power transformer. A primary winding of the power transformer is connected to the inverter. |
