Voltage Control of Magnetron Power Supply Utilizing Active Clamp Flyback Converter

In this paper, a new driving method is presented for a magnetron bulb utilizing a phase-shifted active clamp fly-back converter. The converter is of a booster, isolated and high gain type. The active clamping structure is used to reduce the main transistor’s voltage stress. By controlling the timing of the transistor clamp, the voltage required for the magnetron is adjusted. The main advantage of the proposed method is the simplicity of the control circuit of the magnetron lamp driver. In addition, the proposed method reduces the size, weight and price of the power transformer core. The power transformer leakage inductance has also been developed to provide a soft switching condition while reducing converter losses. The converter presents a maximum power of 1.6 kW with an average power of 400 W, by setting the timing of the activation of the driving circuit. The design results are simulated and verified by PSCAD Simulink software.