A New Control Method for Magnetron Lamp Power Supply Using Forward-Flyback Converter With Active Clamp

In this article, a new power supply for the driving of magnetron lamps is presented. In the power supply structure, the active clamp double-switch fly-back converter is used. In the converter provided, focusing on controlling a switch, the power supply control is simplified; thus, the magnetron beam voltage is controlled by changing the duty cycle of the clamp transistor. The most important advantage of the proposed method is the simplicity of the magnetron lamp power supply (MLPS) in controlling the circuit. The converter is a high-gained, boosted, and isolated type. Also, the active clamp structure is used to reduce the voltage stress of the main transistors of the converter. In addition, the resonant circuit is created using the power transformer leakage inductance. Consequently, while reducing the losses of the converter, soft switching conditions are provided. Also, in MLPS, a power factor correction (PFC) block is used to modify the power factor. MLPS delivers the maximum power of 1 kW with an average power of 250 W by controlling the power supply activation time. The design results have been confirmed by laboratory implementation.