A design of an improved RCD clamping circuit

To address the issue of ineffective absorption of the initial voltage spike across the switching transistor during startup in conventional RCD clamping circuits, an improved RCD clamping circuit is proposed. This circuit enhances the traditional design by incorporating a voltage-regulating diode and a dual-diode sub-circuit, which clamps the initial voltage spike to the breakdown voltage of the voltage-regulating diode. Additionally, the reverse voltage across individual diodes is significantly reduced, while the clamping capacitor can be minimized, and the resistance increased, without compromising the effectiveness of spike absorption. Simulation results obtained using the Simplis software demonstrate that, in the improved circuit, the drain-source voltage of the switching transistor is effectively clamped to approximately 450V, and the reverse voltage across the diode is reduced to -185.43V.