Two Output Soft-Switched Full Bridge Based LED Driver With Reduced Voltage Stress

This work presents a full-bridge-based driver circuit for powering two light-emitting diode (LED) lamps of different wattages. In the proposed topology, the LED lamp strings are connected in anti-series across the full bridge, which significantly reduces voltage stress on the switches. Zero-voltage switching (ZVS) is achieved through an LC resonant circuit, minimizing switching losses and improving efficiency. The current through the LC series circuit is inherently determined by the voltage difference between the two LED lamp strings. The system is powered by two equal-magnitude DC sources with series inductors, making it suitable for future DC-grid lighting applications. Additional advantages include low output ripple, reduced component count for cost-effectiveness, and high efficiency through soft-switching operation. A detailed theoretical analysis of the converters operating modes is provided to explain its performance and behavior. The concept is experimentally validated using a 73.4 W laboratory prototype, confirming the effectiveness and practical feasibility of the proposed solution in real-world LED driver applications.