An efficient full-bridge resonant converter for light emitting diode (LED) application with simple current control

Abstract

New power control is introduced in the full‐bridge dc‐dc converter to drive an LED lamp in this paper. LEDs are semiconductor devices that behave like a constant voltage load with low equivalent series resistance (ESR). Hence, they require precise control for current regulation. In the proposed driver, the LED lamp is driven by two voltage sources connected in series through a series res onant circuit. It processes the majority of lamp power through the full‐bridge diode rectifier and supplies small power through a center‐tapped rectifier. The LED lamp current is controlled at the selected operating current by using center‐tapped rectifier output voltage. In addition, pulse‐width modulation (PWM) dimming is implemented. The proposed topology features zero voltage switching (ZVS), regulation of lamp current, dimming operation, and high efficiency. The working principle, performance, and prototype validation are given for the proposed LED driver.