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In this study, a phase shift controlled full-bridge series resonant converter (SRC) integrated with buck converters for light-emitting diode (LED) driver application is proposed. This LED driver supplies four LED loads simultaneously. The current through LED loads is controlled by phase shift control of the SRC, and its output is added to the input voltage. Zero-voltage switching (ZVS) switching of all the switches is achieved by operating the SRC at lagging power factor for all input voltage variations. As the only part of the output power is processed through the SRC and all the switches operating with ZVS, the efficiency of the converter is 95.7%, which is high. A 142 W LED driver is designed, and its performance is tested with PSPICE simulations and experimental prototype.

In this paper output voltage modulated half-bridge series resonant converter (HBSRC) for LED driver application is proposed. In this converter HBSRC is cascaded with a buck-boost converter (BBC). The sum of output voltages of buck-boost converter and HBSRC drives the LED load. The LED current is controlled by regulating the buck-boost converter output voltage. Thus the HBSRC is working at firm frequency and duty ratio to achieve Zero voltage switching (ZVS) operation for input voltage variations. In this arrangement the BBC handles only fraction of the LED power, which doesn’t influence the overall efficiency of the converter much. The analysis of the proposed concept and a 26 Watt LED driver simulation results are presented.

This paper proposes a dual-frequency series resonant converter based LED driver which can drive two LED loads with independent control. In this converter one leg of the full bridge inverter operated at high frequency (HF) and the other leg of the inverter is operated at low frequency (LF). Two series resonant converters are connected across output of full-bridge inverter, which are tuned for HF and LF. The output voltages of LED loads are regulated independently by controlling duty cycle of respective legs of full-bridge inverter. To validate the proposed concept a 60 W (20W LF and 40 HF) LED driver is simulated in PSPICE and results are presented.