LED dimming technique without frequency and pulse width modulations

摘要

In this paper, a novel dimmable light-emitting diode (LED) driver is implemented by a series-parallel resonant converter. Variable resonant inductor is used for dimming purposes. This technique is not requiring switching frequency variation or pulse width modulation, unlike commonly used techniques. The proposed technique is implemented on 40 one-watt series connected power LEDs at 60-kHz constant switching frequency. The experimental results show that LEDs can be dimmed to a desired power level within the range of nominal and low power.