A Dimmable LED Driver Based on H-Bridge and Differential-Mode Transformer

A dimmable LED driver based on the H-bridge and current-sharing transformer is presented in this paper. The LED currents are as equal as possible based on the current-sharing transformers. Moreover, the magnitudes of the LED currents can be changed by controlling the duty cycle of one switch, and the conduction time of the LED currents can be adjusted by controlling the duty cycle of the other switch. Accordingly, not only the current-sharing transformers can be demagnetized via the H-bridge without additional components, but also the LED dimming can be achieved without complicated control.