Line-frequency dual input-voltage-level LED driver

In this paper, a line-frequency dual input-voltage-level LED driver is proposed. The conventional AC LED topologies are operated with single input voltage level, which cannot be suitable for both two major utility voltage levels of 110 V and 220 V. The proposed LED driver utilizes the automatic parallel/series switching mechanism to achieve the compatibility with the input voltages of 110 V and 220 V. Since the LED driver possesses the current-limiting mechanism, it can prevent LEDs from overcurrent no matter what the input voltage is. Finally, the prototype circuit of line-frequency dual input-voltage-level LED driver is built to verify the performances.