Design of LED Operation Circuit Based on Cockcroft-Walton Circuit

The optimum specifications of an LED operation circuit based on a Cockcroft-Walton circuit were investigated. It was found that the four-times-circuit with an LED operating voltage set to about 50 % of the non-load output voltage is preferable, since the number of elements in the circuit and the capacitance of each capacitor could be minimized. Then, the cost of the LED operation circuit could be minimized by using a four-times-circuit. The input power factor is maximum when the LED operating voltage was set to about 80 % of the non-load output voltage, and the maximum value of the input power factor increases with increasing step-up voltage of the circuit. It was also found that the eight-times-circuit could satisfy the harmonics regulation regarding the input current of electronic equipment by adjusting the LED operation voltage and capacitance ratio.