Improvement in Efficiency of LED Lighting System Based on Reduction of Voltage across MOSFET

Abstract

In this paper, a LED dimming circuit powered by the KY converter, which is named after the first capitals of two authors' names: Kuo-Ing Hwu and Yeu-Torng Yau, is presented, which is controlled based on the field-programmable gate array (FPGA). By a given dimming command and the proposed maximum gate voltage detector, the voltage across the MOSFET in the linear current regulator can be reduced so as to upgrade the efficiency of the overall system. Aside from this, each LED string takes level dimming, and is powered by the KY converter, which has an output inductor and hence upgrades the life of the output capacitor. Furthermore, via some experimental results, the efficiency based on the proposed control method is higher than that based on the traditional control one.

Output Current Ripple Reduction of LED Driver Using Ceramic-Capacitor-Input Circuit and Buck-Boost Converter

“…Electrolytic capacitors are often used for the smoothing capacitor C in , and there are commercial products suitable for LED illumination. 22,23 With capacitance of 8.2 µF and rated voltage of 200 V, the cylindrical portion is 8 mm in diameter and 9 mm in height, the volume being about 452 mm 3 . Assuming…”

“…[1][2][3][4] Electrolytic capacitor-less LED drivers are a means to further extend service life of LED lighting equipment. There are a number of studies on various aspects of LED drivers including efficiency improvement and dimming schemes.…”

“…There are a number of studies on various aspects of LED drivers including efficiency improvement and dimming schemes. [1][2][3][4] Electrolytic capacitor-less LED drivers are a means to further extend service life of LED lighting equipment. [5][6][7] Electrolytic capacitors are superior to other types of capacitors in terms of compact size and low price, thus, being widely used as smoothing capacitors in LED drivers.…”

Output current ripple reduction of LED driver using ceramic‐capacitor‐input circuit and buck‐boost converter

“…LED lighting equipment requires LED drivers to control current flowing in LEDs. There are a number of studies on various aspects of LED drivers including efficiency improvement and dimming schemes …”