Experimental study on luminous intensity of white LEDs of different configurations

Abstract

Abstract The relationship with input voltage to the light intensity at constant current supply of four (04) separate white LEDs containing different number (5,9,13 and 27 pcs) of SMD chips are investigated in this research. Voltage between 10 and 16 volts is applied to LED lights at constant current supply. The light intensity produced by the LEDs was measured. Light intensity was found linear related to the voltage. The phosphor coating over the chips are also observed by microscope and found that the light intensity has an important impact on phosphor coating. The light intensity found lower than the expected due to the non-uniformity of phosphor coating.