Peltier Elements vs. Heat Sink in Cooling of High Power LEDs

LEDs generate visible light when current passes across the junction of the semiconductor chip. LEDs are not 100 % efficient; much of the power running through an LED is lost as heat, which thus needs to be evacuated. This paper made a comparison between a light fixture that uses Peltier element and a light fixture cooled by heat sink. This paper shows how the Peltier element can contribute to LEDs function optimally at low temperature. The idea of using the Peltier effect for cooling LEDs is not new: there is a patent to this (US 6964501 [1]). This paper refers to a high power LED which requires a very high value of the heat to be evacuated (20 W) on a very small area (phi=18 mm) and compare the results with those obtained from measurements made on the same LED without Peltier element. This paper examines how Peltier elements can cool high power LEDs without consuming energy more than LED, without increasing too much the lamp size (LED and cooling system) and investigates the way to remove heat without added complexity. Finally the paper presents the measurement results according to the developed vehicle test.