Experimental study on optical-thermal associated characteristics of LED car lamps under the action of ionic wind.

The working temperature of a LED chip has a great influence on its photoelectric properties. This paper is concerned with the application of ionic wind produced by corona discharge to cool a LED car headlamp. Both theoretical and experimental procedures are studied. A DC ‘needles-to-mesh’ ionic wind generator was designed for the experimental study. The mechanism of the association between optical and thermal properties was explored. The results indicated that the ionic wind could weaken the red shifting of the chromaticity coordinates and reduce the radiant power. It also showed a better working performance when the corona discharge power increased, but it only changed slightly as the corona power continued increasing. Ultimately, it would result in more symmetrical and uniform light distribution and the illumination gradient varied gently, which was more suitable for the driving beam lighting. The luminous flux was 1957.6 lm and the junction temperature was 29.8 °C after 6 min working of the ionic wind generator under a corona discharge power of 3 W. All the test values complied with the regulatory requirements. [ABSTRACT FROM AUTHOR]