Abstract: An instrument for measuring the temperature characteristic of a high power LED is developed by using a semiconductor heating/cooling element to make the LED＇s temperature rise or fall, in which a pt100 surface mounted resistor is used as a temperature sensor, and a light sensor with spectral response that emulates the human eye is used as a luminous intensity detector. The temperature characteristics of the photoelectric parameters, such as luminous intensity, luminous efficiency, of the 1 watt white LED supplied by a constant current source or a constant voltage source are investigated, respectively. The experimental results show that this instrument has advantages of fast temperature measurement, high accuracy, low cost and simple operation.

Key words: high power LED, luminous intensity, temperature characteristics, measurement instrument