Experimental Investigation on Thermal-Optical- Current Characteristics of Commercial Light Emitting Diodes

LED lighting is one of the dominant lighting technologies in the current era due to its ability of energy savings and control ability. LED being semiconductor-based diode device, only some amount of input DC current is converted to light output and rest is converted to heat. This work is an experimental investigation of the light output variations at different drive current and operating temperature on light output of the LEDs. The LED light output is linearly dependent on the drive current. But, with increase in drive current light output droop is observed and droop amount increase with increase in operating temperature. In addition, the effect of pulsed and continuous operation of drive current on the light output is studied. The work can be used by LED Luminaire manufacturers to obtain a optimum design based on the operating condition of temperature, drive current and nature of drive current to give maximum possible light output.