LEDs' operation optimizing for long term lumen maintenance

Investigations deals with optimization of operating regimes of LEDs in lighting equipment for obtaining two purposes - maximum light output in dependence of ambient conditions and long term lumen maintenance. Thermal management calculations and heat sink choice are experimentally tested at various ambient conditions (air temperatures from 20^oC to 55^oC) and different current values through LEDs - up to 700 mA. Infrared thermography is used for evaluation of temperature distribution on LEDs and heat sink. Thermal management investigations allow determining safety operating conditions for LEDs at maximum light output in dependence of ambient conditions.