A method of operating a LED based light source and a lighting device comprising such a LED based light source

摘要

The invention relates to a method of operating a light source comprising one or more LEDs by supplying power to the light source whenever illumination is required. A condition of the LEDs is monitored and an amount of power supplied to the light source is controlled on the basis of the monitored condition. The monitored condition may be a light emitting efficiency of the LEDs, and the amount of power supplied to the light source may be controlled such as to maintain a total amount of light output by the light source at a constant level for a predetermined period of time. The light emitting efficiency may decreases with increasing age of the LEDs and the amount of power supplied to the light source may be increased over time to compensate for the decreasing efficiency. The invention further relates to a lighting device with which the above method may be carried out. Such a lighting device may comprise a light source including one or more LEDs, a power supply and a controller. The controller may be adapted to monitor a condition of the LEDs and to control the power supply on the basis of the monitored condition.