DRIVING CIRCUIT FOR DRIVING A PLURALITY OF LIGHT SOURCES ARRANGED IN A SERIES CONFIGURATION

摘要

A driving circuit (10) for driving a plurality of light sources (1) arranged in a series configuration (2) is described. A controllable current source (20) is connected to said series arrangement of light sources. Each light source (1(i)) is bridged by a corresponding controllable switch (25(i)). A controller (30) controls the operation of the current source (20) to set a current level and controls the operative states of the respective switches (25(i)) in order to individually control the light output of the corresponding light sources. The controller (30) is capable of individually setting the switch control signals (SL(O) for the respective switches (25(i)). Especially, the controller (30) is capable of boosting the light output of one selected light source (1(x)) while maintaining the light output of other light sources in the series arrangement (2). To this end, the current level is increased while the other light sources are dimmed.