Led failure detection

A fault detecting circuit in a string of light emitting diodes comprising an evaluating element, wherein the string comprises light emitting diodes D1 to Dc configured for connection to a source of driving current is divided into three sections, a first section comprising diodes D1 to Da, a second section comprising diodes D2 to Db, and a third section comprising diodes D3 to Dc, and wherein a first common point between a cathode of a last diode Da of the first section and an anode of the first diode D2 of the second section is connected to an input of a first evaluating element (IC1), while a second common point between a cathode of the last diode Db of the second section and an anode of the first diode D3 of the third section is connected to an input of a second evaluating element (IC2), and a portion of the string comprising diodes D1 to Db is connected in parallel to a divider comprising a first resistor (R1) and a second resistor (R2), while a portion of the string comprising diodes D2 to Dc is connected in parallel to a divider comprising a third resistor (R3) and a fourth resistor (R4), and a third common point of R1 and R2 is connected to the input of the IC1 and a fourth common point of R3 and R4 is connected to the input of IC2, while an output of each of the two evaluating elements IC1, IC2 is connected to an input of an adding unit formed by transistors T1, T2, each having an emitter connected to a ground and a collector connected to a voltage source and also to an output terminal (OUT).