Regulation of sequentially operating light source and device for carrying out the method

A method for sequentially operating light source on a vehicle, in particular a lighting system for signalizing a change of driving direction of a motor vehicle, comprising a plurality of light emitting diodes (LED) (11, 12. . . 1n) connected in series, said diodes can be activated in a pre-determined sequence within a required time frame (t0), characterized in that, the method comprises the following steps:

• a) activating within a required time frame (t0) a sequential operation of a plurality of LEDs (11, 12 . . . 1n), wherein the operation of the first LED (11) in the plurality of LEDs and operation of the last LED (1n) in the plurality of LEDs is carried out within an actual time frame (t1) of operation;
• b) activating by means of a reserve security element and after lapse of a safety time frame (t2) of all LEDs (11, 12 . . . 1n) simultaneously.