Method for controlling an electrical load

Method for controlling an electrical load consisting of at least two single loads connected in series by means of switching cycles of predefined duration sequentially following one another, wherein a controllable switch is connected in parallel to each single load so that each single load is switched independently of the other single load in the switching cycle, wherein the electrical current, which is supplied by a driver stage and flows in the electrical load, is monitored and, by means of a target-performance comparison, adjusted to an adjustable setpoint by a control unit within the switching cycle, so that a current that is substantially constant flows in the electrical load and, by means of the controllable switch, the control unit switches each of the single loads on and off within the switching cycle at predefined turn-on and turn-off times, characterized in that:

• in the switching cycle in which the number of single loads to be switched on and the number of single loads to be switched off are equal, one single load is switched on and another single load is simultaneously switched off, or
• in the switching cycle in which the number of single loads to be switched on is larger than the number of single loads to be switched off, the switching cycle is extended by a correction period, wherein the correction period substantially corresponds to the period that the control unit is to correct the output current of the driver stage to the desired current in case of a load surge arising from switching on the single load without switching off another single load at the same time, and
• the time positions of the predefined turn-on times and turn-off times of the single loads are then varied or remain the same or their ON times are extended or reduced or else remain the same as a function of the time of the load surge in the switching cycle.