1. An electronic operating device for light sources, comprising:an input part for inputting an input voltage;
an output part for outputting an output voltage and an output current for the light sources;
wherein the electronic operating device is configured
to operate the output part as a voltage source for a period of time after the input voltage has been applied;
subsequently to operate the output part as a current source after this period of time;
to measure the output voltage and to identify a point of discontinuity in a time profile of the output voltage; and
to prescribe the output voltage at the point of discontinuity as a setpoint voltage for a control loop, which regulates the output voltage and the output current during operation after the period of time.