Method and driving device for running up a discharge lamp

A driving device for a discharge lamp comprising

• connection terminals for applying electrical power to the electrodes of the discharge lamp, and
• a driver running up the discharge lamp by increasing a driving power to a target value during a single or during two consecutive time periods, the driver being adapted to estimate the discharge lamp voltage and calculate an instantaneous output power,
• said driver being designed to generate an increasing driving power and controlling the driving power to reach the power target value during the single or during a second of said two consecutive time periods,
• wherein the driver does not allow the driving current during the single or second time period to increase faster than a preset rate and to exceed a fixed upper current limit, which is selected to avoid an overheating of electrodes of the lamp;
• and
• wherein an adaptive upper current limit is set which the driving current is not allowed to exceed, the adaptive upper limit being increased by a first present amount every time when the current requested exceeds the adaptive upper limit, and being lowered by a second present amount every time when the driving current decreases.