摘要 |
<p>A lighting device and a method for operating a discharge lamp (10) are de-scribed. The discharge lamp (10) comprises a sealed discharge vessel and two electrodes (22) to produce an arc. A driver circuit (20) delivers electrical power to the electrodes (22). In a run-up interval (56), electrical power is supplied as an alternating current IL. During the run-up inter-val (56), the waveform of the alternating current IL is changed at least once to a spot-enforcing waveform in order to change the mode of attachment of the arc to the electrodes (22) to spot mode.</p> |