Patent ID: 7045970

Claim:
An electronic ballast for a lamp (L) having an inductor (W 1 , W 2 , W 3 ) for generating iterative voltage pulses (U L ) in a lamp circuit including the lamp (L), which inductor (W 1 , W 2 , W 3 ) has a first winding (W 1 ) to which current is applied by a voltage source (U B ), characterized by a second winding (W 2 ), which is short-circuited via a controllable short-circuiting switch (T 3 , T 4 , T 5 ), for the purpose of generating an operating phase of the ballast in which the second winding (W 2 ) is short-circuited, a first switch (T 1 , T 2 ) controlling the injection of the voltage pulses (U L ) is switched on approximately at a zero crossing of the lamp voltage (U L ) or is opened approximately at a current zero crossing.