A METHOD AND A CIRCUIT ARRANGEMENT FOR OPERATING A HIGH INTENSITY DISCHARGE LAMP

摘要

A method and a circuit arrangement (1) for operating a high intensity discharge lamp (2), which is supplied by direct current (DC) supply lines (4, 6), comprising a transformer (40), of which a primary winding (42) is connected in series with an inductor (46) and a capacitor (48) to the DC supply lines (4, 6), a secondary winding (44) of the transformer is connected in series with the lamp, a switch (52) is connected in parallel to the capacitor (48), and a control circuit (56) is connected to the switch (52), whereby the control circuit (56) controls the switch to conduct upon detecting a zero crossing of a voltage (Vsw) at the switch, and the control circuit controls the switch to not conduct upon detecting a value of a current through the switch which is greater than a reference value.