Circuit arrangement for operating fluorescent lamp, has preheating load circuit with inductor that is switched against zero voltage, and primary-sided reflected spiral coil preheating stream determined over measuring resistor or transformer

摘要

The arrangement has a preheating load circuit (ILKB) including an inductor (LZVS) that is connected to a coupling capacitor (CK1) and to a primary side (TRW1) of a preheating transformer over a measuring resistor (RMESS) or transformer of a preheating circuit switch (S3). The inductor is switched against zero voltage between a nodal point of the inductor and the measuring resistor or transformer such that the zero-voltage switches a half bridge during preheating by the inductor. A primary-sided reflected spiral coil preheating stream is determined over the measuring resistor or transformer.