Abstract: A bridge circuit arrangement for the operation of discharge lamps comprises a direct voltage source-supplied inverter (2) whose terminals {8,9) are connected to the series circuit of an inductor (10) and a discharge lamp (11}. By means of the symmetrical arrangement of the capacitor (14) with regard to the branches of the bridge circuit, the asymmetrical pulse load on the operating voltage is minimized and the grid filter {1) can have a simpler design. This allows economical manufacture of the discharge lamp with electronic ballast.

Abstract: The invention relates to a circuit arrangement for operating a discharge lamp. According to the invention the series connection of a PTC thermistor V1 with a bi-directionally acting breakdown voltage component V2 is disposed parallel to the inductance L1 and/or the capacitor C1 in a load circuit which has a discharge lamp H1, an inductance L1 connected in series with the discharge lamp and a capacitor C1 disposed parallel to the discharge lamp H1, wherein the PTC thermistor V1 and the bi-directionally acting breakdown voltage component V2 are thermally coupled. The object of the invention is to provide a simple circuit arrangement for operating a discharge lamp which allows a substantially constant ignition of a discharge lamp.