Abstract: The invention relates to a circuit arrangement suitable for high-frequency operation of a discharge lamp, provided withinput terminals (1, 2) for connection to a low-frequency supply voltage source,a rectifier circuit (G) coupled to the input terminals for rectifying a low-frequency supply voltage supplied by the low-frequency supply voltage source,a DC-AC converter,a branch (22) of which a first end is connected to a point of the DC-AC converter at which a high-frequency voltage is present during lamp operation and of which a further end is coupled to the rectifier circuit,the branch being conductive at least for alternating current in both directions, and the further end of the branch being connected to a first input terminal,where by the amount of interference caused by the circuit arrangement is considerably reduced, while the circuit arrangement can be realized with a comparatively small number of components.

Abstract: A circuit arrangement suitable for operating low-pressure mercury discharge lamp by means of a high-frequency current includes circuitry (I) for generating the high-frequency current from a supply voltage, and a modulator (II) for the substantially square-wave modulation of the amplitude of the high-frequency current at a modulation frequency f. The circuit arrangement is further provided with circuitry (V) for limiting the amplitude of the re-ignition voltage across the low-pressure mercury discharge lamp to a voltage Vi. As a result, interference with infrared systems caused by a discharge lamp operated by the circuit arrangement is substantially fully suppressed.

Abstract: An electrodeless low-pressure mercury vapor discharge lamp whose discharge vessel is provided with a core of magnetic material and a coil surrounding the core which coil connected to a high-frequency supply unit. An interference-suppressing, light transmissive electrically conductive layer is present on the outside of the discharge vessel, which layer can be connected to the supply mains through an electric conductor. The electric conductor comprises one or several capacitors connected in series to keep the conducting layer safe to touch during operation.

Abstract: Electrodeless low-pressure discharge lamp having a glass lamp vessel (1) which is sealed in a gaas-tight manner and which is filled with at least a metal vapor and a rare gas, said lamp having a first winding (6) which is connected to a high-frequency electric power supply unit and which generates an electric discharge in the lamp vessel (1), one of the supply wires of the first winding being electrically connected to a supply wire of a second winding (12) which extends at the area of the first winding and which has a free end (13), whilst the potential gradient between the ends of the first winding (6) is substantially equal to that of the second winding (12) during operation, ignition antennas (14, 15) being secured to the free end (13) of the second winding (12) and to one end (16) of the first winding (6).