Abstract: A headlight for a vehicle has a reflector, a light source, a lens through which a light reflected by the reflector passes, at least one optical element which surrounds the lens, the optical element being formed as at least one ring-shaped lens element and together with the lens forming an optical unit in appearance.

Abstract: A high-pressure gas discharge lamp is connected on one side to a lead across the secondary winding of a starter transformer and to a second lead on the second side. Starting energy is applied with a pulse. For this purpose, a controllable switch which becomes conducting on reaching a certain voltage or is connected by a drive is provided in series with the primary winding. A capacitor connected in parallel to the series connection is charged by voltage U between the input terminals across a resistor connected in series and a diode. An input circuit provided between these input terminals of the starter has a capacitor, a protective element or a combination of the two for protection against voltage peaks.

Abstract: An ignition device for gas discharge lamps is proposed, in particular for motor vehicle lights. The ignition device contains a first transformer (17) which is supplied on its primary side with an alternating current produced from a direct current supply voltage. To generate this alternating current, a capacitor (14), which is acted upon by a charging current, constitutes a closed circuit together with the primary winding of the first transformer and a spark gap (16), wherein the spark gap (16) arcs at a predetermined charge state of the capacitor (14). This device makes a simple, inexpensive, and space-saving device possible for generating the required operating voltage for the transformer (17), wherein the spark gap can be reliably used, even at higher temperatures.

Abstract: On one side, a high-pressure gas discharge lamp (10) is connected, by way of the secondary winding (16) of an ignition transformer (14), to a line (11) and, on its second side, to a second line (12). It is therefore connected to a first voltage U.sub.1. A third line (13) delivers a further voltage U.sub.2. The ignition energy is supplied with the aid of a pulse. For this purpose, a spark gap (17) is provided in series with the primary winding (15), which gap abruptly becomes conductive when the breakdown voltage is attained. A first capacitor (18) that is charged by the voltage U.sub.2 by way of a resistor (20) connected in series is disposed in parallel to the first capacitor. The series connection of a second capacitor (19) and a diode (22) is provided in parallel to the first capacitor. The connecting point of the second capacitor and the diode is connected to the second line (12) by way of a resistor (21). This second capacitor 19 is charged by the voltage U.sub.1.

Abstract: A headlight for vehicles has a light source formed as a gas discharge lamp, a ballast unit connected with the gas discharge lamp and producing high voltage, and a unit for preventing dispersion of electromagnetic radiation caused by the gas discharge lamp. The unit includes an electrical filtering circuit arranged near the gas discharge lamp and having a plurality of components, and a housing surrounds at least a part of the components of the electrical filtering circuit.