Robert Boschgmbh

Gerhard Decker

Robert Kern

Karl-Heinrich Preis

Wolfgang Krauth

Thomas Mohr

Thomas Riehemann

Klaus Eckert

Lothar Borho

Claus Schmiederer

A starter for a gas discharge lamp, in particular a high-pressure gas discharge lamp for a motor vehicle headlight. The gas discharge lamp is supplied with operating power over the secondary side of a transformer. The required starting power is supplied on the primary side of the transformer and is transferred to the secondary side at the starting time. The starting voltage is generated by a cascade circuit, with the cascade circuit of capacitors and diodes provided in the starter circuit to generate the starting voltage at a charge capacitor. The starter circuit is supplied by the bridge circuit which supplies the gas discharge lamp with power for operation, and for the purpose of starting, the bridge circuit is cycled at a frequency which is much higher than the normal frequency for lamp operation. After the lamp has been started, the bridge circuit is switched to the normal frequency in lamp operation. The starter can be implemented in a two-wire concept, a three-wire concept or a four-wire concept. The starter is connected to the control circuit with two, three or four lines accordingly.

Starter for a gas discharge lamp, especially a high pressure gas discharge lamp for automobile headlights

Fixed-cycle power-supply circuit with an at least temporarily active

A circuit arrangement for converting a DC voltage into another DC voltage, with simultaneous regulation of the emittable voltage (U.sub.A) at a predetermined value. The circuit arrangement includes a combination of an upward and a downward transformer having at least one switching transistor (3) connected in series with a common memory coil (1) to a circuit output terminal, and a smoothing capacitor (5) connected in parallel to the output load (6), i.e., across the output terminals. The coil (1) is connected for a specific time to the supply voltage source (U.sub.Bat) by a time function circuit (9, 10). The coil (1) is connected directly to the positive pole (+) of the supply-voltage source (U.sub.Bat), and a current limiter circuit is provided in the long or forward branch of the circuit arrangement in front of the output of the circuit arrangement, with the current limiter circuit comprising a resistor (4) and a transistor (15) and influencing the switching transistor (3) disposed in the long branch. In addition to a first voltage limiting circuit formed of a series connection of a resistor and a Zener diode (16, 17), a further voltage limiter circuit (18, 19) is provided in parallel with the first voltage limiting circuit as short-circuit protection, with the further limiter likewise comprising the series connection of a resistor (18) and a Zener diode (19) which, however, has a different breakdown voltage than the first Zener diode (17).

Circuit arrangement for converting a DC voltage into another DC voltage

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Achern, Germany

Gerhard Decker