Electronic ballast for high pressure discharge lamps used in automotive applications

摘要

In a ballast for high-pressure gas-discharge lamps in motor vehicles, which ballast is supplied from a vehicle battery, the ballast having at least one voltage converter which is connected to the vehicle battery and to the vehicle earth, produces a lamp supply voltage and/or a starting auxiliary voltage, and is electrically conductively connected to a starting device for starting and operating high-pressure gas-discharge lamps, in order to create a ballast in which people who touch the live parts of the ballast are protected as well as possible and in which the ballast is reliably protected in the event of defects such as short-circuits or excess currents, the lamp supply voltage and/or the starting auxiliary voltage are/is produced from the battery voltage of the vehicle battery, isolated in DC terms, and the reference potential of the starting auxiliary voltage and/or of the lamp supply voltage is connected via a low-resistance first measuring resistor to the vehicle earth. …IMAGE…