OUTPUT CONTROL SYSTEM FOR AN A.C. HIGH-PRESSURE GAS-DISCHARGE LAMP INTENDED IN PARTICULAR FOR MOTOR VEHICLES

摘要

The output control system for an a.c. high-pressure gas-discharge lamp intended in particular for a motor vehicle contains a bridge circuit in which two controlled switching transistors provided in at least one branch and in which the high-pressure gas-discharge lamp is supplied with ignition or arcing power via the bridge branch of the bridge circuit. It is proposed that the switching transistors should switch the current in the form of pulse packets each of which should contain a specific number of high-frequency pulses; switching should be carried out with minimum waste during current zero crossing; and regulation should be made to ensure that a defined output of the high-pressure gas-discharge lamp is maintained by a continuous averaging process over a predetermined interval (44, 45) of the supplied output packet.