High pressure discharge lamp operating circuit arrangement, has comparison device designed so that instantaneous value lies below upper threshold such that preset duty cycle of signals is increased for preset time period

摘要

The arrangement has a voltage measuring device (10) measuring an instantaneous value of voltage by a high pressure discharge lamp (LA). A reference value device (12) provides an upper threshold for the voltage. A comparison device (14) compares the value with the threshold. The comparison device is designed such that the value lies below the threshold to control a control device (16) such that a predetermined duty cycle of signals is increased for a preset time period. A switch (S1) of a half bridge circuit is controlled during in-phase of another switch (S2) with the duty cycle. An independent claim is also included for an operating method for a high pressure discharge lamp in a circuit arrangement.