Circuit arrangement and method for operating a high-pressure discharge lamp

摘要

A circuit arrangement for operating a high pressure discharge lamp includes a bridge circuit with at least two switches, a control device controlling the switches. The bridge circuit is a half-bridge circuit having exactly two switches. The control device switches on and off in an alternating manner, the first switch and the second switch of the bridge circuit having a first frequency. When the first switch is switched off for controlling the other switch with a rectangular signal of a second frequency which is greater than the first frequency and a predeterminable connection duration. The circuit also includes a tension measuring device measuring an actual value of tension over the high pressure discharge lamp. A reference device provides at least one upper threshold value for the voltage via the high pressure discharge lamp. A comparison device compares the actual voltage over the high pressure discharge lamp with the threshold value.