Abstract: The invention relates to a circuit arrangement for operating a discharge lamp, comprising a DC-AC converter provided with a switching element for generating a current whose polarity changes with a frequency f, a current sensor (SE), a drive circuit (III) for generating a drive signal to make the switching elements alternately conducting with the frequency f, a measuring circuit (I) coupled to the current sensor and having at least one switching element for generating a control signal which is dependent on a phase difference between a voltage across the load circuit B and a current through the load circuit B and on a second signal which is a measure for a minimum required phase difference, and a control circuit (II) for effecting a change in an operating condition of the DC-AC converter, this change being dependent on the control signal.

Abstract: The invention relates to a circuit arrangement for operating a discharge lamp, comprising a DC-AC converter provided with switching elements and a drive circuit for rendering the switching elements alternately conducting. The circuit arrangement is furthermore provided with a control circuit C for controlling the power consumed by the lamp. To this end, the control circuit is coupled to a current sensor. According to the invention, the current sensor is so positioned that the power consumed by the lamp can be controlled independently of the build-up of the drive circuit and that a simple construction of the control circuit C is possible.