METHOD AND BALLAST FOR DRIVING A HIGH-PRESSURE GAS DISCHARGE LAMP

摘要

Method of driving a high-pressure gas discharge lamp during its steady-state operation, wherein a steady-state current signal is sent through the lamp for maintaining a discharge arc in the lamp, comprising the step of comparing the lamp conductivity response to a current step in said current signal with reference parameters; and in response to said comparison at least one of the following steps: stopping the current supply to the lamp, generating a signal indicating the end-of-life status of the lamp, changing the steady-state current through the lamp, changing the steady-state waveform of the current signal through the lamp, and generating a signal indicating the lamp type, wherein said current step is obtained by sending a current pulse which is superimposed on said steady-state current signal through the lamp.