Patent ID: 6586892
Filing Date: 2003-07-01
Classification: H05B

Abstract:
A method of operating a gas discharge lamp which is fed with an alternating electric power source, wherein the lamp has electrodes having respective electrode front faces, and the lamp has operational characteristics after lamp starting which vary in time over periods which are a multiplicity of cycles of said electric power source, comprising:providing lamp starting power at start-up frequencies, and after lamp start-up providing operating power at operating frequencies, and after start-up, increasing the instantaneous power of the lamp to a value greater than the mean lamp power during each of a succession of given time intervals shorter than said periods, characterized in that the method further comprises: measuring the values of at least one operational datum representative of at least one of said operational characteristics, and responsive to the measured values, causing growth of structures on said electrodes having respective cross sections less than the respective electrode front faces, and respectively forming projecting electrode tips, by selecting the operating frequency of the alternating electric power source.