Stabilisation and control of photometric properties of metal halide gas-discharge lamp - having load pulse applied at fixed time intervals from ballast unit, then resultant impedance matching is compared with stored properties

摘要

A procedure for stabilising and controlling the photometric properties of metal halide high pressure gas discharge lamps driven from electronic ballast has a positive or negative load pulse impressed upon the lamp during operation with the help of the ballast unit. The type and duration of the matching of the lamp impedance to the new discharge state and the return to the original state are compared with stored theoretical values and the output of the lamp is adjusted correspondingly. The pulses are applied at regular fixed time intervals.