| 摘要 |
<p>A method of controlling run-up of a metal halide lamp that has a nominal (full) light output during steady state operation and that has a current limit I lim , includes, during run-up of the metal halide lamp to steady state operation, evaluating requested power P req and requested current I req to operate the lamp at the nominal light output L n during the run-up, supplying I lim to operate the lamp so long as I req ‰¥ I lim and supplying P req to operate the lamp when I req < I lim , and modulating power P supplied to the lamp. The power modulation is preferably at an acoustic resonance frequency of the lamp, such as the first azimuthal resonance mode of the lamp. Power modulation may include sweeping a sine wave ripple on top of an input voltage waveform, wherein a frequency range of the sine wave ripple includes an acoustic resonance frequency.</p> |
