| 摘要 |
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 Ilim, includes a lamp ballast sensing lamp current and voltage and calculating power, and evaluating requested power Preq and requested current Ireq to operate the lamp at the nominal light output during run-up to steady state operation, supplying Ilim to operate the lamp when Ireq>=Ilim, and supplying Preq to operate the lamp when Ireq<Ilim. The method may determine Preq in various ways, including determining a light output L of the lamp; comparing lamp voltage to a nominal voltage Vn for the lamp during steady state operation; determining energy E delivered to the lamp; and estimating lamp efficacy. The method may also be used to characterize an unknown lamp attached to the ballast.
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