| 摘要 |
Sodium high-pressure lamps can be operated by a circuit arrangement which rectifies the AC line voltage and, dispensing with smoothing, feeds it directly to an inverter for generating a frequency above 1 kHz. Via an RF inductor and an ignition transformer, the lamp, which preferably contains a xenon filling above 1 bar, is fed the voltage modulated with twice the line frequency. The saving in electric energy of the lamp/ballast system is 30% by comparison with an inductor-driven Hg-free standard lamp, given the same luminous flux. The use of a microprocessor to control the half bridge permits an externally controlled or automatic lowering of power with a further potential energy saving of 35% on average over the year, and an end-of-life shutdown of the system in order to avoid cycling.
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