| 摘要 |
Drivers (1-7) comprise respective switching circuits (1, 2) for guiding respective current signals during respective time-intervals for the sequential driving of light emitting circuits (91, 92). The respective time-intervals are defined by the fact that amplitudes of a mains signal are in respective ranges during the respective time-intervals. More specifically, there is a bypass switching circuit (5) for guiding a bypass current signal which bypasses all light emitting circuit (91, 92) during an initial time-interval. An adaptation circuit (6, 7) adapts amplitudes of the respective current signals during the respective time-intervals, to reduce a total harmonic distortion. Said adapting may comprise an adaptation in response to information derived from the amplitude of the mains signal, and may comprise shaping the amplitudes of the current signals in response to information derived from the amplitude of the mains signal. Preferably, the shaped amplitudes of the respective current signals will be substantially identical to shapes of the amplitude of the mains signal in the respective ranges. The adaptation circuit (6, 7) may comprise a current source (6) and a definition circuit (7). |
