摘要 |
<p>An improved dimming apparatus adapted for use in distributed dimming systems, in which dimmer enclosures each containing at least one semiconductor power controlling means are located in a plurality of spaced apart locations, each such enclosure located in proximity to at least one of its associated lamp loads. The disclosed dimming apparatus achieves unique advantages in the application through the use of a semiconductor power controlling means capable of modulating the instantaneous amplitude of the voltage or current supplied to the lamp load under the active control of its control input, a signal being applied to the control input of the power controlling means such that an output waveform is supplied to the lamp load in which at least one transition between a substantially off condition and a substantially on condition occurs during substantially each discrete half-cycle of the AC source and the duration of the transition is increased to suppress electro-magnetic interference.</p> |