In general terms, dimmers are devices that vary light level (intensity) of lamps by controlling the amount of power that is delivered to the lamp. Dimming can be controlled by either manual or automatic means.
There are two methods of dimming: reducing the voltage applied (i.e., voltage modulation), as shown in Fig. 1, to the lamp and reducing the amount of time that full voltage is applied to the lamp (i.e., phase control). The applicable dimming method must be compatible with the lamp type. This article will focus on phase control.
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