| 摘要 |
A ceiling fan assembly includes a fan and a light-sensitive circuit for controlling an illumination level of a light as a function of an ambient illumination level surrounding the ceiling fan assembly by selectively controlling or fixing a conduction phase angle of an AC power signal provided to the light. The light-sensitive circuit includes a photocell, a phase control circuit and a cutoff Circuit which prevents flicker at low illumination levels. The photocell is responsive to the ambient illumination level and has a conduction state. The conduction state changes in response to the ambient illumination level. The phase control circuit selectively varies or fixes a conduction phase angle associated with the AC power signal, which correspondingly determines a variation in the illumination level of the light. In response to the photocell, the phase control circuit selectively varies or fixes the conduction phase angle, and thus the illumination level associated with the light when the photocell exhibits an open circuit, and conversely, prevents the AC power signal from being provided to the light when the photocell exhibits a short circuit.
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