| 摘要 |
1522533 Automatic control of lighting intensity ESQUIRE Inc 26 March 1976 [27 May 1975] 12249/76 Heading G3R The total illumination of a work area (e.g. lit by daylight and artifically) is kept constant by controlling at least one lamp in response to a comparison of the output of a photo-detector with a reference voltage, the rate of change of the difference being limited so as to prevent response to transient changes in the ambient lighting, e.g. by the passage of clouds. The circuits are described in detail, the limitation to transients being provided by an integrating capacitor on the output of a buffer amplifier supplying a dimming control voltage. The output of the photo-detector is also compared with a second reference value which, when passed, signals the need for lamp replacement. |
