Dual-mode automatic window covering system responsive to AC-induced flicker in ambient illumination

Abstract

A system for the automatic operation of window coverings which is responsive to the presence of artificial illumination. A preferred embodiment, automatic window covering system 10, consists of a conventional optical flicker detector 11, a conventional control apparatus 12, and a conventional motorized window covering 13. Control apparatus 12 and motorized window covering 13 constitute an automatic window covering system capable of regulating the illumination passing through a host window, and of operating in a plurality of modes, including a thermal management mode (the object of which is to reduce heating and cooling loads) and a daylighting mode (the object of which is to reduce the need for artificial illumination). Optical flicker detector 11 detects the presence of the periodic variation, or flicker, in the illumination produced by electric lamps powered by alternating current. Flicker detector 11 is connected to control apparatus 12 in such a manner that control apparatus 12 is capable of registering the output of detector 11, and of selecting between the operating modes on the basis of the presence or absence of illumination flicker.

Dependencies are inferred from the claim text.