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

• US 5,598,000 A
• Filed: 02/22/1996
• Issued: 01/28/1997
• Est. Priority Date: 02/22/1996
• Status: Expired due to Term

• Current Assignee: Pradeep P. Popat
• Original Assignee: Pradeep P. Popat
• Inventors: Popat, Pradeep P.
• Primary Examiner(s): Le, Que T.
• Application Number:
  US08/567,244
• Time in Patent Office: 341 Days
• Field of Search: 250/206, 250/205, 250/214 D, 250/214 B, 250/214 AL, 250/554, 359/601-610, 359/613, 359/227-229, 40/25, 40/31, 362/276, 362/802, 318/266, 318/268, 318/286, 318/466-468, 318/480
• US Class Current: 250/206
• CPC Class Codes: E06B 9/32 Operating, guiding, or securing devices therefor operation of tilting bars E06B9/307
• CPC Class Codes: E06B 9/68 Operating devices or mechanisms, e.g. with electric drive
• CPC Class Codes: F24S 50/80 for controlling collection or absorption of solar radiation
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: Y02A 30/24 Structural elements or technologies for improving thermal insulation
• CPC Class Codes: Y02B 10/20 Solar thermal
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection
• CPC Class Codes: Y02B 80/00 Architectural or constructional elements improving the thermal performance of buildings
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers

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.

Claims

1. A system for automatic control of illumination transmitted through a host window, said system including:

A. means for electronically varying the illumination transmitted through said host window, said means having a control input, said means responsive to electrical signals registered on said control input;

B. means for detecting the periodic fluctuations in the illumination produced by an electric lamp powered by alternating current, said means having an output; and

C. a control apparatus having a sensing input and a control output, said sensing input being connected to said output of said detecting means and said control output being connected to said control input of said variable illumination transmission means, so that said control apparatus is capable of registering the presence of said fluctuations, and of regulating the illumination transmitted through said host window on the basis of said presence.

2. A method of controlling the operation of a system for the automatic control of illumination transmitted through a host window, said system capable of a plurality of operating modes, said method comprising:

A. a first step of checking for the presence of periodic fluctuations in the ambient illumination, said fluctuations being produced by an electric lamp powered by alternating current; and

B. a second step of selecting between said operating modes on the basis of the results of said first step.