System to control variable transmission windows having a security system interface

• US 6,829,511 B2
• Filed: 04/10/2003
• Issued: 12/07/2004
• Est. Priority Date: 07/25/2000
• Status: Expired due to Term

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Poll, David L., Bechtel, Jon H.
• Primary Examiner(s): Paladini, Albert W.
• Assistant Examiner(s): FRANK, ELLIOT L
• Application Number:
  US10/411,564
• Publication Number:
  US 20030191546A1
• Time in Patent Office: 607 Days
• Field of Search: 700/3, 700/19, 700/21, 700/80, 700/293, 359/265, 359/275
• US Class Current: 700/19
• CPC Class Codes: E06B 2009/2464 featuring transparency control by applying voltage, e.g. LCD, electrochromic panels
• CPC Class Codes: E06B 9/24 Screens or other constructions affording protection against light, especially against sunshine; Similar screens for privacy or appearance; Slat blindsoperating, guiding or securing devices or arrangements for roll-type closures E06B9/56; free-hanging flexible screens A47H23/00
• CPC Class Codes: G02F 1/163 Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor
• CPC Class Codes: G05B 19/0421 Multiprocessor system
• CPC Class Codes: G05B 2219/2231 Master slave
• CPC Class Codes: G05B 2219/24024 Safety, surveillance
• CPC Class Codes: G05B 2219/2628 Door, window
• CPC Class Codes: G05B 2219/2642 Domotique, domestic, home control, automation, smart house
• CPC Class Codes: H04L 12/2803 Home automation networks
• CPC Class Codes: H04L 12/2838 Distribution of signals within a home automation network, e.g. involving splitting/multiplexing signals to/from different paths adaptations of television systems for transmission by electric cable for domestic distribution H04N7/106; hybrid transport H04L12/6418; home network arrangements specially adapted for distribution of digital video signals H04N7/24
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling
• CPC Class Codes: H04L 2012/2841 Wireless
• CPC Class Codes: H04L 2012/285 Generic home appliances, e.g. refrigerators
• CPC Class Codes: H04L 2012/4026 Bus for use in automation systems
• CPC Class Codes: H04L 67/125 involving control of end-device applications over a network
• CPC Class Codes: Y04S 40/18 Network protocols supporting networked applications, e.g. including control of end-device applications over a network

Abstract

An electrical control system is disclosed for controlling a plurality of variable transmittance windows. The electrical control system of the present invention comprises a master control circuit for supplying control signals representing transmittance levels for the variable transmission windows, and a plurality of window control circuits coupled to each of the master control circuit. Because the window control circuits can sense abnormal load conditions in the variable transmission windows, the system further includes an interface to a security system to inform of a potential intrusion. Each window control circuit controls the transmittance of at least one of the variable transmission windows in response to control signals received from the master control circuit.

Claims

1. An electrical control system for controlling the transmittance of at least one variable transmission window having a variable transmittance medium and first and second electrodes electrically coupled to one another through the variable transmittance medium, the variable transmittance medium having a transmittance that varies in response to electrical energy applied thereto via the first and second electrodes, said control system comprising:

a control circuit coupled to the first and second electrodes of the at least one variable transmission window for selectively varying the electrical energy applied across the electrodes to thereby vary the transmittance of the variable transmission window;

a sensing circuit for sensing an abnormal electrical load condition across the first electrode, the variable transmittance medium, and the second electrode of the variable transmission window; and

a security system interface coupled to receive an indication from said sensing circuit that an abnormal electrical load condition exists in the variable transmission window.

2. The electrical control system of claim 1, wherein said abnormal electrical load condition is a near short or near open circuit.

3. The electrical control system of claim 1, wherein said control circuit comprises a window control circuit coupled to a master control circuit, said window control circuit controls the transmittance of the variable transmission window in response to control signals received from the master control circuit.

4. The electrical control system of claim 3, wherein said window control circuit includes a memory device in which an address is stored that uniquely identifies said window control circuit to the master control circuit.

5. The electrical control system of claim 1 and further including a device coupled to said control circuit for supplying information to said control circuit.

6. The electrical control system of claim 5, wherein said device includes a temperature sensor.

7. The electrical control system of claim 5, wherein said device includes a light sensor.

8. The electrical control system of claim 1, wherein the variable transmission window is an electrochromic window.

9. The electrical control system of claim 1, wherein at least one of said control circuit includes a micro controller and a switching regulator circuit for supplying power to the variable transmission window, said switching regulator circuit is coupled to said micro controller and is responsive to signals received from said micro controller to selectively vary the power supplied to the variable transmission window.

10. The electrical control system of claim 9 and further including an over-voltage protection circuit coupled to an output of said switching regulator circuit for protecting the variable transmission window from over-voltage conditions.

11. The electrical control system of claim 9 and further including a current limiting circuit coupled to said switching regulator circuit for preventing excessive current from flowing through the variable transmission window.

12. The electrical control system of claim 9 and further including a temperature sensor coupled to said micro controller for supplying a temperature signal indicative of an internal air temperature proximate the variable transmission window, wherein said micro controller responds to said temperature signal by controlling said switching regulator circuit to vary the transmission of the variable transmission window.

13. The electrical control system of claim 9 and further including a light sensor coupled to said micro controller for supplying a light level signal indicative of a light level on the inside of the variable transmission window, wherein said micro controller responds to said light signal by controlling said switching regulator circuit to vary the transmission of the variable transmission window.

14. The electrical control system of claim 9 and further including an input device coupled to said micro controller for receiving input from a user and supplying the input to said micro controller.

15. The electrical control system of claim 9 and further including a display coupled to said micro controller for displaying status information to a user.

16. The electrical control system of claim 9 and further including a receiver for receiving a command from a remote control device via a wireless communication link, said receiver is coupled to said micro controller to supply a control signal representing the received command, wherein said micro controller responds to the receipt of a control signal by causing said switching regulator circuit to vary the transmittance of the variable transmission window.

17. The electrical control system of claim 1, wherein said sensing circuit is electrically coupled to the first electrode and the second electrode of the variable transmission window.

18. A building comprising:

a plurality of variable transmission windows, each including a variable transmission medium and a pair of electrodes to which signals may be applied to said variable transmission medium to vary the transmission of said variable transmission medium;

a master control circuit for supplying control signals representing transmittance levels for said variable transmission windows;

a plurality of window control circuits coupled to said master control circuit, each window control circuit coupled to the pair of electrodes of at least one of said variable transmission windows for controlling the transmittance of at least one of said variable transmission windows in response to control signals received from said master control circuit;

a sensing circuit for sensing an abnormal electrical load condition across the pair of electrodes and the variable transmission medium of at least one of the variable transmission windows; and

a security system interface coupled to receive an indication from said sensing circuit that an abnormal electrical load condition exists in one of the variable transmission windows.

19. The building of claim 18, wherein said master control unit polls each of the window control units to signal changes which indicate a probable breach of security.

20. The building of claim 18, wherein said window control units detect window closure status and report window opening to the security system interface.

21. The building of claim 18, wherein said window control circuits each include a memory device in which an address is stored that uniquely identifies the window control circuit to said master control circuit.

22. The building of claim 18, wherein said master control circuit and said window control circuits are coupled via a two-way data link.

23. The building of claim 18, wherein said master control circuit and said window control circuits are coupled via a low voltage power line pair.

24. The building of claim 23, wherein said master control circuit supplies power to said window control circuits over said low voltage power line pair.

25. The building of claim 24, wherein said master control circuit and said window control circuits perform bi-directional communication over said low voltage power line pair.

26. The building of claim 18, wherein said variable transmission windows are electrochromic windows.

27. The building of claim 18, wherein said sensing circuit is electrically coupled to both of the pair of electrodes of at least one of the variable transmission windows.

28. A method of determining whether a security breach has occurred through the breakage or opening of a variable transmission window, the variable transmission window providing a current path when closed, where the current path passes through a pair of electrodes and a variable transmission medium of the variable transmission window and where the current path is used to selectively vary the transmission of the variable transmission window, the method comprising the steps of:

sensing whether there is an abnormal electrical load condition in the current path through the variable transmission window; and

determining that there has been a security breach through the variable transmission window when an abnormal electrical load condition is sensed.

29. The method of claim 28, wherein the abnormal electrical load condition is a near short or near open circuit.

30. The method of claim 28, wherein the abnormal electrical load condition includes an open circuit that occurs when a window is open.