Thermal control of variable transmittance windows

Patent metadata

Field	Value
Publication number	US-10247996-B2
Application number	US-201715630100-A
Country	US
Kind code	B2
Filing date	Jun 22, 2017
Priority date	Jun 22, 2016
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

An electrical control system for controlling a variable transmittance window is disclosed. The system comprises a driver circuit in communication with an electro-optic element. A controller is in communication with the driver circuit. The controller is configured to identify a temperature condition of the electro-optic element and adjust an output voltage supplied to the electro-optic element in response to the temperature condition.

First claim

What is claimed is:

1. A variable transmittance window system, comprising:
an electro-optic element disposed in a window assembly;
a driver circuit in communication with the electro-optic element;
a current sensor configured to identify a current draw of the driver circuit; and
a controller in communication with the driver circuit and the current sensor, wherein the controller is configured to:
identify a temperature of the electro-optic element based on the current draw;
compare the temperature to a temperature threshold; and
increase a transmittance of the electro-optic element in response to the temperature exceeding the temperature threshold.

2. The window system according to claim 1 , wherein the controller is configured to increase the transmittance by limiting an output voltage supplied to the electro-optic element.

3. The window system according to claim 1 , further comprising a photo sensor disposed proximate to the electro-optic element.

4. The window system according to claim 3 , wherein the controller is further configured to:
identify a transmittance level of the electro-optic element based on a transmittance signal received from the photo sensor.

5. The window system according to claim 4 , wherein the controller is further configured to:
identify the temperature based on the current draw of the electro-optic element and the transmittance signal.

6. The window system according to claim 4 , wherein the controller is further configured to:
identify a condition of the temperature based on a correlation of the current draw to a transmittance level of the electro-optic element identified from the transmittance signal.

7. An electrical control system for controlling a variable transmittance window, comprising:
a driver circuit in communication with an electro-optic element; and
a controller in communication with the driver circuit, wherein the controller is configured to:
identify a temperature condition of the electro-optic element;
adjust an output voltage supplied to the electro-optic element in response to the temperature condition; and
adjust the output voltage increasing a transmittance of the electro-optic element in response to the temperature condition indicating that a temperature threshold is exceeded.

8. The control system according to claim 7 , wherein the controller comprises a current sensor configured to identify a current draw of the electro-optic element.

9. The control system according to claim 8 , wherein the controller is further configured to:
identify the temperature condition in response to the current draw by the electro-optic element.

10. The control system according to claim 8 , further comprising a photo sensor disposed proximate to the electro-optic element.

11. The control system according to claim 10 , wherein the controller is further configured to:
identify a transmittance level of the electro-optic element based on a transmittance signal received from the photo sensor.

12. The control system according to claim 11 , wherein the controller is further configured to:
identify the temperature condition based on the current draw of the electro-optic element and the transmittance signal.

13. The control system according to claim 11 , wherein the controller is further configured to:
identify the temperature condition based on a correlation of the current draw to a transmittance level of the electro-optic element identified from the transmittance signal.

14. The control system according to claim 7 , further comprising a temperature sensor disposed proximate the electro-optic element.

15. The control system according to claim 14 , wherein the controller is further operable to:
identify the temperature condition of the electro-optic element based on a temperature signal from the temperature sensor.

16. A variable transmittance window system, comprising:
an electro-optic element disposed in a window assembly;
a driver circuit in communication with the electro-optic element;
at least one sensor configured to identify a property of the electro-optic element; and
a controller in communication with the driver circuit and the at least one sensor, wherein the controller is configured to:
identify a temperature of the electro-optic element based on the property of the electro-optic element;
compare the temperature to a temperature threshold; and
increase a transmittance of the electro-optic element in response to the temperature exceeding the temperature threshold.

17. The window system according to claim 16 , wherein the sensor comprises at least one of a current sensor, a temperature sensor, and a photo sensor.

18. The window system according to claim 16 , wherein the sensor comprises a current sensor configured to identify a current draw of the driver circuit.

19. The window system according to claim 18 , wherein the controller is further configured to:
identify the temperature of the electro-optic element based on a correlation of the current draw to a temperature of the electro-optic element.

Assignees

• Gentex Corp

Inventors

• Driscoll David I
• Busscher Bradley L
• Stephenson Michael T
• Ash Kevin L
• Tonar William L

Classifications

• E06B2009/2464

  featuring transparency control by applying voltage, e.g. LCD, electrochromic panels · CPC title

• B60J3/04 Primary

  adjustable in transparency · CPC title

• G02F1/153

  Constructional details · CPC title

• E06B2009/2417

  Light path control; means to control reflection · CPC title

• G01R21/06

  by measuring current and voltage (G01R21/08 - G01R21/133 take precedence) · CPC title