Multi-zone closed loop daylight harvesting having at least one light sensor

• US 8,110,994 B2
• Filed: 04/29/2009
• Issued: 02/07/2012
• Est. Priority Date: 05/05/2005
• Status: Expired due to Fees

• Current Assignee: Leviton Manufacturing Company Incorporated
• Original Assignee: Leviton Manufacturing Company Incorporated
• Inventors: Hick, Robert L., Leinen, Richard A.
• Primary Examiner(s): Vu, David Hung
• Application Number:
  US12/432,066
• Publication Number:
  US 20090212708A1
• Time in Patent Office: 1,014 Days
• Field of Search: 315/155, 315/156, 315/157, 315/158, 315/159, 315/149, 250/214.AL
• US Class Current: 315/149
• CPC Class Codes: H05B 39/042 by measuring the incident light
• CPC Class Codes: H05B 41/3922 and measurement of the incident light
• CPC Class Codes: H05B 47/175 by remote control

Abstract

A multi-zone daylight harvesting method and apparatus having a closed loop system utilizing a single light sensor is disclosed herein. This light control system includes an ambient light sensor connected to a detection circuit for detecting the amount of ambient light within a given zone and converting the light signal to an digital one. A control device couples to receive a predetermined rate of change for each respective zone from a storage unit along with the converted digital signal. The control device connects each zone of a plurality of electrical loads to control the power supplied to the electrical load at the predetermined corresponding rate of change and responsive to the amount of ambient light detected.

Claims

1. A method for adjusting a plurality of electrical loads in a plurality of zones, comprising:

determining an ambient light level with a light sensor; and

adjusting the light output in each zone at a different predetermined rate of change for each zone responsive to the ambient light level determined by the light sensor

wherein;

the plurality of zones are located in a space that receives light from an external source; and

the zones can receive unequal amounts of light from the external source.

2. A method according to claim 1, wherein the plurality of zones includes a first zone, a second zone and a third zone, and wherein the first zone has a first predetermine rate of change, the second zone has a second predetermined rate of change, and a third zone has a third predetermined rate of change.

3. A method according to claim 1 wherein the light from the external source comprises sunlight.

4. A method according to claim 1 wherein the light sensor is located in one of the plurality of zones.

5. A method according to claim 1 wherein the plurality of zones includes a first zone and a second zone, and the plurality of electrical loads includes a first light source and a second light source, the method further comprising:

storing a first rate of change and a second rate of change, wherein the first and second rates of change are different;

wherein adjusting the light output includes controlling the first light source in the first zone and the second light source in the second zone in response to the ambient light;

wherein the brightness of the first light source in the first zone is changed at the first rate of change in response to a change in the ambient light; and

wherein the brightness of the second light source in the second zone is changed at the second rate of change in response to the change in ambient light.

6. A method according to claim 5 wherein the first rate of change is proportional to the change in the ambient light.

7. A method according to claim 6 wherein the first and second rates of change are proportional to the change in the ambient light.

8. A method according to claim 6 wherein the first and second rates of change are accessed by software.

9. A method according to claim 5 wherein the first and second rates of change are stored with an electro-mechanical device.

10. A method according to claim 9 wherein the electro-mechanical device comprises one or more potentiometers.

11. A method according to claim 5 wherein detecting ambient light comprises sensing light only from an exterior source.

12. A method according to claim 5 wherein detecting ambient light comprises sensing light from an exterior source and the first light source.

13. A method according to claim 5 wherein detecting ambient light comprises sensing light from an exterior source, the first light source, and the second light source.

14. A method according to claim 1:

wherein adjusting the light output includes adjusting an amount of power supplied to a first electrical load in a first one of the plurality of zones at a first rate of change relative to the ambient light level detected by the light sensor, and

adjusting an amount of power supplied to a second electrical load in a second one of the plurality of zones at a second rate of change relative to the ambient light level detected by the light sensor.