Method and system for luminance characterization

• US 20090001893A1
• Filed: 09/02/2008
• Published: 01/01/2009
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: LED Roadway Lighting Ltd.
• Original Assignee: Streetlight Intelligence, Inc. (LED Roadway Lighting Ltd.)
• Inventors: Kurz, Gerald E., Kubek, Laurence E., Wong, Carol A., Cleland, Donald A.
• Granted Patent: US 7,834,555 B2
• Time in Patent Office: Days
• US Class Current: 315/151
• CPC Class Codes: G01J 1/42 using electric radiation detectors optical or mechanical part G01J1/04; by comparison with a reference light or electric value G01J1/10
• CPC Class Codes: G01J 2001/4247 for testing lamps or other light sources
• CPC Class Codes: H05B 41/2882 the control resulting from an action on the static converter
• CPC Class Codes: H05B 41/2885 Static converters especially adapted therefor; Control thereof H05B41/2882 takes precedence
• CPC Class Codes: H05B 41/30 in which the lamp is fed by pulses, e.g. flash lamp
• CPC Class Codes: H05B 41/40 discontinuously
• CPC Class Codes: H05B 47/195 the transmission using visible or infrared light
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A system for luminance characterization of a luminaire includes a ballast coil and a multi-tap capacitor connected in series with the ballast coil. The multi-tap capacitor has a plurality of tap capacitors integrated into a capacitor housing. A plurality of switches are each coupled to one of the plurality of tap capacitors for selectively coupling the tap capacitors together to produce a multi-tap capacitance corresponding to a configuration of the plurality of switches. A lamp is connected in series with the multi-tap capacitor and the ballast coil. A photometer is located to measure light intensity of the lamp and to produce a lumen output measurement. A memory is used to store a database having a plurality of lumen output measurements, each corresponding to a multi-tap capacitance corresponding to all configurations of the plurality of switches.

Claims

1. A system for controlling the output of a streetlight comprising:

a streetlight;

a light sensor coupled with the streetlight;

a controller coupled to the streetlight;

a radio transceiver coupled with said controller;

at least a second radio transceiver coupled to a second controller;

a central controller;

wherein said central controller is operable to generate a message to command said controller to change an output of said streetlight;

wherein the message is transmitted from said central controller via said second controller to the radio transceiver; and

further wherein said controller uses an input from said light sensor to determine an adjustment to said output.

2. The system of claim 1 wherein said message is generated in response to a request to reduce electrical demand.

3. The system of claim 2 wherein said request is provided by a power company.

4. The system of claim 1 wherein said message is generated from a schedule.

5. A streetlight controller for controlling a luminance output of an associated streetlight that is coupled thereto, the streetlight controller comprising:

a light sensor coupled with the associated streetlight;

a radio transceiver operable to receive a message from an other transmitter;

one or more switches selectively operative to control the luminance output; and

a processor coupled to the light sensor, the radio transceiver, and the one or more switches and operative to selectively control the one or more switches and thereby control the luminance output,

the processor further cooperatively operable with the radio transceiver to interpret the message from the other radio transceiver, the message including an indicated change in the luminance output of the associated streetlight,

wherein the processor uses an input from the light sensor and the indicated change to selectively control the one or more switches to change the luminance output.

6. The streetlight controller of claim 5 wherein the processor in cooperation with the radio transceiver receives and interprets a message to reduce the luminance output to thereby reduce electrical demand.

7. The streetlight controller of claim 5 wherein the processor in cooperation with the radio transceiver receives and interprets a message from an other transmitter, the other transmitter comprising a second transmitter that is part of a mesh network.

8. The streetlight controller of claim 5 wherein the processor in cooperation with the radio transceiver receives and interprets a message from a central controller, the message responsive to a request to reduce power demand, the request originating from a power company.

9. The streetlight controller of claim 5 wherein the processor in cooperation with the radio transceiver receives and interprets a message to change the luminance output, responsive to an emergency.

10. The streetlight controller of claim 5 wherein the processor in cooperation with the radio transceiver receives and interprets the message, which is generated from a schedule.

11. The streetlight controller of claim 5 wherein the processor in cooperation with the radio transceiver receives and interprets the message from one of an emergency vehicle transmitter, a power company transmitter, and an alarm transmitter.

12. A method of controlling a luminance output of a streetlight, the method comprising:

receiving, at a radio transceiver a message from a central controller;

interpreting, at a processor, the message, the message including an indicated change to the luminance output;

obtaining an input from a light sensor; and

responsive to the message and the input, adjusting the luminance output in accordance with the indicated change.

13. The method of claim 12 wherein the message from the central controller is responsive to a request to reduce power consumption.

14. The method of claim 12 wherein the message from the central controller is responsive to a request to reduce power consumption, the request provided by a power company.

15. The method of claim 12 wherein the message from the central controller is responsive to an emergency.

16. The method of claim 12 wherein the message from the central controller is provided via a mesh network.

17. The method of claim 12 wherein the adjusting the luminance output further comprises selectively enabling a plurality of switches to control power supplied to a lamp from a ballast.