Low-Cost Power Measurement Circuit

• US 20100301834A1
• Filed: 07/09/2010
• Published: 12/02/2010
• Est. Priority Date: 04/14/2009
• Status: Active Grant

• Current Assignee: OSRAM Sylvania Inc. (Ams-Osram AG)
• Original Assignee: Digital Lumens, Inc. (Ams-Osram AG)
• Inventors: Chemel, Brian J., Kondo, Steve T., Johnston, Scott D., Piepgras, Colin
• Granted Patent: US 8,593,135 B2
• Time in Patent Office: Days
• US Class Current: 324/105
• CPC Class Codes: H05B 47/155 Coordinated control of two or more light sources
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

In embodiments of the present invention, a method and system is provided for designing improved intelligent, LED-based lighting systems. The LED based lighting systems may include fixtures with one or more of rotatable LED light bars, integrated sensors, onboard intelligence to receive signals from the LED light bars and control the LED light bars, and a mesh network connectivity to other fixtures.

Claims

1. A power measurement system, comprising:

an optoisolator and a Zener diode in electrical communication with one another and an AC power line;

a current transformer in electrical communication with the AC power line that provides an isolated current measurement;

a temperature sensor, located in proximity to the Zener diode that measures a temperature of the system and communicates the temperature to a temperature compensation system; and

a processor that decodes the AC voltage pulses, by measuring the digital pulse width which is indicative of the amount of time the AC voltage spends above a Zener reference voltage, to determine an instantaneous AC voltage, the processor further combining the instantaneous AC voltage with the analog current measurement to provide an instantaneous power consumption.