Equipment and methods for emergency lighting that provides brownout detection and protection

• US 7,256,556 B2
• Filed: 09/28/2004
• Issued: 08/14/2007
• Est. Priority Date: 09/28/2004
• Status: Active Grant

• Current Assignee: ABL IP Holding LLC (Acuity Brands, Inc.)
• Original Assignee: Acuity Brands, Inc.
• Inventors: Lane, John Evan, Zulim, Don
• Primary Examiner(s): Dinh; Trinh
• Assistant Examiner(s): Le; Tung X
• Application Number:
  US10/952,013
• Publication Number:
  US 20060066258A1
• Time in Patent Office: 1,050 Days
• Field of Search: 315/86, 315/172, 315/174, 315/224, 315/247, 315/291, 315/160, 315/171, 315/209.R, 315/246, 315/272, 315/274, 315/276, 315/307, 315/308, 320/5, 320/14, 320/49
• US Class Current: 315/308
• CPC Class Codes: H02J 9/065 for lighting purposes
• CPC Class Codes: H05B 41/28 using static converters
• CPC Class Codes: H05B 45/375 using buck topology

Abstract

The present invention relates to systems, equipment and methods that provide emergency lighting and allow the detection of brownout conditions. One aspect of the present invention is an emergency lighting system with an input voltage interface for receiving an input voltage, a brownout detection component for detecting a brownout condition on the input voltage and generating a brownout signal, a switch mode power converter for altering the input voltage; and an emergency lighting control and battery charging component for controlling the charging of a battery pack and receiving the brownout signal. Another aspect of the invention is a method of providing emergency lighting performed by receiving an input voltage; automatically establishing a brownout threshold relative to the input voltage; and detecting a brownout condition.

Claims

1. An emergency lighting system comprising:

an input voltage interface for receiving an input voltage;

a brownout detection component for determining the input voltage, setting a brownout threshold based on the input voltage, and generating a brownout signal when a brownout condition is detected;

a switch mode power converter for altering the input voltage, wherein the switch mode power converter has a primary and a secondary side and the brownout detection component determines the input voltage on the primary side; and

an emergency lighting control and battery charging component for controlling the charging of a battery pack and receiving the brownout signal.

2. The system of claim 1 wherein the input voltage interface further comprises:

an AC line voltage interface; and

a rectification and filtering circuit.

3. The system of claim 1 wherein the brownout threshold set by the brownout detection component is based on a proportional relationship to the input voltage.

4. The system of claim 1 wherein

the input voltage has an associated AC line frequency;

and

the brownout detection component determines one or more brownout thresholds independent of the line frequency.

5. The system of claim 1 wherein the brownout detection component communicates the brownout signal to the emergency lighting control and battery charging circuit.

6. The system of claim 5 wherein the brownout detection component is electrically isolated from the secondary side of the switch mode power converter.

7. The system of claim 1 further comprising one or more batteries.

8. The system of claim 1 further comprising a remote test interface component.

9. The system of claim 1, wherein the brownout threshold component is configured to determine brownout thresholds over a wide range of input voltages.

10. An emergency lighting unit comprising:

an input voltage interface for receiving a wide range of input voltages;

a converter for receiving an input voltage from among the wide range of input voltages and having a primary and a secondary side;

a brownout detection component for determining one or more brownout thresholds, monitoring the input voltage on the primary side of the converter, and generating a brownout signal; and

an emergency lighting control and battery charging component for controlling the charging of a battery pack and receiving the brownout signal on the secondary side of the converter.