Light fixture emergency power system

Patent metadata

Field	Value
Publication number	US-10129958-B2
Application number	US-201414447937-A
Country	US
Kind code	B2
Filing date	Jul 31, 2014
Priority date	Jul 31, 2014
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

Techniques are presented herein to operate a light fixture as in an emergency mode in order to verify that the light emitted by the light fixture when operated in the emergency mode complies with emergency operating policies, as well as to detect failures. The light emitted by the light fixture in emergency mode may be measured and adjusted to optimize the runtime of the light fixture in the emergency mode. The light fixture is connected to a lighting control system via a control network which supplies electrical power to charge an onboard battery of a light fixture and to operate the light fixture. The light fixture may be caused to operate in the emergency lighting mode when a main electrical power supply is interrupted or when performances of the light fixture and of the onboard battery are tested.

First claim

What is claimed is:

1. A method comprising:
receiving, from a control network, electrical power configured to charge at least one onboard battery of at least one light fixture using the received electrical power, wherein the control network is a communication network that provides both electrical power supply and data communication;
causing the at least one light fixture to operate in an emergency lighting mode upon determining by a fixture processor that the received electrical power from the control network is interrupted;
causing the at least one light fixture to operate in the emergency lighting mode upon determining by the fixture processor that a control has been received from the control network to switch the at least one light fixture to the emergency lighting mode;
wherein a port of a Power over Ethernet (PoE) switch is connected to the control network and the at least one light fixture; and
wherein the received electrical power from the control network and the received control from the control network is provided to the at least one light fixture via the port of the PoE switch.

2. The method of claim 1 , wherein the causing of the at least one light fixture to operate in the emergency lighting mode upon determining that the received electrical power from the control network is interrupted comprises:
changing light settings of the at least one light fixture to predetermined light settings; and
supplying power from the at least one onboard battery to the at least one light fixture to cause the at least one light fixture to emit light according to the predetermined light settings.

3. The method of claim 2 , wherein the causing of the at least one light fixture to operate in the emergency lighting mode upon determining that the control is received from the control network to switch the at least one light fixture to the emergency lighting mode comprises:
terminating charging of the at least one onboard battery;
changing light settings of the at least one light fixture to predetermined light settings; and
supplying power from the at least one onboard battery to cause the at least one light fixture to emit light according to the predetermined light settings.

4. The method of claim 3 , further comprising:
obtaining a measure of a light level emitted from the at least one light fixture by at least one fixture sensor of the at least one light fixture; and
adjusting the light settings of the at least one light fixture to a minimum level of an emergency illumination in accordance with an emergency operating policy for the at least one light fixture.

5. The method of claim 3 , wherein the predetermined light settings to which the light settings of the at least one light fixture are set when operated in the emergency lighting mode comprise settings of at least one of a brightness, a color, or a radiation pattern to control the light emitted by the at least one light fixture such that the light emitted complies with emergency lighting regulations and is optimized to extend a runtime of the at least one light fixture in the emergency lighting mode.

6. The method of claim 1 , wherein a lighting control system includes a local light controller in communication with the at least one light fixture via the control network, the method further comprising:
determining, at the local light controller, that a main electrical power supply is interrupted;
supplying power to the lighting control system from an uninterruptable power system;
transmitting a control to the at least one light fixture to switch the at least one light fixture to the emergency lighting mode; and
changing light settings of the at least one light fixture to predetermined light settings to cause the at least one light fixture to emit light according to the predetermined light settings.

7. The method of claim 6 , further comprising:
terminating charging of the at least one onboard battery of the at least one light fixture; and
supplying power from the at least one onboard battery to the at least one light fixture.

8. The method of claim 6 , further comprising:
obtaining, by a sensor, a measure of a light level emitted from the at least one light fixture;
sending the measure of the light level emitted to the local light controller of the lighting control system; and
adjusting the light settings of the at least one light fixture to a minimum level of an emergency illumination in accordance with an emergency operating policy for the at least one light fixture.

9. The method of claim 6 , further comprising:
periodically measuring a voltage of the at least one onboard battery and recording information about voltage changes of the at least one onboard battery to generate a discharge curve;
sending the recorded information about voltage changes to a central lighting control system; and
analyzing the information about voltage changes in the central lighting control system by estimating a remaining useful float life of the at least one onboard battery and detecting failures of the at least one onboard battery.

10. The method of claim 6 , further comprising:
obtaining a measure of a light level emitted from the at least one light fixture;
sending the measure of the light level to a central lighting control system; and
determining whether the measure of the light level is in accordance with the predetermined light settings.

11. The method of claim 1 , further comprising determining whether an outgoing current of the port of the PoE switch changes to confirm that the at least one light fixture is operating in the emergency lighting mode.

12. A system comprising:
a lighting control system;
at least one light fixture connected to the lighting control system via a control network, wherein the control network is a communication network that provides both electrical power supply and data communication;
an uninterruptable power system to supply electrical power to the lighting control system;
a local light controller of the lighting control system to:
determine that a main electrical power supply is interrupted; and
send the control to the at least one light fixture to switch the at least one light fixture to the emergency lighting mode upon determination that the main electrical power supply is interrupted;

wherein the lighting control system supplies electrical power via the control network to the at least one light fixture to charge at least one onboard battery of the at least one light fixture, causes the at least one light fixture to operate in an emergency lighting mode upon an interruption of the electrical power, and causes the at least one light fixture to operate in the emergency lighting mode upon a control received from the control network to switch the at least one light fixture to the emergency lighting mode; and
wherein the lighting control system further comprises a Power over Ethernet (PoE) switch comprising a port to connect the at least one light fixture to the lighting control system via the control network;
wherein the electrical power supplied via the control network and the received control from the control network is provided to the at least one light fixture via the port of the PoE switch; and
wherein the local light controller determines whether an outgoing current of the port of the PoE switch changes to confirm that the at least one light fixture is operating in the emergency lighting mode.

13. The system of claim 12 , further comprising:
a fixture processor to:
determine whether the electrical power supplied via the control network is interrupted;
upon determination that the electrical power supplied via the control network is interrupted

Assignees

• Cisco Tech Inc

Inventors

• Laherty Matthew A
• Macgowan William
• Byers Charles Calvin

Classifications

• H02J7/865 Primary

  Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence) · CPC title

• H05B47/105

  in response to determined parameters · CPC title

• H02J9/065

  for lighting purposes · CPC title

• H02J7/0068

  Electricity · mapped topic

• H05B37/0227

  Electricity · mapped topic