TRAFFIC LED LAMP WITH INTERNAL CIRCUIT BACKUP SYSTEM

• US 20100039794A1
• Filed: 08/17/2009
• Published: 02/18/2010
• Est. Priority Date: 08/15/2008
• Status: Active Grant

• Current Assignee: Current Lighting Solutions, LLC (f/k/a GE Lighting Solutions, LLC) (American Industrial Partners)
• Original Assignee: Lumination LLC
• Inventors: ESSIAMBRE, BENOIT, CHRISMAN, JOHN, GHANEM, MOHAMED CHERIF, POIRIER, CHRISTIAN
• Granted Patent: US 8,248,271 B2
• Time in Patent Office: Days
• US Class Current: 362/20
• CPC Class Codes: F21W 2111/02 for roads, paths or the like
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G08G 1/095 Traffic lights
• CPC Class Codes: H02J 9/065 for lighting purposes
• CPC Class Codes: H05B 45/355 Power factor correction [PFC]; Reactive power compensation
• CPC Class Codes: H05B 45/36 Circuits for reducing or suppressing harmonics, ripples or electromagnetic interferences [EMI]
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: H05B 45/38 using boost topology
• CPC Class Codes: H05B 45/395 Linear regulators

Abstract

In accordance with one aspect of the present exemplary embodiment, an LED lamp is provided. In one embodiment, the LED lamp is made to be mounted in a traffic signal housing that includes other lamps, where the LED lamp can be red, yellow, green or another color and can represent a full ball aspect, an arrow aspect or another aspect. The LED lamp is adapted to be powered by an external power source and includes an input power circuit receiving an input voltage from the external power source. The input power circuit includes a power detection circuit that is adapted to determine a power state of the traffic LED lamp. The LED lamp further includes an LED load and a battery powered driving circuit. The battery power driving circuit drives the LED load if the power state of the LED lamp is in a power failure state.

Claims

1. An LED lamp powered by an external power source, said system comprising:

an input power circuit receiving an input voltage from the external power source, wherein the input power circuit includes a power detection circuit that is adapted to determine a power state of the LED lamp;

an LED load; and

,

a battery powered driving circuit, wherein said battery power driving circuit drives the LED load if the power state of the LED lamp is in a power failure state.

2. The LED lamp of claim 1, wherein the battery powered driving circuit comprises a flasher circuit operative to periodically drive the LED load.

3. The LED lamp of claim 1, wherein the LED lamp further includes a housing, wherein the input power circuit, the LED load and the battery powered driving circuit are disposed within the housing.

4. The LED lamp of claim 3, wherein a battery associated with the battery powered driving circuit is inside the housing.

5. The LED lamp of claim 3, wherein a battery associated with the battery powered driving circuit is external to the housing.

6. The LED lamp of claim 1, further including a battery charging circuit.

7. The LED lamp of claim 1, wherein the power detection circuit determines the power state by generating a measurement of the input voltage.

8. The LED lamp of claim 7, wherein the power detection circuit determines the power state by further comparing the measurement of the input voltage against a reference threshold.

9. The LED lamp of claim 7, wherein the measurement of the input voltage exceeds a first predetermined threshold when the power state of the LED lamp is in an on state or an off state.

10. The LED lamp of claim 9, wherein the measurement of the input voltage exceeds a second predetermined threshold when the power state of the LED lamp is in the on state, but not when the LED lamp is in the off state.

11. The LED lamp of claim 9, wherein the measurement of the input voltage is less than the first predetermined threshold when the power state of the traffic LED lamp in the power failure state.

12. The LED lamp of claim 1, wherein the LED load is driven by the external power source when the LED lamp is in an on state, wherein the LED load is not driven when the LED lamp is in an off state.

13. The LED lamp of claim 1, wherein the power state of the LED lamp is one of an on state, an off state, or the power failure state.

14. A self backup system for an LED lamp, wherein the LED lamp includes an LED load, said self backup system comprising:

a line detector circuit adapted to generate a measurement of a voltage from a power supply;

a battery comprising a voltage;

a voltage converter circuit adapted to convert the voltage of the battery to a driving voltage;

a flasher circuit adapted to periodically drive the LED load with the driving voltage; and

,

a flasher enabling circuit adapted to determine whether to enable the flasher circuit based upon the measurement of the voltage.

15. The LED lamp of claim 14, wherein the measurement of the voltage exceeds a first predetermined threshold when the LED lamp is in an on state or an off state.

16. The LED lamp of claim 15, wherein the measurement of the voltage exceeds a second predetermined threshold when the LED lamp is in the on state, but not when the LED lamp is in the off state.

17. The LED lamp of claim 15, wherein the measurement of the voltage is less than the first predetermined threshold when the LED lamp in a power failure state.

18. The self backup system of claim 14, wherein the flasher enabling circuit compares the measurement of the voltage against a reference threshold.

19. A method for providing a safety backup signal in an LED lamp, wherein said LED lamp receives power from an external power source, said method comprising:

detecting a power state of the LED lamp based upon a measurement of an input voltage from the external power source;

determining whether the power state is in a power failure state;

generating the safety backup signal from a backup power source if the power state is in the power failure state, wherein the safety backup signal is periodic; and

,

providing the safety backup signal to the LED lamp if the power state is in the power failure state.

20. The method of claim 19, wherein said detecting procedure is operative to distinguish between an on state, an off state and the power failure state, said detecting procedure comprising:

scaling the input voltage, wherein the scaled voltage is the minimum of a first predetermined threshold and the input voltage; and

comparing the scaled voltage with a second predetermined threshold to determine the power state.