Lighting device

• US 9,307,599 B2
• Filed: 06/02/2015
• Issued: 04/05/2016
• Est. Priority Date: 03/31/2011
• Status: Expired due to Fees

• Current Assignee: Litonics Limited
• Original Assignee: Litonics Limited
• Inventors: Williams, Nicolas
• Primary Examiner(s): Le, Tung X
• Application Number:
  US14/728,622
• Publication Number:
  US 20150296586A1
• Time in Patent Office: 308 Days
• Field of Search: 315/86, 315/88, 315/224, 315/246, 315/274, 315/276, 315/291, 315/297, 315/307
• US Class Current: 1/1
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21S 9/024 using a supplementary light source for emergency lighting
• CPC Class Codes: F21V 3/00 Globes; Bowls; Cover glasses with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506
• CPC Class Codes: F21Y 2113/20 of different form
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01R 33/9453 for screw type coupling devices
• CPC Class Codes: H02J 9/065 for lighting purposes
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 47/17 Operational modes, e.g. switching from manual to automatic mode or prohibiting specific operations
• CPC Class Codes: H05B 47/175 by remote control
• CPC Class Codes: H05B 47/20 Responsive to malfunctions or to light source life; for protection
• CPC Class Codes: H05B 47/29 Circuits providing for substitution of the light source in case of its failure
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

In one embodiment of lighting devices and lighting systems, the lighting device has a connection for connecting to a primary power supply and has a secondary power supply, such as a battery. A measuring circuit is operable to measure an impedance of the primary power supply connection and to determine from the measurement if a main power supply has failed, and if so whether to power light sources using power from the secondary power supply.

Claims

1. A lighting device comprising:

one or more light sources;

a primary input power connection for receiving primary power from a primary power supply, for powering at least one of the one or more light sources;

a secondary input power connection for receiving secondary power from a secondary power supply, for powering at least one of the one or more light sources; and

electronic circuitry coupled to the input power connections and arranged to control power delivery to at least one of the one or more light sources using power received at the input power connections;

wherein the electronic circuitry comprises sensing circuitry connected to the primary input power connection and configured to sense an external impedance connected to the primary input power connection and an isolator for isolating the sensing circuitry from other components of the lighting device, the other components of the lighting device being electrically connected to the primary input power connection and presenting a low impedance across the primary input power connection at least when said sensing circuitry is sensing said external impedance.

2. A lighting device according to claim 1, wherein the isolator comprises a semiconductor junction device isolating said sensing circuitry from the other components of said electronic circuitry.

3. A lighting device according to claim 2, wherein said semiconductor junction device comprises a zener diode.

4. A lighting device according to claim 2, wherein the semiconductor junction device is coupled to the primary input power connection and is connected to the sensing circuitry such that the semiconductor junction device is reverse biased when said sensing circuitry is sensing the external impedance connected to the primary input power connection.

5. A lighting device according to claim 2, wherein the sensing circuitry is arranged to apply a measurement voltage to the primary input power connection and wherein an amplitude of the measurement voltage is lower than a breakdown voltage of the semiconductor junction device.

6. A lighting device according to claim 1, wherein the isolator comprises a transformer.

7. A lighting device according to claim 1, wherein said isolator comprises a relay device isolating one or more of said light sources from the sensing circuitry.