Light emitting diode lighting device

• US 8,253,344 B2
• Filed: 05/27/2011
• Issued: 08/28/2012
• Est. Priority Date: 02/06/2008
• Status: Expired due to Fees

• Current Assignee: C Crane Company Incorporated
• Original Assignee: C Crane Company Incorporated
• Inventors: Guest, Ralph E., Johansen, Jarl J., Nelson, Theodore G.
• Primary Examiner(s): Chang, Daniel D
• Application Number:
  US13/117,719
• Publication Number:
  US 20110227495A1
• Time in Patent Office: 459 Days
• Field of Search: 315/244, 315/193, 315/307, 315/276, 315/287, 315/291
• US Class Current: 315/224
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21K 9/238 Arrangement or mounting of circuit elements integrated in the light source
• CPC Class Codes: F21V 17/164 the parts being subjected to bending, e.g. snap joints
• CPC Class Codes: F21V 23/002 Arrangements of cables or conductors inside a lighting device, e.g. means for guiding along parts of the housing or in a pivoting arm
• CPC Class Codes: F21V 23/006 the substrate being distinct from the light source holder
• CPC Class Codes: F21V 29/77 with essentially identical diverging planar fins or blades, e.g. with fan-like or star-like cross-section
• CPC Class Codes: F21V 3/061 the material being glass
• CPC Class Codes: F21V 3/062 the material being plastics
• CPC Class Codes: F21Y 2107/40 on the sides of polyhedrons, e.g. cubes or pyramids
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/32 Pulse-control circuits
• CPC Class Codes: H05B 45/355 Power factor correction [PFC]; Reactive power compensation
• CPC Class Codes: H05B 45/3577 Emulating the dimming characteristics, brightness or colour temperature of incandescent lamps
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/56 involving measures to prevent abnormal temperature of the LEDs
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A lighting device comprises a mounting head having multiple facets each configured to retain an associated Light Emitting Diode (LED). The LEDs are mounted to the facets with a thermally conductive metal pad and thermally conductive adhesive. A connector for the lighting device inserts into a light socket and receives power for operating the LEDs. A heat transfer body is coupled between the mounting head and the connector and transfer heat generated by the LEDs downward from the mounting head and then radially outward. The mounting head, adhesive, metal pad, and heat transfer body form a heat transfer structure that more effectively removes heat generated by the LEDs. In one embodiment, a dimmer circuit is also provided that allows the LED lighting device to operate with conventional dimmer switches.

Claims

1. A control circuit for a lighting device, comprising:

Light Emitting Diodes (LEDs);

a rectifier circuit for converting an Alternating Current (AC) power source into a Direct Current (DC) power source;

a power conditioning circuit coupled across the rectifier circuit and configured to condition the DC power source;

a controller configured to monitor an analog reference signal corresponding with the DC power source and generate pulses according to the reference signal that enable current from the DC power source to activate the LEDs; and

a dimmer circuit configured to reduce the analog reference signal and cause the controller to reduce a duty cycle of the generated pulses that reduce an amount of light generated by the LEDs.

2. The control circuit according to claim 1 further comprising a low pass filter coupled to the dimmer circuit and configured to delay a time response for changing the reference signal.

3. The control circuit according to claim 1 wherein the dimmer circuit reduces an amount of light output by the LEDs responsive to a conventional incandescent light dimmer switch until the LEDs are substantially turned off causing the control circuit to operate with the dimmer circuit in a manner similar to an incandescent light bulb.

4. The control circuit according to claim 1 wherein the dimmer circuit comprises:

a diode coupled across the rectifier circuit and configured to generate a negative voltage; and

a voltage divider coupled between the diode and the controller and configured to reduce the reference signal monitored by the controller.

5. The control circuit according to claim 4 wherein the voltage divider comprises:

a first resistor coupled at a first end to a first end of the diode and coupled at a second end to a voltage monitoring input of the controller;

a second resistor coupled at a first end to a second end of the diode and coupled at a second end to the voltage monitoring input of the controller; and

a third resistor coupled at a first end to the rectifier circuit and coupled at a second end to the voltage monitoring input of the controller.

6. The control circuit according to claim 5 further comprising a delay capacitor coupled at a first end to the second end of the diode and coupled at a second end to the voltage monitoring input of the controller.

7. The control circuit according to claim 6 wherein the delay capacitor and the third resistor cause the control circuit to appear more inductive and change a power factor toward one when powering the LEDs.

8. An apparatus for a lighting device, comprising:

a Light Emitting Diode (LED);

a power conditioning circuit configured to generate a power signal;

a controller configured to monitor the power signal at a monitoring input and generate pulses for activating the LED based on the power signal at the monitoring input; and

a dimmer circuit configured to delay the power signal supplied to the monitoring input of the controller and cause the controller to delay generation of the pulses.

9. The apparatus of claim 8, wherein the delayed power signal is configured to make the power conditioning circuit, controller, and dimmer circuit appear more inductive.

10. The apparatus according to claim 8, wherein the dimmer circuit is configured to reduce the power signal at the monitoring input of the controller and cause the controller to reduce a duty cycle of the pulses.

11. The apparatus according to claim 8, wherein the dimmer circuit comprises:

a diode configured to generate a negative voltage; and

a voltage divider coupled between the diode and the monitoring input of the controller.

12. The apparatus according to claim 11 wherein the voltage divider comprises:

a first resistor coupled at a first end to a first end of the diode and coupled at a second end to the monitoring input of the controller;

a second resistor coupled at a first end to a second end of the diode and coupled at a second end to the monitoring input of the controller; and

a third resistor coupled at a first end to the power signal and coupled at a second end to the monitoring input of the controller.

13. The apparatus according to claim 12 further comprising:

a delay capacitor coupled at a first end to the second end of the diode and coupled at a second end to the monitoring input of the controller.

14. The apparatus according to claim 13 wherein the delay capacitor and the third resistor are configured to adjust a power factor for the power conditioning circuit, controller, and dimmer circuit toward one.

15. The apparatus according to claim 12 further comprising a rectifier circuit having a first terminal coupled to a first end of the diode and a second terminal coupled to the first end of the third resister.

16. The apparatus according to claim 8, wherein the dimmer circuit comprises:

a diode configured to generate a negative voltage;

a voltage divider coupled between the diode and the monitoring input of the controller; and

a delay capacitor coupled to the monitoring input of the controller.

17. An apparatus for a lighting device, comprising:

a Light Emitting Diode (LED);

a power conditioning circuit configured to generate a power signal;

a controller configured to monitor the power signal at a monitoring input and generate pulses for activating the LED based on the power signal at the monitoring input; and

a dimmer circuit configured to delay the power signal supplied to the monitoring input of the controller and cause the controller to delay generation of the pulses, wherein the power conditioning circuit comprises;

a rectifier circuit configured to convert an Alternating Current (AC) power source into a Direct Current (DC) power source;

a first capacitor circuit coupled at a first end to a first terminal of the rectifier circuit;

a second capacitor circuit coupled at a first end to a second terminal of the rectifier circuit;

a first diode coupled at a first end to a second end of the first capacitor circuit and coupled at a second end to a second end of the second capacitor circuit;

a second diode coupled at a first end to the second terminal of the rectifier circuit and coupled at a second end to the second end of the first capacitor circuit;

a third diode coupled at a first end to the first terminal of the rectifier circuit and coupled at a second end to the second end of the second capacitor circuit.