Thermally self-stabilizing LED module

• US 8,847,520 B2
• Filed: 07/09/2011
• Issued: 09/30/2014
• Est. Priority Date: 09/15/2005
• Status: Active Grant

• Current Assignee: Stacey H. West
• Original Assignee: Stacey H. West
• Inventors: West, Stacey H.
• Primary Examiner(s): Vo, Tuyet Thi
• Application Number:
  US13/135,628
• Publication Number:
  US 20120062150A1
• Time in Patent Office: 1,179 Days
• Field of Search: 315/247, 315/224, 315/225, 315/209.R, 315/185.S, 315/291, 315307-326
• US Class Current: 315/309
• CPC Class Codes: F21L 4/005 the device being a pocket lamp F21L4/022, F21L4/045, F21L4/085 take precedence
• CPC Class Codes: F21V 23/0414 specially adapted to be used with portable lighting devices
• CPC Class Codes: F21V 23/0442 activated by means of a sensor, e.g. motion or photodetectors
• CPC Class Codes: F21V 23/0457 the sensor sensing the operating status of the lighting device, e.g. to detect failure of a light source or to provide feedback to the device
• CPC Class Codes: F21Y 2101/00 Point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/38 using boost 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

An improved LED module that is thermally self-stabilizing, and that is able to be retrofitted into an existing flashlight is provided. In one embodiment, the LED module includes a light emitting diode, an amplifying circuit and a microchip. The amplifying circuit includes a temperature sensing device to sense heat from the light emitting diode. The output of the amplifying circuit is input to the microchip which output to a switching device that regulates energy that is delivered to the light emitting diode. The switching device may be part of a boosting circuit, a bucking circuit or an inverting circuit.

Claims

1. A lighting module for flashlights, said lighting module comprising:

a light emitting diode;

an amplifying circuit including a thermistor, said thermistor arranged to sense heat from said light emitting diode; and

a microchip having an input and an output, said amplifying circuit coupled to said input, said output coupled to a switching device that regulates energy delivered to the light emitting diode.

2. The lighting module of claim 1, wherein said switching device is part of a boosting circuit.

3. The lighting module of claim 1, wherein said switching device is part of a bucking circuit.

4. The lighting module of claim 1, wherein said switching device is part of an inverting circuit.

5. The lighting module of claim 1, wherein said switching device is a MOSFET.

6. The lighting module of claim 1, wherein said microchip is configured to operate the switching device such that 875 mA to 930 mA is delivered to the light emitting diode when said thermistor senses between 20°

C. to 30°

C.

7. The lighting module of claim 1, wherein said microchip is configured to operate the switching device such that 880 mA to 910 mA is delivered to the light emitting diode when said thermistor senses between 23°

C. to 27°

C.

8. The lighting module of claim 1, wherein said microchip is configured to operate the switching device such that substantially 900 mA is delivered to the light emitting diode when said thermistor senses 25°

C.

9. The lighting module of claim 1, wherein said microchip is configured to regulate the energy that is delivered to said light emitting diode by adjusting the switching duty cycle of said switching device.

10. The lighting module of claim 1, wherein said microchip is configured to operate the switching device such that 330 mA to 450 mA is delivered to the light emitting diode when said thermistor senses between 80°

C. to 100°

C.

11. The lighting module of claim 1, wherein said microchip is configured to operate the switching device such that 330 mA to 370 mA is delivered to the light emitting diode when said thermistor senses between 90°

C. to 100°

C.

12. The lighting module of claim 1, wherein said microchip is configured to operate the switching device such that substantially 330 mA is delivered to the light emitting diode when said thermistor senses 100°

C.

13. The lighting module of claim 1, wherein said microchip provides a thermally regulated signal to the LED based on the temperature sensed by the thermistor.

14. The lighting module of claim 1, wherein said microchip is a microprocessor.

15. The lighting module of claim 1, wherein said microchip is an integrated circuit.

16. The lighting module of claim 1, wherein said microchip is energized by a power source, wherein the energy of said power source depletes over time.