LED replacement for low voltage lamps

• US 7,812,550 B2
• Filed: 05/28/2008
• Issued: 10/12/2010
• Est. Priority Date: 05/28/2008
• Status: Expired due to Fees

• Current Assignee: Revlite Technologies, Inc.
• Original Assignee: Revlite Technologies, Inc.
• Inventors: Wylde, Jonathan, Harmgardt, Hans L. G.
• Primary Examiner(s): Owens; Douglas W
• Assistant Examiner(s): Vu; Jimmy T
• Application Number:
  US12/154,000
• Publication Number:
  US 20090295292A1
• Time in Patent Office: 867 Days
• Field of Search: 362/264, 362/273, 362/294, 362/227, 362/235, 362/240, 362/241, 362543-546, 362/800, 315/50, 315/51, 315/200.R, 315/224, 315/246, 315/247, 315/272, 315/276, 315/291, 315307-309, 315/312
• US Class Current: 315/291
• CPC Class Codes: F21K 9/233 specially adapted for generating a spot light distribution, e.g. for substitution of reflector lamps
• CPC Class Codes: F21K 9/238 Arrangement or mounting of circuit elements integrated in the light source
• CPC Class Codes: F21V 23/003 the elements being electronics drivers or controllers for operating the light source, e.g. for a LED array
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/325 Pulse-width modulation [PWM]
• CPC Class Codes: H05B 45/357 specially adapted for retrofit LED light sources
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

The LED replacement for low voltage lamps has a plurality of LED lights disposed in a housing capped by a multifaceted reflector to provide lighting having comparable lighting characteristics to non-LED sourced low voltage lamps. Power conditioning solid state circuitry is disposed in the housing and provides the LED lights with a regulated excitation voltage source. The power conditioning circuitry has at least one ceramic capacitor in parallel with output leads of a power supply for the lamp. A zener diode pair having anodes connected together is disposed in parallel with the ceramic capacitor. The power conditioning circuitry is disposed in advance of a voltage rectifier and filter bank, whose output is provided to a voltage regulator that provides regulated DC voltage to the LED light sources. Output of the voltage regulator is modulated by thermal protection circuitry that throttles the LEDs off responsive to lamp overheating.

Claims

1. An LED replacement for low voltage lamps, comprising:

a housing;

a plurality of light emitting diodes disposed in the housing;

a translucent, reflective lens disposed on the housing, the translucent, reflective lens focusing light emissions from the light emitting diodes away from the housing;

lamp-energizing electrical contacts disposed at the back of the housing;

voltage rectification-voltage regulation LED driver circuitry, the voltage rectification-voltage regulation LED driver circuitry accepting as input a low voltage alternating current from a transformer and producing a constant current regulated voltage responsive thereto as output to the LEDs;

a ceramic capacitor electrically connected across the low voltage alternating current input, the ceramic capacitor providing an adequate load to the transformer to cause the transformer to energize the input;

thermal protection circuitry connected to the voltage rectification-voltage regulation LED driver circuitry, the thermal protection circuitry throttling back power to the light emitting diodes as the LED lamp exceeds a predetermined threshold temperature; and

a pair of zener diodes in parallel with the ceramic capacitor at the low voltage alternating current input, the zener diodes having their respective anodes connected together and their respective cathodes connected to respective terminals of the low voltage alternating current input.

2. The LED replacement according to claim 1, wherein the housing is compatible with an MR-16 form factor.

3. The LED replacement according to claim 1, wherein the voltage rectification circuitry comprises a plurality of diodes in a full-wave rectification configuration.

4. The LED replacement according to claim 1, further comprising a Schottky diode electrically disposed at the output of a voltage regulator/driver portion of the voltage rectification-voltage regulation LED driver circuitry.

5. The LED replacement according to claim 1, wherein the voltage rectification portion of the LED driver circuitry further comprises a plurality of tantalum capacitors electrically disposed in parallel across the rectifier output.

6. The LED replacement according to claim 1, wherein the thermal protection circuitry has a configuration for pulse width modulation dimming.

7. The LED replacement according to claim 1, wherein the thermal protection circuitry is configured for linear dimming.

8. The LED replacement according to claim 1, wherein the plurality of light emitting diodes is electrically disposed in parallel rows, a smoothing capacitor being disposed in parallel across the rows of LEDs.

9. The LED replacement according to claim 1, wherein the ceramic capacitor has a value that is approximately 0.015 uF at approximately a 50-volt rating.

10. The LED replacement according to claim 1, wherein the pair of zener diodes provides an approximately 19-volt clipping action.

11. An LED replacement for low voltage lamps, comprising:

a housing;

a plurality of light emitting diodes disposed in the housing;

a translucent, reflective lens disposed on the housing, the translucent, reflective lens focusing light emissions from the light emitting diodes away from the housing;

lamp-energizing electrical contacts disposed at the back of the housing;

voltage rectification-voltage regulation LED driver circuitry, the voltage rectification-voltage regulation LED driver circuitry accepting as input a low voltage alternating current from a transformer and producing a constant current regulated voltage responsive thereto as output to the LEDs, wherein a voltage regulator/driver portion of the voltage rectification-voltage regulation LED driver circuitry comprises approximately 2 MHz high-brightness LED drivers having high-side current sense and approximately 5000;

1 dimming;

a ceramic capacitor electrically connected across the low voltage alternating current input, the ceramic capacitor providing an adequate load to the transformer to cause the transformer to energize the input; and

thermal protection circuitry connected to the voltage rectification-voltage regulation LED driver circuitry, the thermal protection circuitry throttling back power to the light emitting diodes as the LED lamp exceeds a predetermined threshold temperature.

12. An LED replacement for low voltage lamps, comprising:

a housing;

a plurality of light emitting diodes disposed in the housing;

a translucent, reflective lens disposed on the housing, the translucent, reflective lens focusing light emissions from the light emitting diodes away from the housing;

lamp-energizing electrical contacts disposed at the back of the housing;

voltage rectification-voltage regulation LED driver circuitry, the voltage rectification-voltage regulation LED driver circuitry accepting as input a low voltage alternating current from a transformer and producing a constant current regulated voltage responsive thereto as output to the LEDs;

a ceramic capacitor electrically connected across the low voltage alternating current input, the ceramic capacitor providing an adequate load to the transformer to cause the transformer to energize the input; and

thermal protection circuitry connected to the voltage rectification-voltage regulation LED driver circuitry, the thermal protection circuitry throttling back power to the light emitting diodes as the LED lamp exceeds a predetermined threshold temperature, wherein the thermal protection circuitry has a configuration that initiates power throttleback at approximately 60°

C., the configuration being characterized by a throttling back gradient cutting the power by 50% at approximately 85% of the maximum allowable temperature.