3-way LED bulb

• US 8,198,819 B2
• Filed: 09/17/2009
• Issued: 06/12/2012
• Est. Priority Date: 09/17/2008
• Status: Expired due to Fees

• Current Assignee: Switch Bulb Company, Inc.
• Original Assignee: Switch Bulb Company, Inc.
• Inventors: Lenk, Ronald J.
• Primary Examiner(s): Chang, Daniel D
• Application Number:
  US12/561,514
• Publication Number:
  US 20100090609A1
• Time in Patent Office: 999 Days
• Field of Search: 315/201, 315/205, 315/193, 315/185.R, 315/187, 315/306, 315/307, 315/317, 315/228
• US Class Current: 315/201
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

Circuits to make a 3-way LED light bulb correctly interface to a standard 3-way light socket, producing three levels of light corresponding to the three settings of the socket. One of the circuits prevents color shift due to varying LED current.

Claims

1. A circuit for driving an LED light bulb at varying levels of brightness depending on the energization of a 3-way socket comprising:

a pair of inputs, each input having a rectifier bridge associated therewith and producing parallel outputs;

at least one LED;

a power system for the at least one LED, which runs from the parallel outputs of the rectifier bridges;

an energization detector circuit for each pair of inputs; and

a selection circuit that selects a current feedback for the power system, and

wherein the feedback is dependant on an output of the energization detector circuits.

2. A circuit for driving an LED light bulb at varying levels of brightness depending on the energization of a 3-way socket as set forth in claim 1, wherein said energization detector circuit consists of a half wave rectifier, a resistor divider and a capacitive filter.

3. A circuit for driving an LED light bulb at varying levels of brightness depending on the energization of a 3-way socket as set forth in claim 1, wherein the selection circuit consists of a pair of gain-setting circuits for each pair of inputs.

4. A circuit for driving an LED light bulb at varying levels of brightness depending on the energization of a 3-way socket as set forth in claim 3, wherein each of the pair of gain-setting circuits consist of a transistor in series with a current-sense resistor.

5. A circuit for driving an LED light bulb at varying levels of brightness depending on the energization of a 3-way socket comprising:

a pair of inputs, each input having a rectifier bridge associated therewith and producing parallel outputs;

at least two strings of LEDs, each consisting of at least one LED;

a power system for the at least two strings of LEDs, which runs from the parallel outputs of the rectifier bridges;

an energization detector circuit for each pair of inputs;

a selection circuit that selectively shunts one or more of the at least two strings of LEDs dependant on an output of the energization detector circuits; and

wherein the selection circuit consists of a pair of shunt circuits for each input.

6. A circuit for driving an LED light bulb at varying levels of brightness depending on the energization of a 3-way socket as set forth in claim 5, wherein the shunt circuits consist of a transistor.

7. A circuit for driving an LED light bulb at varying levels of brightness depending on the energization of a 3-way socket as set forth in claim 5, wherein the shunt circuits consist of a transistor along with a gate protection circuitry.

8. A circuit for driving an LED light bulb at varying levels of brightness depending on the energization of a 3-way socket comprising:

a pair of inputs, each input having a rectifier bridge associated therewith and producing parallel outputs;

at least two strings of LEDs, each consisting of at least one LED;

a power system for the at least two strings of LEDs, which runs from the parallel outputs of the rectifier bridges;

an energization detector circuit for each pair of inputs;

a selection circuit that selectively shunts one or more of the at least two strings of LEDs dependant on an output of the energization detector circuits; and

wherein each of the energization detector circuits consist of a half wave rectifier, a resistor divider and a capacitive filter.