System and method providing LED emulation of incandescent bulb brightness and color response to varying power input and dimmer circuit therefor

• US 8,890,419 B2
• Filed: 10/18/2010
• Issued: 11/18/2014
• Est. Priority Date: 05/28/2009
• Status: Expired due to Fees

• Current Assignee: Q Technology Limited
• Original Assignee: Q Technology Limited
• Inventors: Stack, Thomas E.
• Primary Examiner(s): A, Minh D
• Application Number:
  US12/906,986
• Publication Number:
  US 20110031890A1
• Time in Patent Office: 1,492 Days
• Field of Search: 315/185.R, 315/185.S, 315191-192, 315/200.R, 315/205, 315/224
• US Class Current: 315/185.R
• CPC Class Codes: H05B 31/50 specially adapted for ac
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/42 Antiparallel configurations
• CPC Class Codes: H05B 45/50 responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
• CPC Class Codes: H05B 47/24 Circuit arrangements for protecting against overvoltage

Abstract

A lighting system is disclosed, including a first lighting module and a second lighting module connected parallel to the first lighting module. The first lighting module, with a first activation voltage, generates light at a first color temperature and the second lighting module, with a second activation voltage, generates light at a second color temperature. The two lighting modules generate light when current flows through them. When input voltage is changed, both the amount of current flowing through the two modules changes and the ratio of current flowing through the two lighting modules changes. The change in ratio changes the color temperature of the light produced by the lighting system resulting from combination of the light produced by the two modules. The combined output brightness and color temperature each change with applied power in such a way to emulate the lighting profile of an incandescent lamp.

Claims

1. A lighting system comprising:

a first lighting module including at least one light emitting element, the light emitting element of said first lighting module generating, when power is applied, light at a first color temperature;

wherein said first lighting module having a first activation voltage;

a second lighting module including at least one light emitting element, the light emitting element of said second lighting module generating, when power is applied, light at a second color temperature;

wherein said second lighting module having a second activation voltage;

a current limiting element in series with said second lighting module; and

whereby the ratio of the amount of current flow to the first module relative to the amount of current flow to the second module varies with the applied power amplitude.

2. The lighting system recited in claim 1 wherein said first lighting module including at least one pair of lighting elements, each pair including a first lighting element connected in a first electrical direction and a second lighting element connected in a second electrical direction, the second electrical direction opposite the first electrical direction.

3. The lighting system recited in claim 2 wherein the lighting elements are light emitting diodes.

4. The lighting system recited in claim 1 wherein said second lighting module is electrically connected in parallel to said first lighting module.

5. The lighting system recited in claim 1 further comprising:

an input for power;

a first capacitor connected in series between said input for power and said first lighting module;

a second capacitor connected in series between said second lighting module and the connection of said first capacitor to said first lighting module;

wherein, when electrical power is applied to the lighting system, said first lighting module conducts electrical current during a first conduction period within each power cycle and said second lighting module conducts electrical current during a second conduction period within each power cycle.

6. The lighting system recited in claim 5 wherein the second conduction period occurs within the first conduction period.

7. The lighting system recited in claim 5 wherein a portion of the first conduction period overlaps a portion of the second conduction period.

9. The lighting system recited in claim 1 further comprising supporting circuit, said supporting circuit comprising at least one protective element from a group consisting of a thermistor that presents resistance when cold to suppress in-rush current and when heated decreases resistance to lighting system current flow, a spark gap, and a transient voltage suppressor.

10. The lighting system recited in claim 1 wherein said first lighting module includes a first predetermined number of LEDs and said second lighting module includes a second predetermined number of LEDs wherein the first predetermined number is less than the second predetermined number.

8. A lighting system comprising:

an input for power;

a first lighting module including at least one light emitting element, the light emitting element of said first lighting module generating, when power is applied, light at a first color temperature;

a second lighting module including at least one light emitting element, the light emitting element of said second lighting module generating, when power is applied, light at a second color temperature; and

a first rectifier connected to said first lighting module;

a second rectifier connected to said second lighting module;

a first capacitor connected in series between said input for power and said first rectifier;

a second capacitor connected in series between said first rectifier and said second rectifier;

a third capacitor connected in parallel to said first lighting module;

a fourth capacitor connected in parallel to said second lighting module;

wherein said first lighting module comprises a plurality of light emitting elements connected in series, having a first activation voltage; and

wherein said second lighting module comprises a plurality of light emitting elements connected in series, having a second activation voltage.

11. A method of generating light, the method comprising:

applying electrical energy having an amplitude;

activating a first lighting module at a first activation voltage;

activating a second lighting module at a second activation voltage;

wherein the first lighting module including at least one light emitting element, the light emitting element of the first lighting module, when activated, generating light at a first range of color temperature;

wherein the second lighting module including at least one light emitting element, the light emitting element of the second lighting module, when activated, generating light at a second range of color temperature; and

varying the ratio of current flow amount to the first module relative to current flow amount to the second module, as a function of the amplitude of applied electrical energy.

12. The method recited in claim 11 wherein said first lighting module includes at least one pair of lighting elements, each pair including a first lighting element connected in a first electrical direction and a second lighting element connected in a second electrical direction, the second electrical direction opposite the first electrical direction.

13. The method recited in claim 12 wherein the lighting elements are light emitting diodes.

14. The method recited in claim 11 with a current path to the first lighting module through a first capacitor;

and said second lighting module is electrically connected in parallel to said first lighting module through a second capacitor, the current path to the second lighting module extending through both first and second capacitors.

15. The method recited in claim 11 wherein the first lighting module conducts electrical current during a first conduction period within each power cycle and the second lighting module conducts electrical current during a second conduction period within each power cycle.

16. The method recited in claim 15 wherein the second conduction period occurs within the first conduction period.

17. The method recited in claim 15 wherein a portion of the first conduction period overlaps a portion of the second conduction period.

18. A lighting system adapted to connect to an electrical power source providing alternating current (AC) electrical power, the electrical power having power cycles and adapted to provide variable level of voltage, the lighting system comprising:

a first current path including at least one light emitting element, the light emitting element of said first current path generating, when power is applied, light at a first color temperature;

wherein said first current path has a first activation voltage;

a second current path including at least one light emitting element, the light emitting element of said second current path generating, when power is applied, light at a second color temperature;

wherein said second current path has a second activation voltage; and

a current limiting element in series with the second current path so that the ratio of the amount of current flow to the first module relative to the amount of current flow to the second module varies with the amplitude of applied power.