Led light string employing series-parallel block coupling

• US 6,072,280 A
• Filed: 08/28/1998
• Issued: 06/06/2000
• Est. Priority Date: 08/28/1998
• Status: Expired due to Fees

• Current Assignee: Fiber Optic Designs Incorporated
• Original Assignee: Fiber Optic Designs Incorporated
• Inventors: Allen, Mark R.
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): VO, TUYET THI
• Application Number:
  US09/141,914
• Time in Patent Office: 648 Days
• Field of Search: 315/185 S, 315/323, 315/324, 315/325, 315/322, 315/192, 315/185 R, 315/294, 315/292, 315/295, 315/312
• US Class Current: 315/185.00S
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]

Abstract

An LED light string employs a plurality of LEDs wired in a series-parallel block. Further, each series-parallel block may be coupled in parallel, the parallel connection coupled across a supply voltage through an electrical interface. LEDs of the light string may comprise either a single color LED or an LED including multiple sub-dies, each sub-die of a different color. LED series-parallel blocks of the light string may be operated in continuous, periodic or pseudo-random state. The LED light string may provide polarized connectors to couple LED light strings end-to-end and in parallel with the supply voltage. The electrical interface may have one or more parallel outputs and a switch so as to operate multiple LED light strings in continuous, periodic or pseudo-random states. The LED light string may be adapted so as to employ LEDs of different drive voltages in each series section of the series-parallel block. Fiber optic bundles may be coupled to individual LEDs to diffuse LED light output in a predetermined manner.

Claims

1. A light string comprising:

a pair of wires;

an electrical interface adapted to interface with a standard voltage supply;

a plurality of LEDs electrically coupled in series to form at least one series-parallel block,

wherein each series-parallel block and the electrical interface are electrically coupled in parallel between each wire of the pair; and

wherein the electrical interface further includes a voltage converter, the voltage converter adapted to convert a first voltage potential of the standard voltage supply to a second voltage potential across a pair of output terminals and between each wire of the pair; and

wherein the voltage converter includes a transformer to convert between the first and second voltage potentials, and a ratio of the first and second voltage potentials being matched to an input voltage of the series-parallel block; and

wherein the voltage converter includes at least two pairs of output terminals, each pair of output terminals providing the second voltage potential between the corresponding terminals, and the LED light string further comprises at least two pairs of wires, each pair of wires coupled to a respective pair of output terminals and at least one series-parallel block being electrically coupled between each pair of wires.

2. The invention as recited in claim 1, wherein each LED of the plurality of LED has a drive voltage, and a number of LEDs of the series parallel block being selected based on the drive voltage of each LED so as to match the input voltage of the series block with the second voltage potential.

3. The invention as recited in claim 1, wherein the voltage converter includes a bridge rectifier coupled in parallel across a pair of output terminals of the transformer, the output terminal pair being the output terminals of the bridge rectifier, the voltage converter converting from a first voltage potential having an alternating current to a second voltage potential across the output terminal pair having a direct current.

4. The invention as recited in claim 1, wherein the series-parallel block includes a blinking LED, the blinking LED intermittently breaking the electrical coupling of the plurality of LEDs.

5. The invention as recited in claim 1, wherein the LED light string further includes a polarized connector coupled between each of the pair of wires, and an electrical interface of another LED light string being electrically coupled to the polarized connector so as to couple each LED light string end-to-end in parallel to the supply voltage.

6. The invention as recited in claim 1 wherein the electrical interface further includes a solar panel and a battery, the solar panel adapted to charge the battery so as to maintain the standard voltage supply.

7. The invention as recited in claim 1, wherein a resistor is electrically coupled in series with the plurality of LEDs and is electrically coupled between the input voltage of the series-parallel block and the second voltage potential so as to match the input voltage of each series-parallel block with the second voltage potential.

8. The invention as recited in claim 7, wherein the resistor is electrically coupled in series with the plurality of LEDs of a series-parallel block to electrically couple the resistor between the pair of wires.

9. The invention as recited in claim 1, wherein the voltage converter comprises:

a transformer to convert between the first and second voltage potentials;

a blinking circuit adapted to provide an intermittent voltage from the second voltage potential; and

a switch adapted to select either of two nodes, one node providing the second voltage potential from the transformer to the pair of wires, and the other node providing the intermittent voltage from the blinking circuit to the pair of wires.

10. The invention as recited in claim 9, wherein the voltage converter further comprises a processor adapted to select the position of the switch based on a predetermined algorithm.

11. The invention as recited in claim 1, wherein each LED of the plurality LEDs has a corresponding light output color, and the plurality of LEDs either being of a single color or multiple colors.

12. The invention as recited in claim 11, wherein the plurality LEDs being arranged such that, for multiple colors, each LED color of the plurality of LEDs appears either periodically or pseudo-randomly.

13. The invention as recited in claim 11 wherein at least one LED includes a housing, a fiber-optic bundle removeably mounted to the housing so as to diffuse a light output of the LED through the fiber-optic bundle.