AC driven light-emitting diodes

• US 8,084,945 B2
• Filed: 06/03/2005
• Issued: 12/27/2011
• Est. Priority Date: 06/03/2004
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Deppe, Carsten, Wendt, Matthias
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): Chen, Jianzi
• Application Number:
  US11/569,707
• Publication Number:
  US 20080054814A1
• Time in Patent Office: 2,398 Days
• Field of Search: 315/185.S, 315194-196, 315/32, 362/800, 362/551
• US Class Current: 315/32
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/37 Converter circuits
• CPC Class Codes: H05B 45/42 Antiparallel configurations
• CPC Class Codes: H05B 45/46 having LEDs disposed in parallel lines
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

The invention relates to a circuit (2) comprising at least two parallel-connected light-emitting diodes (4, 5) opposite poled in a first parallel branch (12) and comprising at least two parallel-connected light-emitting diodes (6, 7) opposite poled in a second parallel branch (13), and also comprising a capacitor (8) and a coil (9). According to the invention, the first parallel branch (12) has a capacitor (8) and the second parallel branch (13) has the coil (9). On account of the capacitive parallel branch (10) and the inductive parallel branch (11), idle currents arise which are phase-shifted with respect to one another. The idle currents compensate one another and light changes of the oppositely-poled diode pairs take place at different points in time. A light current is then smoothed.

Claims

1. A device, comprising

first and second electrically conductive supply rods;

a first reflector cup disposed on an upper end of the first electrically conductive supply rod;

a first light-emitting diode (LED) chip in the first reflector cup;

a second LED chip arranged on the second electrically conductive supply rod; and

an electrically conductive connection extending from a surface of the first LED chip to the second electrically conductive supply rod.

2. The device of claim 1, wherein at least one of the diodes emits cold white light.

3. The device of claim 1, wherein at least one of the diodes) emits warm white light.

4. The device of claim 1, wherein at least one of the diodes emits red light.

5. The device of claim 1, wherein at least one of the diodes emits blue light.

6. The device of claim 1, wherein a second electrically conductive connection extends from a surface of the second LED chip to the first electrically conductive supply rod.

7. The device of claim 1, wherein the second LED chip is arranged in a second reflector cup.

8. The device of claim 1, wherein the electrically conductive connection consists of a bond wire directly connected between the surface of the first LED chip and a top surface of the second electrically conductive supply rod on which the second LED chip is arranged.