Ac Driven Light-Emitting Diodes

• US 20080054814A1
• Filed: 06/03/2005
• Published: 03/06/2008
• 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: Wendt, Matthias, Deppe, Carsten
• Granted Patent: US 8,084,945 B2
• Time in Patent Office: Days
• US Class Current: 315/192
• 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 thun smoothed.

Claims

1. A circuit (2, 41, 71, 91, 111) comprising at least two parallel-connected light-emitting diodes (4, 5, 46-53, 74-77, 96, 97, 118-121) of opposite pole in a first parallel branch (12, 42, 72, 92, 112) and comprising at least two parallel-connected light-emitting diodes (6, 7, 56-63, 78-81, 98, 99, 122-125) of opposite pole in a second parallel branch (13, 43, 73, 93, 113), and also comprising a capacitor (8) and a coil (9), characterized in that the first parallel branch (12, 42, 72, 92, 112) has the capacitor (8) and the second parallel branch (13, 43, 73, 93, 113) has the coil (9).

2. A circuit as claimed in claim 1, characterized in that a parallel branch (42, 43) has two diode chains (44, 45, 54, 55).

3. A circuit as claimed in claim 1, characterized in that a parallel branch (72, 73, 112, 113) has a series connection of a number of parallel-connected diodes (74-81, 118-121, 122-125) of opposite pole.

4. A circuit as claimed in claim 1, characterized in that a diode (98, 99) emits cold white light.

5. A circuit as claimed in claim 1, characterized in that a diode (96, 97) emits warm white light.

6. A circuit as claimed in claim 1, characterized in that a diode (118, 119) emits red light.

7. A circuit as claimed in claim 1, characterized in that a diode (122, 123) emits blue light.

8. A circuit as claimed in claim 1, characterized in that the diodes (4-7) are arranged closely next to one another.

12. A lighting device (1, 31, 40, 70, 90, 110) comprising a circuit (2, 41, 71, 91, 111) as claimed in claim 1.

13. A lighting device as claimed in claim 12, characterized in that the lighting device (1) has a transformer (3).

14. A lighting device as claimed in claim 12, characterized in that the lighting device (31, 40, 70, 90, 110) has an electronic converter (33).

15. A lighting device as claimed in claim 14, characterized in that a secondary frequency of the electronic converter (33) is adjustable.

9. A housing (142) for a light-emitting diode (141), comprising two electrically conductive supply rods (143, 144) and comprising a light-emitting diode chip (149) in a reflector cup (145) at an upper end (151) of one supply rod (143), wherein an electrically conductive connection (147) extends from a surface of the chip (149) to the second supply rod (144), characterized in that a second chip (150) is arranged on the second supply rod (144).

10. A housing as claimed in claim 9, characterized in that an electrically conductive connection (148) extends from a surface of the second chip (150) to the first supply rod (143).

11. A housing as claimed in claim 9, characterized in that the second chip (150) is arranged in a reflector cup (146).

16. A circuit (2, 41, 71, 91, 111) comprising light-emitting diodes (4-7, 46-53, 56-63, 74-81, 96-99, 118-125) connected in pairs, and also comprising a capacitor (8) and a coil (9), wherein the diodes (4-7, 46-53, 56-63, 74-81, 96-99, 118-125) of each diode pair (10, 11, 82, 83, 84, 85, 94, 95, 114, 115, 116, 117) are connected in parallel and are of opposite pole, with a first diode pair (10, 82, 83, 94, 114, 115) in a first parallel branch (12, 42, 72, 92, 112) and a second diode pair (11, 84, 85, 95, 116, 117) in a second parallel branch (13, 43, 73, 93, 113), characterized in that the first parallel branch (12, 42, 72, 92, 112) has the capacitor (8) in series with the first diode pair (10, 82, 83, 94, 114, 115) and the second parallel branch (13, 43, 73, 93, 113) has the coil (9) in series with the second diode pair (11, 84, 85, 95, 116, 117).