CURRENT SUPPLY FOR LUMINESCENT DIODES

• US 20120086348A1
• Filed: 10/12/2011
• Published: 04/12/2012
• Est. Priority Date: 07/04/2002
• Status: Active Grant

• Current Assignee: Tridonic AG (Zumtobel Group AG), Tridonic Jennersdorf GMBH (Zumtobel Group AG)
• Original Assignee: Tridonic AG (Zumtobel Group AG), Tridonic Jennersdorf GMBH (Zumtobel Group AG)
• Inventors: Tobler, Felix, Zimmermann, Michael, Tasch, Stefan
• Granted Patent: US 8,698,415 B2
• Time in Patent Office: Days
• US Class Current: 315/186
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/36 Circuits for reducing or suppressing harmonics, ripples or electromagnetic interferences [EMI]
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/382 with galvanic isolation between input and output
• CPC Class Codes: H05B 45/56 involving measures to prevent abnormal temperature of the LEDs
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A regulation circuit is provided for making available a constant current supply on the basis of a transformer principle, in which there flows through the luminescent diodes a triangular a.c. current varying periodically around a d.c. current value. Circuitry is provided so that both the charging and the discharging current of an inductive reactance connected in series to the luminescent diodes, functioning as a storage choke for filtering of mains harmonics, flows as diode current through the luminescent diodes. An advantage of this method consists in a significant reduction of the overall power loss of the LED illumination module. According to one embodiment, the ceramic circuit board of the LED illumination module has a direct mains current supply, which, for protection from mechanical damage, is accommodated in a transparent housing having a highly transparent polymer mass serving as an optically active lens surface.

Claims

1-24. -24. (canceled)

25. A current supply circuitry for at least one luminescent diode having:

at least one inductive reactance connected as a storage choke in series with the luminescent diode;

switching stages for switching over between a charging or a discharging process occurring in the storage choke upon over-shooting or under-shooting of threshold values of respective control voltages of the switching stages; and

a free running current path, connected in parallel with the series connection of the luminescent diodes and the storage choke, for at least a part of the discharge current released by the storage choke to the luminescent diodes upon blocking of the first switching stage.

26. The circuitry according to claim 25, comprising a first shunt measurement resistance for detecting the diode current flowing through the luminescent diodes during a charging process occurring in the storage choke.

27. The circuitry of claim 25, comprising a second shunt measurement resistance for detecting the diode current flowing through the luminescent diodes during a discharge process occurring in the storage choke.

28. The circuitry of claim 27, comprising a signal transfer element for feeding back the current flowing through the luminescent diodes, tapped off at the second measurement resistance, to the control input of the first switching stage, the member serving for galvanic de-coupling of the voltage dropping at the second measurement resistance and the control voltage of the first switching stage.

29. The circuitry according to claim 28, wherein the signal transfer element employed for potential separation is a level offset stage.

30. The circuitry of claim 25, wherein a free-running diode in the free-running current path connected in connected anti-parallel to the series circuit of the luminescent diodes and the storage choke.

31. The circuitry of claim 25, furthermore comprising a time dependent controller for switching over between the charging and discharging processes occurring in the storage choke.

32. A current supply circuitry for at least one luminescent diode, having:

at least one inductive reactance connected as storage choke in series to the luminescent diode;

a free running current path, connected in parallel to the series connection of the luminescent diodes and the storage choke, for at least a part of the discharge current released by the storage choke to the luminescent diodes upon blocking of the first switching stage; and

time dependent controller for switching over between the charging and discharging processes occurring in the storage choke.

33. A method for regulating a current supply of at least one luminescent diode comprising charging and discharging current of an inductive reactance connected in series to the luminescent diodes as a storage choke, wherein responsive to charging and discharging, current flows as diode current through the luminescent diodes and is used for the generation of an alternating current varying periodically about a settable direct current value.

34. The method according to claim 33, wherein a direct current offset constituting a middle value of a resulting triangular diode current is set by means of a suitable dimensioning of at least one shunt measurement resistance.

35. The method according to claim 33, comprising:

switching over by switching stages between the charging or discharging occurring in the storage choke upon over-shooting or under-shooting of threshold values of respective control voltages of the switching stages; and

releasing at least a part of the discharge current by the storage choke to the luminescent diodes upon blocking of the switching stages.

36. A light-emitting diode module, comprising an arrangement of series connected light-emitting diodes, which are applied on a circuit board, wherein

the light-emitting diode illumination module has a regulation circuit for providing a constant current supply;

and

the constant current supply comprises;

at least one inductive reactance connected as a storage choke in series to the light-emitting diodes;

a free running current path, connected in parallel to the series connection of the light-emitting diodes and the storage choke, for at least a part of the discharge current released by the storage choke to the light-emitting diodes upon blocking of the first switching stage; and

a time dependent controller for switching over between the charging and discharging processes occurring in the storage choke.

37. The light-emitting diode module of claim 36, wherein the light-emitting diodes are applied to the circuit board in a Chip-On-Board technology.

38. The light-emitting diode module of claim 36, the light-emitting diode module is accommodated in a transparent housing.

39. The light-emitting diode module of claim 38, wherein Fresnel lenses, each in the form of a lens plate for the attainment of a bundled homogenous light distribution in the region of the main emission directions, are positioned centrally above each light-emitting diode within the transparent housing.

40. The light-emitting diode module of claim 38, wherein the inner sides of the transparent housing, with the exception of the light emitting region, are of a thermally good conducting material, which on the outer side for heat discharge is covered over with an electrically non-conducting material.

41. The light-emitting diode module of claim 38, wherein the transparent housing can be contacted with the aid of a plug, socket and/or connection cable light-emitting diod out of the housing to the side.

42. The light-emitting diode module of claim 36 further including a parabolic or funnel-shaped reflector of a reflector plate, formed of a thermally-good conductive, highly reflecting material, which is electrically insulated on the underside of the reflector, wherein the reflector is disposed around each light-emitting diode, and where the reflector is constructed to be placed around the light-emitting diode from above the circuit board.

43. The light-emitting diode module according to claim 42, wherein each individual reflector is formed of a plastic having a mirrored inner side.

44. The light-emitting diode module of claim 36, wherein the rear side of the circuit board is coup light-emitting diode to a cooling body which is constructed to transfer heat arising from operation of the light-emitting diode illumination module to the housing or a mounting.

45. A method for producing the light-emitting diode module of claim 36, comprising assembling the light-emitting diode of the light-emitting diode illumination module directly with a highly transparent polymer mass.

46. The method of claim 45, wherein assembling includes molding directly unhoused light-emitting diodes with the polymer mass in an injection molding process and/or by means of a casting process.

47. A method for producing the module of claim 36, wherein at least one light-emitting diode is a blue light-emitting diode which produces white light by means of a color conversion layer arranged above the light-emitting diode.