EP2796003B1 - Method and circuit arrangement for dimmable generation of light by means of leds, with colour temperature control - Google Patents

Method and circuit arrangement for dimmable generation of light by means of leds, with colour temperature control Download PDF

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Publication number
EP2796003B1
EP2796003B1 EP12815674.2A EP12815674A EP2796003B1 EP 2796003 B1 EP2796003 B1 EP 2796003B1 EP 12815674 A EP12815674 A EP 12815674A EP 2796003 B1 EP2796003 B1 EP 2796003B1
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Prior art keywords
auxiliary
current
led section
led
voltage
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German (de)
French (fr)
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EP2796003A1 (en
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Philip JERMYN
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Tridonic GmbH and Co KG
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Tridonic GmbH and Co KG
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/40—Details of LED load circuits
    • H05B45/44—Details of LED load circuits with an active control inside an LED matrix
    • H05B45/46—Details of LED load circuits with an active control inside an LED matrix having LEDs disposed in parallel lines
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/20—Controlling the colour of the light
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/20—Controlling the colour of the light
    • H05B45/24—Controlling the colour of the light using electrical feedback from LEDs or from LED modules

Definitions

  • the invention relates to a method and a circuit arrangement for the dimmable generation of light.
  • the light In an undimmed state, the light is generated by mixing longer-wavelength light of at least a first LED and shorter-wavelength light of at least one second LED. With increasing dimming, the proportion of shorter-wave light is reduced. In a maximum dimmed state, the resulting light consists only of light from the first LED.
  • the boundary between the longer-wavelength and the shorter-wavelength light may be, for example, 500 nm (with respect to the peak of the spectrum).
  • mixed light of a predetermined color by mixing the light emitted from at least two LEDs, the light emitted from one LED and from the other LED having different wavelengths.
  • 'warm' white light may be obtained by mixing the light emitted by a red light LED and that of a color converted blue light LED or UV light LED (for example, a blue light or UV light generating LED chip, the is covered with a phosphor layer which converts the blue light or the UV light into a longer wavelength light with a correspondingly different color
  • white light can also be generated by RGB (red, green, blue) mixture or other mixtures ,
  • the patent document US-A1-2010 / 111123 A1 discloses an operating circuit having a current source (26) powered by a total current and supplying power to an LED track (202).
  • the operating circuit (200) further comprises a control circuit (22) which controls the current source (26) in response to a voltage on the LED path (202).
  • a control circuit (22) which controls the current source (26) in response to a voltage on the LED path (202).
  • the invention has for its object to provide a method and a circuit arrangement which allow simulating the change in color temperature in a dimming operation of a conventional incandescent lamp with the least possible effort and at the same time the highest possible efficiency.
  • An operating circuit according to the invention for an LED track with at least one LED of a first type and an auxiliary LED track with at least one LED of a second type is designed to be supplied preferably by a first current source with an adjustable, preferably regulated total current.
  • a main current through the LED track is powered directly from the total current.
  • the Operating circuit has a second current source, which is powered by the total current and supplies the auxiliary LED track with an auxiliary current.
  • the operating circuit further comprises a control circuit which controls the second current source in response to a voltage across the LED path.
  • the second current source is preferably designed as a high-frequency clocked current source, in particular as a high-frequency clocked switching regulator.
  • the control circuit is preferably designed to control, when a threshold value is exceeded by the voltage, the second current source in order to supply the auxiliary LED path with the auxiliary current, and to control the second current source when the voltage drops below the threshold value, not to supply the auxiliary LED track with the auxiliary power.
  • a threshold voltage of the LED track is greater than the threshold value. In this way, unstable operating conditions can be avoided particularly reliably.
  • the second current source is preferably arranged such that when the total current is amplitude-dimming, the auxiliary current through the auxiliary LED path is constant and thus the auxiliary LED path constantly emits light as long as the LED path receives a main current and thus emits light.
  • the auxiliary current through the auxiliary LED path is subject to an amplitude dimming, so that the auxiliary LED route emits dimmed light, as long as the LED Streckek receives a main current and so emits no light. Unstable operating states can thus be safely avoided in the case of amplitude modulation.
  • the second current source is preferably designed such that, when dimming by means of pulse width modulation of the total current, the auxiliary current through the auxiliary LED path follows the course of the total current and the auxiliary LED path emits light in dimmed fashion. Thus, an afterglow of the auxiliary LED route can be avoided in a pulse width modulation operation.
  • the second current source is alternatively designed such that when dimming by means of pulse width modulation of the total current, the auxiliary current through the auxiliary LED path has no pulse width modulation and the auxiliary LED path emits light so constant and undimmed. This ensures that in a pure pulse width modulation operation, a color change occurs during dimming.
  • the control circuit preferably includes a comparator which compares the voltage at least indirectly with the threshold value.
  • the control circuit is designed to transmit a control signal to the second current source as a function of the comparison.
  • the second current source is preferably designed to supply the auxiliary LED path with the auxiliary current as a function of the control signal.
  • the control circuit preferably has a switch, preferably a transistor, which generates the control signal as a function of the comparison.
  • the comparator preferably has a voltage divider and a voltage reference.
  • the voltage divider then reduces the voltage by a factor.
  • the voltage reference preferably generates a reference voltage which corresponds to the threshold value reduced by the factor.
  • the comparator preferably compares the lowered operating voltage with the constant voltage of the voltage reference.
  • An LED module according to the invention comprises at least one operating circuit described above and an LED track with at least one LED of a first type and an auxiliary LED track with at least one LED of a second type.
  • the LEDs of the first type and the LEDs of the second type preferably have different emission spectra. So it is possible to achieve a desired color temperature depending on the degree of dimming.
  • An LED luminaire according to the invention is preferably a retrofit LED luminaire with at least one previously described LED module and a first current source. So conventional lights can be easily replaced.
  • An inventive method is used to operate an LED track with at least one LED of a first type and an auxiliary LED track with at least one LED of a second type.
  • the LED track and the auxiliary LED track are supplied by an adjustable, preferably regulated total current.
  • a main current through the LED track is powered directly from the total current.
  • the auxiliary LED track is supplied with an auxiliary current.
  • the auxiliary current is dependent on a voltage at the LED track controlled. Unstable operating states can thus be safely avoided in the case of amplitude modulation.
  • a LED lamp which emits a ⁇ warmer ⁇ light with increasing dimming
  • an amber LED in addition to at least one white LED.
  • one or more yellow, red or RGB LEDs it is intended to use one or more yellow, red or RGB LEDs.
  • the present invention is based on the underlying idea that operate colored LED or the colored LEDs at constant brightness, while the dimming process only affects the white or white LEDs.
  • a dimming of the colored LED can also be used.
  • a dimming of an LED light is achieved by an amplitude modulation and / or a pulse width modulation of an operating current.
  • amplitude modulation of the operating current it is an object of the present invention to keep the operating current of the colored LED constant, while reducing the operating current of the white LED (s) depending on the degree of dimming.
  • pulse width modulation it is an optional goal of the present invention to achieve a permanent operation of the colored LED as independent as possible of the pulse width modulation. That the white LED or the white LEDs are thus pulse-width modulated, while the colored LED as possible undergoes no such modulation.
  • the present invention is not limited to white or red LEDs. It is only important that at least two LED sections are used, each with at least one LED. The emission spectra of the two sections must differ in order to represent a color change in dimming can.
  • Fig. 1 shows a first embodiment of an LED lamp according to the invention.
  • a rectifier module 20 is supplied with an AC voltage 10.
  • the rectifier module 20 generates from the AC voltage 10 a DC voltage 11.
  • the DC voltage 11 supplies a first current source 21.
  • the first current source 21 is a DC power source, which is preferably designed as a DC-DC converter, for example as an isolated flyback converter. It generates a total current I G , with which an LED module 22 is operated.
  • the rectifier module 20 and the first current source 21 may also be integrated in a single module.
  • a dimming device 24 generates a dimming signal 15a, which is supplied to the current source 21.
  • the current source 21 generates the current I G in response to the dimming signal 15a.
  • the dimming signal 15a causes the first current source 21 to generate a constant direct current I G of an adjustable current intensity and thus to operate the LED module 22.
  • the dimming device 24 determines the dimming signal 15a as a function of a dimming value, which is set, for example, by a user on a dimmer.
  • a pulse width modulation can be used.
  • the dimmer 24 generates the dimming signal 15a as a pulse width modulation signal. That the dimming signal specifies a frequency and a duty cycle of the pulse width modulation by the first current source 21.
  • Fig. 2 a second embodiment of the LED lamp according to the invention is shown.
  • the structure largely corresponds to the structure Fig. 1 ,
  • the LED light here includes a control device 23, which processes a signal 13, which allows conclusions about the current brightness of the light, which is generated by the LED module 22.
  • a dimming signal 15b is supplied to the controller 23.
  • the control device 23 generates a control signal 14 for controlling the first current source 21 from the dimming signal 15b and the brightness signal 13.
  • further signals may be included in the control by the controller 23.
  • additional temperature signal Since LEDs have a temperature characteristic, it is helpful to consider the current temperature for controlling the LEDs.
  • the use of a temperature signal is very advantageous since LEDs of different types and thus different wavelengths often have different temperature characteristics. That with a change in temperature, it may be necessary to adjust the mixture of light through the LED module 22.
  • the first current source 21 generates a pulse width modulated current I G.
  • the pulse width modulation corresponds to the desired degree of dimming or as is based on Fig. 2 shown, determined in dependence on other control parameters.
  • FIG. 3 a first embodiment of the LED module according to the invention is shown.
  • An LED module 22 has connections 12a, 12b. It has an LED track 30, a control circuit 40, a power source 60 and an auxiliary LED track 70.
  • the LED section 30 consists of series-connected LEDs 31-39.
  • the LEDs 31-39 here are white LEDs of a first type w.
  • the LED track 30 is connected directly to the terminals 12a, 12b and is supplied by the total current I G. It turns a main current I 1 through the LED Strecke30 one.
  • the second current source 60 includes an integrated circuit 67, such as a TS19373 device, as an example of a buck regulator regulator IC.
  • the integrated circuit 67 is connected via a first terminal 67 3 by a capacitor 62 to the terminal 12a.
  • the connection 12a here corresponds to the supply current I G.
  • Via a connection 67 2 the integrated circuit 67 is connected directly to ground. It is connected via a connection 67 1 to the connection 12 b by means of a coupling capacitor 68.
  • the connection 12b here corresponds to ground.
  • Via a connection 67 4 it is connected to a voltage divider 69 consisting of an ohmic resistor 64 and an ohmic resistor 66.
  • connection 67 5 Via a connection 67 5 , it is furthermore connected to an inductance 65, which in turn is connected to the center of the voltage divider 69.
  • the terminal 67 5 is further connected via a diode 61 to the terminal 12 a.
  • the integrated circuit 67 facing away from the end of the voltage divider 69 is also connected to the auxiliary LED track 70.
  • the auxiliary LED track includes here only one LED 63 of a second type a. On its other side, the LED 63 is connected to the terminal 12a.
  • the second current source 60 corresponds here to a down converter as an example of a high-frequency clocked switching regulator. From the terminals 12a and 12b, the power source 60 draws so much current to produce a constant current. The LED section 70 is supplied with this current. This results in a negative current-voltage characteristic of the constant current source 60th D.h. as the operating voltage increases, the extracted current decreases.
  • the integrated circuit 67 determines the voltage drop across the resistor 64 via the voltage divider 69. The voltage drop is determined between the connection 67 1 and the connection 67 4 . The integrated circuit 67 adjusts the current through the auxiliary LED path 70 so that the voltage drop always assumes a fixed value, for example, 0.3 volts. The current can thus be adjusted by selecting the resistor 64. Otherwise it is a constant current. The integrated circuit 67 stores energy in the inductance 65. The energy stored in the inductance 65 is used to generate the constant current as an output signal.
  • a continuous current I G is applied to the LED module 22 (as in the case of amplitude modulation), then a constant amount of energy is always stored in the inductance 65.
  • the production of a constant output current is thus unproblematic for the constant current source 60.
  • the energy stored in the inductance 65 decreases, while the constant current source 60 continues to generate a constant current as an output signal and the LED 63 supplies.
  • the inductance 65 is designed so small that the LED module 22 according to the invention meets the special property of the color change in the course of dimming only with an amplitude modulation. That is, the energy in the inductance is not enough to bridge a turn-off period of a pulse width modulation. An afterglow during the off periods of a pulse width modulation can be avoided.
  • the inductance 65 is designed such that the operating current for the LED 63 is sufficient even with a minimum duty cycle of the pulse width modulation in order to permanently supply the LED 63 with a constant current. In this case, the color change in dimming can be maintained even with a pure pulse width modulation.
  • the constant current source 60 Without further action there are operating conditions in which the constant current source 60 is unstable. Thus, the input of the current source 60 acts as a load negative resistance. That is, the supply voltage increases while the operating current decreases. This combination is not stable, as is a Feedback mechanism developed with the power source 21. Trying to increase the current will actually reduce it.
  • the current source 21 During power up, or at the rising edge of each pulse width modulation pulse, the current source 21 must ramp up its output voltage until the LED trace 30 becomes conductive. If the current source 60 is connected, a very large current is drawn, which leads to a breakdown of the supply voltage U G. A drop in the supply voltage U G, in turn, causes an increase in the current drawn by the constant current source 60.
  • the constant current source 60 is caused by means of a control circuit 40 to show the behavior of an LED path with regard to its current-voltage characteristic. That is, the current source 60 is caused to receive a portion I 2 of the operating current I G only from a threshold value.
  • the following will discuss the exact function of the control circuit 40.
  • the control circuit 40 has a voltage divider 51 consisting of ohmic resistors 41 and 42, which also connected to the terminals 12a and 12b.
  • the center of the voltage divider 51 is connected to a negative input of an operational amplifier 45.
  • the center of the voltage divider 51 is connected via an ohmic resistor 44 to the output of the operational amplifier 45.
  • a voltage divider 52 is formed by an ohmic resistor 43 and a Zener diode 46. The center of this voltage divider 52 is connected to the positive input of the operational amplifier 45.
  • the operational amplifier 45 thus compares an operating voltage U G reduced by the first voltage divider 51 in the ratio of the ohmic resistances 41, 42 with the breakdown voltage of the zener diode 46. If the reduced operating voltage U G predominates, the operational amplifier 45 outputs a LOW signal at its output , On the other hand, if the breakdown voltage of the Zener diode 46 predominates, the operational amplifier 45 outputs a HIGH signal at its output. These resulting signals are dissipated via a third voltage divider 53 to ground.
  • the voltage divider 53 consists of ohmic resistors 47 and 49. At the midpoint of the voltage divider 53, the signal is supplied to the base of a transistor 48. The collector is connected via an ohmic resistor 50 to ground. The emitter of the transistor 48 is connected to the power source 60.
  • the transistor 48 here has the function of a switch. That is, when the operational amplifier outputs a HIGH signal at its output, the collector-emitter path of the transistor 48 becomes conductive.
  • the emitter of the transistor 48 is connected to the terminal 67 4 of the integrated circuit 67. Is the Transistor conductive, a voltage drop is generated at the terminal 67 4 , since the current through the transistor 48 via the resistor 66 is pulled. The mentioned voltage drop leads to a shutdown of the constant current source 60.
  • the current source 60 and thus also the auxiliary LED path 70 is switched off. This allows the power source 21, which powers the LED module 22, to reach a stable operating state before the power source 60 is turned on. Once the threshold is exceeded by the voltage U G , the output of the operational amplifier 45 changes to low, the transistor 48 is non-conductive and an artificial voltage drop at the terminal 67 4 is no longer generated. The power source 60 thus starts operating. Since a significant current flow I 1 already exists through the LED path 30, the negative current-voltage characteristic of the current source 60 can no longer adversely affect the current source 21.
  • the amplification factor of the operational amplifier 45 can be set.
  • the amplification factor can be used to set the current-voltage characteristic of the overall circuit.
  • a low gain provides a "soft" threshold.
  • the auxiliary LED path 70 is not switched on instantaneously but slowly, when the threshold value is exceeded by the voltage U G.
  • the integrated circuit 67 performs its own pulse width modulation of the duty cycle of the auxiliary LED path 70.
  • the integrated circuit 67 is informed of the dimming value of the auxiliary LED path 70 via an additional signal.
  • the pulse width modulation of the auxiliary LED path 70 in this case is completely independent of the pulse width modulation by the current source 21 or of the amplitude modulation by the current source 21.
  • a buffer capacitor can be arranged as an energy storage. This can, for example, in the operating phase, in which the auxiliary LED path 70 is supplied to the auxiliary power I 2, between a store energy. Within this phase, this energy is taken from the LED track 30. In a further phase, the buffered energy of the buffer capacitor can be released again. For example, this energy may then be used in a further phase of the operation of the auxiliary LED track 70 to power the auxiliary LED track 70.
  • Fig. 4 an embodiment of the method according to the invention is shown.
  • the method corresponds to a ramp-up of an operating voltage and the reaction of the affected circuit elements.
  • an operating voltage U G is powered up from a power source.
  • a second step 81 it is determined whether the voltage exceeds a threshold value. If this is not the case, the first step 80 is continued. If this is the case, then a third step 82 is continued.
  • an auxiliary LED route is activated.
  • the process continues with a fourth step 83.
  • the operating voltage U G is further increased. It is continued with a fifth step 84. It is now determined whether the voltage exceeds a threshold voltage of an LED track. If this is not the case, the fourth step 83 is continued. If this is the case, a sixth step 85 is continued. In the sixth step 85, the LED route is activated. The said steps are repeated each time the operating voltage U G is raised .
  • the steps are carried out in the reverse order. That After an initial shutdown of the voltage, it is first checked whether the threshold voltage of the LED track has been undershot. If this is the case, the LED route is deactivated. After further lowering of the voltage is checked whether the threshold was exceeded. As soon as the threshold value has been undershot, the auxiliary LED route is deactivated.
  • the invention is not limited to the illustrated embodiment.
  • any number of different LEDs can be used.
  • the only important thing is that the directly from the current source 21 LEDs differ in terms of their radiation characteristics of the operated by the power source 60 LEDs. All features described above or features shown in the figures can be combined with each other in any advantageous manner within the scope of the invention.
  • a high-frequency clocked second power source also ensures a safe and constant operation of the auxiliary LED track, since the operation of this auxiliary LED track is controlled by an independent of the regulation of the LED route control. At the same time the LED track is evenly loaded by the high-frequency clocked second power source, since due to the high-frequency clocking a uniform power consumption is ensured by the high-frequency clocked second power source.

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Description

Die Erfindung betrifft ein Verfahren und eine Schaltungsanordnung zur dimmbaren Erzeugung von Licht. In einem ungedimmten Zustand wird das Licht durch Mischen von längerwelligem Licht zumindest einer erste LED und kürzerwelligen Licht zumindest einer zweiten LED erzeugt. Mit zunehmender Dimmung wird der Anteil des kürzerwelligen Lichts reduziert. In einem maximal gedimmten Zustand besteht das resultierende Licht lediglich aus Licht der ersten LED. Die Grenze zwischen dem längerwelligen und dem kürzerwelligen Licht kann beispielsweise bei 500nm (bzgl. des Peaks des Spektrums) liegen.The invention relates to a method and a circuit arrangement for the dimmable generation of light. In an undimmed state, the light is generated by mixing longer-wavelength light of at least a first LED and shorter-wavelength light of at least one second LED. With increasing dimming, the proportion of shorter-wave light is reduced. In a maximum dimmed state, the resulting light consists only of light from the first LED. The boundary between the longer-wavelength and the shorter-wavelength light may be, for example, 500 nm (with respect to the peak of the spectrum).

Es ist bekannt, Mischlicht einer vorbestimmten Farbe durch Mischen des von mindestens zwei LEDs emittierten Lichts zu erzeugen, wobei das von der einen LED und das von der anderen LED emittierte Licht unterschiedliche Wellenlängen haben. Beispielsweise kann 'warmes' Weißlicht durch Mischen des von einer Rotlicht-LED emittierten Lichts und des von einer farbkonvertierten Blaulicht-LED oder UV-Licht-LED (es handelt sich dabei beispielsweise um einen blaues Licht oder UV-Licht erzeugenden LED-Chip, der mit einer Phosphorschicht bedeckt ist, die das blaue Licht bzw. das UV-Licht in ein längerwelliges Licht mit einer entsprechend anderen Farbe umwandelt, erzeugt werden. Alternativ kann Weißlicht auch durch RGB (rot, grün, blau) -Mischung oder andere Mischungen erzeugt werden.It is known to produce mixed light of a predetermined color by mixing the light emitted from at least two LEDs, the light emitted from one LED and from the other LED having different wavelengths. For example, 'warm' white light may be obtained by mixing the light emitted by a red light LED and that of a color converted blue light LED or UV light LED (for example, a blue light or UV light generating LED chip, the is covered with a phosphor layer which converts the blue light or the UV light into a longer wavelength light with a correspondingly different color, alternatively, white light can also be generated by RGB (red, green, blue) mixture or other mixtures ,

So zeigt z.B. die internationale Patentanmeldung WO 2001/054547 A1 eine LED-Ansteuerschaltung, welche einen passiven Kompensationszweig einsetzt, welcher die Spannung an einer oder an mehreren LEDs reduziert, um die Farbtemperatur einzustellen. Dabei wird jedoch ein Teil der elektrischen Leistung thermisch umgesetzt was zu einem hohen Energieverbrauch führt.For example, shows the international patent application WO 2001/054547 A1 an LED drive circuit having a passive compensation branch which reduces the voltage on one or more LEDs to adjust the color temperature. However, part of the electric power is thermally converted resulting in high energy consumption.

Das Patentdokument US-A1-2010/111123 A1 offenbart eine Betriebsschaltung die eine Stromquelle (26) aufweist, die von einem Gesamtstrom versorgt wird und eine LED-Strecke (202) mit einem Strom versorgt. Die Betriebsschaltung (200) weist ferner eine Steuerschaltung (22) auf, welche die Stromquelle (26) in Abhängigkeit einer Spannung an der LED-Strecke (202) steuert. Von herkömmlichen Glühlampen sind es Nutzer gewöhnt, beim Dimmen eine Änderung der Farbtemperatur, d.h. der spektralen Verteilung des emittierten Lichts wahrzunehmen. Bei Glühlampen ergibt sich bei zunehmenden Dimmgrad üblicherweise eine Verschiebung hin zu wärmerem Licht. Herkömmliche Glühlampen weisen jedoch eine sehr geringe Energieeffizienz auf.The patent document US-A1-2010 / 111123 A1 discloses an operating circuit having a current source (26) powered by a total current and supplying power to an LED track (202). The operating circuit (200) further comprises a control circuit (22) which controls the current source (26) in response to a voltage on the LED path (202). From conventional incandescent lamps, users are accustomed to perceiving a change in the color temperature, ie the spectral distribution of the emitted light, when dimming. With incandescent lamps, a shift towards warmer light usually results with increasing degree of dimming. However, conventional incandescent lamps have a very low energy efficiency.

Der Erfindung liegt die Aufgabe zugrunde, ein Verfahren und eine Schaltungsanordnung zu schaffen, welche eine Nachbildung der Änderung der Farbtemperatur bei einem Dimmvorgang einer herkömmlichen Glühlampe mit möglichst geringem Aufwand und gleichzeitig möglichst hohem Wirkungsgrad ermöglichen.The invention has for its object to provide a method and a circuit arrangement which allow simulating the change in color temperature in a dimming operation of a conventional incandescent lamp with the least possible effort and at the same time the highest possible efficiency.

Die Aufgabe ist durch die Merkmale der unabhängigen Ansprüche gelöst. Die abhängigen Ansprüche bilden den zentralen Gedanken der Erfindung in besonders vorteilhafter Weise weiter.The object is solved by the features of the independent claims. The dependent claims further form the central idea of the invention in a particularly advantageous manner.

Eine erfindungsgemäße Betriebsschaltung für eine LED-Strecke mit zumindest einer LED eines ersten Typs und eine Hilfs-LED-Strecke mit zumindest einer LED eines zweiten Typs ist ausgebildet, um bevorzugt von einer ersten Stromquelle mit einem einstellbaren, bevorzugt geregelten Gesamtstrom versorgt zu werden. Ein Hauptstrom durch die LED-Streckeist direkt von dem Gesamtstrom versorgt. Die Betriebsschaltung weist dabei eine zweite Stromquelle auf, die von dem Gesamtstrom versorgt ist und die Hilfs-LED-Strecke mit einem Hilfsstrom versorgt. Die Betriebsschaltung weist weiterhin eine Steuerschaltung auf, welche die zweite Stromquelle in Abhängigkeit einer Spannung an der LED-Strecke steuert. So kann eine Farbänderung während des Dimmens realisiert werden, ohne dass instabile Betriebszustände auftreten. Die zweite Stromquelle ist vorzugsweise als hochfrequent getaktete Stromquelle ausgebildet, insbesondere als hochfrequent getakteter Schaltregler. Durch den Einsatz einer hochfrequent getakteten Stromquelle wird es ermöglicht, dass die Energie nur zwischengespeichert und auf verschiedene Zweige verteilt wird, es wird hier aber keine Energie in thermische Energie umgewandelt.An operating circuit according to the invention for an LED track with at least one LED of a first type and an auxiliary LED track with at least one LED of a second type is designed to be supplied preferably by a first current source with an adjustable, preferably regulated total current. A main current through the LED track is powered directly from the total current. The Operating circuit has a second current source, which is powered by the total current and supplies the auxiliary LED track with an auxiliary current. The operating circuit further comprises a control circuit which controls the second current source in response to a voltage across the LED path. Thus, a color change during dimming can be realized without unstable operating conditions occur. The second current source is preferably designed as a high-frequency clocked current source, in particular as a high-frequency clocked switching regulator. By using a high-frequency clocked power source, it is possible that the energy is only temporarily stored and distributed to different branches, but it is not converted into energy energy here.

Die Steuerschaltung ist bevorzugt ausgebildet, um bei Überschreiten eines Schwellwerts durch die Spannung, die zweite Stromquelle zu steuern, um die Hilfs-LED-Strecke mit dem Hilfsstrom zu versorgen, und um bei Unterschreiten des Schwellwerts durch die Spannung, die zweite Stromquelle zu steuern, um die Hilfs-LED-Strecke nicht mit dem Hilfsstrom zu versorgen. Bevorzugt ist eine Einsatzspannung der LED-Strecke größer ist als der Schwellwert. So können instabile Betriebszustände besonders sicher vermieden werden.The control circuit is preferably designed to control, when a threshold value is exceeded by the voltage, the second current source in order to supply the auxiliary LED path with the auxiliary current, and to control the second current source when the voltage drops below the threshold value, not to supply the auxiliary LED track with the auxiliary power. Preferably, a threshold voltage of the LED track is greater than the threshold value. In this way, unstable operating conditions can be avoided particularly reliably.

Die zweite Stromquelle ist vorzugsweise derart ausgebildet, dass bei einem Amplitudendimmen des Gesamtstroms, der Hilfsstrom durch die Hilfs-LED-Strecke konstant ist und so die Hilfs-LED-Strecke konstant Licht emittiert, solange die LED-Streckeeinen Hauptstrom aufnimmt und so Licht emittiert. Der Hilfsstrom durch die Hilfs-LED-Strecke unterliegt dabei einem Amplitudendimmen, so dass die Hilfs-LED-Strecke gedimmt Licht emittiert, solange die LED-Streckek einen Hauptstrom aufnimmt und so kein Licht emittiert. Instabile Betriebszustände können so bei einer Amplitudenmodulation sicher vermieden werden.The second current source is preferably arranged such that when the total current is amplitude-dimming, the auxiliary current through the auxiliary LED path is constant and thus the auxiliary LED path constantly emits light as long as the LED path receives a main current and thus emits light. The auxiliary current through the auxiliary LED path is subject to an amplitude dimming, so that the auxiliary LED route emits dimmed light, as long as the LED Streckek receives a main current and so emits no light. Unstable operating states can thus be safely avoided in the case of amplitude modulation.

Die zweite Stromquelle ist bevorzugt derart ausgebildet, dass bei einem Dimmen mittels Pulsweitenmodulation des Gesamtstroms, der Hilfsstrom durch die Hilfs-LED-Strecke dem Verlauf des Gesamtstroms folgt und die Hilfs-LED-Strecke so gedimmt Licht emittiert. So kann ein Nachglühen der Hilfs-LED-Strecke bei einem Pulsweitenmodulations-Betrieb vermieden werden.The second current source is preferably designed such that, when dimming by means of pulse width modulation of the total current, the auxiliary current through the auxiliary LED path follows the course of the total current and the auxiliary LED path emits light in dimmed fashion. Thus, an afterglow of the auxiliary LED route can be avoided in a pulse width modulation operation.

Die zweite Stromquelle ist alternativ derart ausgebildet, dass bei einem Dimmen mittels Pulsweitenmodulation des Gesamtstroms, der Hilfsstrom durch die Hilfs-LED-Strecke keine Pulsweitenmodulation aufweist und die Hilfs-LED-Strecke so konstant und ungedimmt Licht emittiert. So wird erreicht, dass bei einem reinen Pulsweitenmodulations-Betrieb eine Farbänderung beim Dimmen auftritt.The second current source is alternatively designed such that when dimming by means of pulse width modulation of the total current, the auxiliary current through the auxiliary LED path has no pulse width modulation and the auxiliary LED path emits light so constant and undimmed. This ensures that in a pure pulse width modulation operation, a color change occurs during dimming.

Die Steuerschaltung beinhaltet bevorzugt einen Vergleicher, der die Spannung zumindest mittelbar mit dem Schwellwert vergleicht. Die Steuerschaltung ist dabei ausgebildet, um der zweiten Stromquelle in Abhängigkeit des Vergleichs ein Steuersignal zu übertragen. Die zweite Stromquelle ist dabei bevorzugt ausgebildet, um in Abhängigkeit des Steuersignals die Hilfs-LED-Strecke mit dem Hilfsstrom zu versorgen. Die Steuerschaltung weist bevorzugt einen Schalter, bevorzugt einen Transistor auf, der in Abhängigkeit des Vergleichs das Steuersignal erzeugt. So kann mit einfachen schaltungstechnischen Mitteln das gewünschte Verhalten der Betriebsschaltung erreicht werden.The control circuit preferably includes a comparator which compares the voltage at least indirectly with the threshold value. The control circuit is designed to transmit a control signal to the second current source as a function of the comparison. The second current source is preferably designed to supply the auxiliary LED path with the auxiliary current as a function of the control signal. The control circuit preferably has a switch, preferably a transistor, which generates the control signal as a function of the comparison. Thus, the desired behavior of the operating circuit can be achieved with simple circuit technology.

Der Vergleicher weist bevorzugt einen Spannungsteiler und eine Spannungsreferenz auf. Der Spannungsteiler setzt dann die Spannung um einen Faktor herab. Die Spannungsreferenz erzeugt bevorzugt eine Referenzspannung, welche dem um den Faktor herabgesetzten Schwellwert entspricht. Der Vergleicher vergleicht vorzugsweise die herabgesetzte Betriebsspannung mit der konstanten Spannung der Spannungsreferenz. So kann mit einfachen schaltungstechnischen Mitteln das gewünschte Verhalten der Betriebsschaltung erreicht werden.The comparator preferably has a voltage divider and a voltage reference. The voltage divider then reduces the voltage by a factor. The voltage reference preferably generates a reference voltage which corresponds to the threshold value reduced by the factor. The comparator preferably compares the lowered operating voltage with the constant voltage of the voltage reference. Thus, the desired behavior of the operating circuit can be achieved with simple circuit technology.

Ein erfindungsgemäßes LED-Modul beinhaltet zumindest eine zuvor beschriebene Betriebsschaltung und eine LED-Streckemit zumindest einer LED eines ersten Typs und eine Hilfs-LED-Strecke mit zumindest einer LED eines zweiten Typs. Die LEDs des ersten Typs und die LEDs des zweiten Typs weisen dabei bevorzugt unterschiedliche Emissionsspektren auf. So ist es möglich eine gewünschte Farbtemperatur je nach Dimmgrad zu erreichen.An LED module according to the invention comprises at least one operating circuit described above and an LED track with at least one LED of a first type and an auxiliary LED track with at least one LED of a second type. The LEDs of the first type and the LEDs of the second type preferably have different emission spectra. So it is possible to achieve a desired color temperature depending on the degree of dimming.

Eine erfindungsgemäße LED-Leuchte ist bevorzugt eine Retrofit-LED-Leuchte mit zumindest einem zuvor beschriebenen LED-Modul und einer ersten Stromquelle. So können herkömmliche Leuchten einfach ersetzt werden.An LED luminaire according to the invention is preferably a retrofit LED luminaire with at least one previously described LED module and a first current source. So conventional lights can be easily replaced.

Ein erfindungsgemäßes Verfahren dient dem Betrieb einer LED-Strecke mit zumindest einer LED eines ersten Typs und einer Hilfs-LED-Strecke mit zumindest einer LED eines zweiten Typs. Die LED-Strecke und die Hilfs-LED-Strecke werden von einem einstellbaren, bevorzugt geregelten Gesamtstrom versorgt. Ein Hauptstrom durch die LED-Strecke wird direkt von dem Gesamtstrom versorgt. Die Hilfs-LED-Strecke wird mit einem Hilfsstrom versorgt. Der Hilfsstrom wird in Abhängigkeit einer Spannung an der LED-Strecke gesteuert. Instabile Betriebszustände können so bei einer Amplitudenmodulation sicher vermieden werden.An inventive method is used to operate an LED track with at least one LED of a first type and an auxiliary LED track with at least one LED of a second type. The LED track and the auxiliary LED track are supplied by an adjustable, preferably regulated total current. A main current through the LED track is powered directly from the total current. The auxiliary LED track is supplied with an auxiliary current. The auxiliary current is dependent on a voltage at the LED track controlled. Unstable operating states can thus be safely avoided in the case of amplitude modulation.

Weitere Merkmale, Vorteile und Eigenschaften der Erfindung sollen nunmehr unter Bezugnahme auf die Figuren der begleitenden Zeichnungen erläutert werden. Es zeigen:

Fig. 1
ein erstes Ausführungsbeispiel einer erfindungsgemäßen Leuchte;
Fig. 2
ein zweites Ausführungsbeispiel einer erfindungsgemäßen Leuchte;
Fig. 3
ein erstes Ausführungsbeispiel eines erfindungsgemäßen LED-Moduls, und
Fig. 4
ein Ausführungsbeispiel des erfindungsgemäßen Verfahrens.
Further features, advantages and characteristics of the invention will now be explained with reference to the figures of the accompanying drawings. Show it:
Fig. 1
a first embodiment of a lamp according to the invention;
Fig. 2
A second embodiment of a lamp according to the invention;
Fig. 3
a first embodiment of an LED module according to the invention, and
Fig. 4
an embodiment of the method according to the invention.

Zunächst werden anhand der Fig. 1 - 3 der Aufbau und die Funktionsweise unterschiedlicher Ausführungsbeispiele der erfindungsgemäßen Vorrichtung erläutert. Anschließend wird anhand von Fig. 4 im Detail die Funktionsweise einer Ausführungsbeispiels des erfindungsgemäßen Verfahrens dargestellt. Identische Elemente wurden in ähnlichen Abbildungen zum Teil nicht wiederholt dargestellt und beschrieben.First, based on the Fig. 1-3 explains the structure and operation of different embodiments of the device according to the invention. Subsequently, based on Fig. 4 shown in detail the operation of an embodiment of the method according to the invention. Identical elements have not been repeatedly shown and described in similar figures.

Um eine LED-Lampe, welche mit zunehmender Dimmung ein `wärmeres` Licht abgibt zu schaffen, ist vorgesehen, neben zumindest einer weißen LED eine bernsteinfarbene LED einzusetzen. Auch der Einsatz einer oder mehrerer gelber, roter oder RGB-LEDs ist denkbar. Der gegenwärtigen Erfindung liegt die grundliegende Idee zugrunde, die farbige LED oder die farbigen LEDs bei konstanter Helligkeit zu betreiben, während der Dimmvorgang lediglich die weiße bzw. weißen LEDs betrifft. Optional kann zusätzlich nach verlöschen der weißen LED ein Dimmen der farbige LED einsetzen.In order to create a LED lamp, which emits a `warmer` light with increasing dimming, it is intended to use an amber LED in addition to at least one white LED. It is also conceivable to use one or more yellow, red or RGB LEDs. The present invention is based on the underlying idea that operate colored LED or the colored LEDs at constant brightness, while the dimming process only affects the white or white LEDs. Optionally, after dimming the white LED, a dimming of the colored LED can also be used.

Üblicherweise wird ein Dimmen einer LED-Leuchte durch eine Amplitudenmodulation und/oder eine Pulsweitenmodulation eines Betriebsstroms erreicht. Im Fall einer Amplitudenmodulation des Betriebsstroms ist es somit Ziel der gegenwärtigen Erfindung, den Betriebsstrom der farbigen LED konstant zu halten, während der Betriebsstrom der weißen LED bzw. LEDs in Abhängigkeit des Dimmgrads reduziert wird.Usually, a dimming of an LED light is achieved by an amplitude modulation and / or a pulse width modulation of an operating current. Thus, in the case of amplitude modulation of the operating current, it is an object of the present invention to keep the operating current of the colored LED constant, while reducing the operating current of the white LED (s) depending on the degree of dimming.

Im Fall der Pulsweitenmodulation ist es optional Ziel der gegenwärtigen Erfindung, einen dauerhaften Betrieb der farbigen LED möglichst unabhängig von der Pulsweitenmodulation zu erreichen. D.h. die weiße LED bzw. die weißen LEDs werden somit pulsweitenmoduliert, während die farbige LED möglichst keiner derartigen Modulation unterliegt.In the case of pulse width modulation, it is an optional goal of the present invention to achieve a permanent operation of the colored LED as independent as possible of the pulse width modulation. That the white LED or the white LEDs are thus pulse-width modulated, while the colored LED as possible undergoes no such modulation.

Die gegenwärtige Erfindung ist jedoch nicht auf weisse oder rote LEDs beschränkt. Wichtig ist lediglich, dass zumindest zwei LED-Strecken mit jeweils zumindest einer LED eingesetzt werden. Die Emissionsspektren der beiden Strecken müssen sich dabei unterscheiden, um eine Farbveränderung beim Dimmen darstellen zu können.However, the present invention is not limited to white or red LEDs. It is only important that at least two LED sections are used, each with at least one LED. The emission spectra of the two sections must differ in order to represent a color change in dimming can.

Fig. 1 zeigt ein erstes Ausführungsbeispiel einer erfindungsgemäßen LED-Leuchte. Ein Gleichrichtermodul 20 wird mit einer Wechselspannung 10 versorgt. Das Gleichrichtermodul 20 erzeugt aus der Wechselspannung 10 eine Gleichspannung 11. Die Gleichspannung 11 versorgt eine erste Stromquelle 21. Bei der ersten Stromquelle 21 handelt es sich um eine Gleichstromquelle, die vorzugsweise als Gleichspannungswandler ausgebildet ist, beispielsweise als isolierter Sperrwandler. Sie erzeugt einen Gesamtstrom IG, mit welchem ein LED-Modul 22 betrieben wird. Es kann auch das Gleichrichtermodul 20 und die erste Stromquelle 21 in einem einzelnen Modul integriert sein. Fig. 1 shows a first embodiment of an LED lamp according to the invention. A rectifier module 20 is supplied with an AC voltage 10. The rectifier module 20 generates from the AC voltage 10 a DC voltage 11. The DC voltage 11 supplies a first current source 21. The first current source 21 is a DC power source, which is preferably designed as a DC-DC converter, for example as an isolated flyback converter. It generates a total current I G , with which an LED module 22 is operated. The rectifier module 20 and the first current source 21 may also be integrated in a single module.

Eine Dimmeinrichtung 24 erzeugt dabei ein Dimmsignal 15a, welches der Stromquelle 21 zugeführt wird. Die Stromquelle 21 erzeugt den Strom IG dabei in Abhängigkeit des Dimmsignals 15a.A dimming device 24 generates a dimming signal 15a, which is supplied to the current source 21. The current source 21 generates the current I G in response to the dimming signal 15a.

Im Folgenden wird zunächst von einer reinen Amplitudenmodulation ausgegangen. D.h. das Dimmsignal 15a veranlasst die erste Stromquelle 21 einen konstanten Gleichstrom IG einer einstellbaren Stromstärke zu erzeugen und damit das LED-Modul 22 zu betreiben. Die Dimmeinrichtung 24 bestimmt das Dimmsignal 15a dabei in Abhängigkeit eines Dimmwerts, welcher z.B. von einem Nutzer an einem Dimmer eingestellt wird.In the following, initially a pure amplitude modulation is assumed. That is, the dimming signal 15a causes the first current source 21 to generate a constant direct current I G of an adjustable current intensity and thus to operate the LED module 22. The dimming device 24 determines the dimming signal 15a as a function of a dimming value, which is set, for example, by a user on a dimmer.

Alternativ kann auch eine Pulsweitenmodulation eingesetzt werden. In diesem Fall erzeugt die Dimmeinrichtung 24 das Dimmsignal 15a als Pulsweitenmodulationssignal. D.h. das Dimmsignal gibt eine Frequenz und ein Tastverhältnis der Pulsweitenmodulation durch die erste Stromquelle 21 vor.Alternatively, a pulse width modulation can be used. In this case, the dimmer 24 generates the dimming signal 15a as a pulse width modulation signal. That the dimming signal specifies a frequency and a duty cycle of the pulse width modulation by the first current source 21.

Auf den genauen Aufbau und die Funktionsweise des LED-Moduls 22 wird anhand von Fig. 3 im Detail eingegangen.On the exact structure and operation of the LED module 22 is based on Fig. 3 discussed in detail.

In Fig. 2 ist ein zweites Ausführungsbeispiel der erfindungsgemäßen LED-Leuchte dargestellt. Der Aufbau entspricht weitgehend dem Aufbau aus Fig. 1. Zusätzlich beinhaltet die LED-Leuchte hier eine Steuereinrichtung 23, welche ein Signal 13 verarbeitet, welches Rückschlüsse auf die gegenwärtige Helligkeit des Lichts, welches von dem LED-Modul 22 erzeugt wird, zulässt. Hier wird ein Dimmsignal 15b der Steuereinrichtung 23 zugeführt. Die Steuereinrichtung 23 erzeugt aus dem Dimmsignal 15b und dem Helligkeitssignal 13 ein Steuersignal 14 zur Steuerung der ersten Stromquelle 21.In Fig. 2 a second embodiment of the LED lamp according to the invention is shown. The structure largely corresponds to the structure Fig. 1 , In addition, the LED light here includes a control device 23, which processes a signal 13, which allows conclusions about the current brightness of the light, which is generated by the LED module 22. Here, a dimming signal 15b is supplied to the controller 23. The control device 23 generates a control signal 14 for controlling the first current source 21 from the dimming signal 15b and the brightness signal 13.

Zusätzlich zu dem Dimmsignal 15b und dem Helligkeitssignal 13 können weitere Signale in die Steuerung durch die Steuereinrichtung 23 einbezogen werden. So ist z.B. denkbar, ein zusätzliches Temperatursignal zu verarbeiten. Da LEDs eine Temperaturcharakteristik aufweisen, ist es hilfreich die gegenwärtige Temperatur zur Steuerung der LEDs zu berücksichtigen. Insbesondere, um die Farbtemperatur bei einem bestimmten Dimmwert konstant zu halten ist die Nutzung eines Temperatursignals sehr vorteilhaft, da LEDs unterschiedlichen Typs und damit unterschiedlicher Wellenlänge häufig unterschiedliche Temperaturcharakteristiken aufweisen. D.h. bei einer Temperaturveränderung kann es notwendig sein, die Mischung des Lichts durch das LED-Modul 22 anzupassen.In addition to the dimming signal 15b and the brightness signal 13, further signals may be included in the control by the controller 23. For example, e.g. conceivable to process an additional temperature signal. Since LEDs have a temperature characteristic, it is helpful to consider the current temperature for controlling the LEDs. In particular, in order to keep the color temperature constant at a certain dimming value, the use of a temperature signal is very advantageous since LEDs of different types and thus different wavelengths often have different temperature characteristics. That with a change in temperature, it may be necessary to adjust the mixture of light through the LED module 22.

Im Fall einer Pulsweitenmodulation erzeugt die erste Stromquelle 21 einen pulsweitenmodulierten Strom IG. Die Pulsweitenmodulation entspricht dabei dem gewünschten Dimmgrad bzw. wird wie anhand von Fig. 2 dargestellt, in Abhängigkeit von weiteren Steuerparametern bestimmt.In the case of pulse width modulation, the first current source 21 generates a pulse width modulated current I G. The pulse width modulation corresponds to the desired degree of dimming or as is based on Fig. 2 shown, determined in dependence on other control parameters.

In Fig. 3 ist ein erstes Ausführungsbeispiel des erfindungsgemäßen LED-Moduls dargestellt. Ein LED-Modul 22 verfügt über Anschlüsse 12a, 12b. Es weist eine LED-Strecke30, eine Steuerschaltung 40, eine Stromquelle 60 und eine Hilfs-LED-Strecke 70 auf.In Fig. 3 a first embodiment of the LED module according to the invention is shown. An LED module 22 has connections 12a, 12b. It has an LED track 30, a control circuit 40, a power source 60 and an auxiliary LED track 70.

Die LED-Strecke30 besteht dabei aus in Serie geschalteten LEDs 31 - 39. Die LEDs 31 - 39 sind hier weiße LEDs eines ersten Typs w. Die LED-Strecke30 ist dabei mit den Anschlüssen 12a, 12b direkt verbunden und wird durch den Gesamtstrom IG versorgt. Es stellt sich ein Hauptstrom I1 durch die LED-Strecke30 ein.The LED section 30 consists of series-connected LEDs 31-39. The LEDs 31-39 here are white LEDs of a first type w. The LED track 30 is connected directly to the terminals 12a, 12b and is supplied by the total current I G. It turns a main current I 1 through the LED Strecke30 one.

Die zweite Stromquelle 60 beinhaltet eine integrierte Schaltung 67, beispielsweise ein Bauelement des Typs TS19373 als Beispiel für einen Regler-IC für einen Abwärtswandler. Die integrierte Schaltung 67 ist dabei über einen ersten Anschluss 673 mittels eines Kondensators 62 mit dem Anschluss 12a verbunden. Der Anschluss 12a entspricht hier dem Versorgungsstrom IG. Über einen Anschluss 672 ist die integrierte Schaltung 67 direkt mit Masse verbunden. Über einen Anschluss 671 ist sie mittels eines Koppelkondensators 68 mit dem Anschluss 12b verbunden. Der Anschluss 12b entspricht hier Masse. Über einen Anschluss 674 ist sie mit einem Spannungsteiler 69 bestehend aus einem ohmschen Widerstand 64 und einem ohmschen Widerstand 66 verbunden. Über einen Anschluss 675 ist sie weiterhin mit einer Induktivität 65 verbunden, welche ihrerseits mit dem Mittelpunkt des Spannungsteilers 69 verbunden ist. der Anschluss 675 ist weiterhin über eine Diode 61 mit dem Anschluss 12a verbunden. Das der integrierten Schaltung 67 abgewandte Ende des Spannungsteilers 69 ist darüber hinaus mit der Hilfs-LED-Strecke 70 verbunden. Die Hilfs-LED-Strecke beinhaltet hier nur eine LED 63 eines zweiten Typs a. Auf ihrer anderen Seite ist die LED 63 mit dem Anschluss 12a verbunden.The second current source 60 includes an integrated circuit 67, such as a TS19373 device, as an example of a buck regulator regulator IC. The integrated circuit 67 is connected via a first terminal 67 3 by a capacitor 62 to the terminal 12a. The connection 12a here corresponds to the supply current I G. Via a connection 67 2 , the integrated circuit 67 is connected directly to ground. It is connected via a connection 67 1 to the connection 12 b by means of a coupling capacitor 68. The connection 12b here corresponds to ground. Via a connection 67 4 , it is connected to a voltage divider 69 consisting of an ohmic resistor 64 and an ohmic resistor 66. Via a connection 67 5 , it is furthermore connected to an inductance 65, which in turn is connected to the center of the voltage divider 69. the terminal 67 5 is further connected via a diode 61 to the terminal 12 a. The integrated circuit 67 facing away from the end of the voltage divider 69 is also connected to the auxiliary LED track 70. The auxiliary LED track includes here only one LED 63 of a second type a. On its other side, the LED 63 is connected to the terminal 12a.

Die zweite Stromquelle 60 entspricht hier einem Abwärtswandler als Beispiel eines hochfrequent getakteten Schaltreglers. Aus den Anschlüssen 12a und 12b entnimmt die Stromquelle 60 so viel Strom, um einen konstanten Strom zu erzeugen. Die LED-Strecke 70 wird mit diesem Strom beaufschlagt. Es ergibt sich somit eine negative Strom-Spannungs-Charakteristik der Konstantstromquelle 60. D.h. bei ansteigender Betriebsspannung sinkt der entnommene Strom.The second current source 60 corresponds here to a down converter as an example of a high-frequency clocked switching regulator. From the terminals 12a and 12b, the power source 60 draws so much current to produce a constant current. The LED section 70 is supplied with this current. This results in a negative current-voltage characteristic of the constant current source 60th D.h. as the operating voltage increases, the extracted current decreases.

Über den Spannungsteiler 69 ermittelt die integrierte Schaltung 67 den Spannungsabfall über den Widerstand 64. Der Spannungsabfall wird zwischen dem Anschluss 671 und dem Anschluss 674 ermittelt. Die integrierte Schaltung 67 passt den Strom durch die Hilfs-LED-Strecke 70 so an, dass der Spannungsabfall stets einen festen Wert, beispielsweise 0,3 Volt annimmt. Der Strom kann somit durch Auswahl des Widerstands 64 eingestellt werden. Ansonsten handelt es sich um einen konstanten Strom. Die integrierte Schaltung 67 speichert dabei Energie in der Induktivität 65. Die in der Induktivität 65 gespeicherte Energie wird dabei zur Erzeugung des Konstantstroms als Ausgangssignal herangezogen.The integrated circuit 67 determines the voltage drop across the resistor 64 via the voltage divider 69. The voltage drop is determined between the connection 67 1 and the connection 67 4 . The integrated circuit 67 adjusts the current through the auxiliary LED path 70 so that the voltage drop always assumes a fixed value, for example, 0.3 volts. The current can thus be adjusted by selecting the resistor 64. Otherwise it is a constant current. The integrated circuit 67 stores energy in the inductance 65. The energy stored in the inductance 65 is used to generate the constant current as an output signal.

Liegt an dem LED-Modul 22 ein durchgehender Strom IG an (wie im Fall der Amplitudenmodulation), so ist stets eine konstante Menge an Energie in der Induktivität 65 gespeichert. Die Herstellung eines konstanten Ausgangsstroms ist somit für die Konstantstromquelle 60 unproblematisch. Liegt jedoch eine wechselnde Spannung (wie z. B. bei einer Pulsweitenmodulation) an den Anschlüssen 12a, 12b an, so verändert sich die in der Induktivität 65 gespeicherte Energie im Laufe der Zeit. Solange eine Spannung zwischen den Anschlüssen 12a, 12b anliegt, steigt die in der Induktivität 65 gespeicherte Energie bzw. bleibt konstant auf ihrem maximalen Wert. Solange keine Spannung an den Anschlüssen 12a, 12b anliegt, so sinkt die in der Induktivität 65 gespeicherte Energie ab, während die Konstantstromquelle 60 weiterhin einen konstanten Strom als Ausgangssignal erzeugt und der LED 63 zuführt. Die Induktivität 65 ist dabei so klein ausgelegt, dass das erfindungsgemäße LED-Modul 22 nur bei einer Amplitudenmodulation die besondere Eigenschaft der Farbveränderung im Zuge des Dimmens erfüllt. D.h. die Energie in der Induktivität genügt nicht, um eine Ausschaltperiode einer Pulsweitenmodulation zu überbrücken. Ein Nachleuchten während der ausgeschalteten Zeiten einer Pulsweitenmodulation kann so vermieden werden.If a continuous current I G is applied to the LED module 22 (as in the case of amplitude modulation), then a constant amount of energy is always stored in the inductance 65. The production of a constant output current is thus unproblematic for the constant current source 60. However, there is an alternating voltage (as in pulse width modulation, for example) at terminals 12a, 12b, the energy stored in inductor 65 changes over time. As long as a voltage is applied between the terminals 12a, 12b, the energy stored in the inductance 65 increases or remains constant at its maximum value. As long as no voltage is applied to the terminals 12a, 12b, the energy stored in the inductance 65 decreases, while the constant current source 60 continues to generate a constant current as an output signal and the LED 63 supplies. The inductance 65 is designed so small that the LED module 22 according to the invention meets the special property of the color change in the course of dimming only with an amplitude modulation. That is, the energy in the inductance is not enough to bridge a turn-off period of a pulse width modulation. An afterglow during the off periods of a pulse width modulation can be avoided.

Alternativ ist die Induktivität 65 ist dabei derart ausgelegt, dass der Betriebsstrom für die LED 63 selbst bei minimaler Einschaltdauer der Pulsweitenmodulation ausreicht, um die LED 63 dauerhaft mit einem konstanten Strom zu versorgen. In diesem Fall kann die Farbveränderung beim Dimmen auch bei einer reinen Pulsweitenmodulation aufrechterhalten werden.Alternatively, the inductance 65 is designed such that the operating current for the LED 63 is sufficient even with a minimum duty cycle of the pulse width modulation in order to permanently supply the LED 63 with a constant current. In this case, the color change in dimming can be maintained even with a pure pulse width modulation.

Ohne weitere Maßnahmen gibt es Betriebszustände, in welchen die Konstantstromquelle 60 instabil arbeitet. So wirkt der Eingang der Stromquelle 60 als eine Last negativen Widerstands. D.h. die Versorgungsspannung erhöht sich, während der Betriebsstrom sich verringert. Diese Kombination ist nicht stabil, da sich ein Rückkopplungsmechanismus mit der Stromquelle 21 entwickelt. Ein Versuch den Strom zu erhöhen wird ihn tatsächlich verringern.Without further action there are operating conditions in which the constant current source 60 is unstable. Thus, the input of the current source 60 acts as a load negative resistance. That is, the supply voltage increases while the operating current decreases. This combination is not stable, as is a Feedback mechanism developed with the power source 21. Trying to increase the current will actually reduce it.

Diese Kombination arbeitet stabil, während die LED-Strecke30 in Betrieb ist. Die Spannung UG wird durch die LED-Strecke 30 in diesem Fall auf einem festen Wert gehalten. Dies sorgt für eine Quelle niedriger Impedanz für die Stromquelle 60. Probleme entstehen somit lediglich während die LED-Strecke30 nicht-leitend ist. Dies ist beim Einschalten, beim Ausschalten und bei einer Pulsweitenmodulation der Fall.This combination works stably while the LED track 30 is operating. The voltage U G is kept at a fixed value by the LED path 30 in this case. This provides a source of low impedance for the current source 60. Thus, problems only arise while the LED track 30 is nonconductive. This is the case when switching on, when switching off and during pulse width modulation.

Während des Einschaltens bzw. bei der steigenden Flanke jedes Pulses der Pulsweitenmodulation muss die Stromquelle 21 ihre Ausgangsspannung hochfahren, bis die LED-Strecke30 leitfähig wird. Ist die Stromquelle 60 angeschlossen, so wird ein sehr großer Strom gezogen, was zu einem Zusammenbruch der Versorgungsspannung UG führt. Ein Abfall der Versorgungsspannung UG wiederum sorgt für einen Anstieg des von der Konstantstromquelle 60 gezogenen Stroms.During power up, or at the rising edge of each pulse width modulation pulse, the current source 21 must ramp up its output voltage until the LED trace 30 becomes conductive. If the current source 60 is connected, a very large current is drawn, which leads to a breakdown of the supply voltage U G. A drop in the supply voltage U G, in turn, causes an increase in the current drawn by the constant current source 60.

Um die genannten Probleme zu überwinden, wird die Konstantstromquelle 60 mittels einer Steuerschaltung 40 veranlasst, hinsichtlich ihrer Strom-Spannungs-Charakteristik das Verhalten einer LED-Strecke zu zeigen. D.h. die Stromquelle 60 wird veranlasst, erst ab einem Schwellwert einen Teil I2 des Betriebstroms IG aufzunehmen. Im Folgenden wird auf die genaue Funktion der Steuerschaltung 40 eingegangen.In order to overcome the above problems, the constant current source 60 is caused by means of a control circuit 40 to show the behavior of an LED path with regard to its current-voltage characteristic. That is, the current source 60 is caused to receive a portion I 2 of the operating current I G only from a threshold value. The following will discuss the exact function of the control circuit 40.

Die Steuerschaltung 40 weist einen Spannungsteiler 51 bestehend aus ohmschen Widerständen 41 und 42 auf, welcher ebenfalls mit den Anschlüssen 12a und 12b verbunden ist. Der Mittelpunkt des Spannungsteilers 51 ist dabei mit einem negativen Eingang eines Operationsverstärkers 45 verbunden. Zusätzlich ist der Mittelpunkt des Spannungsteilers 51 über einen ohmschen Widerstand 44 mit dem Ausgang des Operationsverstärkers 45 verbunden.The control circuit 40 has a voltage divider 51 consisting of ohmic resistors 41 and 42, which also connected to the terminals 12a and 12b. The center of the voltage divider 51 is connected to a negative input of an operational amplifier 45. In addition, the center of the voltage divider 51 is connected via an ohmic resistor 44 to the output of the operational amplifier 45.

Ein Spannungsteiler 52 wird dabei durch einen ohmschen Widerstand 43 und eine Zenerdiode 46 gebildet. Der Mittelpunkt dieses Spannungsteilers 52 ist mit dem positiven Eingang des Operationsverstärkers 45 verbunden. Der Operationsverstärker 45 vergleicht somit eine durch den ersten Spannungsteiler 51 im Verhältnis der ohmschen Widerstände 41, 42 herabgesetzte Betriebsspannung UG mit der Durchbruchspannung der Zenerdiode 46. Überwiegt die herabgesetzte Betriebsspannung UG, so gibt der Operationsverstärker 45 an seinem Ausgang ein LOW-Signal aus. Überwiegt dagegen die Durchbruchspannung der Zenerdiode 46, so gibt der Operationsverstärker 45 an seinem Ausgang ein HIGH-Signal aus. Diese resultierenden Signale werden über einen dritten Spannungsteiler 53 gegen Masse abgeführt. Der Spannungsteiler 53 besteht aus ohmschen Widerständen 47 und 49. An dem Mittelpunkt des Spannungsteilers 53 wird das Signal der Basis eines Transistors 48 zugeführt. Der Kollektor ist über einen ohmschen Widerstand 50 gegen Masse geschaltet. Der Emitter des Transistors 48 ist mit der Stromquelle 60 verbunden. Der Transistor 48 hat hier die Funktion eines Schalters. D.h. wenn der Operationsverstärker an seinem Ausgang ein HIGH-Signal ausgibt, wird die Kollektor-Emitter-Strecke des Transistors 48 leitend.A voltage divider 52 is formed by an ohmic resistor 43 and a Zener diode 46. The center of this voltage divider 52 is connected to the positive input of the operational amplifier 45. The operational amplifier 45 thus compares an operating voltage U G reduced by the first voltage divider 51 in the ratio of the ohmic resistances 41, 42 with the breakdown voltage of the zener diode 46. If the reduced operating voltage U G predominates, the operational amplifier 45 outputs a LOW signal at its output , On the other hand, if the breakdown voltage of the Zener diode 46 predominates, the operational amplifier 45 outputs a HIGH signal at its output. These resulting signals are dissipated via a third voltage divider 53 to ground. The voltage divider 53 consists of ohmic resistors 47 and 49. At the midpoint of the voltage divider 53, the signal is supplied to the base of a transistor 48. The collector is connected via an ohmic resistor 50 to ground. The emitter of the transistor 48 is connected to the power source 60. The transistor 48 here has the function of a switch. That is, when the operational amplifier outputs a HIGH signal at its output, the collector-emitter path of the transistor 48 becomes conductive.

Der Emitter des Transistors 48 ist mit dem Anschluss 674 der integrierten Schaltung 67 verbunden. Ist der Transistor leitend, wird ein Spannungsabfall an dem Anschluss 674 erzeugt, da der Strom durch den Transistor 48 über den Widerstand 66 gezogen wird. Der genannte Spannungsabfall führt zu einer Abschaltung der Konstantstromquelle 60.The emitter of the transistor 48 is connected to the terminal 67 4 of the integrated circuit 67. Is the Transistor conductive, a voltage drop is generated at the terminal 67 4 , since the current through the transistor 48 via the resistor 66 is pulled. The mentioned voltage drop leads to a shutdown of the constant current source 60.

D.h. solange die Spannung UG unterhalb eines Schwellwerts ist, ist die Stromquelle 60 und damit auch die Hilfs-LED-Strecke 70 abgeschaltet. Dies ermöglicht, dass die Stromquelle 21, welche das LED-Modul 22 versorgt, einen stabilen Betriebszustand erreichen kann, bevor die Stromquelle 60 eingeschaltet wird. Sobald der Schwellwert durch die Spannung UG überschritten ist, wechselt der Ausgang des Operationsverstärkers 45 auf Low, der Transistor 48 wird nicht-leitend und ein künstlicher Spannungsabfall am Anschluss 674 wird nicht länger erzeugt. Die Stromquelle 60 nimmt somit den Betrieb auf. Da nun bereits ein signifikanter Stromfluss I1 durch die LED-Strecke30 besteht, kann die negative Strom-Spannungs-Charakteristik der Stromquelle 60 die Stromquelle 21 nicht länger negativ beeinflussen.That is, as long as the voltage U G is below a threshold value, the current source 60 and thus also the auxiliary LED path 70 is switched off. This allows the power source 21, which powers the LED module 22, to reach a stable operating state before the power source 60 is turned on. Once the threshold is exceeded by the voltage U G , the output of the operational amplifier 45 changes to low, the transistor 48 is non-conductive and an artificial voltage drop at the terminal 67 4 is no longer generated. The power source 60 thus starts operating. Since a significant current flow I 1 already exists through the LED path 30, the negative current-voltage characteristic of the current source 60 can no longer adversely affect the current source 21.

Durch den Wert der ohmschen Widerstände 41, 42 und 44 kann dabei der Verstärkungsfaktor des Operationsverstärkers 45 eingestellt werden. Über den Verstärkungsfaktor kann die Strom-Spannungs-Charakteristik der Gesamtschaltung eingestellt werden. Ein geringer Verstärkungsfaktor sorgt für einen "weichen" Schwellwert. Dies führt dazu, dass die Hilfs-LED-Strecke 70 nicht augenblicklich sondern langsam zugeschaltet wird, wenn der Schwellwert durch die Spannung UG überschritten wird.By the value of the ohmic resistors 41, 42 and 44, the amplification factor of the operational amplifier 45 can be set. The amplification factor can be used to set the current-voltage characteristic of the overall circuit. A low gain provides a "soft" threshold. As a result, the auxiliary LED path 70 is not switched on instantaneously but slowly, when the threshold value is exceeded by the voltage U G.

Findet eine Pulsweitenmodulation statt, so findet der Vorgang des An- und Abschaltens der Konstantstromquelle 60 bei jedem einzelnen Puls statt.If a pulse width modulation takes place, then the process of turning on and off the constant current source 60 takes place at each individual pulse.

Im Fall der Amplitudenmodulation des Betriebsstroms IG findet der genannte Vorgang lediglich einmal beim Einschalten und beim Ausschalten statt.In the case of the amplitude modulation of the operating current I G , said operation takes place only once at power up and at power off.

Alternativ ist es auch denkbar, dass die integrierte Schaltung 67 eine eigene Pulsweitenmodulation der Einschaltdauer der Hilfs-LED-Strecke 70 durchführt. In diesem Fall wird der integrierten Schaltung 67 über ein zusätzliches Signal der Dimmwert der Hilfs-LED-Strecke 70 mitgeteilt. Die Pulsweitenmodulation der Hilfs-LED-Strecke 70 ist in diesem Fall vollständig unabhängig von der Pulsweitenmodulation durch die Stromquelle 21 bzw. von der Amplitudenmodulation durch die Stromquelle 21.Alternatively, it is also conceivable that the integrated circuit 67 performs its own pulse width modulation of the duty cycle of the auxiliary LED path 70. In this case, the integrated circuit 67 is informed of the dimming value of the auxiliary LED path 70 via an additional signal. The pulse width modulation of the auxiliary LED path 70 in this case is completely independent of the pulse width modulation by the current source 21 or of the amplitude modulation by the current source 21.

Innerhalb der zweiten Stromquelle 60 kann auch ein Pufferkondensator als Energiespeicher angeordnet sein. Dieser kann beispielsweise in der Betriebsphase, in der die Hilfs-LED-Strecke 70 mit dem Hilfsstrom I2 versorgt wird, eine Energie zwischenspeichern. Innerhalb dieser Phase wird diese Energie der LED-Strecke 30 entnommen. In einer weiteren Phase kann die zwischengespeicherte Energie des Pufferkondensators wieder abgegeben werden. Beispielsweie kann diese Energie dann in einer weiteren Phase des Betriebs der Hilfs-LED-Strecke 70 zum Speisen der Hilfs-LED-Strecke 70 genutzt werden.Within the second current source 60 and a buffer capacitor can be arranged as an energy storage. This can, for example, in the operating phase, in which the auxiliary LED path 70 is supplied to the auxiliary power I 2, between a store energy. Within this phase, this energy is taken from the LED track 30. In a further phase, the buffered energy of the buffer capacitor can be released again. For example, this energy may then be used in a further phase of the operation of the auxiliary LED track 70 to power the auxiliary LED track 70.

In Fig. 4 ist ein Ausführungsbeispiel des erfindungsgemäßen Verfahrens dargestellt. Das Verfahren entspricht einem Hochfahren einer Betriebsspannung und der Reaktion der betroffenen Schaltungselemente. In einem ersten Schritt 80 wird eine Betriebsspannung UG von einer Stromquelle hochgefahren. In einem zweiten Schritt 81 wird ermittelt, ob die Spannung einen Schwellwert überschreitet. Ist dies nicht der Fall, wird mit dem ersten Schritt 80 fortgefahren. Ist dies jedoch der Fall, so wird mit einem dritten Schritt 82 fortgefahren. In dem dritten Schritt 82 wird eine Hilfs-LED-Strecke aktiviert.In Fig. 4 an embodiment of the method according to the invention is shown. The method corresponds to a ramp-up of an operating voltage and the reaction of the affected circuit elements. In one First step 80, an operating voltage U G is powered up from a power source. In a second step 81, it is determined whether the voltage exceeds a threshold value. If this is not the case, the first step 80 is continued. If this is the case, then a third step 82 is continued. In the third step 82, an auxiliary LED route is activated.

Fortgefahren wird mit einem vierten Schritt 83. In dem vierten Schritt 83 wird die Betriebsspannung UG weiter hochgefahren. Fortgefahren wird mit einem fünften Schritt 84. Es wird nun ermittelt, ob die Spannung eine Einsatzspannung einer LED-Strecke überschreitet. Ist dies nicht der Fall, wird mit dem vierten Schritt 83 fortgefahren. Ist dies jedoch der Fall, wird mit einem sechsten Schritt 85 fortgefahren. In dem sechsten Schritt 85 wird die LED-Strecke aktiviert. Die genannten Schritte werden bei jedem Hochfahren der Betriebsspannung UG wiederholt.The process continues with a fourth step 83. In the fourth step 83, the operating voltage U G is further increased. It is continued with a fifth step 84. It is now determined whether the voltage exceeds a threshold voltage of an LED track. If this is not the case, the fourth step 83 is continued. If this is the case, a sixth step 85 is continued. In the sixth step 85, the LED route is activated. The said steps are repeated each time the operating voltage U G is raised .

Bei einem Herunterfahren der Betriebsspannung UG werden die Schritte in umgekehrter Reihenfolge durchgeführt. D.h. nach einem initialen Herunterfahren der Spannung wird zunächst überprüft, ob die Einsatzspannung der LED-Strecke unterschritten wurde. Ist dies der Fall, so wird die LED-Strecke deaktiviert. Nach weiterem Herunterfahren der Spannung wird überprüft, ob der Schwellwert unterschritten wurde. Sobald der Schwellwert unterschritten wurde, wird die Hilfs-LED-Strecke deaktiviert.When the operating voltage UG shuts down, the steps are carried out in the reverse order. That After an initial shutdown of the voltage, it is first checked whether the threshold voltage of the LED track has been undershot. If this is the case, the LED route is deactivated. After further lowering of the voltage is checked whether the threshold was exceeded. As soon as the threshold value has been undershot, the auxiliary LED route is deactivated.

Die Erfindung ist nicht auf das dargestellte Ausführungsbeispiel beschränkt. Insbesondere können beliebige Anzahlen unterschiedlicher LEDs eingesetzt werden. Wichtig ist lediglich, dass sich die direkt von der Stromquelle 21 betriebenen LEDs hinsichtlich ihrer Strahlungscharakteristik von den durch die Stromquelle 60 betriebenen LEDs unterscheiden. Alle vorstehend beschriebenen Merkmale oder in den Figuren gezeigten Merkmale sind im Rahmen der Erfindung beliebig vorteilhaft miteinander kombinierbar.The invention is not limited to the illustrated embodiment. In particular, any number of different LEDs can be used. The only important thing is that the directly from the current source 21 LEDs differ in terms of their radiation characteristics of the operated by the power source 60 LEDs. All features described above or features shown in the figures can be combined with each other in any advantageous manner within the scope of the invention.

Durch den Einsatz einer hochfrequent getakteten zweiten Stromquelle wird zudem ein sicherer und konstanter Betrieb der Hilfs-LED-Strecke gewährleistet, da der Betrieb dieser Hilfs-LED-Strecke durch eine von der Regelung der LED-Strecke unabhängigen Regelung erfolgt. Gleichzeitig wird die LED-Strecke durch die hochfrequent getaktete zweiten Stromquelle gleichmäßig belastet, da aufgrund der hochfrequenten Taktung eine gleichmäßige Stromaufnahme durch die hochfrequent getaktete zweiten Stromquelle gewährleistet ist.The use of a high-frequency clocked second power source also ensures a safe and constant operation of the auxiliary LED track, since the operation of this auxiliary LED track is controlled by an independent of the regulation of the LED route control. At the same time the LED track is evenly loaded by the high-frequency clocked second power source, since due to the high-frequency clocking a uniform power consumption is ensured by the high-frequency clocked second power source.

Claims (14)

  1. An operating circuit (22), through which an LED section (30) with at least one LED (31 - 39) of a first type (w) and an auxiliary LED section (70) with at least one LED (63) of a second type (a), the spectrum of which differs from the first type (w), is operable,
    wherein the operating circuit is designed, in order to be supplied by a first current source (21) with an adjustable, preferably regulated, overall current (IG),
    wherein a main current (I1) is supplied through the LED section (30) directly by the overall current (IG),
    characterized in
    that the operating circuit has a second current source (60), which is supplied by the overall current (IG) and is configured to supply the auxiliary LED section (70) with an auxiliary current (I2),
    wherein the operating circuit has a control circuit (40),
    which controls the second current source (60) as a function of a voltage (UG) on the LED section (30), and wherein the second current source (60) is clocked with high frequency and the LED section (30) and the auxiliary LED section (70) are connected in parallel and can be supplied from the first current source (21) with an adjustable overall current (IG).
  2. An operating circuit according to Claim 1,
    characterized in
    that the control circuit (40) is designed, in order to control the second current source (60) when a threshold value is exceeded by the voltage (UG), in order to supply the auxiliary LED section (70) with the auxiliary current (I2), and in order
    to control the second current source (60) when the voltage (UG) falls below the threshold value, in order not to supply the auxiliary LED section (70) with the auxiliary current (I2), and
    that an starting voltage of the LED section (30) is greater than the threshold voltage.
  3. An operating circuit according to Claim 1 or 2,
    characterized in
    that the second current source (60) is designed in such a manner in response to an amplitude dimming of the overall current (IG) to keep the auxiliary current (I2) constant through the auxiliary LED section (70), wherein the auxiliary LED section (70) emits light constantly, as long as the LED section (30) receives a main current (I1), wherein the LED section (30) emits light, and wherein the operating circuit is configured in response to the amplitude dimming to dim the auxiliary current (I2) through the auxiliary LED section (70), wherein the auxiliary LED section (70) emits dimmed light, as long as the LED section (30) receives no main current (I1) and thus emits no light.
  4. An operating circuit according to Claim 1, 2, or 3,
    characterized in
    that the second current source (60) is designed in such a manner that in the case of a dimming by means of the pulse width modulation of the overall current (IG), the auxiliary current (I2) through the auxiliary LED section (70) follows the course of the overall current (IG) and the auxiliary LED section (70) emits thus dimmed light.
  5. An operating circuit according to Claim 1, 2, or 3,
    characterized in
    that the second current source (60) is designed in such a manner in response to a dimming by means of pulse width modulation of the overall current (IG), to operate the auxiliary LED section (70) constantly, wherein the auxiliary current (I2) through the auxiliary LED section (70) has no pulse width modulation and wherein the auxiliary LED section (70) emits undimmed light.
  6. An operating circuit according to any one of Claims 2 to 5,
    characterized in
    that the control circuit (40) has a comparator (54), which compares the voltage at least indirectly with the threshold value,
    that the control circuit (40) is designed, in order to transmit a control signal to the second current source (60) as a function of the comparison,
    that the second current source (60) is designed, in order to supply the auxiliary. LED section (70) with the auxiliary current (I2) as a function of the control signal, and
    that the control circuit (40) has a switch, preferably a transistor (48), which generates the control signal as a function of the comparison.
  7. An operating circuit according to Claim 6,
    characterized in
    that the comparator (54) has a voltage divider (51) and a voltage reference (52),
    that the voltage divider (51) decreases the voltage by a factor,
    that the voltage reference (52) generates a reference voltage, which corresponds to the threshold value decreased by the factor, and
    that the comparator (54) compares the decreased operating voltage with the constant voltage of the voltage reference.
  8. An LED module with at least one operating circuit according to any one of Claims 1 to 7 and an LED section (30) with at least one LED (31 - 39) of a first type (w) and an auxiliary LED section (70) with at least one LED (63) of a second type (a),
    wherein LEDs (31 - 39) of the first type (w) and LEDs (63) of the second type (a) have different emission spectra.
  9. LED lamp, preferably retrofit LED lamp with at least one LED module (22) according to Claim 8 and a first current source (21).
  10. A method for operating a LED section (30) with at least one Led (31 - 39) of a first type (w) and an auxiliary LED section (70) with at least one LED (63) of a second type (a), the spectrum of which differs from that of the first type,
    wherein the LED section (30) and the auxiliary LED section (70) are supplied by an adjustable, preferably regulated, overall current (IG),
    wherein the main current (I1) is supplied through the LED section (30) directly by the overall current (IG),
    characterized in
    that the auxiliary LED section (70) is supplied with an auxiliary current (I2), which is supplied by the overall current (IG), wherein the auxiliary current (I2) is controlled as a function of a voltage (UG) on the LED section (30), and
    wherein the LED section (30) and the auxiliary LED section (70) are connected in parallel and are supplied from the first current source (21) with the adjustable overall current (IG).
  11. A method according to Claim 10,
    characterized in
    that when a threshold is exceeded by the voltage (UG), the auxiliary LED section (70) is supplied with the auxiliary current (I2), and
    that when the voltage (UG) falls short of the threshold, the auxiliary LED section (70) is not supplied with the auxiliary current (I2), and
    that an starting voltage of the LED section (30) is greater than the threshold value.
  12. A method according to Claim 11,
    characterized in
    that in the case of an amplitude dimming of the overall current (IG), the auxiliary current (I2) is made constant through the auxiliary LED section (70) and thus light is constantly emitted through the auxiliary LED section (70), as long as the LED section (30) receives a main current (I1) and thus emits light, and
    the auxiliary current (I2) is adjusted through the auxiliary LED section (70) to one such that it is subjected to an amplitude dimming and thus dimmed light is emitted through the auxiliary LED section (70), as long as the LED section (30) receives no main current (I1) and thus emits no light.
  13. A method according to claim 11 or 12,
    characterized in
    that when the overall current (IG) is dimmed by means of pulse width modulation, the auxiliary current (I2) through the auxiliary LED section (70) is adjusted such that it follows the course of the overall current (IG) and the auxiliary LED section (70) thus emits dimmed light.
  14. A method according to Claim 11 or 12,
    characterized in
    that when the overall current (IG) is dimmed by means of pulse width modulation, the auxiliary current (I2) is adjusted through the auxiliary LED section (70) such that it has no pulse width modulation and the auxiliary LED section (70) thus emits constant and undimmed light.
EP12815674.2A 2011-12-23 2012-12-20 Method and circuit arrangement for dimmable generation of light by means of leds, with colour temperature control Active EP2796003B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102011089816 2011-12-23
PCT/EP2012/076359 WO2013092843A1 (en) 2011-12-23 2012-12-20 Method and circuit arrangement for dimmable generation of light by means of leds, with colour temperature control

Publications (2)

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EP2796003A1 EP2796003A1 (en) 2014-10-29
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EP12815674.2A Active EP2796003B1 (en) 2011-12-23 2012-12-20 Method and circuit arrangement for dimmable generation of light by means of leds, with colour temperature control

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DE202015103127U1 (en) 2015-06-15 2016-09-19 Tridonic Gmbh & Co Kg LED module with changeable color location and lighting device with such a LED module
DE102015223071A1 (en) * 2015-11-23 2017-05-24 Tridonic Gmbh & Co Kg Color temperature dimming of AC-powered LED circuits using phase information
CN109526104A (en) * 2018-12-13 2019-03-26 广东新昇电业科技股份有限公司 A kind of light modulation toning circuit temperature of LED light

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DE10003766C2 (en) 2000-01-28 2002-05-08 Koch Bernd Martin Christmas tree stand with safety wedges
WO2007129131A1 (en) * 2006-05-10 2007-11-15 Nokia Corporation Apparatus having supply voltage adaptive light emitting component circuitry country and method of controlling
AT506417B1 (en) * 2008-06-30 2009-09-15 Lunatone Ind Elektronik Gmbh LOW VOLTAGE LIGHTING
US8665922B2 (en) * 2008-10-31 2014-03-04 Sanyo Electric Co., Ltd. Driver circuit of light-emitting element
TW201038115A (en) * 2009-02-20 2010-10-16 Koninkl Philips Electronics Nv Dimmable light source with temperature shift
US8330394B2 (en) * 2010-04-09 2012-12-11 Young Lighting Technology Inc. Light source of LED and method for producing light source with varying color while dimming

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DE112012005371A5 (en) 2014-09-04
EP2796003A1 (en) 2014-10-29
WO2013092843A1 (en) 2013-06-27

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