EP2548412B1 - Led-lighting system - Google Patents

Description

The present invention relates generally to the operation of LEDs, including inorganic LEDs as well as organic LEDs (OLEDs).

In principle, it is already known to supply an LED track, which may have one or more series-connected LEDs, starting from a constant current source with electrical power. It is also known to use a PWM modulation for performing dimming, so that in the ON periods of a PWM pulse train, said constant current control is performed. When dimming so then the duty cycle of the PWM signal is changed.

To provide the supply voltage of the constant current source, for example, an actively clocked PFC circuit (Power Factor Correction Circuit, power factor correction circuit) can be used.

Finally, other requirements for the operation of LEDs are to be considered, for example, that usually a galvanic isolation between the LED track and the supply voltage of the PFCs, typically an AC line voltage, is required.

From the above it follows that for a proper and advantageous operation of an LED track functionally several circuit blocks must be present (rectifier, PFC, galvanic isolation, constant current source, etc.). This may lead to relatively complex circuits.

In particular, are out WO 2007/062662 A1 a method and apparatus for controlling a variable color light source is known.

The invention now makes several approaches to how an LED track can be operated in a particularly advantageous manner.

This 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.

A first aspect of the invention provides a method for operating a light source with an LED module, which has at least two LED channels (53, 53 ') each having an LED path of different emission colors,
wherein in order to achieve a light output with a hue corresponding to a desired color location, the intensity of the LED lines is individually controlled,
wherein the intensities for the LED paths are each normalized such that when changing the color locus within a controllable color range provided for the operation, the overall intensity of the light output remains constant.

The normalization of the intensities of the LED paths can be carried out on the basis of a reference value which corresponds to the intensity of the color locus which has the lowest efficiency within the controllable color range provided for the operation.

The color location with the lowest efficiency can be determined on the basis of previously determined efficiencies for the individual LED routes.

The color location with the lowest efficiency can be determined experimentally as part of a scan.

The scan can be performed periodically and / or operationally.

The controllable color range provided for the operation may comprise at least part of the Planck's white light curve.

The controllable color range provided for the operation can substantially correspond to the Planck's white light curve.

The light source may comprise at least one monochromatic and at least one dye-converted LED, and may in particular comprise a monochromatic blue LED, a monochromatic red LED and a greenish-white dye-converted LED.

The dimming or setting of the intensities of the individual LED sections can be done by means of pulse width modulation.

• zumindest zwei LED-Kanäle mit jeweils eine LED-Strecke unterschiedlicher Emissionsfarben, sowie
• eine Steuereinheit, welche dazu ausgebildet ist, zum Erzielen einer Lichtabgabe mit einem Farbton entsprechend einem gewünschten Farbort die LED-Strecken in ihrer Intensität individuell anzusteuern,

wobei die Intensitäten für die LED-Strecken durch die Steuereinheit jeweils derart eingestellt bzw. normiert werden, dass bei einem Wechsel des Farborts innerhalb eines für den Betrieb vorgesehenen ansteuerbaren Farbbereichs die Intensität der Gesamtlichtabgabe konstant bleibt.The invention also relates to an arrangement for emitting light with a light source having an LED module, comprising

• at least two LED channels, each with an LED track of different emission colors, as well
• a control unit which is designed to individually control the intensity of the LED paths in order to achieve a light output with a color tone corresponding to a desired color location,

wherein the intensities for the LED paths are respectively set or normalized by the control unit in such a way that when the color locus is changed within a controllable color range provided for the operation, the intensity of the total light output remains constant.

The normalization of the intensities of the LED paths can be carried out on the basis of a reference value which corresponds to the intensity of the color locus which has the lowest efficiency within the controllable color range provided for the operation.

The arrangement can be designed to independently determine the color location with the lowest efficiency.

The arrangement may further comprise a sensor for detecting the light output, wherein the control unit (E) may be configured to generate light corresponding to different color loci within the scope of a scan by differently driving the LED paths and based on the sensor obtained at the different color loci -Information to determine the color location with the lowest efficiency.

The control unit may be designed to perform the scan at regular intervals and / or depending on the operation.

The provided for the operation controllable color range lamb at least include a part of the Planck's white light curve.

The controllable color range provided for the operation can substantially correspond to the Planck's white light curve.

The light source may comprise at least one monochromatic and at least one dye-converted LED, and may in particular comprise a monochromatic blue LED, a monochromatic red LED and a greenish-white dye-converted LED.

The dimming or setting of the intensities of the individual LED paths can be done, for example, by means of pulse width modulation (PWM).

The invention also relates to an integrated control circuit, in particular ASIC or microcontroller, which is designed to carry out a method according to one of the preceding claims.

Fig. 1

zeigt den modularen Aufbau eines erfindungsgemäßen modularen LED-Beleuchtungssystems.

Fig. 2

zeigt ein Ausführungsbeispiel für einen isolierten DC/DC-Wandler, in Form eines Wechselrichters mit folgerndem Resonanzkreis und Transformator.

Fig. 3

schematisch weitere Steuermodi für den DC/DC-Wandler von Figur 2.

Fig. 4

zeigt die erfindungsgemäße Kommunikation zwischen einer Mastereinheit und mehreren Slave-Einheiten des modularen LED-Beleuchtungssystems.

Fig. 5

zeigt die erfindungsgemäße Erzeugung einer DC-Niedervoltspannung.

Fig. 6a und 6b

zeigen das LED-Modul mit mehreren voneinander unabhängigen steuerbaren Kanälen.

Further advantages, features and characteristics of the invention will become apparent from the following description of preferred embodiments and with reference to the accompanying figures.

Fig. 1

shows the modular structure of a modular LED lighting system according to the invention.

Fig. 2

shows an embodiment of an isolated DC / DC converter, in the form of an inverter with consequential resonant circuit and transformer.

Fig. 3

schematically further control modes for the DC / DC converter of FIG. 2 ,

Fig. 4

shows the communication according to the invention between a master unit and a plurality of slave units of the modular LED lighting system.

Fig. 5

shows the inventive generation of a DC low-voltage.

Fig. 6a and 6b

show the LED module with several independent controllable channels.

General structure of the modular circuit concept:

The general structure of the modular circuit concept according to the invention for an LED-based illumination, for example for a so-called "downlight" (radiator embedded in the ceiling), will now be explained. Both inorganic LEDs and / or organic LEDs (OLED) can be used.

As in FIG. 1 can be seen, the modular circuit concept according to the invention on a first module 1, which is preferably supplied with the input voltage 9, in particular AC line voltage. This input voltage 9 is supplied to a first sub-module A, which typically carries out a rectification of the AC voltage supplied as input voltage 9, in which case the rectified AC voltage is fed to an actively clocked PFC (Power Factor Correction) circuit of the sub-module A, if present. The output voltage of the first submodule A is a DC voltage, hereinafter referred to as ' _bus voltage V _bus ', which is supplied to a second submodule B of the first module 1. The second sub-module B has essentially the function of a galvanic isolation (insulation) and can, for example, have as a galvanic separating element a transformer.

The submodule G is a control unit of the module 1, which may be implemented in particular as an integrated circuit, such as ASIC or microprocessor or hybrid thereof. As schematically in FIG. 1 shown, controls this control unit G active switching elements of the second sub-module B, for example in the form of a half-bridge (for example, a half-bridge driver and two switches in series, see below Fig. 2 ), which generates an AC voltage supplied to the transformer 19 of the second sub-module B. The control unit G may have programming inputs, whereby programming or calibration programming of the control unit G is possible. For this, the terminals of the control unit G can be led out to the board of the second sub-module B, to allow programming of this sub-module B and thus the control unit G even after delivery of the sub-module B.

The control unit G is connected to a memory 52.

The second submodule B of the first module 1 denotes a galvanic decoupling via which the control unit G of the module 1 communicates with the submodule D as an interface circuit. This interface circuit D can have a data interface 11, which can be designed in particular for connecting an external analog or digital bus 10, for example in accordance with the DALI industry standard. Alternatively or additionally, however, it is also possible to transmit unidirectional or bidirectional signals at this data interface 11 or interface circuit D in accordance with other standards. Furthermore, alternatively or additionally signals can be received at this data interface 11 or interface circuit D which are generated starting from a manually actuated pushbutton or switch supplied by the data interface 11 or interface circuit D itself or externally (for example also via the input voltage 9).

The essential functions of the first module 1 are thus the provision (at the output of the second sub-module B) of a DC voltage (by rectifying the output voltage of the transformer 19 of the second sub-module B with the rectifier 22) starting from a supplied input voltage 9 as well as the external communication via the data interface 11 or interface circuit D.

Preferably, spatially separated from said first module 1 is a second module 2 as a circuit module intended. This second module 2 has essentially the function of the so-called 'lamp management', which means that this second module 2 on the one hand supplies the connected lamps (here the LED track 8 with one or more LEDs) with constant current and on the other hand feedback variables (schematically with 13 designated) from the area of the LED track 8 receives.

The DC supply voltage 5 at the output of the second submodule B of the first module 1 is thus fed to a further submodule C as a controllable constant current source. This further submodule C thus supplies the LED path with constant current via an output 7. The second module 2 can contain several converter stages (several further submodules C as constant current sources), wherein these converter stages (further submodules C as constant current sources) can each control separate (independent) LED paths 8.

The further submodule C can be embodied both as a clocked constant current source (that is to say as a buck converter, for example, also referred to as a buck converter or as a flyback converter) or as a linear regulator (realized with transistors or integrated circuits).

Furthermore, the second module 2 has its own control unit E, which in turn can be designed as a microcontroller, ASIC or hybrid thereof. This control unit E of the second module 2 thus contains feedback variables 13 from the region of the LED path 8. The control unit E activates the one or more further submodules C in the second module 2. This is the current controlled by the LED track 8, it can be detected and monitored for correct operation of the LEDs and error detection but also other feedback variables such as the LED voltage or temperature.

In addition, the control unit E via a communication interface 6, which is designed in addition to the DC supply voltage 5, with the control unit G of the first module 1 are unidirectional or bidirectional in data communication. The communication interface 6 can also be used to transmit the low-voltage supply (there is then both a data communication and an energy transfer). The communication interface 6 can also be integrated into the DC supply voltage 5, for example, the polarity of the DC supply voltage 5 can be switched or a carrier signal to the DC supply voltage 5 are modulated.

As in FIG. 1 shown schematically, the second module 2, here as a lamp management module, preferably housed in a common housing 12 with the actual LED module F.

As in FIG. 1 shown schematically, the LED module F may have its own memory 4, for example in the form of an eprom. The reference numeral 3 denotes schematically that the control unit E of the second module 2 can access this memory 4 of the LED module F.

With regard to the first module 1, it should be noted that the PFC circuit is optional only.

In addition, it should be pointed out that the illustrated functions of the submodules A, B and C can also be integrated circuit-wise, so that, as long as these functions are basically present, they do not have to be reflected in a corresponding structure of the circuit topology.

The advantage of the modular design according to Fig. 1 It is, for example, that the first module 1 and the second module 2 can be produced by different manufacturers. In addition, a plurality of second modules 2 in the sense of a master / slave operation can be connected to a first module 1.

Finally, the modular design also allows the respective sub-modules and in particular the second module 2 to be interchangeable while retaining the remaining components.

• Abgleich in der Fertigung oder bei der Inbetriebnahme
• ein geschlossenes Regelsystem innerhalb dieser Kombination (beispielsweise mittels eines internen Sensorsystems)
• Stützwerte
• Verfahren mit LED-Charakterisierung
• oder eine Kombination aus den genannten Verfahren.

If the second module 2 is housed in a common housing 12 with the actual LED module F, there is the advantage that this combination of the second module 2 and LED module F can be adjusted in itself, so that, for example, their radiation characteristics, amount of light, Light color and / or light control parameterized and thus can be adjusted. The first module 1 and also the user can thus have one or more matched systems, which can then be controlled at the same time and behave accordingly. This internal balancing of the combination of the second module 2 and the LED module F can take place, for example, using one of the following methods:

• Adjustment in production or during commissioning
• a closed control system within this combination (for example by means of an internal sensor system)
• supporting values
• Method with LED characterization
• or a combination of the said methods.

The communication between the first module 1 and the second module 2 via the communication interface 6 is accordingly preferably standardized.

From the outside, for example via a bus line of the external bus 10 via the data interface 11 incoming commands or queries are supplied as shown only the first module 1. This can thus be referred to as external data communication, in contrast to the internal data communication via the communication interface 6 between the first module 1 and the second module 2.

This has the advantage that only the first module 1 must be adapted for adaptation to different external buses 10, while the structure and the data protocol for the second module 2 remain unaffected.

The communication via the internal communication interface 6 is thus also standardized, since it is independent of different bus protocols or control signals which can be applied to the first module 1.

The communication via the internal communication interface 6 combined with the modular design of the system provides the advantage that the operating data for the optimal feeding of the second module 2 can be transmitted from the second module 2. The second module 2 (preferably starting from the control unit E) can transmit the required operating data via the internal communication interface 6 to the first module 1. This offers the advantage that a first module 1 can be combined with many different second modules 2, wherein the required operating data can be read from the second module 2.

Examples of the feedback quantities 13 from the LED track 8 are the directly or indirectly measured LED current and / or the voltage across the LED track 8.

In the memory 4, which is assigned to the LED module F, operating data for the LEDs of the LED track 8 can be stored, for example, at the manufacturer. These data in this memory 4 can thus be, for example, characteristic values, the permissible maximum values for current and / or voltage, temperature dependence of electrical or optical (spectra) parameters of the LEDs, etc. Also these operating data for the LEDs (for example data from the memory 4) can be transmitted to the first module 1 via the internal communication interface 6.

As already briefly stated above, a first module 1 in the sense of a master can supply a plurality of second modules 2. This means that a single first module 1 more second modules 2 not only supplied with a DC supply voltage 5, but also communicates with these bidirectionally in the sense of an internal communication interface 6.

As already explained briefly above, the control unit G in the first module 1 can control the second submodule B, which is preferably clocked. The same control unit G or preferably also a further control unit (not shown) can also regulate the operation of the PFC of the first submodule A, ie for example activate the switch of the PFC of the submodule A and for signals from the area of the PFC, such as the input voltage Current through an inductance of the PFC, the current through the switch of the PFC, the output voltage of the PFC, as indicated schematically by arrows in FIG Fig. 1 is shown.

The PFC may be, for example, a boost converter (boost converter), flyback converter (buck-boost converter, an isolated flyback converter) or SEPIC converter.

Typically, the output voltage (bus voltage) V _{bus of} the PFC of the first sub-module A is in a range of several hundred volts DC. Due to the transformer 19 in the second sub-module B, therefore, this DC voltage can be lowered, for example to a voltage in the range of 20 to 60 volts, preferably 40 to 50 volts DC. Thus, the DC supply voltage 5 is after the output of the first module 1 in a lower level than the ruling internally in the first module 1 voltages, which for the requirements, for example, to the isolation of the DC supply voltage 5 to the second module 2 and to the second module 2 even lower claims. In addition, optionally a second output voltage, for example a DC low-voltage supply for the second module 2, can be generated in the first module 1 and provided to the second module 2.

An advantage of the modular construction with internal communication interface 6 as described above is that the second module 2 can be switched off, while the first module 1 can still be addressed by the communication interface 6 or, if necessary, also send messages via the communication interface 6. Thus, the first module 1 can perform an emergency light detection (switching from AC to DC supply or rectified AC supply). Moreover, the control unit G, for example as a microcontroller, of the first module 1 in this idle state can only be supplied with power via the external bus 10 if the idle state of the external bus 10 (for example in the case of DALI) is not equal to 0 volts. It is therefore possible to use an energy transmitted via the external bus 10 to supply the control circuit G (in particular as start-up energy for the control circuit G or a low-voltage supply circuit). Thus, the actual power supply of the first module 1 can be turned off in this idle state. It is also possible that only a wake-up signal is sent via the external bus 10, which provides a starting energy as a power for short-term supply for the control circuit G or a low-voltage supply circuit. In this case, the first module 1 completely in a state of rest without energy consumption be offset. The wake-up signal may also be a data transmission or a momentary connection of a voltage.

Of course, if several second modules 2 are supplied by a first module 1 (central module), selectively selected ones of these several second modules 2 can be switched off. This also leads to a saving of electrical losses. For example, in the emergency case, it can be provided that only one or a subset of the plurality of second modules 2 supplied by the first module 1 is operated to achieve the lower basic brightness for the emergency lighting operation.

With the common housing 12, a passive or preferably active, in particular controlled by the control unit E coolant 40 is connected, for example. A fan or a cooling unit.

In addition to the communication interface 6, the second module 2 (lamp management module) may also have an additional interface (not shown). This additional interface can be designed, for example, wired or wireless. By way of example, data can be read out from the second module 2 via this interface, in particular for maintenance purposes, such as the replacement of a second module 2. However, it is also possible to update the data or control software via this additional interface, in particular in the case of wireless communication. It may also be possible, via this additional interface also missing DC supply voltage 5 (power transmission) for the second module 2 in particular to read data from this second module 2. Preferably, the additional interface is arranged on the second module 2 spatially separated from the communication interface 6.

Adaptive control of the clocked DC-DC converter (second sub-module B) as an energy-transmitting converter

As already explained above, the first module 1 has a second sub-module B, which has the function of an insulating converter. This second sub-module B is supplied starting, for example, from the PFC of the first sub-module A with a DC voltage ( _bus voltage) V _bus .

This second sub-module B has a clocked insulating DC / DC converter as explained in detail below. This will now be with reference to FIG. 2 be explained.

In FIG. 2 is shown that the output voltage of the module A (eg PFCs), namely the _bus voltage V _bus is fed to an inverter 14, which may be formed, for example, as a half-bridge inverter with two switches S1, S2. The control signals for the timing of the switches S1, S2 can be generated by the control unit G of the first module 1.

In the illustrated example, a resonant circuit 15, here designed as a series resonant circuit, namely an LLC resonant circuit, adjoins the center point 29 of the inverter 14. In the example shown has this Resonance circuit 15, a first inductance 16, a coupling capacitor 17, a transformer 19. The resonant circuit 15 is followed by a transformer 19 with a primary winding 20 and a secondary winding 21. The inductance 16 may be integrated in the transformer 19, as will be explained later.

With regard to the illustrated example, it should be noted that the transformer 19 is shown as an equivalent circuit diagram. In this case, the primary winding 20 has in reality an inductance 18 as an integrated leakage inductance and, in addition, a main inductance Lm which carries the magnetizing current.

The transformer 19 is followed by a rectifier 22, at the output of which the lowered DC supply voltage 5 for the lamp management module 2 is provided. The transformer 19 thus provides the necessary galvanic decoupling (insulation with respect to the first module 1 supplied input voltage 9). The rectifier 22 can be designed as known per se with two or four diodes, but it can meanwhile be provided a so-called 'synchronous rectifier' (synchronous rectifier) having two MOSFETs. This synchronous rectifier performs as known per se with the two MOSFETs full bridge rectification. The rectifier 22 can thus be designed both as an active rectifier (with actively connected elements such as MOSFET) or as a passive rectifier (with passively connected elements such as diodes). It can be a full-wave rectification or even a one-way rectification. Follow the rectifier As shown, a storage capacitor 23. It can be present at the output and other filter elements such as one or more inductors and / or additional capacitors for smoothing and stabilizing the output voltage.

With regard to the resonant circuit 15 embodied as an LLC resonant circuit in the illustrated example, it should be noted that the inductance 16 does not have to be present as a separate component. Rather, the scattering of the primary winding 20 of a real transformer can take over this function. Thus, if the first inductance 16 is to be formed by the scattering of the primary winding 20 of the transformer 19, care is taken to ensure that there is no perfect coupling between the primary winding 20 and the secondary winding 21 of the transformer 19. For example, by a corresponding spacing of the primary winding 20 and the secondary winding 21 of the transformer 19, the necessary scattering effect can be achieved in a targeted manner, which can functionally achieve the first inductance 16. While this scattering effect should not be sufficient, an inductance 16 actually present as a separate component will also be provided.

The combination of the inverter 14 with the resonant circuit 15 and the following rectifier 22 thus forms an insulating by the transformer 19 DC / DC converter as a power transmitting converter.

However, this principle is equally applicable to other resonant circuits, such as parallel resonant circuits.

The advantage of using a resonant circuit in such a power transmitting DC / DC converter in the exploitation of a resonance peak to allow at nominal load or high load on the secondary side as low-loss switching of the switches S1, S2 of the inverter 14. This is usually done in the vicinity of the resonance frequency of the resonant circuit or in the vicinity of a harmonic of a resonance of the output circuit.

The output voltage (to the storage capacitor 23) of the transferred converter is thus a function of the frequency of driving the switches S1, S2 of the inverter 14, here as a half-bridge inverter.

If, however, at the exit the in FIG. 2 shown circuit has a low load (ie the module 2 and the LED modules F in FIG. 1 represent a low electrical load), the driving frequency of the switches S1, S2 of the inverter 14 is increased away from the resonance frequency. Meanwhile, as the driving frequency changes, the phase angle between the voltage and the AC current at the center point 29 of the inverter 14 also changes.

At very high load (eg high current through the LEDs) and hence operation near resonance, the phase angle between current and voltage at midpoint 29 is very low. As I said, at low load and thus an operation further away from the resonance, so for example, a low power through the LED track 8 flows and thus no or only a small power is taken on the secondary side of the transformer 19, the phase angle is very large (see Figure 3c ) and may for example be up to 50 °. In this state, therefore, currents continue to flow through the inverter 14, which lead to electrical losses without any appreciable power flowing into the LED track 8.

A combined control can be provided. The combined control is that for the size to be controlled 'output voltage of the energy transferring isolated converter' two control variables are used, namely in addition to the timing of the at least one switch S1, S2 of the inverter 14, the change of the _bus voltage V _{bus of} the inverter 14. Die Modification of the _bus voltage V _Bus can be achieved by appropriate control of the PFCs of the first submodule A.

Additionally or alternatively, not only the _bus voltage V _Bus can be adjusted by appropriate control of the PFCs of the first sub-module A. Depending on the load state or also the operating state, the PFC of the first submodule A can change the operating mode either independently or through a corresponding activation, in particular by the control unit G. In particular, the PFC of the first sub-module A can operate in either high-load operation in either bordering operation between bordering mode or borderline mode or continuous conduction mode, and low load or low-load operation Stand by mode in discontinuous conduction mode. But it would also be possible, for example, that the PFC of the first sub-module A when operating a low load or in stand-by mode in so-called burst mode (ie a pulse-pause operating mode or pulse mode called), changes. In this case, the supply voltage ( _bus voltage V _bus ) is kept the same, but after a number of drive pulses for the switch or switches of the PFC a longer break before the next "Burst" (pulse) is applied as a drive signal for the switches of the PFC. The pause between the pulse trains is much longer, that is, for example, at least twice the addition of the switch-on periods of the switches of the PFC.

Thus, there is a combined control concept in which the said control variables are combined depending on the load absorption of a return signal which directly or indirectly reproduces this load absorption.

Another possibility is, in the control variable "frequency of the switch" at the same frequency, the dead time (see FIG. 3b ) between the switch-on periods of the switches S1, S2 of the inverter 14 to extend. Thus, for example, the frequency reduction of the power supply to a maximum allowable drive frequency of the switches S1, S2 of the inverter 14 can be increased. At this maximum permissible frequency (corresponding to the maximum permissible phase angle), the second control variable is then used to further reduce the power consumption, namely the extension of the dead time between the switch-on periods of the switches S1, S2.

Another option is to use the ratio of on-period to constant frequency Off time of the switches S1, S2 of the inverter 14 to change (ie the duty cycle). Preferably, the duty ratio is reduced as the load decreases. Thus, for example, the frequency reduction of the power supply to a maximum allowable drive frequency of the switches S1, S2 of the inverter 14 can be increased. At this maximum permissible frequency (corresponding to the maximum permissible phase angle), the second control variable is then used to further reduce the power consumption, namely the change in the switch-on time duration of the switches S1, S2 (at the same frequency).

Another possibility to introduce a further control variable is the introduction of a so-called burst mode (ie a pulse-pause operating mode or also pulse mode called), see FIG. 3a , In this case, the supply voltage ( _bus voltage V _bus ) continues to be kept the same, but at least when the drive frequency is given a maximum permissible value, the frequency is no longer increased to reduce the load provision. Rather, after a number of drive pulses for both switches S1, S2 (the number is greater than 1) a longer break is inserted before the next "burst" (pulse) is applied as a drive signal for the switches S1, S2. The pause between the pulse trains is much longer, that is, for example, at least twice the addition of the switch-on periods of the switches S1, S2.

In this burst mode, in which the control quantity is thus the length of the dead time between two pulse trains, becomes Of course, it comes to a certain "ripple" of the voltage at the output side, so the storage capacitor 23, as in 3d figure shown. According to the invention, provision can now be made for a permissible ripple corridor to be predetermined by a desired value for the voltage at the storage capacitor 23. When the voltage reaches the upper limit of the Ripple Corridor after a certain number of pulses of a burst, a longer pulse break is taken. In this pulse break of the burst mode of operation, the voltage on the storage capacitor 23 then decreases until it reaches the lower limit of the predetermined ripple corridor. Upon reaching the lower limit, the next pulse train is applied, so that this rise and fall of the voltage (ripple) on the storage capacitor 23 will repeat cyclically. So there is a hysteretic regulation. The burst packets (ie the period in which is temporarily clocked) can be kept relatively short. In this way disturbances and also audible noises can be counteracted. Alternatively, the bursts may also be generated at a variable repetition rate and / or duration of the packets.

As already mentioned, the adaptive adjustment of the operating mode (control variable) of the DC-DC converter is dependent on the load on the secondary side, ie the load supplied by the voltage on the storage capacitor 23. For this purpose, a load reproducing the signal to the drive circuit (IC in the control circuit G in Fig. 1 ), or an externally supplied dimming signal can be used. The power consumption of the load can on the secondary side (in terms of Transformers 19), but also on the primary side of the transformer 19 are measured. For example, as a signal representing the power consumption of the load, the voltage drop across a measuring resistor 24 in series with the switches S1, S2 or at least in series with one of the switches S1, S2 of the inverter 14 may be used. The actual power consumption then essentially constitutes a product of the supply voltage ( _bus voltage V _bus ) (measured or at least kept constant by the PFC) with this current measured by the inverter 14 via the voltage drop across the measuring resistor 24.

In the above example, a primary-side detection was given for a signal representing the power consumption of the load. Of course, however, secondary-side feedback signals, such as the current through and / or the voltage across the LED track 8, etc., can be used as a feedback signal, which feedback signal represents the power consumption of the load.

A preferred sequence of adaptive combined control is to perform the reduction for the load by continuously increasing the drive frequency of the switches S1, S2 of the inverter 14 until a fixed maximum frequency is reached. When this maximum frequency is reached, but the power supplied to the load is to be further reduced, the drive circuit will then adaptively select one of the other modes listed above. If, for example, when the permissible maximum frequency is reached, the _bus voltage V _{Bus is} lowered, then the permissible maximum frequency of the control of the Switch S1, S2 are maintained, or even if this can be overcompensated by lowering the _bus voltage V _bus or the other selected control variable, the drive frequency even be lowered back to a lower setpoint range.

So it follows a switching of the control variable for the power supply for the secondary side when reaching the maximum frequency. Examples of a further control variable which is then used as a supplement or as an alternative to the change in the drive frequency has already been the change (reduction) in the supply voltage ( _bus voltage V _bus ), the change in the dead time between the switch-on periods of the two switches S1, S2 or the extension of the Dead time between two pulse trains called in burst mode. In this case, a combination of other control variables can be used, for example, both the duty cycle and the dead time can be changed.

Thus, there is basically an alternative control of a clocked DC-DC converter as a sub-module B, wherein the adaptivity relates to the adaptation of the control variables depending on the load of the secondary side of the DC-DC converter. The sub-module B can also be formed by an inverter with a switch, for example as a Class-E converter or quasi-resonant flyback converter.

As in Fig. 1 and 2 already shown may be connected to the storage capacitor 23, a second module 2 with a further converter stage (further sub-module C as a constant current source), wherein the second Module 2 (lamp management module) may have a control unit E, eg as an integrated circuit. The further submodule C can be embodied both as a clocked constant current source (that is to say for example as a step-down converter, ie Buck converter) or as a linear regulator (realized with transistors or integrated circuits). But it can also be directly connected to the output of the second sub-module B LEDs.

External dimming commands can, as in Fig. 1 represented, the control unit G of the first module 1, but also the control unit E of the second module 2 are supplied. In the second case, the control unit E of the second module 2 can transmit the dimming information to the control unit G of the first module 1, so that no measurement signal must be present for the power consumption, but rather from one of the control unit G for the DC-DC converter in the second module B present dimming information can be used.

The adaptive adjustment of the second submodule B can, however, also take place on the basis of a dimming command supplied externally or else due to feedback by the second module 2.

The control of the switches S1, S2 of the inverter 14 can be effected via the control unit G via a driver stage. Preferably, at least the driver stage for the high-potential switch of the inverter is designed for driving at a high voltage potential. For example, this driver stage is a level offset stage, a driver stage with a transformer or a driver stage with air coil. This driver stage can also be integrated in the control unit G.

The control unit G may further comprise means for avoiding errors in the operation of the inverter. For example, over-current shut-offs or current limits for the current may be present through at least one switch. It is also possible to set the dead time for the drive of the inverter (i.e., the time between the opening of the one switch (for example S1) and the closing of the second switch (S2)). Preferably, this dead time is adaptively adjustable, for example, depending on the midpoint voltage at the inverter 14 or the current or the voltage across a switch of the inverter 14th

The control unit G can also monitor the _bus voltage V _Bus , in particular also the ripple of the _bus voltage V _Bus (ie the fluctuations within a certain time). Depending on the evaluation of the ripple of the _bus voltage V _Bus , the control unit G can influence the control of the inverter 14. In particular, it can adapt the frequency of the inverter 14 to the evaluation of the ripple of the _bus voltage V _{Bus in} order to reduce the ripple at the output of the inverter 14. Preferably, the frequency of the inverter is increased with increasing _bus voltage V _bus , and lowered with decreasing _bus voltage V _bus . In this way it can be achieved that this ripple on the _bus voltage V _{bus is} less continued to the output of the inverter 14.

Data communication between the first module 1 and the second module 2 (lamp management module):

Referring to FIG. 4 Now, the communication interface 6 (internal bus) between the first module 1 and one or more second modules 2, 2 'will be explained as lamp management modules.

Due to the fact that via the internal bus several second modules 2, 2 'not only with power (transmission path 5), but also unidirectional or bidirectional with data exchange in communication (communication interface 6), the first module 1 as a central unit or Master be designated. The second modules 2, 2 'may be referred to as slaves.

As already mentioned above, with regard to the internal bus, a standardized communication is provided for the communication interface 6, which is provided in addition to the DC supply voltage 5. By "standardized" is meant that the protocol of the communication interface 6 is independent of the external communication protocol via the data interface 11 of the first module 1.

Preferably, the communication via the communication interface 6 is bidirectional and can be done, for example, according to the SPI protocol (Serial Peripheral Interface Bus).

Also, the data communication via the communication interface 6 (internal bus) takes place preferably electrically isolated, for example using optocouplers or transformers.

A fundamental function of the communication interface 6 may be the transmission of dimming commands from the first module 1 to the second modules 2, which have been received via the external bus 10, for example. In this case, new control information or commands for the second modules 2 can also be derived from the dimming commands received via the external bus 10.

One application for bidirectional data communication via the internal bus (communication interface 6) is that data stored in one of the second modules 2, 2 'is transmitted via the internal bus (communication interface 6) to the control unit G of the first module 1 can be. This is advantageous in that the data storage in the second modules 2, 2 'is closer to the LED track 8, so that there is a higher heating, which leads to a possibly irreproducible loss of data storage in the field of lamp management modules ( second modules 2, 2 ') can follow. Also by the transmission via the communication interface 6 to the first module 1, these data can then be the first module 1 in the sense of a backup again stored.

Examples of this data transmitted via the communication interface 6 are operating data for the LED route 8, such as temperatures, operating times, electrical parameters, etc.

After the data has been transferred from one of the lamp management modules (second modules 2, 2 ',..., 2 ⁿ ') to the first module 1, it is of course also possible to further process them if they are also read out via the external bus 10 connected to the data interface 11. Thus, via the external bus 10, a further analysis of the operating data, for example a failure analysis, an aging compensation depending on the transmitted operating time duration of the LED route 8, etc., take place.

The standardized approach for the internal bus (communication interface 6) also has the advantage that lamp management modules (second modules 2, 2 ') can be exchanged in a simple manner. The data stored in a lamp management module (second modules 2, 2 ') to be exchanged can be stored in the first module 1 already described above after transmission via the communication interface 6. If then the lamp management module is replaced, the stored in the first module 1 operating data can be transferred back to the newly installed lamp management module so that it is then configured identically to the replaced lamp management module.

Further examples of such operating data are color coordinates, color coordinates or other parameters influencing the spectrum of the LED route 8.

Over the communication interface 6 can also load changes or special operating conditions or Comparable events are transmitted from a second module 2, 2 'via the communication interface 6 to the first module 1. It can thus be a Vorabsignalisierung of expected load changes or operating state changes, so that the control unit G in the first module 1, the control of the PFCs in the first sub-module A and / or the control of the second sub-module B adaptively adaptively. For example, depending on a via the communication interface 6 of a second module 2, 2 'transmitted expected load change or operating state change, the control unit G of the first module 1 parameters for in FIG. 2 shown inverter 14 and / or adjust controller characteristics for the control of the PFCs in the first sub-module A.

Of course, some kind of prior information may be reversed, i. from the first module 1 to the second modules 2, 2 'take place. If, for example, the first module 1 receives dimming commands via the external bus 10 and the data interface 11 or the interface circuit D, which indicate a load change of the LED route 8, such information or a signal representing the operating state change can be transmitted via the bus or the communication interface 6 are transmitted to the second modules 2, 2 ', so that the control unit E provided in the second modules 2, 2' can also adapt control parameters, for example for the constant current source (further submodule C) in accordance with the expected load change.

This in FIG. 4 shown master / slave system also has advantages in terms of reducing electrical Losses, since a kind of standby operation can be provided in which one, several, or even all of the second module 2, 2 'connected to a first module 1 are switched off, while at least the control unit G of the first module 1 continues to be connected externally Bus 10 can monitor via the data interface 11 and the interface circuit D.

Externally this is in the FIG. 4 illustrated master / slave system preferably only via the connected to the data interface 11 and the interface circuit D of the first module 1 bus 10 responsive. However, there may be an internal hierarchical distribution, possibly including addressing via the internal bus (communication interface 6) to the plurality of connectable second modules 2, 2 '.

Thus, on the one hand, an addressed communication can take place towards the second modules 2, 2 '. Alternatively or additionally, however, a broadcast mode may also be provided, i. an undressed data transmission from the first module 1 to all connected second modules 2, 2 '. In this broadcast mode, a command transmitted by the first module 1 via the internal bus (communication interface 6) is received and evaluated by all second modules 2, 2 '.

The communication interface 6 can also be used to transmit the low-voltage supply (there is then both a data communication and an energy transfer). For example, a so-called active low data transmission can be used, wherein at rest, a level of a few volts, for example 12V, is applied. In the case of a coupling, for example via transformers, energy could nevertheless also be transmitted even if the communication interface 6 is electrically isolated.

Low-voltage supply

With reference to Fig. 5 Now is a low-voltage supply in the in Fig. 1 illustrated modular system will be explained.

It will then be explained how such a low-voltage supply, for example by a second module 2 (lamp management module) active coolant 40, such as a fan, etc. can be supplied. Such active coolant 40 is thus not supplied directly from the first module 1, but preferably individually via each connected lamp management module 2 with electrical power.

In the FIG. 5 is again shown how the _bus voltage V _bus , for example, generated by the PFC module of the first module 1, an inverter is supplied. In the illustrated example, the inverter has only one switch S1 in contrast to the inverter 14 as a half-bridge inverter of Fig. 2 on. In the example shown, the primary winding 20 of the transformer 19 is shown following the inverter with the switch S1. Again, starting from the secondary winding 21 of the transformer 19, a rectifier 22 is supplied, in which the output voltage of the rectifier 22 directly or indirectly the LED track 8 is supplied. Thus, the primary and secondary windings 20, 21 represent the already explained above path to the electrical power supply (DC supply voltage 5) of the LED track of the LED module F.

In the inverter according to Fig. 5 It can be a converter with one or more switches, such as a half-bridge inverter (see example Fig.2 ) or isolated flyback converters.

• zur Versorgung der integrierten Steuereinheit E im Lampenmanagementmodul (zweiten Modul 2),
• zur selektiv gesteuerten Ansteuerung von aktiven Kühlmitteln 40, und/oder zur aktiven Versorgung weiterer angeschlossener Aktoren oder Sensoren, die schematisch mit dem Bezugszeichen 41 bezeichnet sind.

In addition to this transmission path, there is now according to the invention a further low-voltage transmission path. This has a further secondary winding 30, which is therefore also magnetically coupled to the primary winding 20. By means of a rectifier circuit having a diode 31 and a capacitor 32, a secondary-side DC low-voltage power supply V _{CCS is} generated by appropriately selecting the winding ratios of the windings 20, 30. Also shown in the figure, this secondary-side DC low-voltage power supply V _{CCS is} also supplied to the second module 2. The second module 2 can then use this low-voltage power supply in different ways, namely:

• for supplying the integrated control unit E in the lamp management module (second module 2),
• for the selectively controlled activation of active cooling means 40, and / or for the active supply of further connected actuators or sensors, which are designated schematically by the reference numeral 41.

Like in the FIG. 5 Further illustrated, yet another (and thus third) secondary winding 33 is magnetically coupled to the primary winding 20 of the transformer 19. This secondary winding 33 feeds a rectifier with a diode 42 and a capacitor 43, serves to generate a primary-side low-voltage power supply V _CCP . Under primary side is to be understood that this low-voltage power supply V _{CCP is used} in the first module 1 (ie on the network side, ie before electrical isolation), for example, as a low-voltage power supply for the internal integrated control unit G of the first module. 1

For example, while the power transfer across the DC power supply 5 supply to the LED module F may be 48 volts DC, the voltage levels of the low voltage power supplies V _CCS and V _{CCP are} significantly lower, for example in the range of 2 to 12 volts DC.

Thus, two different DC power supplies can be supplied from the first module 1 to each connected second module 2.

The sensor 41, which is functionally associated with the second module 2, may be a brightness sensor, for example a photodiode with optional evaluation logic.

Of course, the sensor 41, which is functionally associated with the second module 2, can also be a temperature sensor whose output signal is, for example, for determining the temperature of the LED junction of the LEDs of the LED module F can be used. On the other hand, this sensor 41 can also be used as a temperature sensor for regulating the operation of the active cooling, for example of the coolant 40 (preferably as a fan).

Alternatively or additionally, of course, a temperature determination of the temperature of the LED junction by evaluating the characteristic and measuring electrical parameters of the LED route of the LED module F done.

Characterized in that the primary-side low-voltage power supply V _CCP via an independent for the generation of the secondary-side low-voltage power supply V _CCS winding 33, thus there is a potential separation.

Like a synopsis of FIG. 2 and FIG. 5 can recognize an inverter with a switch S1 or more switches S1, S2 are present. As further examples besides in FIG. 2 Inverter 14 shown as a half-bridge inverter are called the flyback converter, a SEPIC or a forward converter. In any case, there is an isolated converter.

For the startup phase of the control unit G of the first module 1 can be fed in a conventional manner with the input voltage 9, a starting resistor R1, which supplies the control unit G with energy until the primary-side low-voltage supply V _{CCP is} generated as expected, since the generation of the primary-side and also the secondary-side low-voltage supplies V _CCP and V _CCS a clocking of the second sub-module B (DC / DC converter). If the actual low-voltage power supply then started from the isolated converter (second sub-module B), the ohmic starting resistor R1 can be switched off again with the switch S3, so as to avoid electrical losses via the starting resistor R1 in the regular operation of the circuit.

Preferably, the low-voltage power supplies V _CCS , V _{CCP are obtained} by means of a full-bridge rectifier. But it can also be used only a single diode for rectification.

The secondary DC low voltage power supply V _CCS for the second module 2 can be used for voltage stabilization as in FIG. 5 shown again a coolant control 50, for example, a DC / DC converter or a linear regulator are supplied, in which case the stabilized output voltage of this DC / DC converter or linear regulator 50 feeds the control unit E of the second module 2.

Memory balance communication between lamp management module and LED module

As in FIG. 1 shown, the LED module F may be provided in a memory 4 associated with it, for example with an EPROM, FLASH or OTP.

By the reference numeral 3 in FIG. 1 shown schematically, the control unit E, for example, an integrated circuit or a microcontroller of the second module 2 access the memory 4 of the LED module F, so as to selectively read out, for example, its memory contents. The data read out from this memory 4 can then also be sent, for example, from the control unit E of the second module 2 to the first module 1 via the communication interface 6 (internal bus). The data in the memory 4 may be, for example, the runtime, manufacturing data, error logging, maximum value, minimum values (eg for current and voltage) and / or the temperature.

This has the advantage that a possible impairment of the memory contents of the memory 4 of the LED module F, for example due to the temperature degradation due to the large physical proximity to the LED track 8, is reduced. Thus, the control unit E of the second module 2 read this data and store it in a memory associated with it in the sense of a backup. In addition, the control unit E of the second module 2 can refresh the memory 4 of the LED module F periodically or depending on the operating state or event.

However, it may also be possible that the LED module F itself has no memory. The corresponding data, for example the permissible forward current for the LEDs of the LED track 8 can in this case be written in the memory 51 assigned to the control unit E of the second module 2. This can be done during the production of the second module 2, for example.

Yet another alternative or additional option is that the LED module F is provided with an identification tag, such as the operating data represents or at least represents an identification for the LED module F. The identification tag is then read out by the control unit E of the second module 2 and stored, for example, in a memory assigned to the control unit E of the second module 2. This thus only once read data content of the identification tag can then be used for the further operation of the LED module F.

As I said, the identification tag can only be a pure identification. In this case, the lamp management module (second module 2) would determine the identification data and then determine operating data independent of the LED module F, for example also a database content accessible via the external bus 10. Of course, the approach has the advantage that thus the cost of the additional memory 4, for example, an Eprom of the LED module F can be saved.

The possibility of reading out the memory 4 of the LED module F by the control unit E has the advantage that a very different LED modules F can be combined with a lamp management module (second module 2), the required operating data being from the LED Module F can be read and the lamp management module (second module 2) can thus adapt flexibly to the connected LED module F.

Light power calibration

Preferably, the LED module F as shown schematically in FIG FIG. 6a . 6b already shown, two, three or even more independently controllable channels 53, 53 ', 53 "in. Each channel 53, 53', 53" may have an LED track 8, 8 ', 8 "with one or more LEDs. Preferably, of course, the LEDs of an LED track 8, 8 ', 8 "are almost identical in terms of their spectrum.

The goal is that the different LED channels 53, 53 ', 53 "of the LED module F in the color space (eg CIE standard color chart) span a space within which the desired controllable color coordinates lie.

In this case, an embodiment of the two or more LED channels 53, 53 ', 53 "of the LED module F is preferred such that the encompassed space comprises at least large areas of the Planck's white light curve.

• ein erster Kanal mit einer oder mehreren monochromatischen blauen LEDs,
• ein zweiter Kanal mit einer oder mehreren monochromatischen roten LEDs und
• ein dritter Kanal mit einer oder mehreren farbstoffkonvertierten LEDs, vorzugweise im grünlichweißen Spektrum.

An example embodiment could thus be:

• a first channel with one or more monochromatic blue LEDs,
• a second channel with one or more monochromatic red LEDs and
• a third channel with one or more dye-converted LEDs, preferably in the green-white spectrum.

In the case of three different LED channels, therefore, in the color coordinate system (CIE) a triangle is formed clamped. By different individual control of the intensities of the different LED channels each color locus (coordinate) can be controlled within the triangle formed thereby.

The example above spans a triangle in color space that covers at least large areas of Planck's white light curve. Thus, by individually driving the three LED channels mentioned above, substantially every point of the Planck's white light curve can be driven, i. it can - as a result of a mixture of the light of the multiple LED channels - white light with different color temperature are emitted.

As mentioned, in order to control the different color loci, in particular on the Planck's white light curve, the different LED channels must be driven with different intensity, wherein the intensity can be achieved, for example, by amplitude modulation (current through the LEDs) and / or PWM modulation.

For the color location, however, the light intensity of the respective LED is crucial, which is then recalculated into a electrical control variable with known efficiency of the LED.

This is mathematically possible with known or previously known efficiency of the LEDs of the LED channels, ie, starting from an X / Y coordinate of the desired color locus, the intensity to be controlled (expressed in a control variable such as amplitude and / or duty cycle) of the individual channels are calculated.

A problem now is that different LEDs have different efficiencies (lumens / LED current). In particular, the curve of the light output (brightness for a given wavelength) or its slope is not the same for all LEDs. If now different color locations within the spanned triangle in the color coordinate system, in particular for driving off the Planck's white light curve are driven, although the desired spectrum is achieved, but it will usually change the total light output. The overall light output will tend to be lower, the higher the proportion of the intensity of less efficient LEDs.

According to one aspect of the invention, the total light output should now remain constant even when departing from different color loci, in particular on the Planck's white light curve.

For this purpose, it is determined beforehand arithmetically or experimentally at which point within the color loci to be traveled within the spanned color triangle the minimum light output is present. With knowledge of the minimum light output, the drive intensities can then be calibrated for all other color loci to be approached, ie the intensities are 'artificially' scaled down for each color locus deviating from the minimum light output, so that ultimately in the spanned color space constant light is generated everywhere with the minimum achievable light output becomes.

This calibration to the minimum achievable light output thus takes place by means of a calibration factor, which is equally applied to the intensities of all LED channels.

The calibration factor can be calculated based on the known efficiencies of the LEDs used.

In the event that the efficiencies of the different LEDs of the LED sections 8, 8 ', 8' 'should not be known, for example by means of a photosensor, the total light output when departing different color locations, in particular in the manner of a scan of Planck's white light curve with simultaneous Measurement of total light output can be measured. Such a measurement thus determines, on the one hand, the minimum total light output within the color loci to be removed and the dependence of the total light output on the color locus.

For example, the calibration factor for reducing the intensities of the individual LED paths in terms of PWM dimming (by changing the pulse width of the drive) can be performed. Thus, preferably, the calibration is generated by a reduction in the duty cycle of a PWM drive. However, this can also be done by adjusting the amplitude (in the sense of amplitude dimming). Just when the dimming or setting of the intensity via a pulse width modulation (PWM), the calibration can be done on an adjustment of the amplitude.

The said intensity scan can be carried out repeatedly, since the different LEDs with regard to their efficiency (intensity per stream) have different aging phenomena that must be compensated and can lead to different efficiencies. In particular, a dye-converted LED will have a higher degree of aging than monochromatic LEDs.

However, said intensity scan can also be used for monitoring the aging when the operating data of the LED are known (for example stored in the memory 4 of the LED module F).

Meanwhile, such aging parameters can already be determined by the manufacturer and, for example, stored in the memory 4, which is assigned to the LED module F.

List of reference numbers

1:

first module

2, 2 ':

second module

3:

Access from E to 4

4:

Storage

5:

DC supply voltage

6:

Communication Interface

7:

output

8, 8 ', 8 ":

LED range

9:

input voltage

10:

external bus

11:

Data Interface

12:

casing

13:

Return size of 8

14:

inverter

15:

resonant circuit

16:

inductance

17:

coupling capacitor

18:

inductance

19:

transformer

20:

primary

21:

secondary winding

22:

rectifier

23:

storage capacitor

24:

measuring resistor

29:

midpoint

30:

secondary winding

31:

diode

32:

capacitor

33:

secondary winding

40:

coolant

41:

Actuators or sensors

42:

diode

43:

capacitor

50:

Coolant Control

51:

Storage

52:

Memory connected to the control unit G.

53, 53 ', 53 ":

LED channel

A:

first submodule

B:

second submodule

C:

another submodule

D:

Interface circuit

e:

control unit

F:

LED module

G:

control unit

lm:

magnetizing inductance

R1:

starting resistance

S1:

switch

S2:

switch

S3:

switch

_Bus :

bus voltage

V _CCP :

Primary-side low-voltage power supply

V _CCS :

secondary-side DC low-voltage power supply

Claims (16)

1. A method for the operation of a light source with an LED module (F), which has at least two LED channels (53, 53') with in each case an LED series (8, 8') of different emission colors,
   wherein in order to obtain a light emission having a color corresponding to a desired chromaticity the LED series (8, 8') are individually controlled in their intensity,
   wherein
   the intensities for the LED series (8, 8') are in each case standardized in such a manner that when changing the chromaticity within one controllable color range provided for the operation the intensity of the total light emission remains constant, characterized in that the standardization of the intensities of the LED series (8, 8') occurs based on a reference value, which corresponds to the intensity of that chromaticity, which has the lowest efficiency within the controllable color range provided for the operation.
2. A method according to Claim 1,
   characterized in
   that the chromaticity with the lowest efficiency is determined on the basis of the previously determined efficiencies for the individual LED series (8, 8').
3. A method according to Claim 1 or 2,
   characterized in
   that the chromaticity with the lowest efficiency is determined experimentally in the framework of a scan.
4. A method according to Claim 3,
   characterized in
   that the scan is carried out at regular intervals and/or depending on the operation.
5. A method according to any one of the preceding claims,
   characterized in
   that the controllable color range provided for the operation comprises at least one part of the Planckian white light curve.
6. A method according to Claim 5,
   characterized in
   that the controllable color range provided for the operation corresponds substantially to the Planckian white light curve.
7. A method according to Claim 5 or 6,
   characterized in
   that the light source has at least one monochromatic and at least one color-converted LED, in particular a monochromatic blue LED, a monochromatic red LED and a green-white color-converted LED.
8. A method according to any one of the preceding claims,
   characterized in
   that the dimming or setting of the intensities of the individual LED series (8, 8') is carried out by means of pulse width modulation.
9. An arrangement for the light emission with a light source with an LED module (F), having

   • at least two LED channels (53, 53') with in each case an LED series (8, 8') of different emission colors as well as

   • a control unit (E), which is designed to individually control the LED series (8, 8') in their intensity in order to obtain a light emission with a color corresponding to a desired chromaticity,

   wherein
   the intensities for the LED series (8, 8') are set or standardized by the control unit (E) in each case in such a manner that when changing the chromaticity within one controllable color range provided for the operation the intensity of the total light emission remains constant, characterized in that the standardization of the intensities of the LED series (8, 8') occurs based on a reference value, which corresponds to the intensity of that chromaticity, which has the lowest efficiency within the controllable color range provided for the operation.
10. An arrangement for the light emission according to Claim 9,
    characterized in
    that said arrangement is designed to determine the chromaticity with the lowest efficiency on its own.
11. An arrangement for the light emission according to Claim 10,
    characterized in
    that said arrangement also has a sensor (41) for sensing the light emission, wherein the control unit (E) is designed to generate light according to different chromaticities in the framework of a scan by different controlling of the LED series (8, 8') and to determine the chromaticity with the lowest efficiency on the basis of the sensor information obtained for the different chromaticities.
12. An arrangement for the light emission according to Claim 11,
    characterized in
    that the control unit (E) is designed to carry out the scan at regular intervals and/or depending on the operation.
13. An arrangement for the light emission according to any one of Claims 9 to 12,
    characterized in
    that the controllable color range provided for the operation comprises at least one part of the Planckian white light curve.
14. An arrangement for the light emission according to Claim 13,
    characterized in
    that the controllable color range provided for the operation corresponds substantially to the Planckian white light curve.
15. An arrangement for the light emission according to Claim 13 or 14,
    characterized in
    that the light source has at least one monochromatic and at least one color-converted LED, in particular a monochromatic blue LED, a monochromatic red LED and a green-white color-converted LED.
16. An arrangement for the light emission according to any one of the Claims 9 to 15,
    characterized in
    that the dimming or setting of the intensities of the individual LED series (8, 8') is carried out by means of pulse width modulation.

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