EP2936936B1 - Detection of an led module - Google Patents

Description

The present invention relates to an LED module, an LED converter and a method which make it possible to transmit operating parameters of the LED module to the LED converter without a specific communication line between the LED module and the LED converter.

Several approaches are already known from the prior art for specifying operating parameters for a connected LED module to an LED converter. This is necessary, for example, because different forward currents are required for different LED modules in order to make the LED sections of the LED modules glow. Operating parameters are, for example, a required forward current or a setpoint or forward voltage to be applied.

One approach known from the prior art is to set the operating parameters to be set for the connected LED module on the LED converter via DIP switches or resistors. However, this requires interaction with the LED converter.

In another approach, configuration resistors are used on the LED module in order to specify the required operating parameters for the LED converter. On the one hand, however, additional connections are necessary, on the other hand, interaction is required.

It is also known to transmit the necessary operating parameters to the LED converter via a separate digital signal channel. However, additional components have to be installed for this and an interaction is again necessary.

Finally, it is also known to assign an EPROM, for example, to the LED module, from which the LED converter can determine information with regard to the operating parameters to be set on the LED module.

However, the approaches known from the prior art all require either an interaction with the LED converter or the LED module, or require additional connections or components. This increases the cost of the LED module and / or the LED converter. In addition, more space is required for the components, which prevents a more compact design.

The international application WO 201 0/092504 A1 Figure 3 shows a driver for a lighting system having power supply connections and a detector circuit. The power supply connections are set up for supplying electrical energy from the driver to the lighting system. The detector circuit is designed to detect information from the lighting system via the supply connections by detecting an electrical load on the connections by the lighting system and determining an operating state of the lighting system. The driver is also set up to control the energy supplied as a function of the specific operating state.

The European patent application EP 1 517 588 A1 Fig. 13 shows a lighting method capable of generating individual light emitting devices in a headlamp connected to a power supply, each with a rated current regardless of the specification of the headlamp, using a power supply having an identical specification and a lighting device used for the lighting method. The lighting device includes headlights, each having one or more light-emitting devices which are arranged in an arbitrary pattern and which include a lighting circuit. The lighting circuit supplies a current to the light emitting devices when a voltage is equal to or less than a lower limit voltage VLmin determined by the arrangement of the light emitting devices. An identification circuit outputs a current identification signal in accordance with an appropriate current for the lighting circuit when the voltage is applied when the voltage is lower than the lower limit voltage.

The power supply includes an operating power supply that applies a voltage at or above the lower limit voltage for the lighting, an identification power supply that provides a characteristic voltage at or below the lower limit voltage for lighting, a current setting device that sets a suitable current to be supplied to the lighting circuit based on the current identification signal outputted from the identification circuit and a lighting current control circuit that maintains the current flowing in the light circuit in a lighting state of the light emitting devices at an appropriate current according to the current setting signal.

The disclosure EP 1 244 334 A2 discloses a circuit arrangement with a lamp and two connecting lines, a light source of the lamp having at least one LED. An adjustable power source is designed to provide a power supply via the connection lines. The circuit arrangement is characterized by a coding element arranged parallel to the LED light source in the circuit, the coding of which denotes the nominal current of the light source. An evaluation circuit arranged outside the lamp is connected to at least one of the connecting lines of the lamp. The evaluation circuit evaluates the coding of the coding element. Based on the determined coding, the adjustable current source is set to the nominal current of the light source.

The object of the present invention is to improve the known prior art, particularly with regard to the disadvantages mentioned above. In particular, it is the object of the present invention to transmit (report back) information to an LED converter, for example with regard to the operating parameters of an LED module, without additional components or connections or interaction being necessary. It is therefore the object of the present invention to produce an LED module and an LED converter more cost-effectively and to build them more compactly.

The objects of the present invention are achieved by the features of the independent claims. The dependent claims advantageously develop the core concept of the invention.

The invention relates to a system in which information can be transmitted to the LED converter by a generated load or load changes of the LED module. For example, according to the present invention, information can be transmitted to the LED converter through a generated load or load changes of the LED module in a preferably time-limited start phase. Alternatively or additionally, according to the present invention, information can be exchanged between the LED converter and the LED module by means of bidirectional communication, the communication being preferably transmitted from the LED module by a generated load or load changes of the LED module.

The present invention makes use of the fact that to operate an LED module, in particular to light up an LED path of the LED module, a certain forward voltage on the LED path, ie a certain supply voltage on the LED module, is necessary . The LED path blocks below the forward voltage. The LED path is therefore non-conductive and represents an almost infinite resistance for the LED converter. Only at or above the forward voltage does the LED path represent an active power load for the LED converter. A supply voltage on an LED path that is not equal to zero but below the forward voltage defines a voltage window in which the LED path is not yet conductive. This voltage window is used by the present invention in order to transmit information to the LED converter due to a generated load or load changes of the LED module.

In one aspect, the present invention relates to an LED module which has: connections for an LED converter that supplies the LED module with a supply voltage, further connections for an LED path, a circuit that can be activated when the connections are switched on predetermined constant current, which is less than the nominal current of the LED path, or a predetermined constant voltage, which is lower than the forward voltage of the LED path, is applied to the LED module, with the system of the predetermined constant current or the constant voltage a start phase begins.

In this case, the circuit is designed to display a current-variable active power load when activated, which causes a repeated change in the power consumption of the LED module in accordance with at least one predetermined protocol. The circuit can be deactivated and, when deactivated, is designed not to represent an active power load. The circuit is distinguished by the fact that the circuit also has means to automatically deactivate itself after a predetermined period of time from the beginning of the start phase.

A circuit designed to represent an active power load will be activated in a time-limited start phase. After the start phase, which is limited in time, the circuit can be designed not to represent a load. The load for the time-limited start phase causes the LED module to consume power.

The invention also relates to an LED module that has connections for an LED path, as well as a circuit that is designed to represent an active power load when a constant current or a constant voltage is applied to the LED module in a starting phase, and which is designed to represent no load when the start phase has expired, the circuit being designed to represent a current-variable load that causes a change in the power consumption of the LED module in accordance with at least one predetermined protocol.

For example, the present invention relates to an LED module that has: connections for an LED path, a circuit that is designed to represent an active power load when a first non-zero supply current is fed to the LED module, and that is designed to do so not to represent a load when a second supply current, unlike the first supply current, is fed to the LED module or when a time-limited start phase has expired. The load on the voltage window (readout window) in which the LED path is non-conductive causes the LED module to consume power.

An LED converter can recognize this power consumption and can determine parameters of the LED module based on the detected power consumption. The LED converter can, for example, based on stored tables, infer operating and / or maintenance parameters of the LED module to be set from the detected power consumption.

According to the invention, the circuit is designed to be activated every time a supply voltage is applied to the LED module. Furthermore, the circuit is designed to automatically deactivate itself when a time-limited start phase has expired or ended. This means that there is no power loss in the continuous lighting operation of the LED path. No additional connections are required to operate the circuit. The circuit is integrated in the LED module and does not have to be provided as a separate component.

The circuit works automatically after a supply voltage is applied, i.e. a start phase, so no additional interaction has to be carried out.

According to the invention, the circuit is designed to be activated every time a supply voltage between zero and the forward voltage of the LED path is applied to the LED module. Furthermore, the circuit is designed to automatically deactivate itself when the applied supply voltage reaches or exceeds the forward voltage of the connected LED path. Thus, there is no power loss when the LED path is lit. No additional connections are required to operate the circuit. The circuit is integrated in the LED module and does not have to be provided as a separate component. The circuit works automatically according to the applied supply voltage, so no additional interaction has to be carried out.

As an alternative to applying a supply voltage with a value between zero and the forward voltage of the LED path, a predetermined supply current can also be fed into the LED path to activate the circuit in order to activate the circuit on the LED path. For example, the LED converter can output the nominally minimum output current according to its specification or a low minimum current value, at which it is ensured that the LED module is not overloaded. In this case, the circuit is designed to automatically deactivate itself, for example when the supplied supply current reaches or exceeds the nominal current of the connected LED path or when a time-limited start phase has expired.

The circuit is preferably designed to represent a current-constant or power-constant load which causes a constant current consumption or a constant power consumption of the LED module.

The circuit is therefore a constant load that can be selectively activated in the readout window of the supply voltage. Such a circuit enables a particularly simple implementation of the present invention.

According to the invention, the circuit is designed to represent a current-variable load which causes a change in the power consumption of the LED module in accordance with at least one predetermined protocol.

A variable power consumption, i.e. a load change of the LED module in the readout window, more complex information can be displayed.

The circuit is preferably designed to encode at least one operating and / or maintenance parameter of the LED module by changing the power consumption in accordance with the at least one predetermined protocol.

The circuit on the LED module is designed so that it is only activated in a time-limited start phase of the LED module.

An LED converter can detect the change in the power consumption of the LED module and decode it in accordance with the at least one protocol that is stored in the LED converter, for example. A communication path from the LED module to the LED converter is thus made possible without additional lines or pins. Operating parameters of the LED module can be, for example, the forward current of an LED segment of the LED module, the corresponding forward voltage of the LED segment, a target current of the LED module, or a spectrum of the light emitted by the LED segment. Maintenance parameters can be, for example, aging parameters of the LED module or the LED path, an operating time of the LED module, or a temperature on the LED module. The at least one predetermined protocol preferably specifies a frequency and / or an amplitude and / or a pulse duty factor of the change in the power consumption of the LED module.

The at least one protocol can therefore be coded in many ways, namely with regard to a frequency of the power consumption, an amplitude and a switch-on clock. This enables complex information to be encoded. Several differently coded protocols can also be used.

The circuit is preferably designed such that the change in the power consumption of the LED module is independent of a value of a first supply voltage.

The circuit on the LED module therefore reproduces the coding parameters (e.g. amplitude, frequency, duty cycle of the load change) in the readout window (i.e. supply voltage not equal to zero but below the forward voltage of the LED path) independently of the supply voltage. As a result, it is not necessary to set an exact, but only a constant voltage specification in this readout window of the supply voltage.

Alternatively, the circuit is designed in such a way that the change in the power consumption of the LED module is brought about as a function of a value of the first supply voltage in accordance with one of several predetermined protocols.

According to this embodiment of the invention, when a supply voltage is applied in the readout window, as described above, the same return information is not always transmitted to an LED converter that is connected to the LED module. Rather, the voltage range of the supply voltage at which a connected LED path is not yet conductive can be divided into several sub-ranges of the supply voltage. A different predefined protocol can apply to each sub-area.

This means that a different type of change in power consumption can occur in each sub-area (i.e. different in the frequency of the change in power consumption, the amplitude of the change in power consumption or the duty cycle depending on the applied supply voltage). This means that different information can be transmitted back to the LED converter. More complex protocols are also conceivable, which include, for example, the modulation of the supply voltage, selective switching on and off of the supply voltage between zero and a voltage in the readout window, etc. In order to subdivide the area of information transmission even further, frequency modulations, amplitude modulations or PWM of the supply voltage are also conceivable.

The circuit preferably comprises a timer circuit which is designed to specify a frequency of the change in the power consumption of the LED module. The timer circuit therefore specifies the frequency of the load change of the LED module.

The circuit is preferably integrated into a semiconductor material of the LED module. As a result, the circuit can be designed to be particularly space-saving and inexpensive.

At least one sensor, which is designed to influence an electrical parameter of the circuit, is advantageously provided on the LED module. The LED converter can supply the sensor in an operating mode when the LED path is not active by the LED converter emitting a reduced supply voltage to the LED module. The at least one sensor can be, for example, a sensor or a combination of several sensors that can be light sensors, temperature sensors, color sensors, presence sensors, etc. The influenced electrical parameter of the circuit on the LED module can be, for example, a resistance value or a conductivity.

The at least one sensor is preferably a light sensor with a light-dependent resistor and the light sensor is connected to the circuit in such a way that a change in the light-dependent resistance changes the load resistance of the circuit.

A light sensor with a light-dependent resistor (i.e. a "Light Dependent Resistor") is easy to implement. A light power that falls on this resistor has a direct influence on its resistance value and thus also on the circuit's real power load in the readout window.

According to a second aspect, the present invention relates to a system with an LED module, as described above, and an LED converter.

The system has an LED module according to one of the preceding embodiments with an LED path and an LED converter. The LED converter has a high-frequency clocked converter, preferably an isolated flyback converter. The high-frequency clocked converter is operated as a constant current source in a time-limited start phase. The LED converter is designed to supply the LED module with the specified constant current, which is smaller than the nominal current of the LED path, or the constant voltage, which is lower than the forward voltage of the LED path, during the start phase . The clocked converter is designed to detect a repeatedly changing power consumption of the LED module on the primary side of a transformer of the high-frequency clocked converter during the starting phase and to assign at least one operating and / or maintenance parameter of the LED module based on the recorded power consumption determine.

According to an embodiment of the LED converter for an LED module as described above, the LED converter is designed to measure a power consumption of the LED module for a first supply voltage applied to the LED module, at which a supply voltage connected to the LED module LED path is non-conductive, to be recorded and based on the recorded power consumption at least one operating and / or maintenance parameter of the LED module.

Due to the recorded power consumption, the necessary information is transmitted to the LED converter in order to determine the operating and / or maintenance parameters. The LED converter can determine these parameters, for example, based on one or more stored or stored tables which, for example, correlate operating and / or maintenance parameters with constant or variable power consumption within the readout window.

The LED converter is preferably designed to use the at least one specific operating and / or maintenance parameter: to set or regulate the operation of the LED module, to store it in an assigned memory, to display it optically and / or acoustically, and / or via to send out a wireless or wired interface, possibly in response to an external query.

The LED converter is therefore suitable for comprehensively controlling the LED module. There is no need for a separate communication path or additional lines or pins between the LED module and the LED converter. The transfer of information, e.g. The transmission of the operating and / or maintenance parameters takes place via the connections for the supply voltage that are already present.

The at least one operating and / or maintenance parameter is advantageously a target current through an LED path connected to the LED module, an aging parameter, an operating time and / or a spectrum of light emitted by the LED path.

The LED converter is advantageously designed to identify the LED module based on the least one specific operating and / or maintenance parameter.

The identification can be carried out, for example, using one or more stored tables. Once the LED converter has identified the LED module, further information can be stored in the one or more tables that allow comprehensive control of the LED module. In particular, a forward current of the LED path of the LED module is advantageous as stored information.

The LED converter is advantageously designed to signal the LED module by changing the supply voltage of the LED module, for example via pulse or amplitude modulation of the supply voltage, selectively in a mode for changing the power consumption of the LED module ( Load change). The modulation of the supply voltage can adopt different patterns or values, which enables a targeted selection of individual LED modules when an LED converter supplies several LED modules. The LED module selected in this way can then selectively switch to the mode of load change in order to transmit information to the LED converter. The multiple LED modules can be arranged in a series connection or a parallel connection. The LED converter can be designed to query different types of information from the LED module or modules, depending on the particular pattern or value, by changing the supply voltage, for example via pulse or amplitude modulation of the supply voltage. For this purpose, various tables can be stored in the LED module for reporting the various information.

For example, the LED converter is designed to selectively between a mode for detecting a power consumption of the LED module and a mode for lighting operation of an LED connected to the LED module by setting a first supply voltage or a second supply voltage for the LED module. To change route.

The first supply voltage is a voltage in the readout window, that is, a supply voltage between zero and a forward voltage at which the connected LED path is not yet conductive. The second supply voltage is a voltage above the forward voltage at which the connected LED path is conductive, preferably lights up. The LED converter is automatically set to the appropriate mode based on the set supply voltage. The power consumption is only recorded in the aforementioned recording mode. This makes it possible to switch off the converter detection circuits in light mode and to save energy. External interaction with the LED converter is not necessary to change the mode.

The LED converter is preferably designed to carry out a current measurement for direct detection of the power consumption of the LED module.

Alternatively, the LED converter is designed to indirectly record the power consumption of the LED module.
The LED converter is preferably designed to detect a change in the power consumption of the LED module by changing a duty cycle of a clocking of the LED converter, for example a buck converter (also called a step-down converter) or an isolated flyback converter.

Depending on the control concept for an LED module, the LED converter can also detect a change in the peak current in the LED converter, for example in an isolated converter, preferably an isolated flyback converter.

The LED converter is advantageously designed to discharge a capacitor via a load of the LED module, to determine a discharge current of the capacitor directly or indirectly via a discharge time, and based on the at least one operating and / or maintenance parameter of the LED module to determine this discharge current.

In particular, this embodiment of the LED converter is preferably used for an LED module with a constant current load in the area of the readout window of the supply voltage. A capacitor in the LED converter is discharged, for example, via a constant current sink on the LED module, whereby the discharge current flowing can be measured directly or indirectly via a discharge rate (negative slope) of the voltage of the capacitor. The directly or indirectly detected discharge current can then be interpreted by the LED converter with regard to the operating and / or maintenance parameters. The information about the operating and / or maintenance parameters is therefore encoded in the slope of the voltage that the LED converter outputs when the capacitor is discharged. Measuring the discharge rate eliminates the dependence on the absolute supply voltage. A detection of the discharge current over the discharge time of the capacitor is also conceivable. In addition, the LED converter can also receive information about the absolute voltage at the beginning and at the end of the measurement, i.e. the discharge of the capacitor, are present or returned.

According to one embodiment of the present invention, the system is an LED luminaire comprising an LED module, as described above, and an LED converter, as also described above.

The present invention also relates to a method for transmitting information from an LED module to an LED converter. The LED converter has a high-frequency clocked converter, preferably an isolated flyback converter or resonant half-bridge converter. The LED module shows connections for the LED converter supplying the LED module. The LED converter supplies the LED module with a predetermined constant current, which is less than the nominal current of the LED path, or a predetermined constant voltage, which is less than the forward voltage of the LED path, with application of the predetermined constant current or the constant voltage begins a start phase. A circuit of the LED module, which is designed to represent an active power load, is activated when the specified constant current or the specified constant voltage is applied.

The activated switching of the LED module causes a repeated change in the power consumption of the LED module according to at least one predetermined protocol. During the start-up phase, the LED converter detects a repeatedly changing power consumption of the LED module. The circuit of the LED module can be deactivated and the deactivated circuit does not represent an active power load. The circuit is characterized in that the circuit automatically deactivates itself after a specified period of time from the start of the start phase.

One embodiment of the method comprises activating the circuit in order to display a load, preferably an active power load, when a first non-zero supply voltage is applied to the LED module, at which a connected LED path is non-conductive, and deactivating the circuit in order to avoid any Load when a second non-zero supply voltage is applied to the LED module at which a connected LED path is conductive.

One embodiment of the method also relates to a method for determining information relating to an LED module on an LED converter, which comprises: detecting a power consumption of the LED module for a first supply voltage applied to the LED module, at which one is applied to the LED Module connected LED path is not conductive, and determine at least one operating and / or maintenance parameter of the LED module based on the detected power consumption.

One embodiment of the method further relates to a method for transmitting information from an LED module to an LED converter having a high-frequency clocked converter with a transformer, which includes activating a circuit at least during a time-limited start phase around a load, preferably an active power load , and a detection of a power consumption of the LED module on the primary side of the transformer of the high-frequency clocked converter.

The present invention also relates to a method for determining information relating to an LED module on an LED converter having a high-frequency clocked converter with a transformer, which comprises detecting a power consumption of the LED module on the primary side of the transformer of the high-frequency clocked converter, wherein a circuit on the LED module causes a modulated load change at least during a start phase, and determining at least one operating and / or maintenance parameter of the LED module based on the detected power consumption.

Overall, the present invention enables information relating to the operating and / or maintenance parameters to be set on an LED module to be transmitted to an LED converter. No further connections or connections between the LED converter and the LED module are necessary. No further component is necessary apart from a load modulation circuit which is advantageously integrated in a semiconductor material of the LED module. There is no additional interaction with the LED module or the LED converter for the transmission of the information. The present invention thus enables a simpler control of an LED module, as well as a more cost-effective and more compact production of the LED module and / or LED converter.

The present invention also relates to a method for determining information relating to an LED module on an LED converter, comprising: detecting a power consumption of the LED module, a circuit on the LED module causing a modulated load change at least during a start phase, and determining at least one operating and / or maintenance parameter of the LED module based on the detected power consumption.

Fig. 1

zeigt schematisch das Grundprinzip der vorliegenden Erfindung anhand einer erfindungsgemäßen LED-Leuchte (bestehend aus einem erfindungsgemäßen LED-Modul und einem erfindungsgemäßen LED-Konverters).

Fig. 2

zeigt eine Stromspannungskennlinie einer LED-Strecke und das erfindungsgemäße Auslesefenster.

Fig. 3

zeigt einen Schaltkreis, der eine automatische Deaktivierung der Schaltung auf dem erfindungsgemäßen LED-Modul ermöglicht.

Fig. 4

zeigt ein Beispiel der Schaltung auf dem erfindungsgemäßen LED-Modul, die eine stromkonstante Last darstellt.

Fig. 5

zeigt schematisch die Erfassung einer stromkonstanten Last auf dem erfindungsgemäßen LED-Modul durch den erfindungsgemäßen LED-Konverter.

Fig. 6

zeigt eine Schaltung auf dem erfindungsgemäßen LED-Modul, die eine stromveränderliche Last darstellt und insbesondere eine Frequenz der Änderung der Leistungsaufnahme des erfindungsgemäßen LED-Moduls einstellt.

Fig. 7

zeigt wie eine Änderung der Leistungsaufnahme des erfindungsgemäßen LED-Moduls an einem Buck-Konverter als Beispiel eines erfindungsgemäßen LED-Konverters gemessen werden kann.

Fig. 8

zeigt wie eine Änderung des Stroms durch die Schaltung auf dem erfindungsgemäßen LED-Modul mit dem Strom in einem Buck-Konverter des erfindungsgemäßen LED-Konverters korreliert

Fig. 9

zeigt ein weiteres Beispiel der Schaltung auf dem erfindungsgemäßen LED-Modul

Fig. 10

zeigt ein weiteres Beispiel der Schaltung auf dem erfindungsgemäßen LED-Modul

Fig. 11

zeigt ein weiteres Beispiel der Schaltung auf dem erfindungsgemäßen LED-Modul

Fig. 12

zeigt ein weiteres Beispiel der Schaltung auf dem erfindungsgemäßen LED-Modul.

The present invention will now be described in more detail with reference to the accompanying figures.

Fig. 1

shows schematically the basic principle of the present invention using an LED light according to the invention (consisting of an LED module according to the invention and an LED converter according to the invention).

Fig. 2

shows a current-voltage characteristic of an LED path and the readout window according to the invention.

Fig. 3

shows a circuit which enables automatic deactivation of the circuit on the LED module according to the invention.

Fig. 4

shows an example of the circuit on the LED module according to the invention, which represents a current-constant load.

Fig. 5

shows schematically the detection of a constant current load on the LED module according to the invention by the LED converter according to the invention.

Fig. 6

shows a circuit on the LED module according to the invention, which represents a current-variable load and in particular sets a frequency of the change in the power consumption of the LED module according to the invention.

Fig. 7

shows how a change in the power consumption of the LED module according to the invention can be measured on a buck converter as an example of an LED converter according to the invention.

Fig. 8

shows how a change in the current through the circuit on the LED module according to the invention correlates with the current in a buck converter of the LED converter according to the invention

Fig. 9

shows another example of the circuit on the LED module according to the invention

Fig. 10

shows another example of the circuit on the LED module according to the invention

Fig. 11

shows another example of the circuit on the LED module according to the invention

Fig. 12

shows another example of the circuit on the LED module according to the invention.

Figure 1 shows schematically an LED lamp according to the invention, which consists of an LED module 1 according to the invention and an LED converter 10 according to the invention. The LED converter 10 is connected to the LED module 1 via one or more voltage connections 12. The LED converter 10 thus supplies the LED module 1 with a supply voltage. The LED converter 10 can also be designed to operate a plurality of LED modules 1. The supply voltage is preferably a direct voltage, but can also be a clocked voltage or alternating voltage. The LED converter 10 preferably has a high-frequency clocked converter, for example a buck converter (step-down converter), isolated flyback converter or a resonant half-bridge converter (preferably isolated, e.g. an LLC converter). The LED converter 10 can, for example, output a constant output voltage or a constant output current at its voltage connections 12, the voltage at these connections corresponding to the supply voltage of the LED module 1.

The supply voltage is applied via one or more connections 2 of the LED module 1 to at least one LED path 3 connected to it (this also includes a single LED). The LED segment 3 does not have to be part of the LED module 1 according to the invention, but can be a connectable and exchangeable LED segment 3. The LED module 1 according to the invention therefore only requires connections 2 for at least one LED line 3. The LED line 3 can, however, also be permanently installed with the LED module 1. The LED path 3 can have one or more LEDs, which, for example, as in FIG Figure 1 shown are connected in series. LEDs in an LED segment 3 can all light up in the same color, ie emit light of the same wavelength, or light up in different colors. For example, several LEDs, preferably red, green and blue-glowing LEDs, can be combined in order to generate mixed radiation, preferably white light.

When it is connected to the connections 2, the LED path 3 is connected in parallel with a circuit 4 with respect to the supply voltage. The circuit 4 is designed, for example, in such a way that it represents a load, preferably an active power load, for the LED converter 10 if the supply voltage applied by the LED converter 10 to the connections 12 is not equal to zero, but is still so low that the LED path 3 connected to connections 2 is not yet conductive. The circuit 4 can therefore also be referred to as a load circuit or a load modulation circuit.

Figure 2 shows an example of a current-voltage characteristic of an LED path 3 in which a current through the LED path in the vertical direction and the voltage at the LED path (ie the supply voltage in Figure 1 ) is applied in the horizontal direction. For a first voltage range (ie a first supply voltage 5a within the readout window), the voltage across the LED path 3 is not equal to zero, but the current through the LED path 3 is also almost zero, since the LED path 3 is not conductive . The supply voltage is therefore below the forward voltage. The LED path 3 represents an infinite load for the LED converter 10. The LED module 1 therefore does not consume any power via the LED path 3. In a second voltage range (ie for a second supply voltage 5b outside the readout window) the LED path 3 becomes conductive and a current flows through the LED path 3, which makes it glow. The supply voltage is therefore above the forward voltage.

The circuit 4 on the LED module 1 is designed, for example, in such a way that it is activated when the first supply voltage 5a is applied and thereby represents a load, preferably an active power load, for the LED converter 10. For the second supply voltage 5b, that is to say when the LED path 3 is lit, the circuit 4 is deactivated and does not represent a load for the LED converter. This is shown in FIG Figure 1 represented schematically by the switch 6, which automatically activates or deactivates the circuit 4 depending on the applied supply voltage. The circuit 4 can represent either a current-constant load or a current-variable load for the LED converter 10. The circuit 4 causes the LED module 1 to consume power, although an LED path 3 is not yet conductive and does not consume any power. A conventional LED module 1 would not consume any power in the readout window. Additionally or alternatively, the circuit 4 on the LED module 1 can also be designed such that it is only activated in a time-limited start phase of the LED module 1.

The power consumption of the LED module 1 in the readout window can be constant or variable, depending on the type of circuit 4. The LED converter 10 can detect the power consumption of the LED module 1 or a change in the power consumption of the LED module 1 and, based on the detected power consumption, deduce operating and / or maintenance parameters of the LED module 1 to be set. The LED converter 10 can use the operating and / or maintenance parameters directly for setting or regulating the LED module 1. The LED converter 10 can also store the operating and / or maintenance parameters in a memory assigned to it and, if necessary, use them later, or display the parameters optically and / or acoustically to a user, or to another device, for example a control unit of a lighting system , send. The transmission can be done either wirelessly or wired and can be carried out either automatically or only on request from the further device.

To operate an LED module 1 by the LED converter 1 of the present invention, various processes can be carried out in a preferably time-limited starting phase of the LED light. First, the LED converter 10 supplies the LED module 1, for example, with a constant supply voltage, preferably a constant DC voltage. For example, the LED converter 10 can be operated with a reduced switch-on ratio compared to normal operation, as a result of which a lower output voltage is achieved. The supply voltage is included a first supply voltage 5a, ie it is in the readout window shown in Figure 2 is shown. Since the first supply voltage 5a is not equal to zero, the circuit 4 is activated on the LED module 1 and represents a load for the LED converter 10. The load is preferably an active power load and generates a power consumption of the LED module 1. Now can the LED converter 10 can measure, for example, a discharge current of a capacitor via this load, an absolute current consumption of the circuit 4, a frequency of a change in the power consumption of the LED module 1, or a duty cycle or an amplitude of a change in power consumption. Based on the result of the measurement, the LED converter 10 can infer operating and / or maintenance parameters. For example, the LED converter 10 can determine a target or forward voltage or a target current of the LED module and apply this to the LED module 1. A connected LED path 3 thus becomes conductive and the LED converter 10 operates the LED module 1 in lighting mode. The circuit 4 is now preferably deactivated automatically. The circuit 4 therefore does not consume any power in the lighting operation of the LED path 3 and therefore does not influence the lighting operation of the LED path 3. The LED converter 10 of the LED lamp has automatically recognized the LED module 1 and set the appropriate operating parameters .

As an alternative or in addition, the LED converter 10 can also read out the LED module 1 for a limited time, in that the circuit 4 is only active during a start phase on the basis of a predetermined period of time as soon as a supply voltage is applied to the LED module 1. In this case, this supply voltage can also correspond to the nominal output voltage of the LED converter 10 for normal operation. After the supply voltage has been applied, the circuit 4 on the LED module 1 activated and represents a load for the LED converter 10. The load is preferably a repeatedly changing active power load and generates a power consumption of the LED module 1. In addition, the connected LED path 3 can also become conductive in this case, whereby the LED Converter 10 operates the LED module 1 in lighting mode. The LED converter 10 can now measure, for example, a discharge current of a capacitor via this load, an absolute current consumption of the circuit 4, a frequency of a change in the power consumption of the LED module 1, or a duty cycle or an amplitude of a change in power consumption. Based on the result of the measurement, the LED converter 10 can infer operating and / or maintenance parameters. For example, the LED converter 10 can determine a target or forward voltage or a target current of the LED module and apply this to the LED module 1. The circuit 4 is now preferably deactivated automatically after the predetermined time period for the start phase has elapsed. The specification of this time period for the start phase can be established, for example, by a time charging circuit, with a timer capacitor being charged and, after the timer capacitor has been charged, the circuit 4 is deactivated. As a result, the circuit 4 does not consume any power in the continuous lighting operation of the LED segment 3 and therefore does not influence the lighting operation of the LED segment 3.

Figure 3 shows a circuit which is at least a part of the circuit 4 in order to automatically deactivate it when the supply voltage is in the range of the second supply voltage 5b, that is, above the forward voltage of the LED path 3. The circuit 4 can be deactivated by means of the transistors M4 and M3. As the supply voltage, which is provided by the LED converter 10 and is applied to the circuit 4 on the LED module 1, increases, the voltage across the resistor R8 also increases. If this voltage reaches a threshold voltage of the transistor M4, the latter closes and also deactivates the transistor M3 by connecting the gate voltage of the transistor M3 to ground. The threshold voltage can for example be 1.4 volts (at a voltage of 12.5 volts) of the LED converter 10). In order to reduce losses of the voltage divider R8 and R10, the resistance values should be high, preferably in the range from 20 to 200 kΩ, even more preferably in the range from 40 to 100 kΩ. It is also important that the transistor M3 is designed to withstand the maximum supply voltage that the LED converter 10 can apply, and that the voltage across the resistor R8 does not exceed the maximum permitted gate voltage of the transistor M4 when the LED is normally lit. - Distance exceeds 3. Alternatively or optionally, this circuit can be designed, for example by means of an RC element, in such a way that it deactivates itself after a predetermined starting time has elapsed (this time corresponding to the starting phase) by deactivating transistor M3 as a function thereof, ie opening it. For example, a capacitor can be arranged in parallel with the resistor R8. This capacitor can be designed so that it is charged by the applied supply voltage after the specified start time has elapsed and thus the voltage at the parallel resistor R8 has also risen so far that this voltage has reached a threshold voltage of the transistor M4, so that it closes and the Transistor M3 deactivates by pulling the gate voltage of transistor M3 to ground.

Figure 4 shows an example of a circuit TL432, which is at least part of the circuit 4, which is designed to display a current-constant load for the LED converter 10 in the readout window. The left side of the Figure 4 shows a circuit diagram of the circuit, the right-hand side shows a corresponding equivalent circuit diagram for the TL431 circuit or TL432. The constant current is determined by a ratio of the reference voltage of the switching circuit TL431 to the resistance value of the selection resistor R11 (Rcfg). A transistor Q1 is preferably controlled such that the voltage across resistor R11 (Rcfg) is always approximately 2.5 volts. A minimum current of about 1 mA should flow through the TL431 circuit. The in Figure 3 The circuit shown can be used in series with the in Figure 4 The circuit shown can be arranged so that the series circuit of the two is arranged in parallel with the LED path on the LED module 1. Preferably, the virtual ground GNDX of the circuit is the Figure 4 connected to the drain of the transistor M3.
Via a constant current load such as in Figure 4 As shown, the LED converter 10 can discharge a capacitor 11, for example, for measuring the constant current. The constant current through the circuit 4 (which corresponds to the discharge current of the capacitor 11) can be determined directly or indirectly based on either the discharge duration and / or the discharge rate. Based on the discharge current, the LED converter can draw conclusions about the circuit 4 used and thus about the connected LED module 1. Furthermore, the LED converter 10 can determine operating and / or maintenance parameters of the LED module, for example using stored tables.

The concept of determining the constant current through the circuit 4 is shown schematically in FIG Figure 5 shown. For example, the LED converter 10 can be designed as a buck converter. The LED converter 10 is provided with the capacitor 11, which can be connected in parallel to the connections 12 for the supply voltage. The voltage at the connections 12 is monitored by the LED converter 10. When the supply voltage by opening the switch 13, which is arranged in the LED converter 10 and is preferably clocked at high frequency when the LED converter is in operation, is separated from the LED module 1, the capacitor 11 discharges via the preferably constant current load, which is caused by the circuit 4 on the LED Module 1 is shown. The discharge rate, ie the change in the voltage of the capacitor which is applied to the connections 12, is preferably measured by the LED converter 10 in order to draw conclusions about the operating and / or maintenance parameters of the LED module 1 as described. For example, resistor R11, which is shown in Figure 4 constant current load shown, can be determined when the capacitance of the capacitor 11 is known. This resistance value can then encode the operating and / or maintenance parameter, ie the LED converter 10 can, for example, correlate this resistance value with operating and / or maintenance parameters in stored tables.

Figure 6 shows a circuit TLC555, which is at least part of the circuit 4 and is suitable for generating a load change of the LED module 1 with a certain frequency, ie a change in the power consumption of the LED module 1. On the left of the Figure 6 is a circuit diagram, on the right side a corresponding equivalent circuit diagram for the circuit TLC555 is shown. For example, a capacitor C1 can be charged and discharged between 1/3 and 2/3 of the supply voltage 5a applied by the LED converter 10. As long as the supply voltage 5a applied by the LED converter 10 is constant, a frequency of the load change, a duty cycle (pulse duty factor) of the load change or an amplitude of the load change (ie a difference between a load before and a load after the change) can be set. This also requires a change in the power consumption with a corresponding frequency, pulse duty factor (pulse ratio) or an amplitude.

wobei R3, R4 und C1 Widerstands- bzw. Kapazitätswerte der in Fig. 6 gezeigten Komponenten sind.The frequency f of the change is defined as $$\mathrm{f}=1/\left\{\left(\mathrm{R.}\mathrm{3rd}+\mathrm{2nd}\cdot \mathrm{R.}\mathrm{4th}\right)\cdot \mathrm{C1}\cdot \ln \left(\mathrm{2nd}\right)\right\},$$

where R3, R4 and C1 are resistance or capacitance values of the in Fig. 6 components shown.

• T_high = (R3+R4)·C1·ln(2) und
• T_low= R4·C1·In(2).

The duty cycle (clock ratio) is defined by the ON time (T _high, ) and the OFF time (T _low ), with

• T _high = (R3 + R4) * C1 * ln (2) and
• T _low = R4 * C1 * In (2).

The duty cycle can be changed by changing the pulse duration (switch-on time, ON time, T _high ) or by changing the pause duration (switch-off time, OFF time, T _low ).

The size of the load is determined by the resistor R5 and the converter _voltage V _CONV (more precisely the ratio V _CONV / R5).

The circuit 4 is designed so that it is only activated during the starting phase of the LED light. This can be achieved, for example, by supplying the circuit TLC555 with the aid of a timing element such as an RC element, for example, this timing element can be designed in such a way that the supply for the circuit TLC555 is only present for a time of 100 milliseconds, and thereafter due to When the capacitor of the RC element is charged via a series resistor (based on the supply voltage of the LED module 1), a predetermined voltage level is reached, which leads to the switching off of the supply voltage Vcc for the TLC555 circuit (example not shown). For example, via the RC element dropping voltage, the base of a switch-off transistor (not shown) can be controlled, which pulls the supply Vcc for the circuit TLC555 to ground as soon as the RC element has been charged. The charging time of the RC element can be designed so that a time of 100 milliseconds, for example, is achieved, this time corresponding to the start phase. A start-up of the TLC555 circuit at the beginning of the start phase can take place by means of a high-impedance feed directly from the supply voltage of the LED module 1, whereby this occurs at the end of the start phase by means of the voltage drop across the RC element via the shutdown transistor in a kind of pull-down configuration Mass is pulled. The circuit 4 can have a controllable switch which switches the resistor R5 on or off as a function of the output signal OUT of the circuit TLC555 and thus causes the load change.

The in Figure 3 The circuit shown can be used in series with the in Figure 6 The circuit shown can be arranged so that the series circuit of the two is arranged in parallel with the LED path on the LED module 1. Preferably, the virtual ground GNDX of the circuit is the Figure 6 connected to the drain of the transistor M3. A deactivation of the circuit of the Figure 6 can be time-controlled, for example. As with the example of the Figure 3 explained, a capacitor can be arranged in parallel with the resistor R8. In this case an RC element is also formed. The charging time of the RC element can be designed so that a time of 100 milliseconds, for example, is achieved, this time corresponding to the start phase. After the start time specified by the dimensioning of the RC element has elapsed, the voltage at the gate of transistor 4 has reached a threshold voltage of transistor M4, so that it closes and deactivates transistor M3 by setting the gate voltage of transistor M3 to ground sets. In this way the circuit of the Figure 6 can only be activated for a specified start phase.

If the circuit 4 generates and outputs a repetitively changing load change (that is to say a modulated load change), two different items of information can also be transmitted, for example. For example, both the frequency and the duty cycle of the load change can be changed. In this case, a first piece of information (for example the setpoint voltage) could be transmitted encoded by means of the frequency, while a second piece of information (for example the setpoint current) can be transmitted in coded form using the pulse duty factor. Another possibility for the combined transmission of at least two pieces of information would be to change the pulse duration (switch-on time, ON time, T _high ) and the pause duration (switch-off time, OFF time, T _low ) of the load change accordingly.

The change in the power consumption of the LED module 1 can be determined by the LED converter 10, for example, by direct current measurement of the current through the circuit 4. Alternatively, the LED converter can take 10 measurements on a buck converter as in Figure 7 perform shown, wherein the buck converter is preferably part of the LED converter 10. So shows for example Figure 8 how the current through the circuit 4 and the current at the Buck converter, which is measured via a shunt, correlates. Figure 8 shows the current "load current" through circuit 4 and the current "inductor current" through Buck converter plotted against time. The buck converter is only an exemplary example of a high-frequency clocked converter; alternatively, an isolated flyback converter, boost converter (step-up converter) or a resonant half-bridge converter (preferably isolated, for example an LLC converter) for feeding the LED module 1.

The LED converter can be used as in Figure 7 shown have a buck converter. The buck converter can be operated as a constant current source, i.e. regulate to a constant output current. In this case, for example, the output voltage of the buck converter, that is to say the voltage that is output at the output of the LED converter 10 and corresponds to the voltage across the LED module 1, can be recorded and evaluated. Additionally or alternatively, the duration of the switch-on time and the switch-off time of the activation of the high-frequency clocked switch of the buck converter can be monitored and evaluated in order to detect a load change and thus read information from the LED module 1.

The buck converter can also be operated as a constant voltage source, i.e. regulate to a constant output voltage. In this case, a load change on the LED module 1 will lead to a change in the peak current that occurs through the high-frequency clocked switch during the switch-on phase of the high-frequency clocked switch of the buck converter, and this change can be detected. Additionally or alternatively, the duration of the switch-on time and the duty cycle of the activation of the high-frequency clocked switch of the buck converter can also be monitored and evaluated in order to detect a change in load and thus read information from the LED module 1. Alternatively, when operating as a constant voltage source, the level of the output current can also be evaluated in order to detect a change in load.

The buck converter can be operated with a fixed pulse duty factor at a fixed frequency, preferably in a non-discontinuous current mode (continuous conduction mode). In such an operation, the level of the output current and / or the output voltage can be evaluated in order to detect a change in load.

The buck converter of the LED converter 10 can supply the LED module 1 with a constant supply voltage, preferably a constant DC voltage, in a starting phase, for example. In this case, the buck converter is operated as a constant voltage source in the start phase. For example, the LED converter 10 can be operated with a reduced switch-on ratio compared to normal operation, as a result of which a lower output voltage is achieved. The supply voltage can be a first supply voltage 5a, ie it can be in the readout window shown in FIG Figure 2 is shown. In a starting phase, the buck converter can also supply the LED module 1 with a regulated current, then the buck converter is preferably operated as a constant current source.

Figure 8 shows an enlarged view of this plot below. The greater the load on the circuit 4, the greater a pulse duty factor or a peak current at the measuring resistor (shunt). Depending on a control principle of the LED module 1 by the LED converter 10, a peak current can also be measured at the shunt of the buck converter or a change in the duty cycle at the buck converter. The change in the load of the circuit 4 or the power consumption of the LED module 1 can be detected directly on the shunt on the low-potential switch of the buck converter. Either through a periodic change in the duty cycle or a periodic change in the Peak current, which correlates with a periodic change in the power consumption of the LED module 1.

As already mentioned, the LED converter 10 can for example have an isolated converter with a transformer for high-frequency energy transmission (isolated, preferably an isolated flyback converter) for supplying the LED module 1. If the LED converter 10 is designed to be isolated (for example as an isolated flyback converter), that is to say has a transformer, the load change can also be detected by the LED converter 10 on the primary side of the LED converter 10.

For example, when using an isolated flyback converter, the current on the primary side of the LED converter 10, which flows through the primary side of the transformer, can be detected. For example, the current through the clock switch, which is arranged in series with the primary winding of the transformer, or the current through the primary winding of the transformer, preferably by means of a shunt connected in series (current measuring resistor) can be detected. For example, the applied load or the load change of the LED module 1 and thus, for example, a change in the duty cycle on the primary side of the LED converter 10 can be measured on the basis of the peak current at the shunt. For example, the change in the primary-side current can also be recorded over time. For example, the power transmitted from the primary side can be detected using the measurement of the primary-side current and a measurement or at least knowledge of the voltage feeding the converter. For example, it would be possible for an active power factor correction circuit, such as a step-up converter circuit, to be connected upstream of the converter, which would supply the input voltage for the high-frequency clocked, isolated converter such as the isolated flyback converter and regulates it to a specified value. This predetermined value for the input voltage regulated by the active power factor correction circuit for the high-frequency clocked converter is known due to the specification (for example via a voltage divider) and can therefore be taken into account when detecting the power transmitted from the primary side.

As already mentioned, the LED converter can have an isolated flyback converter. The isolated flyback converter can be operated as a constant current source, i.e. regulate to a constant output current. In this case, for example, the output voltage of the isolated flyback converter, that is to say the voltage that is output at the output of the LED converter 10 and corresponds to the voltage across the LED module 1, can be recorded and evaluated. This output voltage can be detected directly or indirectly, for example by measuring the voltage on a primary-side winding of the transformer of the isolated flyback converter. Additionally or alternatively, the duration of the switch-off time of the control of the high-frequency clocked switch of the isolated flyback converter can be monitored and evaluated in order to recognize a change in load and thus to read information from the LED module 1.

The isolated flyback converter can also be operated as a constant voltage source, i.e. regulate to a constant output voltage. In this case, a change in load on the LED module 1 will lead to a change in the output current, and this change can be detected. This change in the output current can, for example, be due to a change in the peak current that occurs lead through the high-frequency clocked switch during the switch-on phase of the high-frequency clocked switch of the isolated speech converter. The monitoring of the primary-side current by the high-frequency clocked switch can thus be used to monitor a change in load in order to read out information from the LED module 1.

The isolated flyback converter can also be operated with a fixed pulse duty factor at a fixed frequency. In such an operation, the level of the output current and / or the output voltage can be evaluated in order to detect a change in load. If only the LED path of the LED module is active, the output voltage will take on the value of the forward voltage of the LED path. If there is a load change through circuit 4, then the output voltage will drop. This change can be recorded as a load change.

As already mentioned, the LED converter can have an isolated resonant half-bridge converter such as a so-called LLC converter. The LLC converter can be operated as a constant current source, i.e. regulate to a constant output current. In this case, for example, the output voltage of the isolated flyback converter, that is to say the voltage that is output at the output of the LED converter 10 and corresponds to the voltage across the LED module 1, can be recorded and evaluated. This output voltage can be detected directly or indirectly, for example by measuring the voltage on a primary-side winding of the transformer of the LLC converter. If only the LED path of the LED module is active, the output voltage will take on the value of the forward voltage of the LED path. If a load change occurs through the circuit 4, then the Output voltage drop. This change can be recorded as a load change. Additionally or alternatively, the clock frequency of the LLC converter that is set on the basis of the control loop can also be monitored and evaluated in order to detect a change in load and thus to read out information from the LED module 1. If the control loop of the LLC converter is designed in such a way that when the load changes by the circuit 4, a frequency limit of the control of the half bridge of the LLC converter is reached, this can also be evaluated in order to read out the information.

The isolated resonant half-bridge converter such as LLC converter can also be operated as a constant voltage source by operating it at a fixed frequency, the frequency being selected so that the resulting voltage at the output is below the value of the forward voltage of the LED path. In this case, a change in load on the LED module 1 will lead to a change in the output current, and this change can be detected. This change in the output current can take place, for example, on the secondary side of the LLC converter and be transmitted to the primary side by means of a coupling element such as a current transformer. The monitoring of the output current can thus be used to monitor a change in load in order to read out information from the LED module 1.

Fig. 13 shows, as an exemplary embodiment for the LED converter 10, an isolated resonant half-bridge converter B, which is shown here as an LLC converter.

In Fig. 13 it is shown that the bus voltage Vbus is fed to an inverter 20 which, for example, can be designed as a half-bridge inverter with two switches S1, S2. The bus voltage Vbus can be, for example, the output voltage of a PFC circuit (not shown here). The control signals for clocking the switches S1, S2 can be generated in a known manner by the switch control unit. The higher-potential switch S1 is controlled by the ctr_HS signal, the lower-potential switch S2 by the ctrl_LS signal.

In the example shown, a resonance circuit, designed here as a series resonance circuit, namely an LLC resonance circuit 22, is connected to the center point 21 of the inverter 10. In the example shown, this resonant circuit 22 has a first inductance Lsigma, a primary winding of the transformer T and a capacitor Cres.

The primary winding of the transformer T has a parallel inductance Lm, which carries the magnetizing current.

The transformer T is followed by a load load, which can be fed with a supply voltage that is lower than that of the bus voltage Vbus. According to the exemplary embodiments, for example Fig. 1 the load includes the LED module 3. At the output of the transformer T additional elements (not shown) for smoothing and stabilizing the output voltage can be present.

In Fig. 13 the resonance circuit 22 is designed as a series resonance circuit. Alternatively, the invention can also be applied to other resonance circuits such as, for example, parallel resonance circuits Find. The resonance circuit according to the invention can accordingly be designed as a parallel resonance circuit in which the resonance capacitor Cres is connected in parallel to the load, namely in parallel to the primary winding of the transformer T.

The combination of the inverter 20 with the resonance circuit 22 forms a DC / DC converter, which is isolated by the transformer T, as an LED converter which transmits energy.

The switches S1, S2 of the inverter 20 are preferably operated in the vicinity of the resonance frequency of the resonance circuit or in the vicinity of a harmonic of a resonance of the output circuit. The output voltage or the output current of the resonant converter or the galvanic decoupling F is a function of the frequency of the control of the switches S1, S2 of the inverter 20, here as a half-bridge inverter.

The LED converter 10 is operated, for example, in a start phase in a certain mode, for example in a fixed-frequency mode or also operated as a current source or voltage source, in order to recognize a change in load and thus to read out information from the circuit 4 which, for example, according to at least one protocol is transmitted.

The circuit 4 can also have a digital control unit IC1 which is designed to output various types of modulated signals as a preferably modulated load change, for example also a specific pulse sequence as digital coding (sequence of zeros and ones). The LED converter 10 can be designed to transmit different types of information, that is to say different types, by changing the supply voltage Query operating parameters and / or maintenance parameters from the LED module 1 and also selectively query one of several LED modules. The supply voltage can be changed, for example, by means of a low-frequency (in the range from a few Hertz to one kilohertz) or high-frequency modulation (in the tens or hundreds of kilohertz or up to the megahertz range).

The digital control unit IC1 of the circuit 4 can be designed as an integrated circuit. For example, the integrated circuit can be designed as an integrated control circuit with only three or four connections.

In an embodiment with three connections, the digital control unit IC1 would have a first connection Vp which is connected to the supply voltage of the LED module 1 ( Fig. 9 ). The digital control unit IC1 can detect the supply voltage of the LED module 1 via this first connection Vp by means of the first analog-digital converter A / D1 connected to this connection Vp. A second connection Vn is connected to the ground of the LED module 1 and enables an internal ground connection within the digital control unit IC1. A third connection Vdd can be connected to a capacitor, the other connection of which is also connected to ground of the LED module 1. The second terminal Vp can be internally connected to the first terminal Vp via a diode and a switch Svdd. This switch Svdd can be compared with a reference value Ref by means of a comparator Compl as a function of a comparison of the voltage currently present at the connection Vdd. Depending on the comparison result, the switch Svdd can be switched on by the driver unit VddCtrl when the actual value of the voltage at the at the terminal Vdd is smaller than the reference value Ref. A current then flows through the switch Svdd into the capacitor, which is connected to the third terminal Vdd. The voltage present at the third terminal Vdd can be used as an internal voltage supply for the digital control unit IC1. In this case, the connection Vdd serves to stabilize the internal voltage supply of the digital control unit IC1.

According to this example, the digital control unit IC1 can be programmed in advance, for example during manufacture or assembly of the LED module 1. This programming of the digital control unit IC1 can, for example, specify an operating parameter of the LED module 1 such as the target current or the target voltage.

In the digital control unit IC1, a switching element S6 is integrated, which in the function of the switch 6 of the example of Fig. 1 and is designed to output at least one modulated signal or different types of modulated signals, preferably as a modulated load change. The voltage at the first terminal Vp is connected internally by closing the integrated switching element S6 to the second terminal Vn directly or indirectly, for example via an integrated resistor R6, and thus pulls the voltage at the terminal Vp to a lower potential. For example, the modulated signal can be a specific pulse sequence and output as digital coding (sequence of zeros and ones). By means of the switching element S6, the digital control unit IC1 can thus transmit information, for example in a run-up phase (i.e. a time-limited start phase of the LED converter and LED module 1), preferably in accordance with the at least one protocol, which is for example in the LED module 1 and is stored in the LED converter 10. The current through the switching element S6 can be monitored by means of the resistor R6, the switching element S6 being able to be opened if the current through the switching element S6 and thus the resistor R6 becomes too great. The voltage drop across resistor R6, and thus the current flowing through it, can be detected by means of a second analog-digital converter A / D2. The reading and evaluation of the two analog-digital converters as well as the control of the switching element S6 can be done by a "Config and Com" control block integrated in the digital control unit IC1. All other operations such as signal evaluations and outputs can also be carried out using this control block.

For example, a sensor system for detecting the temperature can also be integrated into the digital control unit IC1, whereby the digital control unit IC1 can transmit an excess temperature or an operating temperature as a maintenance parameter to the LED converter as information according to the at least one protocol. As a maintenance parameter, the digital control unit IC1 can for example also have a counter for the operating time and the digital control unit IC1 can be designed to output an aging parameter of the LED module or the LED path or an operating time of the LED module as a maintenance parameter. The digital control unit IC1 can also detect an overvoltage on the LED module 1 and output a corresponding error message as a maintenance parameter. Optionally or alternatively, the LED path of the LED module 1 can be bridged by closing the switching element S6 and thus protected against the overvoltage.

The digital control unit IC1 can, for example, also be connected to one or more sensors and / or one or more sensors several sensors can be integrated into the digital control unit IC1. For example, such a sensor system can be formed by a sensor such as a light sensor, temperature sensor, color sensor and / or presence sensor. The digital control unit IC1 can be designed so that it can also supply and read the sensor when the LED converter 10 outputs a reduced supply voltage to the LED module 1 and the LED path is not active. The LED converter 10 can supply the sensor in an operating mode when the LED path is not active, in that the LED converter 10 outputs a reduced supply voltage to the LED module 1.

The circuit 4, in particular the digital control unit IC1, can be designed so that when the supply voltage is in a readout window (ie supply voltage not equal to zero but below the forward voltage of the LED path), that it represents a current-variable load in it that changes the power consumption of the LED module 1 caused in accordance with at least one predetermined protocol. Additionally or alternatively, information from a sensor can also be transmitted directly to the LED converter 10 by the digital control unit IC1 in accordance with at least one predetermined protocol. For example, a detected presence or a drop in ambient brightness can be detected by the digital control unit IC1 with the aid of a sensor and accordingly transmitted to the LED converter 10 with the aid of a transmission by the circuit 4, so that the latter can react accordingly and for example the supply voltage increases so that a second non-zero supply voltage is applied to the LED module, in which a connected LED path is conductive.

A system can thus be set up comprising an LED converter 10 and an LED module 1 supplied by it with a circuit 4 comprising a digital control unit IC1 and with at least one sensor, the digital control unit IC1 sending information from the sensor to the LED converter 10 can transmit through a load change. For example, in a so-called stand-by or standby mode, the connected LED path can be deactivated by reducing the supply voltage output by the LED converter 10 to a low value, i.e. below a second non-zero supply voltage at which a connected LED path is conductive , be lowered. In this case, it would also be possible for the LED converter 10 to have the first non-zero supply voltage applied repeatedly one after the other, at which a connected LED path is not conductive. In this time window of the temporarily applied first supply voltage, the digital control unit IC1 can be activated and read out the at least one sensor.

Depending on whether and which information was detected by the sensor, the digital control unit IC1 can then bring about a load change. This change in load can be detected and evaluated by the LED converter 10. In this way, information from a sensor can be transmitted from the LED module 1 to the LED converter 10 by means of the digital control unit IC1 in accordance with at least one predetermined protocol. Since the LED converter 10, as already explained, can be designed to detect a load change as information transmission from the LED module 1 when a first supply voltage other than zero is output, a complex lighting system with LED converter and LED module can be built with the integration of sensors.

According to the invention, the information is transmitted from the LED module 1 to the LED converter 10 by means of at least one predetermined protocol. The LED converter 10 can be designed to receive at least one piece of information from a sensor from the digital control unit IC1 as at least one specific operating and / or maintenance parameter. The information from a sensor can be used to set or control the operation of the LED module 1. The information from a sensor can also be stored in an assigned memory, displayed optically and / or acoustically, and / or transmitted by the LED converter 10 via a wireless or wired interface, possibly in response to an external query.

In the Fig. 10 shows an embodiment of the digital control unit IC1 with four connections. The digital control unit IC1 has a fourth connection Cfg, to which a configuration element such as a resistor Rcfg (selection resistor R11) can be connected. A controllable current source Icfg can be connected internally to this fourth connection Cfg. The voltage drop across the resistor Rcfg, which results from the current fed in by the controllable current source Icfg and the resistance value of the resistor Rcfg, can be controlled by the control block "Config and Com" of the digital control unit IC1 via a third analog-digital converter A / D3 can be detected. This detected voltage at the fourth connection Cfg can specify an operating parameter of the LED module 1, such as, for example, the target current or the target voltage. Optionally, for example, a temperature-dependent resistor can also be arranged between the fourth connection Cfg and the third connection Vdd. The temperature-dependent resistor can be designed in such a way that its resistance is on the LED module 1 in the event of excess temperature changes greatly, as a result of which the voltage at the fourth terminal Cfg also changes. This change can be detected by the digital control unit IC1 and, for example, an excess temperature can be transmitted to the LED converter as a maintenance parameter as information according to the at least one protocol. For example, an NTC can be used as a temperature-dependent resistor, which lowers its resistance when the temperature is too high, as a result of which the voltage at the fourth terminal Cfg increases. The controllable current source Icfg can, for example, only be active when the digital control unit IC1 is started in order to read out the value of the resistance R11, while in continuous operation of the LED module 1, only the voltage resulting from the voltage divider from the temperature-dependent resistance and resistance R11 is used to detect excess temperature is monitored.

In contrast to the examples of the Fig. 9 and 10th is in this variant the Fig. 11 . the switch not as an integrated switching element S6 but as an external switch 6 analogous to the example of FIG Fig. 1 executed. This switch 6 is controlled via a fifth connection Sdrv by the digital control unit IC1. A resistor R6 is arranged in series with the switch 6. The current through the resistor R6 can be detected and monitored by the digital control unit IC1 on the basis of the voltage drop across the resistor R6 by means of a sixth connection Imon.

The example of Fig. 12 shows a further embodiment of the digital control unit IC1. This example, like the example of the Fig. 10 the connections Vp, Vn and Vdd. There is also the fourth connection Cfg, to which a resistor R11 (Riled) is in turn connected as a configuration element. The digital control unit IC1 also has two further connections. Another Connection Vovt is a resistor Rovt, which is a temperature-dependent resistor, connected. An excess temperature can be detected by monitoring the resistance value of this resistance Rovt. For this purpose, a further controllable current source can be arranged in the digital control unit IC1, which outputs a current at the further connection Vovt, which current flows into the resistor Rovt. Depending on the current resistance value, which is monitored on the basis of the detected voltage at this connection Vovt, the digital control unit IC1 can conclude that the LED module 1 is overheating. In an analogous manner, a current can be fed into the temperature-dependent resistor Ritm connected to it via a further controllable current source at the further connection Vitm, and the digital control unit IC1 can use the current resistance value, which is monitored on the basis of the detected voltage at this connection Vitm, to the Close the operating temperature on the LED module 1. Depending on the value of the detected operating temperature, this can be transmitted to the LED converter as information in exactly the same way as an excess temperature as information in accordance with the at least one protocol. The information about the operating temperature can be evaluated by the LED converter, with an intelligent regulation of the current through the LED module 1 without an excess temperature having to be reached.

The switch 6 or the switching element S6 can perform further functions on the LED module 1, which can be controlled by the digital control unit IC1. For example, afterglow protection can be enabled. The digital control unit IC1 can for example recognize when the LED module 1 is to be switched off or has already been switched off by switching off the supply voltage. To avoid parasitic effects or remaining To avoid residual charges coupled in voltages, the switch 6 or the switching element S6 can be closed in order to prevent the LED from glowing due to the coupled in voltages. Alternatively or additionally, protection of the LED module 1 against overvoltages can also be made possible by at least briefly closing the switch 6 or the switching element S6 in the event of an overvoltage at the supply input of the LED module 1 in order to reduce the overvoltage or to close the LED protect. Protection against overvoltages when the LED module 1 is disconnected from the LED converter when the LED module 1 is in operation can thus also be made possible, as a so-called "hot-plug" protection. Such a disconnection can occur unintentionally as a result of a sudden contact interruption in the supply line or as a result of a user error due to an intervention, such as, for example, changing the LED module 1 during operation.

The LED converter 10 can effect a change of the LED module into a communication mode by selectively changing the supply voltage for the LED module 1, and then the LED converter 10 can detect the change in the power consumption of the LED module 1 and according to the decode at least one protocol that is stored in the LED module 1 and in the LED converter 10, for example. For example, the LED converter 10 can thus request various information from the LED module 1, a specific protocol being able to be stored for each request. This enables a bidirectional communication path between the LED module and the LED converter without additional lines or pins.

The change in the power consumption of the LED module 1 can depend on a value of the first supply voltage 5a according to one of several predetermined protocols are effected and thus a different load change can be effected according to one of several predetermined protocols.

According to the present invention, three concepts for detecting the change in the power consumption of the LED module 1 by the LED converter 10 are preferred. On the one hand, the determination of a current-constant load, with the constant current being able to be measured, for example, via a discharge rate of a capacitor on the LED converter 10. On the other hand, by determining a frequency of the change in the power consumption of the LED module 1, for example by directly detecting the current on the converter side. And finally by indirect detection by determining a peak current within the LED converter, which has, for example, an isolated flyback converter or buck converter that is measured via a shunt. The peak current follows the change in the power consumption of the LED module 1.

In summary, the present invention proposes to transmit information from an LED module 1 to an LED converter 10 which allows conclusions to be drawn about operating and / or maintenance parameters to be set on the LED module 1. The operating parameter to be set can be, for example, the target current or the target voltage. For this purpose, a circuit 4 (load modulation circuit) is provided according to the invention on the LED module, which, for example, in a voltage range of a first supply voltage 5a that is not equal to zero and in which an LED path 3 connected to the LED module 1 is non-conductive, a Represents load for the LED converter, and in a voltage range of a second supply voltage 5b, which is not equal to zero and at which a connected LED path 3 is conductive, no load for the LED converter 10 represents. According to the invention, the circuit 4 is only activated temporarily, namely only during a starting phase of the LED light. The load is variable according to a given protocol. For example, a modulated change in load can take place in accordance with the specified protocol. The power consumption is recorded by the LED converter 10, in particular also a change in the power consumption (amplitude, frequency, duty cycle). As a result, the LED converter 10 can determine the operating and / or maintenance parameters. The transmission of this information between the LED module 1 and the LED converter 10 does not require any additional connections (only the connection of the supply voltage). In addition, no interaction with LED module 1 and / or LED converter 10 is necessary. This improves the disadvantages of the known prior art.

Claims (19)

1. LED module (1) having:

   - terminals for an LED converter (10) that supplies the LED module (1) with a supply voltage;

   - additional terminals (2) for an LED series (3);

   - a circuit (4) that can be activated if a predetermined constant current that is less than the rated current of the LED series (3) or a predetermined constant voltage that is less than the forward voltage of the LED series (3) is applied to the LED module (1) at the terminals for the LED converter (10), wherein a start phase begins with the application of the predetermined constant current or of the constant voltage;

   wherein the circuit (4) is designed to represent, upon activation, a variable-current, active power load which produces a repeated change in the power consumption of the LED module (1) according to at least one predetermined protocol,
   wherein the circuit (4) can be deactivated and, upon being deactivated, is designed to not represent an active power load, and
   characterized in that
   the circuit (4) has means for automatically deactivating itself after a predetermined time interval has elapsed since the beginning of the start phase.
2. LED module (1) according to claim 1, wherein
   the circuit (4) is designed to encode at least one operating and/or maintenance parameter of the LED module (1) via the change in the power consumption according to the at least one predetermined protocol.
3. LED module (1) according to claim 1 or 2, wherein
   the at least one predetermined protocol specifies a frequency and/or an amplitude and/or a duty cycle of the change in the power consumption of the LED module (1).
4. LED module (1) according to one of claims 1 through 3, wherein
   the circuit (4) is designed in such a way that the change in the power consumption of the LED module (1) is effected depending on a value of the constant voltage according to one of several predetermined protocols.
5. LED module (1) according to one of claims 1 through 4, wherein
   the circuit (4) comprises a timer circuit (6) which is designed to specify a frequency of the change in the power consumption of the LED module (1).
6. LED module (1) according to one of claims 1 through 5, wherein
   at least one sensor is provided on the LED module (1), which sensor is designed to influence an electrical parameter of the circuit (4).
7. LED module (1) according to claim 6, wherein
   the at least one sensor is a light sensor having a light-dependent resistance, and
   the light sensor is connected to the circuit (4) in such a way that a change in the light-dependent resistance changes the active power load of the circuit (4).
8. System having an LED module (1) according to one of claims 1 through 7 with an LED series (3) and an LED converter (10),
   wherein the LED converter (10) has a high-frequency clocked converter, preferably an isolated flyback converter, and
   the high-frequency clocked converter is operated as a constant current source at least in a time-limited start phase, and
   the LED converter (10) is designed to supply the LED module (1) during the start phase with the predetermined constant current that is less than the rated current of the LED series (3) or with the constant voltage that is less than the forward voltage of the LED series (3),
   wherein the clocked converter is designed to detect a repeatedly changing power consumption of the LED module (1) on the primary side of a transformer of the high-frequency clocked converter during the start phase and
   to determine, based upon the detected power consumption, at least one operating and/or maintenance parameter of the LED module (1).
9. System according to claim 8, wherein the LED converter (10) is designed:

   - to use the at least one determined operating and/or maintenance parameter to adjust or regulate the operation of the LED module (1),

   - to store the at least one determined operating and/or maintenance parameter in an associated memory,

   - to optically and/or acoustically indicate the at least one determined operating and/or maintenance parameter, and/or

   - to send out the at least one determined operating and/or maintenance parameter via a wireless or wired interface, optionally upon an external query.
10. System according to claim 8 or 9, wherein
    the at least one operating and/or maintenance parameter is a rated current through an LED series (3) connected to the LED module (1), an aging parameter, an operation time duration, and/or a spectrum of a light emitted by the LED series (3).
11. System according to one of claims 8 through 10, wherein the LED converter (10) is designed
    to identify the LED module (1) on the basis of the at least one determined operating and/or maintenance parameter.
12. System according to one of claims 8 through 11, wherein the LED converter (10) is designed
    to selectively switch between a mode for detecting a power consumption of the LED module (1) and a mode for illuminating an LED series (3) connected to the LED module (1) by adjusting a first supply current or a second supply current for the LED module (1).
13. System according to one of claims 8 through 12, wherein the LED converter (10) is designed
    to carry out a voltage measurement for directly detecting the power consumption of the LED module (1).
14. System according to one of claims 8 through 12, wherein the LED converter (10) is designed
    to carry out an indirect detection of the power consumption of the LED module (1).
15. System according to claim 14, wherein the LED converter (10) is designed
    to detect a change in the power consumption of the LED module (1) through a change of a duty cycle of a clocking of the LED converter (10).
16. System according to one of claims 8 through 15, wherein the LED converter (10) is designed

    - to discharge a capacitor (11) via a load of the LED module (1),

    - to determine a discharge current of the capacitor (11) directly, or indirectly via a discharge time, and

    - to determine the at least one operating and/or maintenance parameter of the LED module (1) on the basis of said discharge current.
17. System according to one of claims 8 through 16, wherein the system is an LED luminaire.
18. Method for transmitting information from an LED module (1) to an LED converter (10), the LED converter (10) having a high-frequency clocked converter, preferably an isolated flyback converter or resonant half-bridge converter, and
    the LED module (1) having terminals for the LED converter (10) that supplies the LED module (1);
    wherein, in a first step, the LED converter (10) supplies the LED module (1) with a predetermined constant current that is less than the rated current of the LED series (3) or with a predetermined constant voltage that is less than the forward voltage of the LED series (3), wherein a start phase begins with the application of the predetermined constant current or of the constant voltage;
    wherein, in a second step, a circuit (4) of the LED module (1), which is designed to represent an active power load upon activation, is activated if the constant current or the constant voltage is applied, wherein
    the activated circuit (4) of the LED module (1) effects a repeated change in the power consumption of the LED module (1) according to at least one predetermined protocol, and wherein
    the LED converter (10) detects a repeatedly changing power consumption of the LED module (1) during the start phase; and
    wherein, in a third step, the circuit (4) of the LED module (1) is deactivated, wherein the deactivated circuit (4) does not represent an active power load,
    characterized in that
    the circuit (4) automatically deactivates itself in the third step after a predetermined time interval has elapsed since the beginning of the start phase.
19. Method according to claim 18,
    wherein the converter (10) determines at least one operating and/or maintenance parameter of the LED module (1) on the basis of the detected power consumption of the LED module (1).

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