EP2842391B1 - Operating device for a lamp and method - Google Patents

Description

The invention relates to an operating device for supplying a lighting device and a method for operating such a control device. The invention particularly relates to such devices and methods in which a light source, in particular a light source, which comprises one or more light emitting diodes, with a so-called SELV ("Separated Extra Low Voltage" or "Safety Extra Low Voltage") - device with Energy is supplied.

Operating devices for light sources, for example LED converters, are used to supply the light source with electrical energy. Corresponding electrical circuits are provided with which the operating device, to which, for example, the mains voltage is supplied as an input voltage, reaches a power supply of the luminous means with a specific voltage, a specific current or a specific power. In general, it is desirable to make an operating device configurable so that it can be used for different lamps. For this purpose, a user-defined adjustment possibility can be provided with which the operating device can be switched, for example, between different output currents and / or output powers and / or output voltages.

For safety reasons, operating devices for lighting devices have a potential separation, wherein a galvanically decoupled energy transmission takes place between a region with a higher voltage and a region with a lower voltage. The galvanically decoupled energy transfer can be achieved by using a transformer or other transformer. Such a galvanic isolation or potential separation is required for safety reasons in operating devices for lighting to separate a SELV range by a so-called potential barrier or SELV barrier of Breichen with higher supply voltage, in particular mains voltage. For safety reasons, it is often required that at least the elements adjustable by the end user be provided in the SELV area of the operating device are. If, for safety reasons, setting elements are provided in the SELV range, the SELV range can have a corresponding evaluation logic for determining the setting selected by the user. This setting can be transmitted from the secondary logic via a digital interface over the SELV barrier to be used by control logic in the non-SELV range. The use of a corresponding logic in the SELV range, ie on the secondary side of a transformer, however, is associated with additional costs and additional effort.

LED modules themselves may have resistors which serve as a signature for which class the LEDs used belong. The resistors can be read by a built-in logic module in the LED module and used to control switches in the LED module. The logic integrated into the LED module may have a data interface to return data to other devices. Even with such approaches, the use of appropriate logic for reading the signature in the SELV area, for example in the LED module, is required.

The DE 10 2008 016 752 A1 , which serves as a basis for the preamble of the independent claims, discloses a control gear for a lighting means.

The DE 10 2008 033 176 A1 , the EP 2 385 746 A1 , the DE 20 2010 003 913 U1 and the EP 1 411 750 A1 each reveal LED modules that have resistors or other coding elements that can be read by an operating device.

There is a need for devices and methods that provide improvements to the stated objectives. In particular, there is a need for devices and methods in which easy adjustability of operation, for example to different output currents, can be achieved, even if no data interface is provided.

According to the invention, an operating device and a method are given with the features specified in the independent claims. The dependent claims define embodiments.

According to embodiments of the invention, an operating device on a primary-side circuit and one of them galvanically isolated secondary side. The primary-side circuit may, for example, be the non-SELV region of the operating device. The secondary side can be the SELV range of the control gear. On the secondary side, a selection device with an impedance provided by a user is provided can be set to a plurality of different impedance values. The operating device is set up in such a way that, at a measuring point in the primary-side circuit, a measured quantity which depends on the set impedance value can be detected. The control device, which is provided on the non-SELV side, is set up to detect the set impedance value as a function of the measured variable detected in the primary-side circuit. The controller is configured to control the operating device in response to the detected set impedance value.

In the case of the operating device, the detection of the set impedance value is based on a measured variable which is present at a measuring point of the primary-side circuit, i. in the non-SELV range. The control device, which controls the operating device and which is provided in the non-SELV range, can detect the user-defined impedance value set via the selection device on the secondary side and control the operating device accordingly.

In the operating device and method according to embodiments, it is not necessary to provide a separate logic for detecting the set impedance value on the secondary side and / or a data interface between a secondary-side logic and the control device on the primary side to digital data concerning the set impedance value via a SELV -Barriere back.

The detection of the measured variable in the primary-side circuit can be done in different ways. The operating device has a transformer in order to transfer energy from the primary-side circuit to the secondary side for supplying energy to the luminous means. The operating device includes a further inductance independent of the transformer, which is inductively coupled to the impedance. For this purpose, a further transformer with a first, primary-side inductance and an inductively coupled second, secondary-side inductance can be provided. The second inductance may be connected in series with the impedance that can be set to different impedance values. One by the first Inductance flowing current can be used as a measure on the basis of the set impedance value is detected.

In order to detect the set impedance value, the current flowing through the first inductance can be compared with a reference, for example by means of a resistor, at which the falling voltage is monitored. The time in which, after applying a voltage to the first inductor, the current flowing through the first inductor has reached a reference can be determined. The time thus determined can be used as an indicator of the set impedance value. The determination of the time can take place in different ways, for example by A / D conversion of the measured variable and digital processing. Alternatively, the measured variable can be supplied to one input of a comparator and the reference to another input of the comparator, wherein the control device receives an output signal of the comparator and, based thereon, determines the time in which, after application of a voltage to the first inductance, the current flowing through the first inductance Current has reached the reference.

The control device can determine map-based operating parameters for the operating device, which correspond to the set impedance value. Depending on the determined time in which, after applying a voltage to the first inductance, the current flowing through the first inductance has reached the reference, the control device can determine one or more operating parameters by means of a table query. A corresponding one or more maps may relate the detected set impedance value to one or more operating parameters.

The operating device may include, for example, a power factor correction circuit and a half-bridge drive resonant converter. The operating parameters, which the control device determines as a function of the set impedance value, may include at least one operating parameter of the power factor correction circuit. The at least one operating parameter of the power factor correction circuit may be a switching frequency, an on-time ("tone-time") and / or an off-time ("Toff-time") of a controllable power switch the power factor correction circuit include. Alternatively or additionally, the controller may select an operating mode for the power factor correction circuit depending on the set impedance value. For example, depending on the set impedance value, the power factor correction circuit may be controlled so that CCM (Continuous Conduction Mode) operation, BCM (Borderline Conduction Mode or Boundary Conduction Mode) operation or DCM (Discontinuous Conduction Mode ") operation of the power factor correction circuit is used.

The operating parameters that the controller determines based on the set impedance value may include at least one operating parameter of the resonant converter. The at least one operating parameter of the resonant converter may include a switching frequency, an on time ("tone time"), an off time ("Toff time") and / or the dead time of the switches of the half bridge. Alternatively or additionally, the controller may select an operating mode for the LLC resonant converter depending on the set impedance value. For example, depending on the set impedance value, the LLC resonant converter may be controlled to selectively perform a pulsed operation in which both switches of the half-bridge remain switched off for a time interval or non-pulsed half-bridge drive operation.

The different impedance values can be assigned to different output currents. Depending on the detected set impedance value, the controller may control the operating device to generate the output current associated with the set impedance value.

The impedance on the secondary side, which can be set to the plurality of different impedance values, can be arranged such that it is not electrically coupled to the output via which the energy supply of the luminous means takes place. The impedance on the secondary side, which can be set to the plurality of different impedance values, can be arranged such that it is not electrically coupled to a first transformer, which transmits energy to the secondary side for supplying energy to the luminous means.

The variable impedance selector may comprise a user-operable element. For example, the selection device may comprise a dip switch or a plurality of dip switches with which a plurality of resistors can be selected. The selector may also comprise another adjustable resistor, for example a potentiometer adjustable with a sliding element, bridge or knob.

The operating device may be designed so that detection of the set impedance value is selectively carried out only in certain operating phases of the operating device. The operating device may be configured so that the detection of the impedance value is carried out only in a predetermined time interval after starting the operating device. For example, if a second transformer is used to inductively detect the set impedance value, a voltage may be selectively applied to the primary side inductance of the second transformer only in the predetermined time interval to perform the detection of the set impedance value.

The control device may be a semiconductor integrated circuit, in particular an application-specific integrated circuit (ASIC). The control device may have an input which is coupled to the measuring point in the primary-side circuit, at which the measured variable for detecting the set impedance value is detected. The corresponding input of the control device can be configured such that the input signal received there is further processed only for detection of the set impedance value. For example, the signal received at the corresponding input of the control device can be processed selectively only in the predetermined time interval in which the set impedance value is to be detected after starting the operating device.

The operating device can be an LED converter.

According to a further embodiment, a lighting system is specified, which comprises the operating device and a light source coupled thereto. The lighting means may comprise one or more light-emitting diodes (LEDs). The LEDs may include inorganic and / or organic LEDs. The LEDs can be integrated into an LED module that is separate from the LED converter. The lighting system may further comprise a central controller arranged to transmit dimming commands to the LED converter or to evaluate signals transmitted by the LED converter.

According to a further exemplary embodiment, a control device for controlling an operating device for a lighting device, in particular for controlling an LED converter, is specified. The control device comprises an input for receiving a signal that depends on a measured variable detected in a non-SELV range of the operating device. The control device is set up to detect an impedance value that is set on a secondary side of the operating device depending on the signal.

The control device can be set up in order to determine, depending on the signal at the input, after which time the measured variable detected in the non-SELV region of the operating device reaches a reference. The control device can be set up to determine map-based operating parameters that are assigned to the set impedance value.

Embodiments of the method for operating an operating device according to embodiments and the effects thus achieved correspond to the embodiments described with reference to the devices. The method can be carried out automatically with an operating device according to an embodiment.

• FIG. 1 zeigt eine schematische Darstellung eines Beleuchtungssystems mit einem LED-Konverter nach einem Ausführungsbeispiel.
• FIG. 2 zeigt ein Schaltbild eines Betriebsgeräts nach einem Ausführungsbeispiel.
• FIG. 3 illustriert eine Implementierung einer Auswahleinrichtung bei Betriebsgeräten nach Ausführungsbeispielen.
• FIG. 4 illustriert eine Zeitabhängigkeit einer in der primärseitigen Schaltung erfassten Messgröße zur Erkennung des auf der Sekundärseite gesetzten Impedanzwerts.
• FIG. 5 zeigt ein Schaltbild eines Betriebsgeräts nach einem weiteren Ausführungsbeispiel.
• FIG. 6 zeigt ein Flussdiagramm eines Verfahrens nach einem Ausführungsbeispiel.
• FIG. 7 zeigt eine Blockdiagrammdarstellung einer Steuereinrichtung, die bei Betriebsgeräten nach Ausführungsbeispielen verwendet werden kann.
• FIG. 8 zeigt ein Schaltbild eines Betriebsgeräts nach einem weiteren Ausführungsbeispiel.
• FIG. 9 zeigt ein Schaltbild eines Betriebsgeräts nach einem weiteren Ausführungsbeispiel.

The invention will be explained in more detail with reference to the accompanying drawings with reference to preferred embodiments.

• FIG. 1 shows a schematic representation of a lighting system with an LED converter according to an embodiment.
• FIG. 2 shows a circuit diagram of an operating device according to an embodiment.
• FIG. 3 illustrates an implementation of a selection device in operating devices according to embodiments.
• FIG. 4 illustrates a time dependence of a measured variable detected in the primary-side circuit for detecting the impedance value set on the secondary side.
• FIG. 5 shows a circuit diagram of a control device according to another embodiment.
• FIG. 6 shows a flowchart of a method according to an embodiment.
• FIG. 7 shows a block diagram representation of a control device that can be used in operating devices according to embodiments.
• FIG. 8th shows a circuit diagram of a control device according to another embodiment.
• FIG. 9 shows a circuit diagram of a control device according to another embodiment.

The features of the various embodiments described below can be combined with each other, unless this is expressly excluded in the following description.

FIG. 1 shows an illumination system 1, in which an operating device 2, according to one embodiment, a lighting means 3 with energy. The luminous means 3 may comprise a plurality of light-emitting diodes (LEDs), which may be inorganic and / or organic LEDs. The operating device 2 can be used as an LED converter be designed. The LED converter 2 may be designed such that it outputs a constant current whose current intensity can be selected via a selection device with an impedance 15 which can be set to a user-defined value to a plurality of impedance values. The LED converter 2 may include an interface for communication with a central control unit and be configured to receive commands via the interface and / or output status messages.

The LED converter 2 may be configured as a SELV device in which a non-SELV region 7 and a SELV region 8 are separated by a SELV barrier 9. There is a corresponding potential separation. The non-SELV region 7 and the SELV region 8 may be galvanically isolated. A primary-side circuit, i. the non-SELV area 7, may include an AC / DC converter 10. The AC / DC converter 10 may be configured to be coupled on the input side with a mains voltage. The AC / DC converter 10 may include a rectifier and Power Factor Correction (PFC) circuit. The AC / DC converter 10 provides a bus voltage Vbus to a DC / DC converter having an input side 11 and one of them electrically isolated output side 13. Galvanic isolation is achieved by a transformer 12 or other converter.

The LED converter 2 has a control device 14. The control device 14 may be a semiconductor integrated circuit, in particular an application-specific integrated circuit (ASIC). The controller 14 is in the non-SELV area 7, i. as part of the primary-side circuit provided.

The LED converter 2 is designed so that the control device 14, depending on a measured variable which is detected at a measuring point 17 in the non-SELV range 7, recognizes to which impedance value the impedance 15 which can be set to a plurality of impedance values is set. The plurality of impedance values may, for example, be associated with different output currents. The controller 14 controls the LED converter 2 automatically depending on the detected set impedance value to provide the output current associated with the set impedance value.

The selection device with the impedance 15, which can be set in a user-defined manner to a plurality of impedance values, may include dip switches, for example. To detect the set impedance value, the impedance 15 can be coupled via a readout circuit to the measuring point 17 in the non-SELV range 7. The readout circuit may comprise a second transformer in which a first coil in the non-SELV region 7 is inductively coupled to a second coil in the SELV region 8 to detect the set impedance value. The second transformer acts as an isolator 16 for bridging the SELV barrier 9 in order to detect the set impedance value via the measured variable detected at the measuring point 17. As schematically in FIG. 1 As shown, the impedance 15 may be provided so as not to be electrically coupled to the output side 13 that supplies the lighting means 3 with power.

The control device 14 may be configured to monitor the time-dependent behavior of the measured variable detected on the primary side at the measuring point 17 in order to determine the secondary-side set impedance value. The controller 14 may be configured to determine a time for detecting the secondary side set impedance value, in which a current through a primary-side coil of the second transformer, which couples the measuring point 17 with the impedance 15, to a reference increases.

In the case of the LED converter 2, the impedance value set on the secondary side in the SELV region 8 is detected as a function of the measured variable detected at the measuring point 17 in the primary-side circuit. It is not necessary to provide a separate logic for reading out the set impedance value in the SELV range and / or a data interface for transmitting corresponding data via the SELV barrier 9.

Operating devices and methods according to exemplary embodiments, in which the control device 14 provided on the primary side is set up to control the impedance value set in the SELV region 8 as a function of a primary side detected To detect the measured variable and to control the operating device accordingly, with reference to FIG. 2-9 described in more detail.

FIG. 2 is a circuit diagram of a control gear 2 according to an embodiment. The operating device 2 comprises a primary-side circuit 7 and a secondary side 8. There is potential separation between the primary-side circuit 7 and the secondary side 8. For separation, a transformer with a primary coil 28 and a secondary coil 29 may be provided. The operating device 2 can be configured as an LED converter. The secondary side 8 may be a SELV region, which is separated from the primary-side circuit 7 by a SELV barrier 9. The operating device 2 can further (in FIG. 2 not shown components), for example, a rectifier for rectifying an AC voltage, which may be the mains voltage, and a power factor correction circuit for smoothing the rectified AC voltage.

Depending on the configuration of the operating device, the primary-side circuit 7 may comprise different components, for example a resonant converter with full or half-bridge control. The resonant converter may comprise, for example, a half-bridge circuit 21 having a resonance circuit connected to the half-bridge, for example an LLC resonant circuit. Other embodiments are possible, for example the use of a full bridge circuit or the use of a converter without a resonant circuit. The circuit 21 is powered by a supply voltage Vbus which may be provided, for example, by a power factor correction circuit. In operation, the controller 14 may, for example, control switches of the half-bridge circuit 21. In this case, each of the switches can each be switched with the same switching frequency. The control device 14 controls the first switch and the second switch of the half-bridge circuit so that at most one of the two switches is turned on at any one time. For example, to adapt to different user-selected output currents, the controller 14 may change the switching frequency to adjust the value of the frequency-dependent transfer function or gain.

The secondary side 8 may have a secondary coil 29 downstream rectifier, which may be formed for example by a first diode 31 and a second diode 32. A center of the secondary coil 29 may be coupled to an output of the secondary side 8. Ends of the secondary coil 29 may be coupled to the output 35 via the diodes 31 and 32. To smooth the output current, an inductive element 33, for example a coil, can be provided, through which the output 35 current is supplied. A capacitor 34 may be connected between the outputs of the rectifier. Due to the design of the secondary side 8 with the inductive element 33, the operating device 2 can be operated in particular as a constant current source.

In order to make the operating device 2 configurable by the end user, a selection device is provided, which comprises an impedance 15 which can be set to a plurality of different impedance values. The operating device 2 has a second transformer, which comprises a first inductance 22 and a second inductance 23. Since the second transformer is used only to read out the set impedance value of the impedance, the first inductance 22 and / or the second inductance 23 of the second transformer can also be designed so that only one wire turn or one coil with only a few turns of wire is used. Alternatively, parasitic inductances can also form the second transformer.

The first inductor 22 of the second transformer and a resistor 24 used as a sense resistor may be connected in series with a known constant voltage. For example, the series connection of first inductor 22 and resistor 24 may be coupled to the output of a power factor correction circuit, which also provides the supply voltage for the DC / DC converter of the operating device 2. A controllable switch 25, which may be designed, for example, as a field effect transistor (FET), in particular as a MOSFET, is connected in series with the series circuit of inductance 22 and resistor 24 in order to selectively detect the impedance value of the impedance 15 only in certain Operating conditions or time intervals to perform. The controllable switch 25 can also be controlled by the control device 14. The controller 14 may include a corresponding terminal 42 for driving a signal ctrldet to control the switch 25.

The effective load on the second transformer depends on which of the plurality of impedance values the impedance 15 is set. Accordingly, the impedance value to which the impedance 15 is set may be detected based on a measurand detected at the first inductor 22 of the second transformer or at another suitable location of the primary-side circuit 7. By way of example, the current idet flowing through the first inductance 22 can be used as the measured variable. This can be detected as the drop across the measuring resistor 24 voltage at the measuring point 17 when the switch 25 is switched to the on state.

The control device 14 has an input 41. The input 41 is coupled to the second transformer so as to detect the impedance value of the impedance 15 set on the secondary side 8 as a function of the measured variable. The control device 14 can evaluate the signal received at the input 41 in order to detect the set impedance value depending thereon. This can be done in different ways. By way of example, the control device 14 can determine a time which elapses until the measured variable idet detected on the primary side reaches a reference value after switching of the switch 25 into the on state. Depending on the determined time, the control device 14 can determine operating parameters based on the map, based on which the control device 14 carries out the control of circuit elements of the primary-side circuit. Depending on the measured variable detected on the primary side, the control device 14 can output control signals via at least one further connection 43 in order to control the operating device in accordance with the secondary-side set impedance value. In particular, the control device 14 can control elements of the primary-side circuit 7 such that an output current and / or an output power is provided at the output 35 of the secondary side 8, which is assigned to the impedance value set on the secondary side.

The procedure for detecting the impedance value set on the secondary side can be carried out selectively by the control device 14 only at certain operating phases or time intervals, for example when starting the operating device. The controller 14 may selectively switch the switch 25 to the on state when the secondary side set impedance value is to be detected. The control device 14 can switch the switch 25 into the on state, for example after starting the operating device, and automatically switch back to the off state after a predetermined time interval and / or when the measured variable idet detected on the primary side has reached the reference. Via a connection 42, the control device 14 can control a corresponding control signal ctrldet for controlling the switch 25.

The selection device with the adjustable impedance 15 can have different configurations. The selection means may comprise one or more mechanically operable elements, for example dip-switches.

FIG. 3 FIG. 10 illustrates an embodiment of the variable impedance selection device 15 that may be used on the secondary side of the operating devices of embodiments. The selector may comprise a plurality of dip switches 51, 53, 55, 57. The selector may comprise a plurality of different resistors 52, 54, 56, 58, each of the resistors being connected in series with one of the dip switches 51, 53, 55, 57, respectively. The plurality of series circuits of dip-switches and associated resistor are connected in parallel with each other. By setting the dip-switches 51, 53, 55, 57, a plurality of discrete impedance values can be set. The corresponding total resistance can be detected via the inductors 22, 23 at the primary-side measuring point 17. The resistors 52, 54, 56, 58 may be selected such that each of the various possible switch positions of the entirety of the dip switches 51, 53, 55, 57 is respectively assigned to exactly one of a plurality of impedance values. That is, the resistors 52, 54, 56, 58 may be selected so that each of the adjustable impedance values for only one switch position of the dip switches 51, 53, 55, 57 can be obtained. In particular, the resistors 52, 54, 56, 58 from each other have different resistance values.

Other configurations of the selection device with the impedance that can be set to different impedance values are possible. For example, the selector that allows for user-selected selection of one of multiple configurations of the driver 2 may include a potentiometer or other adjustable resistor.

FIG. 4 illustrates the determination of the impedance depending on the measured variable detected on the primary side in operating devices according to exemplary embodiments. FIG. 4 FIG. 12 shows a plot 60 of time-dependent waveforms of the current through the first inductor 22 used to inductively read out the set impedance value of the impedance 15. The time zero point corresponds to the point in time at which detection of the secondary-side set impedance value is initiated by switching the switch 25 to the on-state.

The controller 14 may be configured to determine the time at which the current flowing through the first inductor 22 reaches a reference value 61 after switching the switch 25 to the on state. From the time to reach the reference value 61 can be deduced the impedance value. This makes a particularly robust detection of the set impedance value possible.

FIG. 4 FIG. 12 shows current waveforms 62-65 as a function of time resulting after switching the switch 25 to the on state. Shown is the time course in a short time window after turning on the switch 25. The primary side detected current increases in each case substantially linear. For different impedance values, to which the impedance 15 is set on the secondary side, each results in a different current offset when turning on the switch 25, which is due to the different load on the second inductor 23 of the second transformer.

For a first impedance value, the current 62 reaches the reference value 61 after a time 66. For a second impedance value that is greater than the first one For a third impedance value greater than the second impedance value, the current 64 reaches the reference value 61 after a time 68. For a fourth impedance value greater than the third Impedance value, the current 65 reaches the reference value 61 after a time 69.

The control device determines the time that elapses until the reference value 61 has been reached, and can deduce the set impedance value as a function thereof. Operating parameters, on the basis of which the control of the primary-side circuit of the operating device takes place, can be determined as a function of the time that elapses until the reference value 61 is reached. This can be done, for example, map-based.

The reference 61 may be chosen so that for each of the adjustable impedance values, which is associated, for example, different output currents and / or output powers of the operating device, the reference 61 is achieved within a relatively short period of time. In particular, the reference 61 may be selected such that, for each of the adjustable impedance values, the reference 61 is reached within a time period that is shorter than a duration of an initialization phase of the operating device 2. As a result, the user-defined configuration of the operating device 2, which is determined by the set impedance value of the impedance 15, can be detected within a short time interval after starting the operating device 2. The reference 2 may be chosen such that for each of the adjustable impedance values, the reference 61 is reached within a time period which may, for example, be less than one millisecond, for example less than 0.1 milliseconds and, for example, less than 0.01 milliseconds.

The determination of the time in which the current through the inductor 22 reaches the reference can be done in different ways. For example, the measured variable detected at the measuring point 17 can be provided as an analog signal or after A / D conversion as digital data to the input 41 of the control device 14. The controller 14 may computationally compare the sampled sample idet to the reference to determine when primary measured variable reaches the reference. In a further exemplary embodiment, the primary-side circuit 7 may comprise a comparator, on the input side of which the detected measured variable is idet and the reference is supplied.

FIG. 5 illustrates such an embodiment of the operating device 2. Elements and devices that correspond in function and / or design elements and devices, with reference to FIG. 1-3 have been described are denoted by the same reference numerals.

In the operating device 2 of FIG. 5 a comparator 26, the primary side detected measured variable idet is supplied, which represents the current in the inductance 22, while the switch 25 is switched to the on state. An output signal cmp of the comparator 25 has a signal edge as soon as the measured variable idet reaches the reference ref. The controller 14 may start timing when the control signal ctrldet is driven to close the switch 25, and may terminate the timing if the signal edge is detected in the output signal cmp of the comparator 26. To determine the appropriate time interval, for example, the output of the control signal to close the switch 25 as a start signal to start a counter. The signal edge in the output signal cmp of the comparator 26 can stop the counter. The counter can be designed as part of the control device 14, in particular as part of a semiconductor integrated circuit.

FIG. 6 FIG. 10 is a flowchart of a method 70 according to one embodiment. The method can be carried out automatically with the operating device according to an embodiment, wherein the control device 14 performs the corresponding control and evaluation functions.

At 71, the operating device is started. After starting the operating device, a measured variable in the primary-side circuit, ie in the non-SELV range of the operating device, can be detected at 72. The measured variable can represent a current through a first inductance with which an impedance value set on the secondary side is determined by inductive coupling.

The sensing of the measure at 72 may be selectively performed for a time interval whose length is, for example, shorter than the time that elapses before the operating device transitions to continuous operation upon startup.

At 73, the measurand is evaluated to detect the set impedance value. The detection of the set impedance value may consist in the determination of the time after which the current through the first inductance has reached a reference value. The determination of the secondary side set impedance value by determining this time is particularly robust.

At 74, at least one operating parameter of the operating device is determined on the basis of the measured variable detected on the primary side. This can be done based on a map, for example by at least one table query. At least one characteristic diagram can be used in which an operating parameter of the operating device is stored as a function of the time determined at 73 at which the current through the first inductance reaches the reference. The corresponding operating parameter can be read based on the time determined at 73. Several maps may also be used, for example, a first map that relates the time determined at 73 to one of a plurality of impedance values, and a second map that relates the impedance values to operating parameters, respectively. The operating parameters ascertained at 74 may be selected such that they are assigned to different output currents and / or output powers and / or output voltages of the operating device.

At 75, the controller controls the operating device in accordance with the operating parameters determined at 74. The controller may control at least one power switch of the primary side circuit to adjust an output current of a plurality of selectable output currents associated with the detected set impedance value. Alternatively or additionally, the control device may control at least one power switch of the primary-side circuit such that an output power is set from a plurality of selectable output powers, which is assigned to the set impedance value. Alternatively or additionally, the control device at least controlling a power switch of the primary side circuit to set an output voltage of a plurality of selectable output voltages associated with the set impedance value. Controlling the operating device at 75 may include controlling a power factor correction circuit and / or controlling switches of a resonant converter.

Such a measurement according to the embodiment of Fig. 6 can also be done once or repeatedly during operation.

FIG. 7 FIG. 12 is a block diagram representation of a controller 14 that may be used with operating devices of embodiments. The control device 14 can be designed as a semiconductor integrated circuit, in particular as an application-specific integrated semiconductor circuit (ASC).

The controller 14 has control logic 77 for generating and outputting control signals through outputs 43-45 for controlling primary side switching of the operating device. For example, a control signal for a power switch of a power factor correction circuit, which is generated by the control logic 77, can be output via the output 43. By means of the outputs 44, 45, for example, control signals for a half-bridge drive which are generated by the control logic 77 can be output. The controller 14 may include inputs to monitor various sizes of the primary-side circuit. For example, at an input 46 information about a bus voltage provided by a power factor correction circuit or through a current in a half-bridge circuit may be received.

The control device 14 has an additional input 41, which is coupled to a measuring point of the primary-side circuit for detecting the measured variable, which depends on the impedance value set on the secondary side. Depending on the input signal at the capture 41, a time determination unit 78 may determine a time duration that is required until the measured variable detected on the primary side reaches a reference value. The unit 78 to Time determination may include a counter which is stopped when the input signal at the input 41 indicates that the measured variable detected on the primary side has reached the reference value. The counter can be started, for example, when an output 42 is used to control a control signal with which the switch 25 is switched to the on state in order to initiate the detection of the set impedance value.

The control logic 77 may perform at least one map exhaustion of a map 79 depending on the determined time. As a result, at least one operating parameter can be determined according to which the control logic 77 generates control signals in order to control components of the primary-side circuit of the operating device.

Other configurations of the controller 14 may also be used. For example, a starting point of the time determination can also be determined depending on when a bus voltage, which is applied to the first inductance 22 for reading out the impedance set on the secondary side, reaches a specific threshold value. It is also not necessary for the controller 14 to determine the impedance set on the secondary side in accordance with a time required for the measured quantity to reach a reference value. By way of example, the control device 14 can use the measured variable, which is detected at a fixed point in time during the starting phase of the operating device, directly as an indicator for the secondary-side set impedance value.

The technique used in embodiments of the invention to determine the impedance value manually set by a user in a SELV range of an operating device as a function of a measured variable detected in the primary-side circuit and correspondingly control the operating device such that an output current corresponding to the set impedance value is generated, for example can be used in principle for control gear for bulbs, in which there is potential separation. A possible embodiment of such a control gear will be described in more detail below to further illustrate which operating parameters, for example, adapted can be to control the operating device according to the secondary side set impedance value.

FIG. 8th illustrates an embodiment of the operating device 2 according to an embodiment. Elements and devices corresponding in function and / or design to elements and devices described with reference to FIG. 1-7 have been described are denoted by the same reference numerals.

In the operating device 80, the detection of an impedance value to which an impedance 15 is set on the secondary side 8 may be dependent on a measured variable in the primary side circuit as described with reference to FIG FIG. 1-7 described described. In particular, a first coil 22 of a second transformer can be used to perform a galvanically decoupled detection of the impedance value, to which an impedance 15 is set on the secondary side 8.

The operating device can have a (in FIG. 8th not shown), rectifying an input voltage of the operating device, such as a mains voltage, and providing the rectified AC voltage Vin to a power factor correction circuit 81 of the primary side circuit 80. The power factor correction circuit 81 may be configured as a boost converter or boost converter. The rectified AC voltage Vin is supplied to an inductance or coil 83. The inductor 83 is connected in series with a diode 85 between the input terminal and an output of the power factor correction circuit 81. The output of the power factor correction circuit 81 is connected to an input of the converter 82 and provides the voltage Vbus generated by the power factor correction circuit 81 as the supply voltage to the converter 82.

The power factor correction circuit 81 has a charging capacitor 86 at the output of the power factor correction circuit 81. Connected to the connection between the inductor 83 and the diode 85 is a controllable electronic switch 84, which is a power switch and which can be designed, for example, as a field-effect transistor (FET), in particular as a MOSFET. The switch 84 may be connected to ground via a shunt resistor (not shown). The switch 84 is switched by the control device 14 of the operating device in the on state and the off state. The control device 14 has a corresponding output 43 for controlling a control signal, with which, for example, the gate voltage of the switch 84 can be controlled.

When the switch 84 is switched on, the inductance 83 is connected to ground via the switch 84, the diode 85 blocking, so that the inductance 83 is charged and energy is stored in the inductance 83. On the other hand, if the switch 84 is turned off, i. open, the diode 85 is conductive, so that the inductance 83 can discharge via the diode 85 in the charging capacitor 86 and the stored energy in the inductance 83 is transferred to the charging capacitor 86. The power factor correction is achieved by repeatedly turning on and off the switch 84, where the switching frequency for the switch 84 is typically much greater than the frequency of the rectified AC voltage Vin.

The output voltage Vbus of the power factor correction circuit 81 can be detected via a voltage divider with resistors 87, 88 and fed to an input 46 of the control device 14. The output voltage Vbus is supplied to the converter 82 in the illustrated operating device. At the same time, the circuit having the first inductance 22 for detecting the secondary side set impedance value may be coupled to the output of the power factor correction circuit 81, so that the output voltage Vbus of the power factor correction circuit 81 may be used as a constant voltage for reading the set impedance value via the second transformer.

For example, the converter 82 may be configured as an LLC resonant converter with a half-bridge circuit. The half-bridge circuit has two controllable switches 91, 92, which can be controlled by the control device 14. The switches 91, 92 can be designed as FETs, in particular as MOS-FETs. At a shunt resistor 93, one may be in the low potential side the half-bridge flowing current iHB be monitored, for example, to perform an overcurrent shutdown automatically. A resonant circuit, which may be configured as a series resonant circuit, may be connected to a node between the switches 91, 92. The resonant circuit may be, for example, an LLC series resonant circuit comprising two inductors 28, 94 and a capacitor 95. An inductance of the LLC resonant circuit may be the primary coil 28 of the first transformer, with which energy is transmitted from the primary-side circuit 80 to the secondary side 8 for supplying energy to the luminous means. The switches 91, 92 are switched alternately by the control device 14. By adjusting the switching frequency and / or the on-time ("tone-time") of the switches 91, 92, the gain of the LLC resonant converter can be adjusted.

The controller 14, which may be configured as an ASIC or other integrated circuit, may set various operating parameters for controlling the power factor correction circuit and / or the converter 82 depending on the set impedance value of the impedance 15, which is detected based on the primary detected sensed idetet. The operating parameters that the controller determines based on the set impedance value and used to appropriately drive switches of the primary-side circuit 80 may include at least one operating parameter of the power factor correction circuit 81. The at least one operating parameter of the power factor correction circuit may include a switching frequency, an on time ("tone time") and / or an off time ("Toff time") of the controllable power switch 84 of the power factor correction circuit 81. Alternatively or additionally, the controller 14 may select an operating mode for the power factor correction circuit 81 depending on the set impedance value. For example, depending on the set impedance value, the power factor correction circuit 81 may be controlled to selectively provide continuous conduction mode (CCM), borderline conduction mode (Borderline Conduction Mode) operation, or DCM (FIG. Discontinuous Conduction Mode ") operation of the power factor correction circuit 81 is used. The operating parameters that the controller 14 determines depending on the set impedance value and the corresponding Driving switches used by the primary-side circuit 80 may include at least one operating parameter of the LLC resonant converter 82. The at least one operating parameter of the LLC resonant converter 82 may include a switching frequency, an on time ("tone time"), and / or an off time ("Toff time") of the switches of the half bridge. Alternatively or additionally, the controller may select an operating mode for the LLC resonant converter 82 depending on the set impedance value. For example, depending on the set impedance value, the LLC resonant converter 82 may be controlled to selectively perform pulsed operation or non-pulsed half-bridge drive operation. As a result, the control device 14 can control the operating device such that an output current assigned to the secondary side impedance value and / or an output power assigned to the secondary side impedance value and / or an output voltage assigned to the secondary side impedance value are provided at the secondary side output 35.

Other embodiments of the operating devices according to embodiments can also be used. For example, other types of transducers can be used.

The procedure for recognizing the secondary-side set impedance value may be selectively carried out at a certain time interval, for example when the operating device is started. To initiate and terminate detection, for example, the switch 25 may be controlled by the controller. In further embodiments, the switch 25 may also be omitted. If the detection of the secondary side set impedance value includes determining the time duration until the measured variable detected on the primary side reaches a reference, the control device can determine the zero point for the time determination by monitoring the supply voltage that is applied to the first inductance 22. If the output voltage of the power factor correction circuit is used as the supply voltage of the first inductance 22 for reading out the set impedance value, this is anyway provided at one of the inputs of the control device for processing and processed by the control device 14. If the switch 25 is provided, the procedure for detecting the secondary side set impedance value may be terminated other than by the controller 14, as exemplified by FIG FIG. 9 is described.

FIG. 9 illustrates an embodiment of the operating device 2 according to a further embodiment. Elements and devices corresponding in function and / or design to elements and devices described with reference to FIG. 1-8 have been described are denoted by the same reference numerals.

The primary-side circuit 100 has a first inductance 22, with which the impedance value set on the secondary side is determined. A power switch 107 is connected in series with the first inductor 22. Via a voltage divider with resistors 103, 104, a charging capacitor 105 can be charged. One terminal of the charging capacitor 105 is connected to the gate of the circuit breaker 25. A Zener diode 106 may be used to protect the power switch 25. The charging capacitor 105 and the resistors 103, 104 are configured such that the charging capacitor 105 is charged after a period in which the detection of the current through the first inductance 22, which is required to detect the secondary-side impedance value, is completed such that the power switch 25 automatically switched to the off state. Such a configuration allows a deactivation of the readout circuit for detecting the impedance value set on the secondary side, without the control device 14 having to have an output for controlling the switch 25.

While embodiments have been described with reference to the figures, modifications may be made in other embodiments. During the time up to which a current through a primary-side inductance, which is inductively coupled to the secondary-side, adjustable impedance, can be used to determine the impedance value set on the secondary side, also another evaluation can take place. For example, the value that the measured variable acquired on the primary side can become certain fixed time, used to detect the secondary side set impedance value. An element of the primary-side circuit used to detect the secondary side set impedance value may have inductive coupling across the potential barrier. While the adjustable impedance may include one or more resistors, the adjustable impedance may also include capacitive and / or inductive elements to set the impedance to different impedance values.

The control device of the operating devices according to embodiments may be configured as a semiconductor integrated circuit. The control device can be designed as an application-specific integrated circuit (ASIC) or as another integrated circuit.

Inductances and capacitances can each be formed by corresponding inductive or capacitive elements, for example as coils or capacitors. However, it is also possible that smaller inductances, for example one of the inductances or both inductances of the second transformer, are designed as stray inductances. Similarly, smaller capacities may be designed as stray capacitors.

Operating devices according to embodiments can be used in particular for the power supply of LEDs.

Claims (14)

1. Operating device (2) for a luminaire (3), comprising:

   - a primary-side circuit (7; 80; 100) with a control device (14) to control the operating device (2),

   - a secondary side (8) which is electrically isolated from the primary-side circuit (7; 80; 100), and which has an output (35) for supplying power to the luminaire (3).

   wherein a first transformer (28, 29) is provided for the power transmission from the primary side circuit (7; 80; 100) to the secondary side (8) in order to provide power for the luminaire (3) at the output (35) of the secondary side (8),
   characterized in that
   the secondary side (8) has a selection device with an impedance (15) which may be set to one of a plurality of different impedance values,
   the control device (14) is configured to detect the set impedance value and to control the operating device (2) as a function of a measured variable (62-65) detected in the primary-side circuit (7; 80; 100), and
   a second transformer (22, 23), which is separate from the first transformer (28, 29), is provided for inductively reading the set impedance value, wherein a controllable switch (25) is connected in series with an inductance (22) of the second transformer.
2. Operating device (2) according to claim 1,
   wherein the control device (14) is configured to detect the set impedance value as a function of the time-dependent behavior of the measured variable (62-65).
3. Operating device (2) according to claim 2,
   wherein the control device (14) is configured to detect the set impedance value as a function of a time (66-69), at which the measured value (62-65) reaches a reference value (61).
4. Operating device (2) according to claim 3,
   wherein the primary-side circuit (7; 80; 100) has an inductance (22) which is inductively coupled to the impedance (15) in order to detect the measured variable (62-65).
5. Operating device (2) according to claim 4,
   wherein the measured variable (62-65) is a current (62-65) flowing through the inductance (22).
6. Operating device according to claim 3,
   wherein the control device (14) is configured to determine at least one operating parameter for the operating device (2) on the basis of the operating field as a function of the time (66-69) at which the measured value (62-65) reaches the reference value (61) .
7. Operating device (2) according to one of the preceding claims,
   wherein the different impedance values are assigned to different output currents of the operating device (2).
8. Operating device (2) according to claim 7,
   wherein the control device (14) is configured to generate a power factor correction circuit (81) and/or a resonance converter (82) of the operating device (2) as a function of the measured variable (62-65) detected in the primary-side circuit (7; 80; 100) in order to provide an output current associated with the set impedance value.
9. Operating device (2) according to one of the preceding claims,
   wherein the control device (14) is configured to carry out recognition of the set impedance value only in a predetermined operating phase, in particular when starting the operating device (2).
10. Operating device (2) according to one of the preceding claims,
    wherein the selection device comprises DIP switches (51, 53, 55, 57).
11. Operating device (2) according to one of the preceding claims in the form of an SELV apparatus, wherein the secondary side (8) of the operating device (2) is in an SELV range.
12. Operating device (2) according to one of the preceding claims is in the form of an LED converter.
13. Method for operating an operating device (2) for a luminaire (3), wherein the operating device (2) comprises a primary-side circuit (7; 80; 100) and a secondary side (8), which is electrically isolated from the primary-side circuit (7; 80; 100) and which comprises an output (35) for power supply to the luminaire (3), wherein a first transformer (28, 29) for the transmission of power from the primary side circuit (7; 80; 100) to the secondary side (8) is provided to supply power for the luminaire (3) at the output (35) of the secondary side (8),
    characterized in that
    the secondary side (8) has a selection device with an impedance (15) which may be set to one of a plurality of different impedance values,
    a second transformer (22, 23), which is separate from the first transformer (28, 29), is provided for inductively reading the set impedance value, wherein a controllable switch (25) is connected in series with an inductance (22) of the second transformer, and
    wherein the method comprises:

    - detecting a measured variable (62-65) in the primary-side circuit (7; 80; 100), wherein the measured variable (62-65) is a function of a set impedance value;

    - controlling the operating device (2) by means of a control device (14) as a function of the measured variable (62-65) detected in the primary-side circuit (7; 80; 100).
14. Method according to claim 13, which is carried out with the operating device (2) according to one of the claims 1-12.

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