EP2690927B1 - Control circuit for a lighting assembly with a controllable circuit breaker - Google Patents

Control circuit for a lighting assembly with a controllable circuit breaker Download PDF

Info

Publication number
EP2690927B1
EP2690927B1 EP12178287.4A EP12178287A EP2690927B1 EP 2690927 B1 EP2690927 B1 EP 2690927B1 EP 12178287 A EP12178287 A EP 12178287A EP 2690927 B1 EP2690927 B1 EP 2690927B1
Authority
EP
European Patent Office
Prior art keywords
switch
drive circuit
circuit according
transducer
converter
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP12178287.4A
Other languages
German (de)
French (fr)
Other versions
EP2690927A1 (en
Inventor
Elmar Hinrichs
Jens Lander
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Vossloh Schwabe Deutschland GmbH
Vossloh Schwabe GmbH
Original Assignee
Vossloh Schwabe Deutschland GmbH
Vossloh Schwabe GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Vossloh Schwabe Deutschland GmbH, Vossloh Schwabe GmbH filed Critical Vossloh Schwabe Deutschland GmbH
Priority to EP12178287.4A priority Critical patent/EP2690927B1/en
Publication of EP2690927A1 publication Critical patent/EP2690927A1/en
Application granted granted Critical
Publication of EP2690927B1 publication Critical patent/EP2690927B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/10—Controlling the intensity of the light
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/37—Converter circuits
    • H05B45/3725—Switched mode power supply [SMPS]
    • H05B45/375—Switched mode power supply [SMPS] using buck topology

Definitions

  • the invention relates to a drive circuit for a lamp arrangement with a converter to which the lamp arrangement is connected.
  • the converter serves to supply electrical energy to the lamp arrangement connected thereto from a reference voltage, for example a DC voltage or a rectified AC voltage.
  • the converter has a converter switch, which is controlled via a converter control signal.
  • the converter control signal can be pulse-width modulated, for example.
  • the luminous means arrangement has at least one luminous means and in particular at least one light-emitting diode. Several light-emitting diodes of the lighting arrangement can be connected in series and / or parallel to one another.
  • the drive circuit also has a measuring circuit which is arranged in series with the lamp arrangement.
  • a measuring circuit which is arranged in series with the lamp arrangement.
  • Such a drive circuit is for example off WO 2010/049 074 A1 known.
  • the problem with such drive circuits is that, when the converter control signal is switched off, when the converter switch is in its blocking or opened state, a current can continue to flow through the lighting arrangement and the measuring circuit. This is undesirable because it also opens when or blocking transducer switch lighting the lamp assembly is caused. If the lamp arrangement is to be switched off via the converter control signal controlling the converter switch, the current which nevertheless flows through the lamp arrangement and the measuring circuit can cause the lighting arrangement to illuminate and a complete switch-off is prevented.
  • WO 2010/049 074 A1 provided to switch a further controlled switch parallel to the lamp arrangement, which bridges the lamp arrangement in its conductive or closed state. If lighting of the lamp arrangement is to be avoided, the second controlled switch is closed and, because of its low resistance, prevents a current flow through the lighting arrangement.
  • US 2009/0195184 A1 describes a drive circuit with a converter, the converter switch is connected between a voltage source and the lamp assembly. In series with the lamp arrangement, a dimmer switch is arranged, via which the brightness of the lamp arrangement can be adjusted. The current through the lamp arrangement is measured at a resistor arranged in series with the dimmer switch.
  • a reference voltage is applied to the lamp arrangement, via which the converter supplies the lamp arrangement with electrical energy.
  • the converter controls or regulates a luminous flux flowing through the illuminant arrangement and adjusts the brightness of the illuminant arrangement (11).
  • a controlled disconnector is provided in addition to the travel switch of the converter.
  • the circuit breaker is arranged in the at least one measuring circuit.
  • the circuit breaker is configured to interrupt the flow of current through the at least one measuring circuit when the converter control signal is switched off. It is thereby achieved that when the transducer signal is switched off or not applied, no current flows through the series connection of the luminous arrangement and the measuring circuit.
  • the bulb arrangement does not light up.
  • the consumption of electrical energy is reduced when the converter control signal is not applied, since no current flows through the measuring circuit.
  • the circuit breaker is arranged in the measuring circuit and is not arranged between the lamp arrangement and the lighting device driving the converter, the current flowing between the converter and the lamp arrangement current does not flow through the circuit breaker, which also contributes to the improved efficiency of the drive circuit since the circuit breaker, which is preferably formed by a semiconductor switch, also has a resistance in the conductive or closed state.
  • both a measuring circuit for determining the luminous flux, as well as a measuring circuit for determining the lighting means voltage available.
  • each measuring circuit can be assigned a separate disconnecting switch.
  • the two measuring circuits can be separated from the lamp arrangement independently of one another.
  • the converter is preferably designed as a buck converter with an inductor connected in series with the lamp arrangement. In one embodiment, it may be implemented as a so-called "inverse buck converter”. Such transducers are available as standard components cost.
  • the converter switch and / or the circuit breaker may be designed as a semiconductor switch and be formed for example by a field effect transistor or a bipolar transistor.
  • a field effect transistor in one embodiment, an n-channel MISFET is preferably used of the enhancement type.
  • a bipolar transistor in particular a pnp transistor can be used for the circuit breaker.
  • the switching state of the circuit breaker depends on a switching state of a controlled by a switching signal control switch.
  • the circuit breaker is thus indirectly switched over the control switch between its conducting and its blocking switching state.
  • the control switch can also be designed as a semiconductor switch.
  • a control switch for example, a field effect transistor or a bipolar transistor can be used.
  • the switching signal and / or the converter control signal are or is generated via a control unit, which may have a microcontroller.
  • control switch is designed as a separate component, in particular a semiconductor component.
  • the converter switch can serve as a control switch, so that no separate component is required.
  • the converter control signal simultaneously represents the switching signal.
  • the converter switch can be connected via a coupling circuit with a control input of the circuit breaker.
  • the coupling circuit has a coupling capacitor or is formed by a coupling capacitor.
  • the coupling capacitor is used when applying a converter control signal, so if the converter switch alternately changes its switching state, to allow a current in the control input or a voltage at the control input of the circuit breaker to hold the circuit breaker in the conductive or closed state. If, however, no converter control signal is present, the converter switch is in its blocking or opened state.
  • the coupling capacitor can then decouple the control input of the circuit breaker from the voltage applied to the converter switch reference voltage, whereby the circuit breaker is switched to its blocking or open switching state.
  • the coupling circuit in addition to the coupling capacitor at least have another component.
  • This further component can serve, for example, for voltage limiting and / or voltage stabilization. This is particularly useful when the circuit breaker is formed by a semiconductor switch, such as a bipolar transistor or a field effect transistor. As a result, the circuit breaker can be kept in its saturation and thus in the conducting state when the converter control signal is present. In addition, the current flow through the circuit breaker can be limited when it is in its conductive state.
  • the at least one further component can connect the control input of the disconnector and one of its two terminals for this purpose. As a component, a zener diode and / or a capacitor and / or an ohmic resistor and / or a diode can serve.
  • control switch is preferably formed by an npn transistor.
  • FIG. 1 a first embodiment of a drive circuit 10 for a lighting device 11 is illustrated in the block diagram.
  • the light-emitting device 11 has at least one light-emitting diode 12.
  • Several light emitting diodes 12 of the lighting device 11 may be connected in series and / or parallel to each other.
  • a light source capacitor 13 is connected in the embodiments described here.
  • the lighting device 11 is connected to a converter 15.
  • a converter 15 About the transducer 15 of the lamp assembly 11 is provided electrical energy.
  • the desired brightness of the illuminant arrangement 11 can also be set via the converter 15.
  • the converter 15 controls or regulates, in particular, the illuminant voltage UL applied to the illuminant arrangement 11 and / or the luminous flux IL flowing through the illuminant arrangement 11.
  • the converter 15 is designed in the embodiment as a buck converter and in particular as a so-called "inverse buck converter”. It has an inductor 16 connected in series with the lamp arrangement 11, for example a coil. The inductance 16 is connected to the first terminal side 11a of the lamp arrangement 11, which has a lower potential. The second terminal side 11 b with a higher potential of the lamp assembly 11 is applied to a reference voltage UB, which may be a rectified AC voltage or a DC voltage.
  • a reference voltage UB which may be a rectified AC voltage or a DC voltage.
  • the converter 15 also includes a converter switch 17 and a converter diode 18.
  • the cathode of the converter diode 18 is connected to the reference voltage UP.
  • the anode of the converter diode 18 is connected both to the converter switch 17, and to the inductor 16.
  • On the converter diode 18 opposite terminal side of the converter switch 17 is connected via a first resistor 19 to ground GND.
  • the value and / or the time profile of the current through the converter switch 17 can be determined via the first resistor, in particular in order to control the converter signal W depending therefrom.
  • a measuring circuit 23 is designed as a current measuring circuit 24 and the other measuring circuit 23 as a voltage measuring circuit 25.
  • the current measuring circuit 24 has a series circuit 26 which is connected directly or indirectly to the ground GND and connected in series with the lighting arrangement 11, comprising a first series resistor 26a and a second series resistor 26b connected in series therewith.
  • the first series resistor 26a is used to compensate for deviations of the luminous flux IL, which depend on the load, so for example according to the number and arrangement of the LEDs 12.
  • the second series resistor 26b is for impedance matching.
  • the voltage applied to the first resistor 19 measurement signal is characterized high impedance and between the two series resistors 26a, 26b.
  • the current measurement 24 is, for example, directly with the lamp assembly 11 is connected and connected via the first resistor 19 indirectly to the ground GND.
  • the voltage measuring circuit 25 has a voltage divider 27 with a first voltage divider resistor 27a and a second voltage divider resistor 27b. Via a center tap between the two voltage divider resistors 27a, 27b, a voltage value is measured over which the luminous flux UL applied to the luminous means arrangement 11 can be determined, since the resistance values of the two voltage dividing resistors 27a, 27 are known. To stabilize the measured voltage applied to the second voltage divider resistor 27b, a first capacitor 28 may be connected in parallel to the second voltage divider resistor 27b.
  • the lamp assembly 11 is connected with its first terminal side 11a to the ground GND.
  • Both measuring circuits 23 thus provide a path over which a luminous flux IL flowing through the luminous means arrangement 11 can flow from the reference voltage UB to the ground GND, independently of the switching state of the converter switch 17. This is undesirable since a luminous flux IL can then flow even when the converter 15 is not operated and, so to speak, switched off, the converter switch 17 being in its blocking or open switching state.
  • the converter switch 17 is driven via a converter control signal W.
  • the converter control signal W may, for example, be a pulse-width-modulated signal, via which, when the illuminant arrangement 11 is switched on, the luminous flux IL is controlled or regulated and consequently the brightness the lamp assembly 11 can be adjusted.
  • the converter control signal W can be generated by a control unit, for example a microcontroller.
  • the control unit can transmit a measured value describing the luminous flux IL via the current measuring circuit 24 and a measured value describing the luminous medium voltage UL via the voltage measuring circuit 25.
  • the first drive circuit 10a has at least one disconnecting switch 32.
  • a disconnect switch 32 is provided in each of the two measurement circuits 23.
  • the disconnectors 32 are controlled switches whose switching state can be switched over a voltage applied to a control input 32a of the circuit breaker 32 disconnector signal T.
  • the circuit breaker signal T can be generated directly by the control unit. However, it is also possible to provide a circuit part with a control switch 33 between the at least one circuit breaker 32 and the control unit, as will be explained later with reference to embodiments.
  • the first drive circuit 10a operates as follows:
  • the converter switch 17 switched.
  • a luminous flux IL flows from the reference voltage UB through the luminous means arrangement 11 via the inductance 16 and the converter switch 17 as well as the first resistor 19 to ground GND.
  • 16 energy is temporarily stored in the inductance.
  • the luminous flux IL increases with closed transducer switch 17 with time. If the traveling switch 17 is then opened, the inductance 16 discharges via the converter diode 19. The luminous flux IL decreases due to the decreasing energy in the inductance 16 with time.
  • clocked opening and closing of the converter switch 17 can be set in this way a desired effective value of the luminous flux IL and thus a predetermined brightness of the lamp assembly 11 can be achieved.
  • the luminous flux IL or its effective value is determined by the measured value of the current measuring circuit 24 and can be controlled by the control unit via the converter control signal W.
  • the control unit can be put into its idle state.
  • the converter control signal W is then turned off and the traveling switch 17 is in its blocking or opened switching state.
  • the circuit breakers 32 are switched to their blocking or open switching state. The current flow through the lamp assembly 11 is now completely prevented. Only when the lamp assembly 11 is to be operated again, the control unit causes the switching of the circuit breaker 32 in its conductive or closed switching state.
  • the circuit breaker 32 and the converter switch 17 are preferably as semiconductor switches, in particular as field effect transistors or bipolar transistors, as will be explained below with reference to concrete embodiments.
  • FIG. 2 a second drive circuit 10b is illustrated in the block diagram.
  • the only difference of the second drive circuit 10b with respect to the first drive circuit 10a after FIG. 1 consists in that both measuring circuits 23, so the current measuring circuit 24 and the voltage measuring circuit 25 only have a common disconnect switch 32.
  • the series circuit 26 and the voltage divider 27 are according to FIG. 2 connected via a common series connected in this circuit breaker 32 to the first terminal 11a of the lamp assembly 11.
  • the structure and function of the second drive circuit 10b correspond to the first drive circuit 10a, so that reference may be made to the above explanations.
  • FIG. 3 shows a variant of the first drive circuit 10a after FIG. 1 .
  • the transducer switch 17 and the circuit breaker 32 are formed by field-effect transistors and, according to the example, n-channel MISFETs of the enhancement type.
  • a control switch 33 is provided, which is also formed in this embodiment by an n-channel MISFET accumulation type.
  • the control switch 33 may be formed generally analogous to at least one circuit breaker 32 and / or the converter switch 17 by a semiconductor switch.
  • the control input here the gate of the control switch 33 is controlled via a switching signal S to the control switch 33 between its conducting and to switch to its blocking state.
  • the drain terminal of the control switch 33 is connected to ground GND.
  • the source terminal of the control switch 23 is connected via a second resistor 34 to a supply voltage UV.
  • the supply voltage UV is a DC voltage or a rectified AC voltage.
  • the source terminal of the control switch 33 is further connected via a third resistor 35 to the control input 32a of the circuit breaker 32 of the current measuring circuit 24 and via a fourth resistor 36 to the control input 32a of the circuit breaker 32 of the voltage measuring circuit 25.
  • the switching state of the circuit breaker 32 can be switched over the voltage applied to the control input 32a. If the gate-source voltage of the field-effect transistor drops below a threshold voltage, the field-effect transistor becomes nonconductive. Otherwise, the field effect transistor is conductive. If, therefore, the control switch 33 is turned on via the switching signal S, the potential at the two control inputs 32a is reduced, and the separating shells 32 change over into their blocking state. In this case, the supply voltage UV is completely applied to the second resistor 34.
  • the gate-source voltage of the disconnector is greater than the threshold voltage and the circuit breaker 32 is conductive.
  • FIG. 4 shows the block diagram of a specific embodiment of the second drive circuit 10b after FIG. 2 .
  • the circuit breaker 32 is formed by a bipolar transistor, for example a pnp bipolar transistor. Of the formed from the base control input 32a is connected via a fifth resistor 40 and a sixth resistor 41 to the first terminal 11a of the lamp assembly 11. The control input 32a is also connected via the fifth resistor 40 and a seventh resistor 42 via the control switch 33 to ground GND.
  • the control switch 33 is in this embodiment as a bipolar transistor and according to FIG. 4 designed as npn transistor.
  • the switching signal S is applied via an eighth resistor 43 to the base of the bipolar transistor forming the control switch 33.
  • a ninth resistor 44 connects the base to the emitter, and the emitter is also connected to ground GND.
  • the collector of the bipolar transistor is connected to the seventh resistor 42.
  • FIG. 5 shows the block diagram of a third drive circuit 10c.
  • the core idea of this third drive circuit 10c is to couple the circuit breaker 32 to the converter 15 in such a way that the circuit breaker 32 switches to its blocking or open switching state when the converter signal W at the converter switch 17 is switched off, for example when the control unit switches to the idle state ,
  • the control input 32a of the circuit breaker 32 connected via a coupling circuit 45 to the converter 15.
  • the coupling circuit 45 connects either the ground-side terminal of the converter switch 17 or - as in FIG. 5
  • the converter switch 17 takes over the function of the control switch 33.
  • the converter switch 17 assumes the function of the control switch 33.
  • the two measuring circuits 23 have according to FIG. 5 a common disconnect switch 32.
  • the series circuit 26 has three resistors connected in series, according to FIG. 5 two first series resistors 26a are connected in series. In principle, a single first series resistor 26a would also suffice.
  • the circuit breaker 32 and the converter switch 17 are analogous to those in FIG. 3 illustrated embodiment formed by a field effect transistor.
  • the source terminal of the circuit breaker 32 is connected to the measuring circuits 23.
  • the drain terminal of the circuit breaker 32 is connected to the lamp assembly 11.
  • the coupling circuit 45 has a coupling capacitor 47 in a connecting line 46 between the reference voltage side terminal of the converter switch 17 and the control input 32a of the circuit breaker 32.
  • the coupling circuit 45 serves as a charge pump with voltage limitation and defined load.
  • the coupling circuit 45 in series with the coupling capacitor 47, a first diode 48, the cathode with the Control input 32 of the circuit breaker 32 is connected.
  • the coupling circuit 45 has parallel to the gate-source connection of the circuit breaker 32, a parallel circuit 49 with a Zener diode 50 and / or a second capacitor 51 and / or a seventh resistor 52.
  • all three components 50, 51, 52 are provided, wherein the cathode of the zener diode 50 is connected to the control input 32a of the circuit breaker 32.
  • the center tap between the coupling capacitor 47 and the first diode 48 is connected, for example, to the cathode of a second diode 53 whose anode is connected to the source terminal of the circuit breaker 32.
  • the third drive circuit 10c operates as follows:
  • the converter switch 17 is clocked by the pulse width modulated converter control signal W between the conductive and the blocking switching state, whereby the voltage at the coupling capacitor 47 substantially between UB, for example, 400 volts, and 0V changes. If this voltage has a falling edge, the second capacitor 51 is charged via the second diode 53. If this voltage has a rising edge, the second capacitor 51 is charged via the first diode 48. The two diodes 48, 53 thus cause a full-wave rectification. The gate of the circuit breaker 32 formed by the field effect transistor is charged and the circuit breaker 32 conducts.
  • the zener diode 50 serves to limit the voltage of the gate-source voltage. Via the second capacitor 51, this gate-source voltage can be stabilized.
  • the converter switch 17 When switching off the converter control signal W, the converter switch 17 remains in its blocking or opened Status. As a result, no electricity flows through the charge pump.
  • the second capacitor 51 discharges via the seventh resistor 52, the potential at the control input 32a (gate) decreases and thus also the gate-source voltage. Finally, the disconnect switch 32 blocks. An undesired current through the measuring circuits 23 when the converter control signal W is switched off is avoided.
  • the invention relates to a drive circuit 10 for driving a light-emitting device 11 with one or more light-emitting diodes 12.
  • the drive circuit 10 has a converter 15 with an inductance 16 connected in series with the light-emitting device 11 and a converter switch 17.
  • the converter switch 17 is preferably controlled via a converter control signal W pulse width modulated when the lamp assembly 11 is to be operated.
  • at least one measuring circuit 23 is provided, which is connected in series with the lighting device 11. In order to avoid current flow through the luminous means arrangement 11 and the measuring circuit 23 in the case of a blocking converter switch 17, for example when the converter control signal W is switched off, at least one disconnecting switch 32 is present in the measuring circuit.
  • Such a means may be, for example, a coupling capacitor 47 between the converter switch and a control input 32a of the circuit breaker 32.

Description

Die Erfindung betrifft eine Ansteuerschaltung für eine Leuchtmittelanordnung mit einem Wandler, an den die Leuchtmittelanordnung angeschlossen ist. Der Wandler dient dazu, aus einer Bezugsspannung, beispielsweise einer Gleichspannung oder einer gleichgerichteten Wechselspannung, die daran angeschlossene Leuchtmittelanordnung mit elektrischer Energie zu versorgen. Der Wandler weist einen Wandlerschalter auf, der über ein Wandlersteuersignal angesteuert wird. Das Wandlersteuersignal kann beispielsweise pulsweitenmoduliert sein. Dadurch kann die Helligkeit der Leuchtmittelanordnung eingestellt werden. Die Leuchtmittelanordnung weist wenigstens ein Leuchtmittel und insbesondere wenigstens eine Leuchtdiode auf. Mehrere Leuchtdioden der Leuchtmittelanordnung können in Reihe und/oder parallel zueinander geschaltet sein.The invention relates to a drive circuit for a lamp arrangement with a converter to which the lamp arrangement is connected. The converter serves to supply electrical energy to the lamp arrangement connected thereto from a reference voltage, for example a DC voltage or a rectified AC voltage. The converter has a converter switch, which is controlled via a converter control signal. The converter control signal can be pulse-width modulated, for example. As a result, the brightness of the lamp arrangement can be adjusted. The luminous means arrangement has at least one luminous means and in particular at least one light-emitting diode. Several light-emitting diodes of the lighting arrangement can be connected in series and / or parallel to one another.

Die Ansteuerschaltung weist außerdem eine Messschaltung auf, die in Reihe zur Leuchtmittelanordnung angeordnet ist. Über die wenigstens eine Messschaltung kann zum Beispiel der durch die Leuchtmittelanordnung fließende Leuchtmittelstrom und/oder die an der Leuchtmittelanordnung anliegende Leuchtmittelspannung bestimmt werden.The drive circuit also has a measuring circuit which is arranged in series with the lamp arrangement. By means of the at least one measuring circuit, it is possible to determine, for example, the luminous flux flowing through the illuminant arrangement and / or the illuminant voltage applied to the illuminant arrangement.

Eine solche Ansteuerschaltung ist beispielsweise aus WO 2010/049 074 A1 bekannt. Problematisch bei solchen Ansteuerschaltungen ist es, dass bei ausgeschaltetem Wandlersteuersignal, wenn sich der Wandlerschalter in seinem sperrendem bzw. geöffnetem Zustand befindet, weiterhin ein Strom durch die Leuchtmittelanordnung und die Messschaltung fließen kann. Dies ist deswegen unerwünscht, weil dadurch auch bei geöffnetem oder sperrendem Wandlerschalter ein Leuchten der Leuchtmittelanordnung hervorgerufen wird. Soll die Leuchtmittelanordnung über das den Wandlerschalter steuernde Wandlersteuersignal ausgeschaltet werden, kann der durch die Leuchtmittelanordnung und die Messschaltung dennoch fließende Strom die Leuchtmittelanordnung zum Leuchten bringen und ein vollständiges Abschalten wird verhindert.Such a drive circuit is for example off WO 2010/049 074 A1 known. The problem with such drive circuits is that, when the converter control signal is switched off, when the converter switch is in its blocking or opened state, a current can continue to flow through the lighting arrangement and the measuring circuit. This is undesirable because it also opens when or blocking transducer switch lighting the lamp assembly is caused. If the lamp arrangement is to be switched off via the converter control signal controlling the converter switch, the current which nevertheless flows through the lamp arrangement and the measuring circuit can cause the lighting arrangement to illuminate and a complete switch-off is prevented.

Zu diesem Zweck ist bei einem Ausführungsbeispiel der WO 2010/049 074 A1 vorgesehen, einen weiteren gesteuerten Schalter parallel zu der Leuchtmittelanordnung zu schalten, der in seinem leitenden oder geschlossenen Zustand die Leuchtmittelanordnung überbrückt. Soll ein Leuchten der Leuchtmittelanordnung vermieden werden, wird der zweite gesteuerte Schalter geschlossen und verhindert wegen seines geringen Widerstandes einen Stromfluss durch die Leuchtmittelanordnung.For this purpose, in one embodiment of the WO 2010/049 074 A1 provided to switch a further controlled switch parallel to the lamp arrangement, which bridges the lamp arrangement in its conductive or closed state. If lighting of the lamp arrangement is to be avoided, the second controlled switch is closed and, because of its low resistance, prevents a current flow through the lighting arrangement.

US 2009/0195184 A1 beschreibt eine Ansteuerschaltung mit einem Wandler, deren Wandlerschalter zwischen eine Spannungsquelle und die Leuchtmittelanordnung geschaltet ist. In Reihe zu der Leuchtmittelanordnung ist ein Dimmschalter angeordnet, über den die Helligkeit der Leuchtmittelanordnung eingestellt werden kann. Der Strom durch die Leuchtmittelanordnung wird an einem in Reihe zum Dimmschalter angeordneten Widerstand gemessen. US 2009/0195184 A1 describes a drive circuit with a converter, the converter switch is connected between a voltage source and the lamp assembly. In series with the lamp arrangement, a dimmer switch is arranged, via which the brightness of the lamp arrangement can be adjusted. The current through the lamp arrangement is measured at a resistor arranged in series with the dimmer switch.

Ausgehend von diesem Stand der Technik kann es als eine Aufgabe der vorliegenden Erfindung angesehen werden, die Ansteuerschaltung für eine Leuchtmittelanordnung, insbesondere im Hinblick auf deren Effizienz zu verbessern.Based on this prior art, it can be regarded as an object of the present invention to improve the drive circuit for a lighting device, in particular with regard to its efficiency.

Diese Aufgabe wird durch eine Ansteuerschaltung mit den Merkmalen des Patentanspruches 1 gelöst.This object is achieved by a drive circuit with the features of claim 1.

An einen Anschluss mit höherem Spannungspotenzial ist an die Leuchtmittelanordnung eine Bezugsspannung anliegt, über die der Wandler die Leuchtmittelanordnung mit elektrischer Energie zu versorgt. Der Wandler steuert oder regelt einen durch die Leuchtmittelanordnung fließenden Leuchtmittelstrom und stellt die Helligkeit der Leuchtmittelanordnung (11) ein. Erfindungsgemäß ist zusätzlich zu dem Wanderschalter des Wandlers ein gesteuerter Trennschalter vorgesehen. Der Trennschalter ist in der wenigstens einen Messschaltung angeordnet. Der Trennschalter ist dazu eingerichtet, bei ausgeschaltetem Wandlersteuersignal den Stromfluss durch die wenigstens eine Messschaltung zu unterbrechen. Dadurch wird erreicht, dass bei ausgeschaltetem bzw. nicht anliegendem Wandlersignal kein Strom durch die Reihenschaltung aus Leuchtmittelanordnung und Messschaltung fließt. Die Leuchtmittelanordnung leuchtet nicht. Außerdem wird der Verbrauch von elektrischer Energie bei nicht anliegendem Wandlersteuersignal verringert, da auch durch die Messschaltung kein Strom mehr fließt.At a connection with a higher voltage potential, a reference voltage is applied to the lamp arrangement, via which the converter supplies the lamp arrangement with electrical energy. The converter controls or regulates a luminous flux flowing through the illuminant arrangement and adjusts the brightness of the illuminant arrangement (11). According to the invention, a controlled disconnector is provided in addition to the travel switch of the converter. The circuit breaker is arranged in the at least one measuring circuit. The circuit breaker is configured to interrupt the flow of current through the at least one measuring circuit when the converter control signal is switched off. It is thereby achieved that when the transducer signal is switched off or not applied, no current flows through the series connection of the luminous arrangement and the measuring circuit. The bulb arrangement does not light up. In addition, the consumption of electrical energy is reduced when the converter control signal is not applied, since no current flows through the measuring circuit.

Dadurch, dass der Trennschalter in der Messschaltung angeordnet ist und nicht zwischen der Leuchtmittelanordnung und dem die Leuchtmittelanordnung ansteuernden Wandler angeordnet ist, muss der zwischen dem Wandler und der Leuchtmittelanordnung fließende Strom nicht durch den Trennschalter fließen, was ebenfalls zur verbesserten Effizienz der Ansteuerschaltung beiträgt, da der Trennschalter, der vorzugsweise durch einen Halbleiterschalter gebildet ist, auch in leitendem bzw. geschlossenem Zustand einen Widerstand aufweist.Characterized in that the circuit breaker is arranged in the measuring circuit and is not arranged between the lamp arrangement and the lighting device driving the converter, the current flowing between the converter and the lamp arrangement current does not flow through the circuit breaker, which also contributes to the improved efficiency of the drive circuit since the circuit breaker, which is preferably formed by a semiconductor switch, also has a resistance in the conductive or closed state.

Bei einer bevorzugten Ausführungsform ist sowohl eine Messschaltung zur Bestimmung des Leuchtmittelstromes, als auch eine Messschaltung zur Bestimmung der Leuchtmittelspannung vorhanden. Dabei kann jeder Messschaltung ein separater Trennschalter zugeordnet sein. Dadurch können die beiden Messschaltungen unabhängig voneinander von der Leuchtmittelanordnung getrennt werden. Alternativ hierzu ist es auch möglich, den beiden Messschaltungen einen gemeinsamen Trennschalter zuzuordnen, über den die beiden Messschaltungen mit der Leuchtmittelanordnung verbunden sind. Dies vereinfacht den Aufbau der Ansteuerschaltung.In a preferred embodiment, both a measuring circuit for determining the luminous flux, as well as a measuring circuit for determining the lighting means voltage available. In this case, each measuring circuit can be assigned a separate disconnecting switch. As a result, the two measuring circuits can be separated from the lamp arrangement independently of one another. Alternatively, it is also possible to assign the two measuring circuits a common disconnecting switch, via which the two measuring circuits are connected to the lighting arrangement. This simplifies the structure of the drive circuit.

Der Wandler ist vorzugsweise als Tiefsetzsteller mit einer in Reihe zur Leuchtmittelanordnung geschalteten Induktivität ausgeführt. Bei einem Ausführungsbeispiel kann er als sogenannter "Inverse Buck Converter" ausgeführt sein. Solche Wandler sind als Standardbauteile kostengünstig verfügbar.The converter is preferably designed as a buck converter with an inductor connected in series with the lamp arrangement. In one embodiment, it may be implemented as a so-called "inverse buck converter". Such transducers are available as standard components cost.

Der Wandlerschalter und/oder der Trennschalter können als Halbleiterschalter ausgeführt sein und beispielsweise durch einen Feldeffekttransistor oder einen Bipolartransistor gebildet sein. Als Feldeffekttransistor wird bei einem Ausführungsbeispiel ein n-Kanal-MISFET vorzugsweise vom Anreicherungstyp verwendet. Als Bipolartransistor kann insbesondere für den Trennschalter ein pnp-Transistor verwendet werden.The converter switch and / or the circuit breaker may be designed as a semiconductor switch and be formed for example by a field effect transistor or a bipolar transistor. As a field effect transistor, in one embodiment, an n-channel MISFET is preferably used of the enhancement type. As a bipolar transistor, in particular a pnp transistor can be used for the circuit breaker.

Bei einem Ausführungsbeispiel hängt der Schaltzustand des Trennschalters von einem Schaltzustand eines mit einem Schaltsignal angesteuerten Steuerschalters ab. Der Trennschalter wird somit mittelbar über den Steuerschalter zwischen seinem leitenden und seinem sperrenden Schaltzustand umgeschaltet. Der Steuerschalter kann ebenfalls als Halbleiterschalter ausgeführt sein. Als Steuerschalter kann beispielsweise ein Feldeffekttransistor oder ein Bipolartransistor verwendet werden.In one embodiment, the switching state of the circuit breaker depends on a switching state of a controlled by a switching signal control switch. The circuit breaker is thus indirectly switched over the control switch between its conducting and its blocking switching state. The control switch can also be designed as a semiconductor switch. As a control switch, for example, a field effect transistor or a bipolar transistor can be used.

Das Schaltsignal und/oder das Wandlersteuersignal werden bzw. wird über eine Steuereinheit erzeugt, die einen Mikrocontroller aufweisen kann.The switching signal and / or the converter control signal are or is generated via a control unit, which may have a microcontroller.

Bei einem Ausführungsbeispiel ist der Steuerschalter als separates Bauteil, insbesondere Halbleiterbauteil ausgeführt. Alternativ dazu kann auch der Wandlerschalter als Steuerschalter dienen, so dass kein separates Bauteil erforderlich ist. Das Wandlersteuersignal stellt dabei gleichzeitig das Schaltsignal dar.In one embodiment, the control switch is designed as a separate component, in particular a semiconductor component. Alternatively, the converter switch can serve as a control switch, so that no separate component is required. The converter control signal simultaneously represents the switching signal.

Insbesondere bei einer Ausgestaltung, bei der der Wandlerschalter auch als Steuerschalter dient, kann der Wandlerschalter über eine Koppelschaltung mit einem Steuereingang des Trennschalters verbunden sein. Die Koppelschaltung weist einen Koppelkondensator auf oder ist durch einen Koppelkondensator gebildet. Der Koppelkondensator dient dazu, beim Anliegen eines Wandlersteuersignals, wenn also der Wandlerschalter abwechselnd seinen Schaltzustand ändert, einen Strom in den Steuereingang bzw. eine Spannung an dem Steuereingang des Trennschalters zuzulassen, um den Trennschalter im leitenden bzw. geschlossenem Zustand zu halten. Liegt hingegen kein Wandlersteuersignal an, befindet sich der Wandlerschalter in seinem sperrenden bzw. geöffneten Zustand. Der Koppelkondensator kann dann den Steuereingang des Trennschalters von der am Wandlerschalter anliegenden Bezugsspannung entkoppeln, wodurch der Trennschalter in seinen sperrenden bzw. geöffneten Schaltzustand umgeschaltet wird. Dies stellt eine besonders vorteilhafte Ausführung dar, weil zum Umschalten des Trennschalters kein zusätzliches Schaltsignal von einer Steuereinheit erforderlich ist.In particular, in an embodiment in which the converter switch also serves as a control switch, the converter switch can be connected via a coupling circuit with a control input of the circuit breaker. The coupling circuit has a coupling capacitor or is formed by a coupling capacitor. The coupling capacitor is used when applying a converter control signal, so if the converter switch alternately changes its switching state, to allow a current in the control input or a voltage at the control input of the circuit breaker to hold the circuit breaker in the conductive or closed state. If, however, no converter control signal is present, the converter switch is in its blocking or opened state. The coupling capacitor can then decouple the control input of the circuit breaker from the voltage applied to the converter switch reference voltage, whereby the circuit breaker is switched to its blocking or open switching state. This represents a particularly advantageous embodiment, because no additional switching signal from a control unit is required to switch the disconnector.

Die Koppelschaltung kann neben dem Koppelkondensator wenigstens ein weiteres Bauelement aufweisen. Dieses weitere Bauelement kann beispielsweise zur Spannungsbegrenzung und/oder Spannungsstabilisierung dienen. Dies ist insbesondere dann zweckmäßig, wenn der Trennschalter von einem Halbleiterschalter, beispielsweise einem Bipolartransistor oder einem Feldeffekttransistor gebildet ist. Dadurch kann der Trennschalter bei anliegendem Wandlersteuersignal in seiner Sättigung und mithin im leitenden Zustand gehalten werden. Außerdem kann der Stromfluss durch den Trennschalter begrenzt werden, wenn dieser sich in seinem leitenden Zustand befindet. Das wenigstens eine weitere Bauelement kann hierfür den Steuereingang des Trennschalters und einen seiner beiden Anschlüsse verbinden. Als Bauelement kann eine Zenerdiode und/oder ein Kondensator und/oder ein ohmscher Widerstand und/oder eine Diode dienen.The coupling circuit, in addition to the coupling capacitor at least have another component. This further component can serve, for example, for voltage limiting and / or voltage stabilization. This is particularly useful when the circuit breaker is formed by a semiconductor switch, such as a bipolar transistor or a field effect transistor. As a result, the circuit breaker can be kept in its saturation and thus in the conducting state when the converter control signal is present. In addition, the current flow through the circuit breaker can be limited when it is in its conductive state. The at least one further component can connect the control input of the disconnector and one of its two terminals for this purpose. As a component, a zener diode and / or a capacitor and / or an ohmic resistor and / or a diode can serve.

Bei einer Ausführungsform, bei der der Trennschalter als separater pnp-Transistor ausgeführt ist, ist der Steuerschalter vorzugsweise durch einen npn-Transistor gebildet.In an embodiment in which the circuit breaker is designed as a separate pnp transistor, the control switch is preferably formed by an npn transistor.

Vorteilhafte Ausgestaltungen der Erfindung ergeben sich aus der Beschreibung sowie den abhängigen Patentansprüchen. Die Beschreibung beschränkt sich auf wesentliche Merkmale der Erfindung. Die Zeichnung ist ergänzend heranzuziehen. Nachfolgend wird die Erfindung anhand von Ausführungsbeispielen unter Bezugnahme auf die Zeichnung näher erläutert. Es zeigen:

  • Figur 1 ein Blockschaltbild eines ersten Ausführungsbeispiels der Ansteuerschaltung,
  • Figur 2 ein Blockschaltbild eines zweiten Ausführungsbeispiels der Ansteuerschaltung,
  • Figur 3 eine Ausführungsvariante mit Feldeffekttransistoren des ersten Ausführungsbeispiels nach Figur 1,
  • Figur 4 eine Ausführungsvariante mit Bipolartransistoren als Trennschalter und Steuerschalter gemäß dem zweiten Ausführungsbeispiel nach Figur 2 und
  • Figur 5 ein drittes Ausführungsbeispiel der Ansteuerschaltung.
Advantageous embodiments of the invention will become apparent from the description and the dependent claims. The description is limited to essential features of the invention. The drawing is to be used as a supplement. The invention will be explained in more detail by means of exemplary embodiments with reference to the drawing. Show it:
  • FIG. 1 a block diagram of a first embodiment of the drive circuit,
  • FIG. 2 a block diagram of a second embodiment of the drive circuit,
  • FIG. 3 an embodiment variant with field effect transistors of the first embodiment according to FIG. 1 .
  • FIG. 4 a variant with bipolar transistors as a circuit breaker and control switch according to the second embodiment according to FIG. 2 and
  • FIG. 5 a third embodiment of the drive circuit.

In Figur 1 ist ein erstes Ausführungsbeispiel einer Ansteuerschaltung 10 für eine Leuchtmittelanordnung 11 im Blockschaltbild veranschaulicht. Die Leuchtmittelanordnung 11 weist wenigstens eine Leuchtdiode 12 auf. Mehrere Leuchtdioden 12 der Leuchtmittelanordnung 11 können in Reihe und/oder parallel zueinander geschaltet sein.In FIG. 1 a first embodiment of a drive circuit 10 for a lighting device 11 is illustrated in the block diagram. The light-emitting device 11 has at least one light-emitting diode 12. Several light emitting diodes 12 of the lighting device 11 may be connected in series and / or parallel to each other.

Parallel zu der Leuchtmittelanordnung 11 ist bei den hier beschriebenen Ausführungsbeispielen ein Leuchtmittel-Kondensator 13 geschaltet.Parallel to the lamp arrangement 11, a light source capacitor 13 is connected in the embodiments described here.

Die Leuchtmittelanordnung 11 ist an einen Wandler 15 angeschlossen. Über den Wandler 15 wird der Leuchtmittelanordnung 11 elektrische Energie zur Verfügung gestellt. Insbesondere kann über den Wandler 15 auch die gewünschte Helligkeit der Leuchtmittelanordnung 11 eingestellt werden. Der Wandler 15 steuert oder regelt hierfür insbesondere die an der Leuchtmittelanordnung 11 anliegende Leuchtmittelspannung UL und/oder den durch die Leuchtmittelanordnung 11 fließenden Leuchtmittelstrom IL.The lighting device 11 is connected to a converter 15. About the transducer 15 of the lamp assembly 11 is provided electrical energy. In particular, the desired brightness of the illuminant arrangement 11 can also be set via the converter 15. For this purpose, the converter 15 controls or regulates, in particular, the illuminant voltage UL applied to the illuminant arrangement 11 and / or the luminous flux IL flowing through the illuminant arrangement 11.

Der Wandler 15 ist beim Ausführungsbeispiel als Tiefsetzsteller und insbesondere als sogenannter "Inverse Buck Converter" ausgeführt. Er weist eine in Reihe zur Leuchtmittelanordnung 11 geschaltete Induktivität 16, beispielsweise eine Spule, auf. Die Induktivität 16 ist mit der ersten Anschlussseite 11a der Leuchtmittelanordnung 11 verbunden, die ein geringeres Potenzial aufweist. Die zweite Anschlussseite 11b mit höherem Potenzial der Leuchtmittelanordnung 11 liegt an einer Bezugsspannung UB an, die eine gleichgerichtete Wechselspannung oder eine Gleichspannung sein kann.The converter 15 is designed in the embodiment as a buck converter and in particular as a so-called "inverse buck converter". It has an inductor 16 connected in series with the lamp arrangement 11, for example a coil. The inductance 16 is connected to the first terminal side 11a of the lamp arrangement 11, which has a lower potential. The second terminal side 11 b with a higher potential of the lamp assembly 11 is applied to a reference voltage UB, which may be a rectified AC voltage or a DC voltage.

Zu dem Wandler 15 gehören neben der Induktivität 16 beim Ausführungsbeispiel außerdem ein Wandlerschalter 17 sowie eine Wandlerdiode 18. Die Kathode der Wandlerdiode 18 ist mit der Bezugsspannung UP verbunden. Die Anode der Wandlerdiode 18 ist sowohl mit dem Wandlerschalter 17, als auch mit der Induktivität 16 verbunden. Auf der der Wandlerdiode 18 entgegengesetzten Anschlussseite ist der Wandlerschalter 17 über einen ersten Widerstand 19 mit Masse GND verbunden. Über den ersten Widerstand kann der Wert und/oder der zeitliche Verlauf des Stromes durch den Wandlerschalter 17 bestimmt werden, insbesondere um das Wandlersignal W abhängig davon zu steuern.In addition to the inductor 16 in the exemplary embodiment, the converter 15 also includes a converter switch 17 and a converter diode 18. The cathode of the converter diode 18 is connected to the reference voltage UP. The anode of the converter diode 18 is connected both to the converter switch 17, and to the inductor 16. On the converter diode 18 opposite terminal side of the converter switch 17 is connected via a first resistor 19 to ground GND. The value and / or the time profile of the current through the converter switch 17 can be determined via the first resistor, in particular in order to control the converter signal W depending therefrom.

Wenn in der Beschreibung von einem Widerstand die Rede ist, ist ein Ohmscher Widerstand gemeint.If in the description of a resistance is mentioned, an ohmic resistance is meant.

In Reihe zur Leuchtmittelanordnung 11 ist wenigstens eine Messschaltung 23 vorhanden. Bei dem in Figur 1 dargstellten Ausführungsbeispiel sind zwei Messschaltungen vorgesehen, wobei eine Messschaltung 23 als Strommessschaltung 24 und die andere Messschaltung 23 als Spannungsmessschaltung 25 ausgeführt ist. Die Strommessschaltung 24 weist eine mittelbar oder unmittelbar mit der Masse GND verbundenen, in Reihe zur Leuchtmittelanordnung 11 geschaltete Reihenschaltung 26 aus einem ersten Reihenwiderstand 26a und einem in Reihe dazu geschalteten zweiten Reihenwiderstand 26b auf. Der erste Reihenwiderstand 26a dient zur Kompensation von Abweichungen des Leuchtmittelstromes IL, die von der Last abhängen, also beispielsgemäß der Anzahl und Anordnung der Leuchtdioden 12. Über den ersten Widerstand 19 wird der Strom durch den Wandlerschalter 17 bestimmt. Der zweite Reihenwiderstand 26b dient zur Impedanzanpassung. Das an dem ersten Widerstand 19 anliegende Messsignal wird dadurch hochohmig und zwischen den beiden Reihenwiderständen 26a, 26b gemessen.In series with the lamp arrangement 11, at least one measuring circuit 23 is present. At the in FIG. 1 dargstellten embodiment, two measuring circuits are provided, wherein a measuring circuit 23 is designed as a current measuring circuit 24 and the other measuring circuit 23 as a voltage measuring circuit 25. The current measuring circuit 24 has a series circuit 26 which is connected directly or indirectly to the ground GND and connected in series with the lighting arrangement 11, comprising a first series resistor 26a and a second series resistor 26b connected in series therewith. The first series resistor 26a is used to compensate for deviations of the luminous flux IL, which depend on the load, so for example according to the number and arrangement of the LEDs 12. About the first resistor 19, the current through the transducer switch 17 is determined. The second series resistor 26b is for impedance matching. The voltage applied to the first resistor 19 measurement signal is characterized high impedance and between the two series resistors 26a, 26b.

Die Strommessung 24 ist beispielsgemäß unmittelbar mit der Leuchtmittelanordnung 11 verbunden und über den ersten Widerstand 19 mittelbar mit der Masse GND verbunden.The current measurement 24 is, for example, directly with the lamp assembly 11 is connected and connected via the first resistor 19 indirectly to the ground GND.

Die Spannungsmessschaltung 25 weist einen Spannungsteiler 27 mit einem ersten Spannungsteilerwiderstand 27a und einem zweiten Spannungsteilerwiderstand 27b auf. Über einen Mittenabgriff zwischen den beiden Spannungsteilerwiderständen 27a, 27b wird ein Spannungswert gemessen, über den die an der Leuchtmittelanordnung 11 anliegende Leuchtmittelspannung UL ermittelt werden kann, da die Widerstandswerte der beiden Spannungsteilerwiderstände 27a, 27 bekannt sind. Zur Stabilisierung der gemessenen, am zweiten Spannungsteilerwiderstand 27b anliegenden Spannung, kann parallel zum zweiten Spannungsteilerwiderstand 27b ein erster Kondensator 28 geschaltet sein.The voltage measuring circuit 25 has a voltage divider 27 with a first voltage divider resistor 27a and a second voltage divider resistor 27b. Via a center tap between the two voltage divider resistors 27a, 27b, a voltage value is measured over which the luminous flux UL applied to the luminous means arrangement 11 can be determined, since the resistance values of the two voltage dividing resistors 27a, 27 are known. To stabilize the measured voltage applied to the second voltage divider resistor 27b, a first capacitor 28 may be connected in parallel to the second voltage divider resistor 27b.

Über die Reihenschaltung 26 und den Spannungsteiler 27 ist die Leuchtmittelanordnung 11 mit ihrer ersten Anschlussseite 11a mit der Masse GND verbunden.About the series circuit 26 and the voltage divider 27, the lamp assembly 11 is connected with its first terminal side 11a to the ground GND.

Beide Messschaltungen 23 stellen somit einen Pfad zur Verfügung, über den ein durch die Leuchtmittelanordnung 11 fließender Leuchtmittelstrom IL unabhängig vom Schaltzustand des Wandlerschalters 17 von der Bezugsspannung UB zur Masse GND fließen kann. Dies ist unerwünscht, da dadurch auch dann ein Leuchtmittelstrom IL fließen kann, wenn der Wandler 15 nicht betrieben und sozusagen ausgeschaltet ist, wobei sich der Wandlerschalter 17 in seinem sperrenden bzw. geöffneten Schaltzustand befindet.Both measuring circuits 23 thus provide a path over which a luminous flux IL flowing through the luminous means arrangement 11 can flow from the reference voltage UB to the ground GND, independently of the switching state of the converter switch 17. This is undesirable since a luminous flux IL can then flow even when the converter 15 is not operated and, so to speak, switched off, the converter switch 17 being in its blocking or open switching state.

Der Wandlerschalter 17 wird über ein Wandlersteuersignal W angesteuert. Das Wandlersteuersignal W kann beispielsweise ein pulsweitenmoduliertes Signal sein, über das bei eingeschalteter Leuchtmittelanordnung 11 der Leuchtmittelstrom IL gesteuert oder geregelt und mithin die Helligkeit der Leuchtmittelanordnung 11 eingestellt werden kann. Das Wandlersteuersignal W kann von einer Steuereinheit, beispielsweise einem Mikrocontroller, erzeugt werden. Zur Einstellung der erforderlichen Pulsweite des Wandlersteuersignals W kann der Steuereinheit über die Strommessschaltung 24 ein den Leuchtmittelstrom IL beschreibender Messwert und über die Spannungsmessschaltung 25 ein die Leuchtmittelspannung UL beschreibender Messwert übermittelt werden.The converter switch 17 is driven via a converter control signal W. The converter control signal W may, for example, be a pulse-width-modulated signal, via which, when the illuminant arrangement 11 is switched on, the luminous flux IL is controlled or regulated and consequently the brightness the lamp assembly 11 can be adjusted. The converter control signal W can be generated by a control unit, for example a microcontroller. In order to set the required pulse width of the converter control signal W, the control unit can transmit a measured value describing the luminous flux IL via the current measuring circuit 24 and a measured value describing the luminous medium voltage UL via the voltage measuring circuit 25.

Befindet sich die Steuereinheit beispielsweise im Ruhezustand (Stand-By-Betrieb), so soll die Leuchtmittelanordnung 11 ausgeschaltet sein. Um einen Stromfluss durch die Leuchtmittelanordnung 11 über eine der Messschaltungen 23 zu vermeiden, weist die erste Ansteuerschaltung 10a wenigstens einen Trennschalter 32 auf. Bei der ersten Ansteuerschaltung 10a ist in jedem der beiden Messschaltungen 23 jeweils ein Trennschalter 32 vorhanden. Bei den Trennschaltern 32 handelt es sich um gesteuerte Schalter, deren Schaltzustand über ein an einem Steuereingang 32a des Trennschalters 32 anliegendes Trennschaltersignal T umgeschaltet werden kann.For example, if the control unit is in the idle state (stand-by mode), then the illuminant arrangement 11 should be switched off. In order to avoid a current flow through the luminous means arrangement 11 via one of the measuring circuits 23, the first drive circuit 10a has at least one disconnecting switch 32. In the first drive circuit 10a, a disconnect switch 32 is provided in each of the two measurement circuits 23. The disconnectors 32 are controlled switches whose switching state can be switched over a voltage applied to a control input 32a of the circuit breaker 32 disconnector signal T.

Das Trennschaltersignal T kann unmittelbar von der Steuereinheit erzeugt werden. Es ist jedoch auch möglich, zwischen dem wenigstens einen Trennschalter 32 und der Steuereinheit einen Schaltungsteil mit einem Steuerschalter 33 vorzusehen, wie dies später anhand von Ausführungsvarianten noch erläutert wird.The circuit breaker signal T can be generated directly by the control unit. However, it is also possible to provide a circuit part with a control switch 33 between the at least one circuit breaker 32 and the control unit, as will be explained later with reference to embodiments.

Die erste Ansteuerschaltung 10a arbeitet wie folgt:The first drive circuit 10a operates as follows:

Beim Betrieb der Leuchtmittelanordnung 11 wird zur Einstellung der gewünschten Helligkeit über das beispielsgemäß pulsweitenmodulierte Wandlersteuersignal W der Wandlerschalter 17 geschaltet. Bei geschlossenem Wandlerschalter 17 fließt ein Leuchtmittelstrom IL von der Bezugsspannung UB durch die Leuchtmittelanordnung 11 über die Induktivität 16 und den Wandlerschalter 17 sowie den ersten Widerstand 19 zur Masse GND. Dabei wird in der Induktivität 16 Energie zwischengespeichert. Der Leuchtmittelstrom IL steigt bei geschlossenem Wandlerschalter 17 mit der Zeit an. Wird der Wanderschalter 17 dann geöffnet, entlädt sich die Induktivität 16 über die Wandlerdiode 19. Der Leuchtmittelstrom IL sinkt wegen der abnehmenden Energie in der Induktivität 16 mit der Zeit. Durch getaktetes Öffnen und Schließen des Wandlerschalters 17 kann auf diese Weise ein gewünschter Effektivwert des Leuchtmittelstromes IL eingestellt und mithin eine vorgegebene Helligkeit der Leuchtmittelanordnung 11 erreicht werden. Der Leuchtmittelstrom IL bzw. dessen Effektivwert wird über den Messwert der Strommessschaltung 24 bestimmt und kann durch die Steuereinheit über das Wandlersteuersignal W geregelt werden.During operation of the lighting device 11 is to set the desired brightness on the example according to pulse width modulated converter control signal W, the converter switch 17 switched. When the converter switch 17 is closed, a luminous flux IL flows from the reference voltage UB through the luminous means arrangement 11 via the inductance 16 and the converter switch 17 as well as the first resistor 19 to ground GND. In this case 16 energy is temporarily stored in the inductance. The luminous flux IL increases with closed transducer switch 17 with time. If the traveling switch 17 is then opened, the inductance 16 discharges via the converter diode 19. The luminous flux IL decreases due to the decreasing energy in the inductance 16 with time. By clocked opening and closing of the converter switch 17 can be set in this way a desired effective value of the luminous flux IL and thus a predetermined brightness of the lamp assembly 11 can be achieved. The luminous flux IL or its effective value is determined by the measured value of the current measuring circuit 24 and can be controlled by the control unit via the converter control signal W.

Soll die Leuchtmittelanordnung 11 ausgeschaltet werden, kann die Steuereinheit in ihren Ruhezustand versetzt werden. Das Wandlersteuersignal W wird dann abgeschaltet und der Wanderschalter 17 befindet sich in seinem sperrenden bzw. geöffneten Schaltzustand. Um einen weiteren Stromfluss von der Bezugsspannung UB über die Messschaltungen 23 zu vermeiden, werden die Trennschalter 32 in ihren sperrenden bzw. geöffneten Schaltzustand umgeschaltet. Der Stromfluss durch die Leuchtmittelanordnung 11 ist nunmehr vollständig unterbunden. Erst wenn die Leuchtmittelanordnung 11 wieder betrieben werden soll, veranlasst die Steuereinheit das Umschalten der Trennschalter 32 in ihren leitenden bzw. geschlossenen Schaltzustand.If the lamp assembly 11 is turned off, the control unit can be put into its idle state. The converter control signal W is then turned off and the traveling switch 17 is in its blocking or opened switching state. In order to avoid a further current flow from the reference voltage UB via the measuring circuits 23, the circuit breakers 32 are switched to their blocking or open switching state. The current flow through the lamp assembly 11 is now completely prevented. Only when the lamp assembly 11 is to be operated again, the control unit causes the switching of the circuit breaker 32 in its conductive or closed switching state.

Die Trennschalter 32 bzw. der Wandlerschalter 17 sind vorzugsweise als Halbleiterschalter, insbesondere als Feldeffekttransistoren oder Bipolartransistoren ausgeführt, wie dies nachfolgend anhand konkreter Ausführungsformen noch erläutert wird.The circuit breaker 32 and the converter switch 17 are preferably as semiconductor switches, in particular as field effect transistors or bipolar transistors, as will be explained below with reference to concrete embodiments.

In Figur 2 ist eine zweite Ansteuerschaltung 10b im Blockschaltbild veranschaulicht. Der einzige Unterschied der zweiten Ansteuerschaltung 10b gegenüber der ersten Ansteuerschaltung 10a nach Figur 1 besteht darin, dass beide Messschaltungen 23, also die Strommessschaltung 24 sowie die Spannungsmessschaltung 25 nur einen gemeinsamen Trennschalter 32 aufweisen. Die Reihenschaltung 26 und der Spannungsteiler 27 sind gemäß Figur 2 über einen gemeinsamen in Reihe dazu geschalteten Trennschalter 32 mit dem ersten Anschluss 11a der Leuchtmittelanordnung 11 verbunden.In FIG. 2 a second drive circuit 10b is illustrated in the block diagram. The only difference of the second drive circuit 10b with respect to the first drive circuit 10a after FIG. 1 consists in that both measuring circuits 23, so the current measuring circuit 24 and the voltage measuring circuit 25 only have a common disconnect switch 32. The series circuit 26 and the voltage divider 27 are according to FIG. 2 connected via a common series connected in this circuit breaker 32 to the first terminal 11a of the lamp assembly 11.

Im Übrigen entsprechen der Aufbau und die Funktion der zweiten Ansteuerschaltung 10b der ersten Ansteuerschaltung 10a, so dass auf die vorstehenden Erläuterungen verwiesen werden kann.Incidentally, the structure and function of the second drive circuit 10b correspond to the first drive circuit 10a, so that reference may be made to the above explanations.

Figur 3 zeigt eine Ausführungsvariante der ersten Ansteuerschaltung 10a nach Figur 1. Der Wandlerschalter 17 sowie die Trennschalter 32 sind dabei durch Feldeffekttransistoren und beispielsgemäß n-Kanal-MISFETs vom Anreicherungstyp gebildet. Zur Ansteuerung der beiden Trennschalter 32 ist ein Steuerschalter 33 vorgesehen, der bei diesem Ausführungsbeispiel ebenfalls durch einen n-Kanal-MISFET vom Anreicherungstyp gebildet ist. Auch der Steuerschalter 33 kann allgemein analog zum wenigstens einen Trennschalter 32 und/oder dem Wandlerschalter 17 durch einen Halbleiterschalter gebildet sein. FIG. 3 shows a variant of the first drive circuit 10a after FIG. 1 , The transducer switch 17 and the circuit breaker 32 are formed by field-effect transistors and, according to the example, n-channel MISFETs of the enhancement type. For driving the two circuit breakers 32, a control switch 33 is provided, which is also formed in this embodiment by an n-channel MISFET accumulation type. Also, the control switch 33 may be formed generally analogous to at least one circuit breaker 32 and / or the converter switch 17 by a semiconductor switch.

Über die Steuereinheit wird der Steuereingang, hier das Gate des Steuerschalters 33 über ein Schaltsignal S angesteuert, um den Steuerschalter 33 zwischen seinem leitenden und seinem sperrenden Zustand umzuschalten. Der Drain-Anschluss des Steuerschalters 33 ist mit Masse GND verbunden. Der Source-Anschluss des Steuerschalters 23 ist über einen zweiten Widerstand 34 mit einer Versorgungsspannung UV verbunden. Die Versorgungsspannung UV ist eine Gleichspannung oder eine gleichgerichtete Wechselspannung. Der Source-Anschluss des Steuerschalters 33 ist ferner über einen dritten Widerstand 35 mit dem Steuereingang 32a des Trennschalters 32 der Strommessschaltung 24 sowie über einen vierten Widerstand 36 mit dem Steuereingang 32a des Trennschalters 32 der Spannungsmessschaltung 25 verbunden.About the control unit, the control input, here the gate of the control switch 33 is controlled via a switching signal S to the control switch 33 between its conducting and to switch to its blocking state. The drain terminal of the control switch 33 is connected to ground GND. The source terminal of the control switch 23 is connected via a second resistor 34 to a supply voltage UV. The supply voltage UV is a DC voltage or a rectified AC voltage. The source terminal of the control switch 33 is further connected via a third resistor 35 to the control input 32a of the circuit breaker 32 of the current measuring circuit 24 and via a fourth resistor 36 to the control input 32a of the circuit breaker 32 of the voltage measuring circuit 25.

Der Schaltzustand der Trennschalter 32 kann über die am Steuereingang 32a anliegende Spannung umgeschaltet werden. Sinkt die Gate-Source-Spannung des Feldeffekttransistors unter eine Schwellenspannung, so wird der Feldeffekttransistor sperrend. Andernfalls ist der Feldeffekttransistor leitend. Wird mithin über das Schaltsignal S der Steuerschalter 33 leitend, verringert sich das Potenzial an den beiden Steuereingängen 32a und die Trennschaler 32 gehen in ihren sperrenden Zustand über. Dabei liegt die Versorgungsspannung UV vollständig am zweiten Widerstand 34 an.The switching state of the circuit breaker 32 can be switched over the voltage applied to the control input 32a. If the gate-source voltage of the field-effect transistor drops below a threshold voltage, the field-effect transistor becomes nonconductive. Otherwise, the field effect transistor is conductive. If, therefore, the control switch 33 is turned on via the switching signal S, the potential at the two control inputs 32a is reduced, and the separating shells 32 change over into their blocking state. In this case, the supply voltage UV is completely applied to the second resistor 34.

Ist umkehrt der Steuerschalter 33 in seinem sperrenden Zustand, ist die Gate-Source-Spannung des Trennschalters größer als die Schwellenspannung und der Trennschalter 32 wird leitend.If the control switch 33 is reversed in its blocking state, the gate-source voltage of the disconnector is greater than the threshold voltage and the circuit breaker 32 is conductive.

Im Übrigen wird auf die Erläuterungen zur ersten Ansteuerschaltung 10a nach Figur 1 verwiesen.Incidentally, the explanations regarding the first drive circuit 10a follow FIG. 1 directed.

Figur 4 zeigt das Blockschaltbild einer konkreten Ausführungsform der zweiten Ansteuerschaltung 10b nach Figur 2. Der Trennschalter 32 ist durch einen Bipolartransistor, beispielsweise einen pnp-Bipolartransistor gebildet. Der von der Basis gebildete Steuereingang 32a ist über einen fünften Widerstand 40 und einen sechsten Widerstand 41 mit dem ersten Anschluss 11a der Leuchtmittelanordnung 11 verbunden. Der Steuereingang 32a ist außerdem über den fünften Widerstand 40 und einen siebten Widerstand 42 über den Steuerschalter 33 mit Masse GND verbunden. FIG. 4 shows the block diagram of a specific embodiment of the second drive circuit 10b after FIG. 2 , The circuit breaker 32 is formed by a bipolar transistor, for example a pnp bipolar transistor. Of the formed from the base control input 32a is connected via a fifth resistor 40 and a sixth resistor 41 to the first terminal 11a of the lamp assembly 11. The control input 32a is also connected via the fifth resistor 40 and a seventh resistor 42 via the control switch 33 to ground GND.

Der Steuerschalter 33 ist bei diesem Ausführungsbeispiel als Bipolartransistor und gemäß Figur 4 als npn-Transistor ausgeführt. Das Schaltsignal S wird über eine achten Widerstand 43 an die Basis des den Steuerschalter 33 bildenden Bipolartransistor angelegt. Ein neunter Widerstand 44 verbindet die Basis mit dem Emitter, wobei der Emitter auch mit der Masse GND verbunden ist. Der Kollektor des Bipolartransistors ist mit dem siebten Widerstand 42 verbunden.The control switch 33 is in this embodiment as a bipolar transistor and according to FIG. 4 designed as npn transistor. The switching signal S is applied via an eighth resistor 43 to the base of the bipolar transistor forming the control switch 33. A ninth resistor 44 connects the base to the emitter, and the emitter is also connected to ground GND. The collector of the bipolar transistor is connected to the seventh resistor 42.

Sperrt der Steuerschalter 33, wenn kein Schaltsignal S anliegt, so wird der Steuereingang 32a und mithin die Basis des als pnp-Transistor ausgeführten Trennschalters 32 über den fünften und sechsten Widerstand 40, 41 mit dem am Emitter anliegenden Potenzial verbunden, so dass der Trennschalter 32 sperrt. Wird hingegen ein Schaltsignal S an den Steuerschalter 33 angelegt, so dass dieser leitet, sinkt das Basispotenzial am Trennschalter 32 und dieser wird leitend.Locks the control switch 33, when no switching signal S is applied, the control input 32a and thus the base of the executed as a pnp transistor circuit breaker 32 via the fifth and sixth resistor 40, 41 connected to the emitter connected potential, so that the circuit breaker 32nd locks. If, by contrast, a switching signal S is applied to the control switch 33 so that it conducts, the base potential at the disconnecting switch 32 drops and this becomes conductive.

Figur 5 zeigt das Blockschaltbild einer dritten Ansteuerschaltung 10c. Kernidee dieser dritten Ansteuerschaltung 10c ist es, den Trennschalter 32 derart mit dem Wandler 15 zu koppeln, dass der Trennschaler 32 in seinen sperrenden bzw. geöffneten Schaltzustand umschaltet, wenn das Wandlersignal W am Wandlerschalter 17 abgeschaltet wird, beispielsweise wenn die Steuereinheit in den Ruhezustand übergeht. Hierfür ist der Steuereingang 32a des Trennschalters 32 über eine Koppelschaltung 45 mit dem Wandler 15 verbunden. Insbesondere verbindet die Koppelschaltung 45 entweder den masseseitigen Anschluss des Wandlerschalters 17 oder - wie in Figur 5 veranschaulicht - den bezugsspannungsseitigen Anschluss des Wandlerschalters 17 mit dem Steuereingang 32a des Trennschalters 32. Bei der dritten Ansteuerschaltung 10c übernimmt der Wandlerschalter 17 die Funktion des Steuerschalters 33. FIG. 5 shows the block diagram of a third drive circuit 10c. The core idea of this third drive circuit 10c is to couple the circuit breaker 32 to the converter 15 in such a way that the circuit breaker 32 switches to its blocking or open switching state when the converter signal W at the converter switch 17 is switched off, for example when the control unit switches to the idle state , For this purpose, the control input 32a of the circuit breaker 32 connected via a coupling circuit 45 to the converter 15. In particular, the coupling circuit 45 connects either the ground-side terminal of the converter switch 17 or - as in FIG. 5 In the case of the third drive circuit 10c, the converter switch 17 takes over the function of the control switch 33. In the third drive circuit 10c, the converter switch 17 assumes the function of the control switch 33.

Den beiden Messschaltungen 23 weisen gemäß Figur 5 einen gemeinsamen Trennschalter 32 auf. Im Unterschied zu den vorangegangenen Ausführungsformen weist die Reihenschaltung 26 drei in Reihe geschaltete Widerstände auf, wobei gemäß Figur 5 zwei erste Reihenwiderstände 26a in Reihe geschaltet sind. Grundsätzlich würde auch ein einziger erster Reihenwiderstand 26a genügen.The two measuring circuits 23 have according to FIG. 5 a common disconnect switch 32. In contrast to the preceding embodiments, the series circuit 26 has three resistors connected in series, according to FIG FIG. 5 two first series resistors 26a are connected in series. In principle, a single first series resistor 26a would also suffice.

Bei dem in Figur 5 veranschaulichten Ausführungsbeispiel sind der Trennschalter 32 und der Wandlerschalter 17 analog zu der in Figur 3 dargestellten Ausführungsform durch einen Feldeffekttransistor gebildet. Der Source-Anschluss des Trennschalters 32 ist mit den Messschaltungen 23 verbunden. Der Drain-Anschluss des Trennschalters 32 ist mit der Leuchtmittelanordnung 11 verbunden.At the in FIG. 5 illustrated embodiment, the circuit breaker 32 and the converter switch 17 are analogous to those in FIG. 3 illustrated embodiment formed by a field effect transistor. The source terminal of the circuit breaker 32 is connected to the measuring circuits 23. The drain terminal of the circuit breaker 32 is connected to the lamp assembly 11.

Die Koppelschaltung 45 weist in einer Verbindungsleitung 46 zwischen dem bezugsspannungsseitigen Anschluss des Wandlerschalters 17 und dem Steuereingang 32a des Trennschalters 32 einen Koppelkondensator 47 auf. Die Koppelschaltung 45 dient als Ladungspumpe mit Spannungsbegrenzung und definierter Last.The coupling circuit 45 has a coupling capacitor 47 in a connecting line 46 between the reference voltage side terminal of the converter switch 17 and the control input 32a of the circuit breaker 32. The coupling circuit 45 serves as a charge pump with voltage limitation and defined load.

Bei dem hier beschriebenen bevorzugten Ausführungsbeispiel weist die Koppelschaltung 45 in Reihe zum Koppelkondensator 47 eine erste Diode 48 auf, deren Kathode mit dem Steuereingang 32 des Trennschalters 32 verbunden ist. Die Koppelschaltung 45 weist parallel zur Gate-Source-Verbindung des Trennschalters 32 eine Parallelschaltung 49 mit einer Zenerdiode 50 und/oder einem zweiten Kondensator 51 und/oder einem siebten Widerstand 52 auf. Bei dem hier beschriebenen Ausführungsbeispiel sind alle drei Bauteile 50, 51, 52 vorgesehen, wobei die Kathode der Zenerdiode 50 mit dem Steuereingang 32a des Trennschalters 32 verbunden ist. Der Mittenabgriff zwischen dem Koppelkondensator 47 und der ersten Diode 48 ist beispielsgemäß an die Kathode einer zweiten Diode 53 angeschlossen, deren Anode mit dem Source-Anschluss des Trennschalters 32 verbunden ist.In the preferred embodiment described here, the coupling circuit 45 in series with the coupling capacitor 47, a first diode 48, the cathode with the Control input 32 of the circuit breaker 32 is connected. The coupling circuit 45 has parallel to the gate-source connection of the circuit breaker 32, a parallel circuit 49 with a Zener diode 50 and / or a second capacitor 51 and / or a seventh resistor 52. In the embodiment described here, all three components 50, 51, 52 are provided, wherein the cathode of the zener diode 50 is connected to the control input 32a of the circuit breaker 32. The center tap between the coupling capacitor 47 and the first diode 48 is connected, for example, to the cathode of a second diode 53 whose anode is connected to the source terminal of the circuit breaker 32.

Die dritte Ansteuerschaltung 10c arbeitet wie folgt:The third drive circuit 10c operates as follows:

Beim Betrieb der Leuchtmittelanordnung 12 wird der Wandlerschalter 17 durch das pulsweitenmodulierte Wandlersteuersignal W getaktet zwischen dem leitenden und dem sperrenden Schaltzustand umgeschaltet, wodurch die Spannung am Koppelkondensator 47 im Wesentlichen zwischen UB, beispielsweise 400 Volt, und 0V wechselt. Hat diese Spannung eine fallende Flanke wird der zweite Kondensator 51 über die zweite Diode 53 geladen. Weise diese Spannung eine steigende Flanke auf, wird der zweite Kondensator 51 über die erste Diode 48 geladen. Die beiden Dioden 48, 53 bewirken also eine Zweiweggleichrichtung. Das Gate des vom Feldeffekttransistor gebildeten Trennschalters 32 ist geladen und der Trennschalter 32 leitet.During operation of the lamp arrangement 12, the converter switch 17 is clocked by the pulse width modulated converter control signal W between the conductive and the blocking switching state, whereby the voltage at the coupling capacitor 47 substantially between UB, for example, 400 volts, and 0V changes. If this voltage has a falling edge, the second capacitor 51 is charged via the second diode 53. If this voltage has a rising edge, the second capacitor 51 is charged via the first diode 48. The two diodes 48, 53 thus cause a full-wave rectification. The gate of the circuit breaker 32 formed by the field effect transistor is charged and the circuit breaker 32 conducts.

Die Zenerdiode 50 dient zur Spannungsbegrenzung der Gate-Source-Spannung. Über den zweiten Kondensator 51 kann diese Gate-Source-Spannung stabilisiert werden.The zener diode 50 serves to limit the voltage of the gate-source voltage. Via the second capacitor 51, this gate-source voltage can be stabilized.

Beim Abschalten des Wandlersteuersignals W verbleibt der Wandlerschalter 17 in seinem sperrenden bzw. geöffneten Zustand. Als Folge davon fließt kein Strom mehr über die Ladungspumpe. Der zweite Kondensator 51 entlädt sich über den siebten Widerstand 52, das Potenzial am Steuereingang 32a (Gate) sinkt und damit auch die Gate-Source-Spannung. Schließlich sperrt der Trennschalter 32. Ein unerwünschter Strom durch die Messschaltungen 23 bei ausgeschaltetem Wandlersteuersignal W ist vermieden.When switching off the converter control signal W, the converter switch 17 remains in its blocking or opened Status. As a result, no electricity flows through the charge pump. The second capacitor 51 discharges via the seventh resistor 52, the potential at the control input 32a (gate) decreases and thus also the gate-source voltage. Finally, the disconnect switch 32 blocks. An undesired current through the measuring circuits 23 when the converter control signal W is switched off is avoided.

Die Erfindung betrifft eine Ansteuerschaltung 10 zur Ansteuerung einer Leuchtmittelanordnung 11 mit einer oder mehreren Leuchtdioden 12. Die Ansteuerschaltung 10 weist einen Wandler 15 mit einer in Reihe zur Leuchtmittelanordnung 11 geschalteten Induktivität 16 und einem Wandlerschalter 17 auf. Der Wandlerschalter 17 wird über ein Wandlersteuersignal W vorzugsweise pulsweitenmoduliert angesteuert, wenn die Leuchtmittelanordnung 11 betrieben werden soll. Außerdem ist wenigstens eine Messschaltung 23 vorhanden, die in Reihe zur Leuchtmittelanordnung 11 geschaltet ist. Um bei sperrendem Wandlerschalter 17, beispielsweise wenn das Wandlersteuersignal W ausgeschaltet ist, einen Stromfluss durch die Leuchtmittelanordnung 11 und die Messschaltung 23 zu vermeiden, ist in der Messschaltung wenigstens ein Trennschalter 32 vorhanden. Es sind Mittel zur Erzeugung eines Trennschaltersignals T vorhanden, über das der gesteuerte Trennschalter 32 in seinen sperrenden Zustand umgeschaltet wird, wenn kein Wandlersteuersignal W am Wandlerschalter 17 anliegt. Ein solches Mittel kann beispielsweise ein Koppelkondensator 47 zwischen Wandlerschalter und einem Steuereingang 32a des Trennschalters 32 sein.The invention relates to a drive circuit 10 for driving a light-emitting device 11 with one or more light-emitting diodes 12. The drive circuit 10 has a converter 15 with an inductance 16 connected in series with the light-emitting device 11 and a converter switch 17. The converter switch 17 is preferably controlled via a converter control signal W pulse width modulated when the lamp assembly 11 is to be operated. In addition, at least one measuring circuit 23 is provided, which is connected in series with the lighting device 11. In order to avoid current flow through the luminous means arrangement 11 and the measuring circuit 23 in the case of a blocking converter switch 17, for example when the converter control signal W is switched off, at least one disconnecting switch 32 is present in the measuring circuit. There are means for generating a circuit breaker signal T, via which the controlled disconnecting switch 32 is switched to its blocking state when no converter control signal W is present at the transformer switch 17. Such a means may be, for example, a coupling capacitor 47 between the converter switch and a control input 32a of the circuit breaker 32.

Bezugszeichenliste:LIST OF REFERENCE NUMBERS

1010
Ansteuerschaltungdrive circuit
10a10a
erste Ansteuerschaltungfirst drive circuit
1111
LeuchtmittelanordnungLamp positioning
11a11a
erster Anschluss der Leuchtmittelanordnungfirst connection of the lamp arrangement
11b11b
zweiter Anschluss der Leuchtmittelanordnungsecond connection of the lamp arrangement
1212
Leuchtdiodeled
1313
Leuchtmittel-KondensatorLamp capacitor
1515
Wandlerconverter
1616
Induktivitätinductance
1717
Wandlerschalterconverter switch
1818
Wandlerdiodeconverter diode
1919
erster Widerstandfirst resistance
2323
Messschaltungmeasuring circuit
2424
StrommessschaltungCurrent measurement circuit
2525
SpannungsmessschaltungVoltage measuring circuit
2626
Reihenschaltungseries connection
26a26a
erster Reihenwiderstandfirst series resistance
26b26b
zweiter Reihenwiderstandsecond series resistor
2727
Spannungsteilervoltage divider
27a27a
erster Spannungsteilerwiderstandfirst voltage divider resistor
27b27b
zweiter Spannungsteilerwiderstandsecond voltage divider resistor
2828
erster Kondensatorfirst capacitor
3232
Trennschalterdisconnectors
32a32a
Steuereingangcontrol input
3333
Steuerschaltercontrol switch
3434
zweiter Widerstandsecond resistance
3535
dritter Widerstandthird resistance
3636
vierter Widerstandfourth resistance
4040
fünfter Widerstandfifth resistance
4141
sechster Widerstandsixth resistance
4242
siebter Widerstandseventh resistance
4343
achter Widerstandeighth resistance
4444
neunter Widerstandninth resistance
4545
Koppelschaltungcoupling circuit
4646
Verbindungsleitungconnecting line
4747
Koppelkondensatorcoupling capacitor
4848
erste Diodefirst diode
4949
Parallelschaltungparallel connection
5050
ZenerdiodeZener diode
5151
zweiter Kondensatorsecond capacitor
5252
siebter Widerstandseventh resistance
5353
zweite Diodesecond diode
GNDGND
MasseDimensions
ILIL
LeuchtmittelstromLamp power
UBUB
Bezugsspannungreference voltage
ULUL
LeuchtmittelspannungLamp voltage
UVUV
Versorgungsspannungsupply voltage
SS
Schaltsignalswitching signal
TT
TrennschaltersignalDisconnectors signal
WW
WandlersteuersignalConverter control signal

Claims (15)

  1. Drive circuit (10) for a lighting assembly (11),
    wherein a reference voltage (UB) is present at a connection (11b) of the lighting assembly (11) with higher voltage potential,
    with a transducer (15), to which the lighting assembly (11) is connected and which has a transducer switch (17) controlled by a transducer control signal (W), wherein the transducer (15) controls or regulates an illumination current (IL) flowing through the lighting assembly and adjusts the brightness of the lighting assembly (11),
    with at least one measurement circuit (23), which is connected in series to the lighting assembly (11) and serves to determine the current flowing through the lighting assembly (11) and/or the transducer switch (17) and/or to determine the illumination voltage (UL) present at the lighting assembly (11),
    characterised in that an actuatable isolation switch (32) is provided, which is arranged in the at least one measurement circuit (23) and the switching status of which can be switched over by means of an isolation switch signal (T), which when the transducer control switch (W) is switched off, assumes a switching status, in which it interrupts the current flow through the at least one measurement circuit (23).
  2. Drive circuit according to claim 1, characterised in that a measurement circuit (23) is provided for determination of the current flowing through the lighting assembly (11) and/or the transducer switch (17) and a measurement circuit (23) is provided for determination of the illumination voltage (UL), and either each measurement circuit has an isolation switch (32) or both measurement circuits (23) are connected to the lighting assembly (11) via a common isolation switch (32).
  3. Drive circuit according to one of the preceding claims, characterised in that the transducer (15) is configured as a buck converter with an inductor (16) connected in series to the lighting assembly (11).
  4. Drive circuit according to one of the preceding claims, characterised in that the transducer switch (17) and/or the isolation switch (32) is configured as a field effect transistor or bipolar transistor.
  5. Drive circuit according to claim 4, characterised in that the field effect transistor is configured as an n-channel MOSFET.
  6. Drive circuit according to claim 4, characterised in that the bipolar transistor is configured as a pnp transistor.
  7. Drive circuit according to one of the preceding claims, characterised in that the switching status of the isolation switch (32) is dependent on the switching status of a control switch (33) actuated with a switching signal (S).
  8. Drive circuit according to claim 7, characterised in that the control switch (33) is configured as a separate component.
  9. Drive circuit according to claim 7, characterised in that the control switch (33) is formed by the transducer switch (17).
  10. Drive circuit according to one of the preceding claims, characterised in that the transducer (15) is connected to a control input (32a) of the isolation switch (32) via a coupling circuit (45) having a coupling capacitor (47).
  11. Drive circuit according to claim 10, characterised in that the coupling capacitor (47) connects the control input (32a) of the isolation switch (32) to the connection of the transducer switch (17), which is connected to a reference voltage (UB).
  12. Drive circuit according to claim 10 or 11, characterised in that in addition to the coupling capacitor (47), the coupling circuit (45) has at least one further component (50, 51) for limiting voltage and/or stabilising voltage.
  13. Drive circuit according to claim 12, characterised in that the further component (50, 51) connects the control input (32a) of the isolation switch (32) to one of the two connections of the isolation switch (32).
  14. Drive circuit according to one of claims 7 to 13, characterised in that the control switch (33) is configured as a field effect transistor or bipolar transistor.
  15. Drive circuit according to claim 14, characterised in that the bipolar transistor is configured as an npn transistor.
EP12178287.4A 2012-07-27 2012-07-27 Control circuit for a lighting assembly with a controllable circuit breaker Active EP2690927B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP12178287.4A EP2690927B1 (en) 2012-07-27 2012-07-27 Control circuit for a lighting assembly with a controllable circuit breaker

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP12178287.4A EP2690927B1 (en) 2012-07-27 2012-07-27 Control circuit for a lighting assembly with a controllable circuit breaker

Publications (2)

Publication Number Publication Date
EP2690927A1 EP2690927A1 (en) 2014-01-29
EP2690927B1 true EP2690927B1 (en) 2015-01-28

Family

ID=46845602

Family Applications (1)

Application Number Title Priority Date Filing Date
EP12178287.4A Active EP2690927B1 (en) 2012-07-27 2012-07-27 Control circuit for a lighting assembly with a controllable circuit breaker

Country Status (1)

Country Link
EP (1) EP2690927B1 (en)

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101473696B (en) * 2006-06-22 2011-04-13 皇家飞利浦电子股份有限公司 Drive circuit for driving a load with pulsed current
EP2347633A1 (en) 2008-10-20 2011-07-27 Tridonic AG Operating circuit for light-emitting diodes

Also Published As

Publication number Publication date
EP2690927A1 (en) 2014-01-29

Similar Documents

Publication Publication Date Title
DE102011087368B4 (en) Driver circuit, arrangement and method for bootstrapping a switch driver
EP2888800B1 (en) Emergency lighting device
DE102011087434B4 (en) Circuit and three methods of driving a switch
DE102016114820A1 (en) System and method for a switch with a normally-on transistor and a normally-off transistor
DE112012001674T5 (en) Cascade switch with self-locking and normally-on components and circuits comprising the switches
DE102006024422A1 (en) Circuit arrangement and method for voltage conversion
DE3914799A1 (en) FLOW CONVERTER
DE112011100594B4 (en) LED voltage measurement
DE102011087431A1 (en) Arrangement and method for driving a cascode switch
EP3525333A1 (en) Bi-directional paralysis circuit
DE112012006360T5 (en) DC power supply circuit
EP2690927B1 (en) Control circuit for a lighting assembly with a controllable circuit breaker
DE112015007243B4 (en) solid state lighting assembly
WO2009062554A1 (en) Switchable current supply for auxiliary current circuits in a current converter
DE102017105560A1 (en) CHANGING ELECTRICAL ENERGY
EP1195885B1 (en) Synchronuous rectifyer circuit
DE102006049228A1 (en) Electromagnetic compatibility, durability, power dissipation optimizing method for inductive load's synchronized operation arrangement, involves controlling gate of free-wheel transistor, so that output voltage of transistor is small
EP3393207B1 (en) Switching regulator for operating lights with afterglow suppression
AT504121B1 (en) Circuit arrangement for varying load connected with different supply potentials, particularly switching power supply, comprises two semiconductor switches, which are connected with control drive units, supply voltage, transformer and diode
DE102007009520A1 (en) Interface for sending of digital signals of operating device for light medium connected by bus line, has input-connection for selectively receiving of mains alternating voltage or digital low-voltage signal
EP0766394A2 (en) Circuit arrangement for controlling a power enhancement MOSFET
EP1943885A1 (en) Apparatus for operating at least one discharge lamp
DE102015217146A1 (en) Clocked flyback converter circuit
DE202012004052U1 (en) Buck converter for providing a current for at least one LED
DE102014202054B3 (en) Circuit arrangement for recovering energy stored in an inductive load

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

17P Request for examination filed

Effective date: 20140203

RBV Designated contracting states (corrected)

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

INTG Intention to grant announced

Effective date: 20141024

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: GERMAN

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 502012002203

Country of ref document: DE

Effective date: 20150312

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 708703

Country of ref document: AT

Kind code of ref document: T

Effective date: 20150315

REG Reference to a national code

Ref country code: NL

Ref legal event code: VDEP

Effective date: 20150128

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150428

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150428

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150429

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150528

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 502012002203

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

26N No opposition filed

Effective date: 20151029

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150727

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20150731

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20150731

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20160331

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20150731

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20150727

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20160727

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20120727

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160727

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20150731

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

Ref country code: MK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

REG Reference to a national code

Ref country code: AT

Ref legal event code: MM01

Ref document number: 708703

Country of ref document: AT

Kind code of ref document: T

Effective date: 20170727

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20150128

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170727

REG Reference to a national code

Ref country code: DE

Ref legal event code: R079

Ref document number: 502012002203

Country of ref document: DE

Free format text: PREVIOUS MAIN CLASS: H05B0033080000

Ipc: H05B0045000000

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 502012002203

Country of ref document: DE

Owner name: VOSSLOH-SCHWABE DEUTSCHLAND GMBH, DE

Free format text: FORMER OWNER: VOSSLOH-SCHWABE DEUTSCHLAND GMBH, 73660 URBACH, DE

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20230626

Year of fee payment: 12