WO2010034739A1 - Method for operating a series circuit of at least two led’s - Google Patents

Method for operating a series circuit of at least two led’s Download PDF

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Publication number
WO2010034739A1
WO2010034739A1 PCT/EP2009/062319 EP2009062319W WO2010034739A1 WO 2010034739 A1 WO2010034739 A1 WO 2010034739A1 EP 2009062319 W EP2009062319 W EP 2009062319W WO 2010034739 A1 WO2010034739 A1 WO 2010034739A1
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WO
WIPO (PCT)
Prior art keywords
led
series circuit
control unit
leds
power
Prior art date
Application number
PCT/EP2009/062319
Other languages
German (de)
French (fr)
Inventor
Josef Studniorz
Ralf Edelmeier
Original Assignee
Hella Kgaa Hueck & Co.
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 Hella Kgaa Hueck & Co. filed Critical Hella Kgaa Hueck & Co.
Priority to EP09783324A priority Critical patent/EP2329686A1/en
Publication of WO2010034739A1 publication Critical patent/WO2010034739A1/en

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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]
    • H05B45/50—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
    • H05B45/58—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits involving end of life detection of LEDs
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/40—Details of LED load circuits
    • H05B45/44—Details of LED load circuits with an active control inside an LED matrix
    • H05B45/48—Details of LED load circuits with an active control inside an LED matrix having LEDs organised in strings and incorporating parallel shunting devices
    • 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
    • H05B47/00—Circuit arrangements for operating light sources in general, i.e. where the type of light source is not relevant
    • H05B47/20—Responsive to malfunctions or to light source life; for protection
    • H05B47/23—Responsive to malfunctions or to light source life; for protection of two or more light sources connected in series

Definitions

  • the present invention relates to methods of operating a series connection of at least two LEDs.
  • DE 10 2005 008 100 B4 discloses a method for operating a series connection of at least two LEDs. In order to satisfy the need for continuous operation of the remaining LEDs in applications such as display panels or the like, it is proposed that in the case of a high-impedance failure of an LED, this LED be automatically detected and short-circuited by means of an electrical bypass line.
  • a predefined voltage Vx is applied to a load resistor Rx, while the voltage Vx becomes zero in the event of a failure of one of the LEDs.
  • the object of the present invention is to provide a method for operating a series connection of at least two LEDs, in which the high-impedance failure of an LED is reliably detected by conventional control devices and at the same time a continuation of the operation of the remaining LEDs is made possible.
  • a significant advantage of the method according to the invention is, in particular, that a high-impedance failure of an LED is reliably detected by conventional control devices and at the same time a continuation of the operation of the remaining LED's is possible.
  • the failure of at least one of the LEDs is indicated by the change of a voltage Vx at a load resistor Rx.
  • Vx a voltage at a load resistor
  • conventional control devices for example for use in motor vehicles, are designed to detect the high-impedance failure of light sources configured as incandescent lamps. This happens because in the case of a high-impedance failure of the incandescent lamp, the current flow fails, which is clearly identifiable as a fault in the control unit.
  • the inventive approach is now to realize an error detection of high-impedance failed LED's, which is analogous to the failure of a light bulb. This is achieved by a method according to claim 1.
  • the conventional, actually designed for incandescent control devices can also be used in LED's designed as light sources.
  • the method according to the invention can be used particularly advantageously in LED arrays in which the series connection is an LED branch of an LED array consisting of at least two LED branches and each of the LED branches is operated in the manner according to the invention.
  • Fig. An embodiment of a series connection of at least two LEDs for carrying out the method according to the invention.
  • the single FIGURE shows a series circuit 2 of at least two LEDs 4.
  • the series circuit 2 is part of a lighting device for a motor vehicle, not shown, and electrically connected to a power source 6 of a power grid 8.
  • the current source 6 is connected in a manner known to those skilled in the art to a control unit 7 in a signal-transmitting manner.
  • the series circuit 2 here has a total of 10 LED's 4, of which only four LED's 4 are shown for the sake of clarity. The remaining LEDs are indicated by a dashed line in the current path of the LEDs 4.
  • a switch 12 is electrically connected in parallel to each individual LED 4 of the series circuit 2 or to a respective group 10 with at least two LEDs 4.
  • a switch 12 is connected in parallel to the first and last LED 4 of the series circuit 2 in the direction of current flow; the remaining LEDs 4 are here combined in groups 10 to two LEDs 4, wherein each of the groups 10 only a single switch 12 is connected in parallel.
  • the remaining LEDs 4 are here combined in groups 10 to two LEDs 4, wherein each of the groups 10 only a single switch 12 is connected in parallel.
  • one or the other solution and the number of LEDs 4 in a group of economic and technical considerations is practical. For example, it makes sense to summarize LED's 4 with a smaller importance for the specific lighting function meaning to a group 10, while a separate switch 12 is connected in parallel to LED's 4 with greater importance.
  • the switches 12 can be selected by type, material and arrangement within wide suitable limits.
  • the series circuit 2 is connected in a manner known to those skilled in the art with a control unit 14 signal transmitting.
  • the control unit 14 is signal transmitting connected to the power source 6, a voltage measuring device 16 and the switches 12, which is symbolized by the solid and dashed arrows in the figure. - A -
  • the switches 12 are open. See the figure.
  • the voltage drop across the entire series circuit 2 is measured by means of the voltage measuring device 16 in the manner known to those skilled in the art and forwarded to the control unit 14 for further processing. Depending on the application, the measurement can be continuous or discontinuous. In normal operation, that is, when the voltage thus determined is below a predetermined threshold, the switches 12 remain open.
  • an LED 4 of the series circuit 2 fails with high resistance, ie if the current path with the LEDs 4 is interrupted, the voltage drop above the limit value increases.
  • the control unit 14 detects this and then switches off the current source 6 in a manner known to those skilled in the art, so that the LEDs 4 of the series circuit 2 are no longer energized.
  • This power cut is limited in time to a minimum and just long enough so that the controller 7 can safely detect the resulting reduced power consumption. In this way it is ensured that on the one hand, the failure, namely the failure of at least one LED 4 of the series circuit 2 is reliably detected. On the other hand, it is achieved that the complete shutdown of the LEDs 4 of the series circuit 2 to the user, here the road users, not noticeable.
  • the control unit 14 After the short-term complete shutdown for fault detection by the control unit 7, ie after the expiry of a predetermined shutdown period, recognizes the control unit 14 in a known manner, the at least one high-impedance failed LED 4 and bridges it by the automatic closing of this LED 4 or By the short circuiting of the at least one faulty LED 4, the current path is closed again and the control unit 14 switches the power supply to the group 10 in which the faulty LED 4 is included. source 6 again, so that the still functioning LEDs 4 of the series circuit 2 shine again.
  • the conventional control units which are actually designed for incandescent lamps, can also be used with light sources designed as LEDs.
  • the series circuit is an LED branch of an LED array consisting of at least two LED branches, each of which is operated in the aforementioned manner.
  • This embodiment is particularly advantageous in motor vehicles in order to achieve the luminous flux required for the respective lighting task, for example the illumination of the vehicle surroundings.
  • the inventive method can also be used advantageously for other lighting tasks and other uses.

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  • Circuit Arrangement For Electric Light Sources In General (AREA)

Abstract

The present invention relates to a method for operating a series circuit (2) of at least two LED’s (4), wherein the method comprises the following steps in the order indicated: - supplying the series circuit (2) with power from a current or voltage source (6) of a power grid (8), - measuring the voltage drop across the entire series circuit (2), - turning off the power supply by a control unit (14) when the measured voltage drop exceeds a previously established limit value, - recognizing the loss of at least one of the LED's (4) by a control device (7) of the power grid (8) based on the reduced power draw, - recognizing and short-circuiting the lost LED (4) by the control unit (14).

Description

Verfahren zum Betrieb einer Reihenschaltung von mindestens zwei LED's Method for operating a series connection of at least two LEDs
Beschreibungdescription
Die vorliegende Erfindung bezieht sich auf Verfahren zum Betrieb einer Reihenschaltung von mindestens zwei LED's.The present invention relates to methods of operating a series connection of at least two LEDs.
Derartige Verfahren sind aus dem Stand der Technik in zahlreichen Ausführungsvarianten bereits bekannt.Such methods are already known from the prior art in numerous embodiments.
Beispielsweise ist aus der DE 10 2005 008 100 B4 ein Verfahren zum Betrieb einer Reihenschaltung von mindestens zwei LED's bekannt. Um bei Anwendungen wie Anzeigetafeln oder dergleichen den Bedarf an einem kontinuierlichen Betrieb der verbleibenden LED's zu befriedigen, wird vorgeschlagen, im Falle eines hochohmigen Ausfalls einer LED diese LED automatisch zu erkennen und mittels einer elektrischen Bypassleitung kurzzuschließen. In der vierten Ausführungsform der DE 10 2005 008 100 B4 liegt dabei an einem Lastwiderstand Rx eine vorher festgelegte Spannung Vx an, während die Spannung Vx bei einem Ausfall einer der LED's gleich null wird.For example, DE 10 2005 008 100 B4 discloses a method for operating a series connection of at least two LEDs. In order to satisfy the need for continuous operation of the remaining LEDs in applications such as display panels or the like, it is proposed that in the case of a high-impedance failure of an LED, this LED be automatically detected and short-circuited by means of an electrical bypass line. In the fourth embodiment of DE 10 2005 008 100 B4, a predefined voltage Vx is applied to a load resistor Rx, while the voltage Vx becomes zero in the event of a failure of one of the LEDs.
Hier setzt die vorliegende Erfindung an.This is where the present invention begins.
Der vorliegenden Erfindung liegt die Aufgabe zugrunde ein Verfahren zum Betrieb einer Reihenschaltung von mindestens zwei LED's anzugeben, bei dem der hochoh- mige Ausfall einer LED durch herkömmliche Steuergeräte sicher detektiert wird und gleichzeitig eine Fortsetzung des Betriebs der restlichen LED's ermöglicht ist.The object of the present invention is to provide a method for operating a series connection of at least two LEDs, in which the high-impedance failure of an LED is reliably detected by conventional control devices and at the same time a continuation of the operation of the remaining LEDs is made possible.
Diese Aufgabe wird durch ein Verfahren mit den Merkmalen des Anspruchs 1 gelöst. Der Unteranspruch betrifft eine vorteilhafte Weiterbildung der Erfindung.This object is achieved by a method having the features of claim 1. The dependent claim relates to an advantageous development of the invention.
Ein wesentlicher Vorteil des erfindungsgemäßen Verfahrens liegt insbesondere darin, dass ein hochohmiger Ausfall einer LED auch durch herkömmliche Steuergeräte sicher detektiert wird und gleichzeitig eine Fortsetzung des Betriebs der restlichen LED's ermöglicht ist. Bei dem aus dem Stand der Technik bekannten Verfahren wird der Ausfall zumindest einer der LED's über die Veränderung einer Spannung Vx an einem Lastwiderstand Rx angezeigt. Grundsätzlich ist es zwar möglich, diese Spannung Vx zu Diagnosezwecken an ein Steuergerät weiterzuleiten, um das Signal, nämlich die Spannung, weiter zu verarbeiten. Herkömmliche Steuergeräte, beispielsweise für den Einsatz in Kraftfahrzeugen, sind jedoch dazu ausgebildet, den hochohmigen Ausfall von als Glühlampen ausgebildeten Lichtquellen zu erkennen. Dies geschieht dadurch, dass bei einem hochohmigen Ausfall der Glühlampe der Stromfluss ausfällt, was in dem Steuergerät eindeutig als Fehler identifizierbar ist.A significant advantage of the method according to the invention is, in particular, that a high-impedance failure of an LED is reliably detected by conventional control devices and at the same time a continuation of the operation of the remaining LED's is possible. In the method known from the prior art, the failure of at least one of the LEDs is indicated by the change of a voltage Vx at a load resistor Rx. In principle, it is possible to forward this voltage Vx to a control unit for diagnostic purposes in order to further process the signal, namely the voltage. However, conventional control devices, for example for use in motor vehicles, are designed to detect the high-impedance failure of light sources configured as incandescent lamps. This happens because in the case of a high-impedance failure of the incandescent lamp, the current flow fails, which is clearly identifiable as a fault in the control unit.
Bei der Verwendung von LED's als Lichtquelle und dem hochohmigen Ausfall einer LED ist dies jedoch nicht zwangsläufig der Fall. Es ist jedoch nicht gewünscht, für diesen Fall neue Steuergeräte zu entwickeln. Das bekannte Verfahren ist aber bei der Verwendung von herkömmlichen, eigentlich für Glühlampen ausgebildeten Steuergeräten nicht einsetzbar, da hierfür zumindest ein weiterer Eingang für das oben genannte Spannungssignal Vx erforderlich wäre. Dieser Eingang steht aber nicht zur Verfügung.However, this is not necessarily the case when using LEDs as the light source and the high-impedance failure of an LED. However, it is not desirable to develop new controllers for this case. However, the known method can not be used with the use of conventional control units, which are actually designed for incandescent lamps, since this would require at least one further input for the above-mentioned voltage signal Vx. This input is not available.
Der erfindungsgemäße Ansatz liegt nun darin, eine Fehlererkennung von hochohmig ausgefallenen LED's zu realisieren, die analog zu dem Ausfall einer Glühlampe ist. Dies wird durch ein Verfahren gemäß Anspruch 1 erreicht. Auf diese Weise können die herkömmlichen, eigentlich für Glühlampen ausgebildeten Steuergeräte auch bei als LED's ausgebildeten Lichtquellen verwendet werden.The inventive approach is now to realize an error detection of high-impedance failed LED's, which is analogous to the failure of a light bulb. This is achieved by a method according to claim 1. In this way, the conventional, actually designed for incandescent control devices can also be used in LED's designed as light sources.
Das erfindungsgemäße Verfahren lässt sich insbesondere vorteilhaft bei LED-Arrays einsetzen, in denen die Reihenschaltung ein LED-Zweig eines aus mindestens zwei LED-Zweigen bestehenden LED-Arrays ist und jeder der LED-Zweige auf die erfindungsgemäße Weise betrieben wird.The method according to the invention can be used particularly advantageously in LED arrays in which the series connection is an LED branch of an LED array consisting of at least two LED branches and each of the LED branches is operated in the manner according to the invention.
Anhand der beigefügten, grob schematischen Zeichnungen wird die Erfindung nachfolgend näher erläutert. Dabei zeigt: Fig. ein Ausführungsbeispiel einer Reihenschaltung von mindestens zwei LED's zur Durchführung des erfindungsgemäßen Verfahrens.Reference to the accompanying, rough schematic drawings, the invention will be explained in more detail below. Showing: Fig. An embodiment of a series connection of at least two LEDs for carrying out the method according to the invention.
Die einzige Fig. zeigt eine Reihenschaltung 2 von mindestens zwei LED's 4. Die Reihenschaltung 2 ist Teil einer nicht dargestellten Beleuchtungseinrichtung für ein Kraftfahrzeug und an eine Stromquelle 6 eines Stromnetzes 8 elektrisch leitend angeschlossen. Die Stromquelle 6 ist auf dem Fachmann bekannte Weise mit einem Steuergerät 7 signalübertragend verbunden. Die Reihenschaltung 2 weist hier insgesamt 10 LED's 4 auf, von denen zum Zwecke der Übersichtlichkeit lediglich vier LED's 4 dargestellt sind. Die übrigen LED's sind durch eine gestrichelte Linie im Strompfad der LED's 4 angedeutet. Grundsätzlich ist es denkbar, dass zu jeder einzelnen LED 4 der Reihenschaltung 2 oder zu jeweils eine Gruppe 10 mit mindestens zwei LED's 4 ein Schalter 12 elektrisch parallel geschaltet ist.The single FIGURE shows a series circuit 2 of at least two LEDs 4. The series circuit 2 is part of a lighting device for a motor vehicle, not shown, and electrically connected to a power source 6 of a power grid 8. The current source 6 is connected in a manner known to those skilled in the art to a control unit 7 in a signal-transmitting manner. The series circuit 2 here has a total of 10 LED's 4, of which only four LED's 4 are shown for the sake of clarity. The remaining LEDs are indicated by a dashed line in the current path of the LEDs 4. In principle, it is conceivable that a switch 12 is electrically connected in parallel to each individual LED 4 of the series circuit 2 or to a respective group 10 with at least two LEDs 4.
Hier ist zu der in Stromflussrichtung ersten und letzten LED 4 der Reihenschaltung 2 ein Schalter 12 parallel geschaltet; die übrigen LED's 4 sind hier in Gruppen 10 zu jeweils zwei LED's 4 zusammengefasst, wobei jeder der Gruppen 10 lediglich ein einziger Schalter 12 parallel geschaltet ist. Je nach Anwendungsfall ist die eine oder andere Lösung sowie die Anzahl der LED's 4 in einer Gruppe aus wirtschaftlichen und technischen Überlegungen praktikabel. Beispielsweise ist es sinnvoll LED's 4 mit einer für die konkrete Beleuchtungsfunktion geringeren Bedeutung zu einer Gruppe 10 zusammenzufassen, während zu LED's 4 mit einer größeren Bedeutung ein eigener Schalter 12 parallel geschaltet wird.Here, a switch 12 is connected in parallel to the first and last LED 4 of the series circuit 2 in the direction of current flow; the remaining LEDs 4 are here combined in groups 10 to two LEDs 4, wherein each of the groups 10 only a single switch 12 is connected in parallel. Depending on the application, one or the other solution and the number of LEDs 4 in a group of economic and technical considerations is practical. For example, it makes sense to summarize LED's 4 with a smaller importance for the specific lighting function meaning to a group 10, while a separate switch 12 is connected in parallel to LED's 4 with greater importance.
Die Schalter 12 sind nach Art, Material und Anordnung in weiten geeigneten Grenzen wählbar.The switches 12 can be selected by type, material and arrangement within wide suitable limits.
Die Reihenschaltung 2 ist auf dem Fachmann bekannte Weise mit einer Steuereinheit 14 signalübertragend verbunden. Darüber hinaus ist die Steuereinheit 14 signalübertragend mit der Stromquelle 6, einem Spannungsmessgerät 16 und den Schaltern 12 verbunden, was durch die durchgezogenen und gestrichelten Pfeile in der Fig. symbolisiert ist. - A -The series circuit 2 is connected in a manner known to those skilled in the art with a control unit 14 signal transmitting. In addition, the control unit 14 is signal transmitting connected to the power source 6, a voltage measuring device 16 and the switches 12, which is symbolized by the solid and dashed arrows in the figure. - A -
Im Nachfolgenden wird das erfindungsgemäße Verfahren anhand der Fig. näher erläutert.In the following, the method according to the invention will be explained in more detail with reference to FIG.
Im Normalbetrieb der Reihenschaltung 2, also bei durch die Stromquelle 6 bestromten und funktionsfähigen LED's 4, sind die Schalter 12 geöffnet. Siehe die Figur. Der Spannungsabfall über die gesamte Reihenschaltung 2 wird mittels des Spannungsmessgeräts 16 auf dem Fachmann bekannte Weise gemessen und an die Steuereinheit 14 zur weiteren Verarbeitung weitergeleitet. Die Messung kann dabei, je nach Anwendungsfall, kontinuierlich oder diskontinuierlich erfolgen. Im Normalbetrieb, also wenn die so ermittelte Spannung unter einem vorher festgelegten Grenzwert liegt, bleiben die Schalter 12 geöffnet.In normal operation of the series circuit 2, that is, when energized by the current source 6 and functioning LED's 4, the switches 12 are open. See the figure. The voltage drop across the entire series circuit 2 is measured by means of the voltage measuring device 16 in the manner known to those skilled in the art and forwarded to the control unit 14 for further processing. Depending on the application, the measurement can be continuous or discontinuous. In normal operation, that is, when the voltage thus determined is below a predetermined threshold, the switches 12 remain open.
Fällt jedoch eine LED 4 der Reihenschaltung 2 hochohmig aus, also wird der Strompfad mit den LED's 4 unterbrochen, steigt der Spannungsabfall über den Grenzwert an. Die Steuereinheit 14 detektiert dies und schaltet daraufhin die Stromquelle 6 auf dem Fachmann bekannte Weise ab, so dass die LED's 4 der Reihenschaltung 2 nicht mehr bestromt werden. Diese Stromabschaltung ist zeitlich auf ein Minimum begrenzt und gerade ausreichend lang, damit das Steuergerät 7 die dadurch verminderte Stromaufnahme sicher detektieren kann. Auf diese Weise ist gewährleistet, dass zum einen der Fehler, nämlich der Ausfall zumindest einer LED 4 der Reihenschaltung 2 sicher erkannt wird. Zum anderen ist dadurch erreicht, dass die Komplettabschaltung der LED's 4 der Reihenschaltung 2 dem Benutzer, hier den Verkehrsteilnehmern, nicht auffällt.If, however, an LED 4 of the series circuit 2 fails with high resistance, ie if the current path with the LEDs 4 is interrupted, the voltage drop above the limit value increases. The control unit 14 detects this and then switches off the current source 6 in a manner known to those skilled in the art, so that the LEDs 4 of the series circuit 2 are no longer energized. This power cut is limited in time to a minimum and just long enough so that the controller 7 can safely detect the resulting reduced power consumption. In this way it is ensured that on the one hand, the failure, namely the failure of at least one LED 4 of the series circuit 2 is reliably detected. On the other hand, it is achieved that the complete shutdown of the LEDs 4 of the series circuit 2 to the user, here the road users, not noticeable.
Nach der kurzzeitigen Komplettabschaltung zur Fehlererkennung durch das Steuergerät 7, also nach dem Ablauf einer vorher festgelegten Abschalt-Zeitspanne, erkennt die Steuereinheit 14 auf dem Fachmann bekannte Weise die zumindest eine hochohmig ausgefallene LED 4 und überbrückt diese durch das automatische Schließen des dieser LED 4 oder der Gruppe 10, in der die fehlerhafte LED 4 beinhaltet ist, zugeordneten Schalters 12. Durch das Kurzschließen der zumindest einen fehlerhaften LED 4 ist der Strompfad wieder geschlossen und die Steuereinheit 14 schaltet die Strom- quelle 6 wieder ein, so dass die noch funktionsfähigen LED's 4 der Reihenschaltung 2 erneut leuchten.After the short-term complete shutdown for fault detection by the control unit 7, ie after the expiry of a predetermined shutdown period, recognizes the control unit 14 in a known manner, the at least one high-impedance failed LED 4 and bridges it by the automatic closing of this LED 4 or By the short circuiting of the at least one faulty LED 4, the current path is closed again and the control unit 14 switches the power supply to the group 10 in which the faulty LED 4 is included. source 6 again, so that the still functioning LEDs 4 of the series circuit 2 shine again.
Auf diese Weise ist gleichzeitig eine Fehlererkennung von hochohmig ausgefallenen LED's realisiert, die analog zu dem Ausfall einer Glühlampe ist, und es ermöglicht, die Beleuchtungsfunktion zumindest teilweise zu erhalten. Durch das erfindungsgemäße Verfahren können die herkömmlichen, eigentlich für Glühlampen ausgebildeten Steuergeräte auch bei als LED's ausgebildeten Lichtquellen verwendet werden.In this way, an error detection of high-impedance LED's is realized at the same time, which is analogous to the failure of a light bulb, and makes it possible to obtain the illumination function at least partially. By the method according to the invention, the conventional control units, which are actually designed for incandescent lamps, can also be used with light sources designed as LEDs.
Die Erfindung ist nicht auf das vorliegende Ausführungsbeispiel begrenzt. Beispielsweise ist die Reihenschaltung ein LED-Zweig eines aus mindestens zwei LED- Zweigen bestehenden LED-Arrays, von denen jeder auf die vorgenannte Weise betrieben wird. Diese Ausführungsform ist insbesondere bei Kraftfahrzeugen von Vorteil, um so den für die jeweilige Leuchtaufgabe, beispielsweise die Beleuchtung des Fahrzeugumfelds, erforderlichen Lichtstrom zu erzielen. Selbstverständlich ist das erfindungsgemäße Verfahren auch für andere Leuchtaufgaben und bei anderen Verwendungen vorteilhaft einsetzbar. The invention is not limited to the present embodiment. For example, the series circuit is an LED branch of an LED array consisting of at least two LED branches, each of which is operated in the aforementioned manner. This embodiment is particularly advantageous in motor vehicles in order to achieve the luminous flux required for the respective lighting task, for example the illumination of the vehicle surroundings. Of course, the inventive method can also be used advantageously for other lighting tasks and other uses.
BezugszeichenlisteLIST OF REFERENCE NUMBERS
2 Reihenschaltung2 series connection
4 LED4 LEDs
6 Stromquelle6 power source
7 Steuergerät7 control unit
8 Stromnetz8 power grid
10 Gruppe von LED's10 group of LEDs
12 Schalter12 switches
14 Steuereinheit14 control unit
16 Spannungsmessgerät 16 voltmeter

Claims

Patentansprüche claims
1. Verfahren zum Betrieb einer Reihenschaltung (2) von mindestens zwei LED's (4), wobei das Verfahren die folgenden Schritte in der angegebenen Reihenfolge aufweist:A method of operating a series circuit (2) of at least two LED's (4), the method comprising the following steps in the order given:
- Versorgung der Reihenschaltung (2) mit Strom durch eine Strom- oder Spannungsquelle (6) eines Stromnetzes (8),Supplying the series circuit (2) with current through a current or voltage source (6) of a power network (8),
- Messung des Spannungsabfalls über die gesamte Reihenschaltung (2),Measurement of the voltage drop over the entire series circuit (2),
- Ausschalten der Stromversorgung durch eine Steuereinheit (14), wenn der gemessene Spannungsabfall einen vorher festgelegten Grenzwert übersteigt,Switching off the power supply by a control unit (14) when the measured voltage drop exceeds a predetermined threshold,
- Erkennung des Ausfalls zumindest einer der LED's (4) durch ein Steuergerät (7) des Stromnetzes (8) aufgrund der verminderten Stromaufnahme,- Detection of the failure of at least one of the LEDs (4) by a control unit (7) of the power grid (8) due to the reduced power consumption,
- Erkennung und Kurzschließen der ausgefallenen LED (4) durch die Steuereinheit (14).- Detection and short-circuiting of the failed LED (4) by the control unit (14).
2. Verfahren nach Anspruch 1 , dadurch gekennzeichnet, dass die Reihenschaltung (2) ein LED-Zweig eines aus mindestens zwei LED-Zweigen bestehenden LED-Arrays ist und jeder der LED-Zweige auf die vorgenannte Weise betrieben wird. 2. The method according to claim 1, characterized in that the series circuit (2) is an LED branch of an LED array consisting of at least two LED branches and each of the LED branches is operated in the aforementioned manner.
PCT/EP2009/062319 2008-09-24 2009-09-23 Method for operating a series circuit of at least two led’s WO2010034739A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP09783324A EP2329686A1 (en) 2008-09-24 2009-09-23 Method for operating a series circuit of at least two led s

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Application Number Priority Date Filing Date Title
DE102008048701.5A DE102008048701B4 (en) 2008-09-24 2008-09-24 Method for operating a series connection of at least two LEDs
DE102008048701.5 2008-09-24

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WO2010034739A1 true WO2010034739A1 (en) 2010-04-01

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2427033A3 (en) * 2010-09-07 2012-05-23 Monolithic Power Systems, Inc. Bypass circuitry for serially coupled light emitting diodes and associated methods of operation
DE102014216085A1 (en) 2014-08-13 2016-02-18 Automotive Lighting Reutlingen Gmbh Monitoring unit for a semiconductor module comprising a light module for a lighting device of a motor vehicle
WO2020048688A1 (en) * 2018-08-07 2020-03-12 HELLA GmbH & Co. KGaA Control system for a motor vehicle and method for diagnosing a failure in a control system

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE202010005779U1 (en) * 2010-04-16 2010-08-05 Conwys Ag Trailer detection device
DE102017000324A1 (en) 2017-01-16 2018-07-19 Osram Gmbh Circuit arrangement and method for its operation

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040080273A1 (en) * 2002-10-08 2004-04-29 Masayasu Ito Lighting circuit
DE102004007278A1 (en) * 2003-03-27 2004-10-07 Goodrich Hella Aerospace Lighting Systems Gmbh Interior lighting system especially suitable for aircraft, is controlled by pulsed switches in parallel with light emitting diodes, operated by control circuit
DE10358447B3 (en) * 2003-12-13 2005-05-25 Insta Elektro Gmbh Illumination device has series LEDs, each with parallel-connected electronic unit with low impedance switch element, diode, threshold switch, capacitor whose voltage supplies threshold switch and is fed to threshold switch as its input
DE102005008100B4 (en) 2005-02-22 2007-03-08 Mitsubishi Denki K.K. Redundancy circuit for series connected diodes
EP1839928A2 (en) * 2006-03-29 2007-10-03 KOMPLED GmbH & Co. KG Vehicle lamp assembly
DE102006018575A1 (en) * 2006-04-21 2007-10-25 Tridonicatco Gmbh & Co. Kg Error detection of LEDs

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2778481B1 (en) 1998-05-05 2000-06-23 Sagem METHOD FOR MANAGING A SOURCE OF ROAD SIGNALING LIGHT
DE10243794B9 (en) 2002-09-20 2007-03-08 Osram Opto Semiconductors Gmbh Circuit arrangement with an LED arrangement
JP2004122913A (en) 2002-10-01 2004-04-22 Koito Mfg Co Ltd Vehicle lighting fixture
US7710050B2 (en) 2005-11-17 2010-05-04 Magna International Inc Series connected power supply for semiconductor-based vehicle lighting systems

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040080273A1 (en) * 2002-10-08 2004-04-29 Masayasu Ito Lighting circuit
DE102004007278A1 (en) * 2003-03-27 2004-10-07 Goodrich Hella Aerospace Lighting Systems Gmbh Interior lighting system especially suitable for aircraft, is controlled by pulsed switches in parallel with light emitting diodes, operated by control circuit
DE10358447B3 (en) * 2003-12-13 2005-05-25 Insta Elektro Gmbh Illumination device has series LEDs, each with parallel-connected electronic unit with low impedance switch element, diode, threshold switch, capacitor whose voltage supplies threshold switch and is fed to threshold switch as its input
DE102005008100B4 (en) 2005-02-22 2007-03-08 Mitsubishi Denki K.K. Redundancy circuit for series connected diodes
EP1839928A2 (en) * 2006-03-29 2007-10-03 KOMPLED GmbH & Co. KG Vehicle lamp assembly
DE102006018575A1 (en) * 2006-04-21 2007-10-25 Tridonicatco Gmbh & Co. Kg Error detection of LEDs

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2427033A3 (en) * 2010-09-07 2012-05-23 Monolithic Power Systems, Inc. Bypass circuitry for serially coupled light emitting diodes and associated methods of operation
DE102014216085A1 (en) 2014-08-13 2016-02-18 Automotive Lighting Reutlingen Gmbh Monitoring unit for a semiconductor module comprising a light module for a lighting device of a motor vehicle
WO2020048688A1 (en) * 2018-08-07 2020-03-12 HELLA GmbH & Co. KGaA Control system for a motor vehicle and method for diagnosing a failure in a control system
CN112566830A (en) * 2018-08-07 2021-03-26 海拉有限双合股份公司 Control system for a motor vehicle and method for fault diagnosis in a control system
US11872996B2 (en) 2018-08-07 2024-01-16 HELLA GmbH & Co. KGaA Control system for a motor vehicle and method for diagnosing a failure in a control system
CN112566830B (en) * 2018-08-07 2024-06-11 海拉有限双合股份公司 Control system for a motor vehicle and method for fault diagnosis in a control system

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