DE3642251A1 - Additional circuit for infrared diodes - Google Patents

Additional circuit for infrared diodes

Info

Publication number
DE3642251A1
DE3642251A1 DE19863642251 DE3642251A DE3642251A1 DE 3642251 A1 DE3642251 A1 DE 3642251A1 DE 19863642251 DE19863642251 DE 19863642251 DE 3642251 A DE3642251 A DE 3642251A DE 3642251 A1 DE3642251 A1 DE 3642251A1
Authority
DE
Germany
Prior art keywords
infrared
diodes
infrared diodes
current
series
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.)
Ceased
Application number
DE19863642251
Other languages
German (de)
Inventor
Hermann Dipl Ing Danzer
Walter Weber
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.)
Siemens AG Oesterreich
Original Assignee
Siemens AG
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 Siemens AG filed Critical Siemens AG
Publication of DE3642251A1 publication Critical patent/DE3642251A1/en
Ceased legal-status Critical Current

Links

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]
    • H05B45/30—Driver circuits
    • H05B45/37—Converter circuits
    • H05B45/3725—Switched mode power supply [SMPS]

Abstract

Once the energising current has been switched off, infrared diodes transmit light which is called afterglow and is produced by recombination of the charge carriers. This afterglow, which produces interferences in some applications, is prevented according to the invention in that an inductance is connected in parallel with the infrared diode or the series-connected infrared diode. The demagnetisation current of this inductance after the infrared diodes have been switched off clears out the charge carriers. In the case of a plurality of series-connected infrared diodes, a rectifier diode of opposite polarity must in each case be connected in parallel with each individual infrared diode in order to allow the demagnetisation current access to the infrared diodes which extinguish later, as well.

Description

Die Erfindung betrifft eine Zusatzschaltung für eine oder mehrere in Serie liegende, schnell geschaltete Infrarotdioden, die einen störungsfreien Betrieb gewährleistet.The invention relates to an additional circuit for one or several series-connected, quickly switched infrared diodes, which ensures trouble-free operation.

Infrarotdioden senden nach Abschalten des erregenden Stromes ein als "Nachleuchten" bezeichnetes Licht aus, das durch die Rekombination der Ladungsträger erzeugt wird. Die Intensität des Nachleuchtens nimmt etwa exponentiell mit einer Halbwerts­ zeit von etwa 1-2 µs ab. Die Infrarotdioden werden üblicher­ weise impulsweise angesteuert, wobei die Impulsbreiten bei­ spielsweise etwa 0,2 µs und die Impulsabstände im Mittel etwa 3 µs betragen. Obwohl hierbei nur die Impulsflanken, also die zeitlichen Änderungen der Lichtintensitäten ausgewertet werden, wirkt das Nachleuchten störend bei Geräten, bei denen der Infrarotempfänger unmittelbar neben dem Infrarotsender ange­ ordnet ist, weil es dort den Empfang weit entfernter Sender be­ einträchtigt.Infrared diodes send after switching off the exciting current a light referred to as "afterglow" which is emitted by the Recombination of the charge carriers is generated. The intensity of afterglow increases approximately exponentially with a half value time from about 1-2 µs. The infrared diodes are becoming more common as driven in pulses, the pulse widths at for example about 0.2 µs and the pulse intervals on average 3 µs. Although only the pulse edges, i.e. the changes in light intensity over time are evaluated, the afterglow has a disruptive effect on devices in which the Infrared receiver is located right next to the infrared transmitter is because it receives the reception of distant stations impaired.

Im Zuge der vermehrten Anwendung der Infrarot-Nachrichtenüber­ tragung, insbesondere bei Dolmetscheranlagen kommt auch der Er­ höhung der Übertragungs-Reichweite eine steigende Bedeutung zu. Der Erfindung liegt daher die Aufgabe zugrunde, das Nachleuch­ ten der Infrarotdioden und die damit verbundenen Störungen zu vermeiden und erzielt dies durch eine Zusatzschaltung für eine oder mehrere in Serie liegende Infrarotdioden erfindungsgemäß in der Weise, daß der einen Infrarotdiode bzw. allen in Serie liegenden Infrarotdioden eine Induktivität parallel geschaltet ist.In the course of the increased use of infrared messages responsibility, especially in the case of interpreting systems increasing the transmission range is becoming increasingly important. The invention is therefore based on the object, the afterglow of the infrared diodes and the associated interference avoid and achieves this by an additional circuit for a or several infrared diodes in series according to the invention in such a way that one infrared diode or all in series lying infrared diodes an inductance connected in parallel is.

Die erfindungsgemäß vorgesehene Induktivität, die während der Einschaltdauer der Infrarotdioden ebenfalls stromdurchflossen ist, liefert nach Abschalten des Speisestromes einen Abmagne­ tisierungsstrom, der die Dioden gegensinnig zum vorher fließen­ den Speisestrom kurzzeitig durchfließt, bis diese zu sperren beginnen. Dieser Abmagnetisierungsstrom räumt in den Infra­ rotdioden die Ladungsträger sofort aus und verhindert dadurch das Nachleuchten.The inductance provided according to the invention during the Duty cycle of the infrared diodes also flows through current  provides a magnitude after switching off the supply current tization current that the diodes flow in the opposite direction to the previous one flows through the feed current for a short time until it is blocked kick off. This demagnetizing current clears the infra red diodes immediately remove the charge carriers and thereby prevent them the afterglow.

Wenn mehrere Infrarotdioden als Sendedioden in Serie ge­ schaltet sind, ist gemäß einem weiteren Merkmal der Erfindung jeder einzelnen dieser Dioden je eine gegensinnig gepolte Gleichrichterdiode parallel geschaltet, um auszuschließen, daß die als erste sperrende Sendediode die weitere Einwirkung des Abmagnetisierungsstromes auf alle anderen, bis dahin noch nicht gesperrten Sendedioden verhindert.If several infrared diodes are used as transmitter diodes in series are switched, is according to a further feature of the invention each one of these diodes is polarized in opposite directions Rectifier diode connected in parallel to rule out that the first blocking diode to block the further action of the Demagnetizing current to all others, not yet blocked transmission diodes prevented.

Da die Induktivität zusammen mit den in der ganzen Schaltung vorhandenen Kapazitäten (z.B. Sperrschichtkapazitäten) ein schwingungsfähiges System bildet, erweist es sich als zweckmäßig, zur Verhinderung von störenden Schwingungen den Speisestromkreis der Sendedioden durch ein RC-Glied zu be­ dämpfen.Because the inductance along with that in the whole circuit existing capacities (e.g. junction capacities) oscillatory system, it proves to be useful to prevent disruptive vibrations Supply circuit of the transmitter diodes to be by an RC element dampen.

Als Ausführungsbeispiel der Erfindung ist in der Zeichnung eine Anordnung von mehreren Infrarotdioden dargestellt, die als Sendedioden eines Infrarotsenders eingesetzt sind.As an embodiment of the invention is in the drawing Arrangement of several infrared diodes shown as Transmitting diodes of an infrared transmitter are used.

Die einheitlich mit D bezeichneten Sendedioden sind in Serie in einem gemeinsamen Speisestromkreis angeordnet, der im Takt der auszusendenden Infrarotimpulse von einem schnell schaltenden Stromschalter S geschlossen wird. Die Ansteuerung des Strom­ schalters S erfolgt durch eine Steuerschaltung ST. Dem gemein­ samen Speisestromkreis aller Sendedioden D ist eine Induktivi­ tät L (Drosselspule) parallel geschaltet, die zugleich mit den Sendedioden D erregt wird und nach Abschalten des Speisestromes einen Abmagnetisierungsstrom in der ursprünglichen Richtung weiter führt. Dieser Strom fließt im ersten Moment als Rückstrom durch die Sendedioden D, bis diese zu sperren beginnen. Um einerseits eine unzulässig hohe Spannung an den Dioden D zu verhindern und um andererseits einen weiteren Stromfluß durch die noch nicht sperrenden Sendedioden zu ermöglichen, ist jeder einzelnen der Sendedioden D je eine gegensinnig gepolte Gleich­ richterdiode G parallel geschaltet.The transmitter diodes, denoted uniformly by D , are arranged in series in a common supply circuit, which is closed by a fast-switching current switch S in time with the infrared pulses to be emitted. The current switch S is controlled by a control circuit ST . The common feed circuit of all transmitter diodes D is an inductance L (choke coil) connected in parallel, which is also excited with the transmitter diodes D and continues to conduct a demagnetization current in the original direction after switching off the feed current. This current flows as reverse current through the transmitter diodes D until they start to block. On the one hand to prevent an impermissibly high voltage on the diodes D and on the other hand to allow a further current flow through the not yet blocking transmission diodes, each of the transmission diodes D is connected in each case with an oppositely polarized rectifier diode G in parallel.

Mögliche elektrische Schwingungen der ganzen Schaltung werden durch ein RC-Glied bedämpft, das aus einem Kondensator C und einem Widerstand R besteht und das dem Stromschalter S parallel liegt. Possible electrical vibrations of the entire circuit are damped by an RC element, which consists of a capacitor C and a resistor R and which is parallel to the current switch S.

  • Bezugszeichenliste D= SendediodenL= Induktivität (Drosselspule)G= GleichrichterdiodenR, C= RC-GliedS= StromschalterST= SteuerschaltungReference symbol list D = transmitter diodes L = inductance (choke coil) G = rectifier diodes R, C = RC element S = current switch ST = control circuit

Claims (3)

1. Zusatzschaltung für eine oder mehrere in Serie liegende, schnell geschaltete Infrarotdioden, dadurch gekennzeichnet, daß der einen Infrarotdiode bzw. allen in Serie liegenden Infrarotdioden (D) eine Induktivität (L) parallel geschaltet ist.1. Additional circuit for one or more series-connected, quickly switched infrared diodes, characterized in that the one infrared diode or all series-connected infrared diodes (D) an inductor (L) is connected in parallel. 2. Zusatzschaltung nach Anspruch 1, mit mehreren in Serie liegenden Infrarotdioden, dadurch gekennzeichnet, daß jeder einzelnen der Infrarotdioden (D) je eine gegensinnig gepolte Gleichrichterdiode (G) parallel geschaltet ist.2. Additional circuit according to claim 1, with a plurality of infrared diodes lying in series, characterized in that each of the infrared diodes ( D) has an oppositely polarized rectifier diode (G) connected in parallel. 3. Zusatzschaltung nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß der Speisestromkreis der Infrarotdioden (D) durch ein RC-Glied (r, c) bedämpft ist.3. Additional circuit according to claim 1 or 2, characterized in that the supply circuit of the infrared diodes (D) is damped by an RC element (r, c) .
DE19863642251 1986-01-17 1986-12-10 Additional circuit for infrared diodes Ceased DE3642251A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AT0010386A AT384916B (en) 1986-01-17 1986-01-17 ADDITIONAL CIRCUIT FOR INFRARED DIODES IN SERIES

Publications (1)

Publication Number Publication Date
DE3642251A1 true DE3642251A1 (en) 1987-07-23

Family

ID=3481591

Family Applications (1)

Application Number Title Priority Date Filing Date
DE19863642251 Ceased DE3642251A1 (en) 1986-01-17 1986-12-10 Additional circuit for infrared diodes

Country Status (2)

Country Link
AT (1) AT384916B (en)
DE (1) DE3642251A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998002020A1 (en) * 1996-07-08 1998-01-15 Siemens Aktiengesellschaft Circuit for signal transmitters with leds
US6069452A (en) * 1996-07-08 2000-05-30 Siemens Aktiengesellschaft Circuit configuration for signal transmitters with light-emitting diodes
WO2001057431A1 (en) * 2000-01-31 2001-08-09 Bebenroth Guenther Lighting device for illuminating objects or buildings
WO2009019634A1 (en) 2007-08-06 2009-02-12 Nxp B.V. Solid state lighting system and a driver integrated circuit for driving light emitting semiconductor devices

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1960251B2 (en) * 1968-12-05 1973-04-26 Western Electric Co Ine , New York, NY (V St A) PICTURE PLAYBACK
DE2255822A1 (en) * 1971-11-26 1973-05-30 Hewlett Packard Co DRIVER CIRCUIT FOR A LIGHT EMITTING DIODE
DE2613647B2 (en) * 1976-03-31 1981-01-22 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Control circuit
JPS6053090A (en) * 1983-09-02 1985-03-26 Mayumi Watanabe Lighting system for led

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57181244A (en) * 1981-04-30 1982-11-08 Fujitsu Ltd Semiconductor laser modulating circuit
DE3308987A1 (en) * 1983-03-14 1984-09-20 Siemens AG, 1000 Berlin und 8000 München Circuit arrangement with an optical transmitter

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1960251B2 (en) * 1968-12-05 1973-04-26 Western Electric Co Ine , New York, NY (V St A) PICTURE PLAYBACK
DE2255822A1 (en) * 1971-11-26 1973-05-30 Hewlett Packard Co DRIVER CIRCUIT FOR A LIGHT EMITTING DIODE
DE2613647B2 (en) * 1976-03-31 1981-01-22 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Control circuit
JPS6053090A (en) * 1983-09-02 1985-03-26 Mayumi Watanabe Lighting system for led

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
"Elektronik" 23 (H. 6, 1974), S. 220-1 *
"Rev. Sci. Instrum." 45 (1974), S. 286-9 *
Patent Abstract of Japan & JP 60-053090 (A) *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998002020A1 (en) * 1996-07-08 1998-01-15 Siemens Aktiengesellschaft Circuit for signal transmitters with leds
US6069452A (en) * 1996-07-08 2000-05-30 Siemens Aktiengesellschaft Circuit configuration for signal transmitters with light-emitting diodes
WO2001057431A1 (en) * 2000-01-31 2001-08-09 Bebenroth Guenther Lighting device for illuminating objects or buildings
WO2009019634A1 (en) 2007-08-06 2009-02-12 Nxp B.V. Solid state lighting system and a driver integrated circuit for driving light emitting semiconductor devices
CN101803455B (en) * 2007-08-06 2012-03-28 Nxp股份有限公司 Solid state lighting system and a driver integrated circuit for driving light emitting semiconductor devices
US8373346B2 (en) 2007-08-06 2013-02-12 Nxp B.V. Solid state lighting system and a driver integrated circuit for driving light emitting semiconductor devices

Also Published As

Publication number Publication date
ATA10386A (en) 1987-06-15
AT384916B (en) 1988-01-25

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Legal Events

Date Code Title Description
8127 New person/name/address of the applicant

Owner name: SIEMENS AG OESTERREICH, WIEN, AT

8128 New person/name/address of the agent

Representative=s name: LIEBAU, G., DIPL.-ING., PAT.-ANW., 8900 AUGSBURG

8110 Request for examination paragraph 44
8125 Change of the main classification

Ipc: H01L 33/00

8128 New person/name/address of the agent

Representative=s name: FUCHS, F., DR.-ING., PAT.-ANW., 81541 MUENCHEN

8131 Rejection