DE2345880B1 - Circuit arrangement for detecting loop states - Google Patents
Circuit arrangement for detecting loop statesInfo
- Publication number
- DE2345880B1 DE2345880B1 DE19732345880 DE2345880A DE2345880B1 DE 2345880 B1 DE2345880 B1 DE 2345880B1 DE 19732345880 DE19732345880 DE 19732345880 DE 2345880 A DE2345880 A DE 2345880A DE 2345880 B1 DE2345880 B1 DE 2345880B1
- Authority
- DE
- Germany
- Prior art keywords
- transistor
- resistor
- lda
- light
- emitting diode
- 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.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q3/00—Selecting arrangements
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Interface Circuits In Exchanges (AREA)
Description
hohen Verstärkung — eine Steuerspannung von nur Bruchteilen eines Volts. Diese Basis-Emitter-Steuerspannung entsteht an dem Widerstand RaI als Spannungsabfall, wenn der Strom durch die Teilnehmerleitung um ein Geringes den Sollwert überschreitet. Damit sind auch die Einfügungsverluste der Transistor-Leuchtdiodenschaltung gering, denn zu der üblichen Leuchtdiodenspannung von unter 2VoIt kommt nur noch der kleine Spannungsabfall an dem Widerstand RaI. high gain - a control voltage of only a fraction of a volt. This base-emitter control voltage arises across the resistor RaI as a voltage drop when the current through the subscriber line exceeds the nominal value by a small amount. This also means that the insertion losses of the transistor light-emitting diode circuit are low, because in addition to the usual light-emitting diode voltage of less than 2VoIt, there is only the small voltage drop across the resistor RaI.
Die Diode D1 dient lediglich als Verpolungsschutz für die Leuchtdiode und den Transistor.The diode D 1 serves only as protection against polarity reversal for the light-emitting diode and the transistor.
Hierzu 1 Blatt Zeichnungen1 sheet of drawings
Claims (2)
Schleifenströme über optoelektronische Koppler 5 Fig. 2 die Beschallung eines optoelektronischen auf Auswerteeinrichtungen gegeben werden, bei Kopplers in einer Ader der Teilnehmerschleife gemäß denen in Reihe zu dem Leuchtelement des opto- der Erfindung.state in telephone systems in which the a- and fr-wires of a subscriber circuit,
Loop currents via optoelectronic coupler 5 Fig. 2 are given the sound of an optoelectronic to evaluation devices, with couplers in a wire of the subscriber loop according to those in series with the lighting element of the opto of the invention.
tretende Spannungen zerstört werden. Um das zu 5° Damit nun die über die Leuchtdioden LDa bzw. vermeiden, wurden bereits den Leuchtdioden dieser LDb fließenden Ströme nicht zu groß werden, sind Koppelelemente als Überspannungsschutz eine oder die Zenerdioden Za bzw. Zb vorgesehen, die von mehrere Dioden parallel geschaltet (DT-OS 2255 752). einem bestimmten Schwellwert der Schleifenströme Würde die Leuchtdiode nicht mit konstanter Speise- an einen Teil der Ströme übernehmen, so daß der Spannung, sondern über eine Transistorschaltung 55 Strom durch den optoelektronischen Koppler einen nach DT-AS 1233 023 mit konstantem Strom ge- bestimmten Grenzwert nicht überschreitet,
speist, dann würde zwar die Frei-Besetzt-Prüfung in Die Erfindung ist in der F i g. 2 gezeigt. Dort ist2, claim 2). These opto-resistors RaI, RbI voltages that are applied to the electronic coupling elements can, however, easily be given kierungspunkt Ma or Mb and further evaluated there by overcurrents or in the reverse direction not shown,
emerging tensions are destroyed. In order to avoid that the currents flowing through the LEDs LDa or LDb are not too large, coupling elements are provided as overvoltage protection one or the Zener diodes Za or Zb , which are connected in parallel by several diodes ( DT-OS 2255 752). a certain threshold value of the loop currents the light-emitting diode would not take over part of the currents with constant supply, so that the voltage, but via a transistor circuit 55 current through the optoelectronic coupler would not a limit value determined according to DT-AS 1233 023 with constant current exceeds,
feeds, then although the free-busy test would be The invention is in the F i g. 2 shown. There is
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19732345880 DE2345880B1 (en) | 1973-09-12 | 1973-09-12 | Circuit arrangement for detecting loop states |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19732345880 DE2345880B1 (en) | 1973-09-12 | 1973-09-12 | Circuit arrangement for detecting loop states |
Publications (1)
Publication Number | Publication Date |
---|---|
DE2345880B1 true DE2345880B1 (en) | 1975-01-09 |
Family
ID=5892303
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE19732345880 Pending DE2345880B1 (en) | 1973-09-12 | 1973-09-12 | Circuit arrangement for detecting loop states |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE2345880B1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2608171A1 (en) * | 1975-02-28 | 1976-09-16 | Hitachi Ltd | SPEECH WAY ARRANGEMENT |
FR2334113A1 (en) * | 1975-12-03 | 1977-07-01 | Constr Telephoniques | LINE CURRENT DETECTION CIRCUIT |
-
1973
- 1973-09-12 DE DE19732345880 patent/DE2345880B1/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2608171A1 (en) * | 1975-02-28 | 1976-09-16 | Hitachi Ltd | SPEECH WAY ARRANGEMENT |
FR2334113A1 (en) * | 1975-12-03 | 1977-07-01 | Constr Telephoniques | LINE CURRENT DETECTION CIRCUIT |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
B1 | Publication of the examined application without previous publication of unexamined application |