USRE39406E1 - Telephone line coupler - Google Patents
Telephone line coupler Download PDFInfo
- Publication number
- USRE39406E1 USRE39406E1 US09/570,415 US57041500A USRE39406E US RE39406 E1 USRE39406 E1 US RE39406E1 US 57041500 A US57041500 A US 57041500A US RE39406 E USRE39406 E US RE39406E
- Authority
- US
- United States
- Prior art keywords
- signal
- ring
- tip
- coupler
- transmit
- 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.)
- Expired - Lifetime
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/738—Interface circuits for coupling substations to external telephone lines
- H04M1/74—Interface circuits for coupling substations to external telephone lines with means for reducing interference; with means for reducing effects due to line faults
- H04M1/745—Protection devices or circuits for voltages surges on the line
Definitions
- the present invention relates to a telephone line coupler circuit for connecting telephone subscriber equipment to a telephone line.
- a telephone line coupler circuit is found in most every type of electronic equipment connected to a telephone line such as modems and fax machines.
- transformers or opto-couplers are used in the coupler circuit to connect the subscriber electronic equipment for the telephone line.
- Coupler circuits which use opto-couplers are known in the art.
- U.S. Pat. No. 4,727,535 to Brandt a coupler circuit is described in which a single opto-coupler is used for relaying the analog AC transmit signal and another opto-coupler device is used for relaying the received AC signal.
- the telephone line connect and disconnect circuit e.g. a line relay
- one opto-coupler is used for relaying a ringing signal to a modem
- a second opto-coupler is used in relaying a line seize signal from the modem to the telephone line access coupler
- a transformer is used in place of a pair of opto-couplers for relaying the received and transmitted AC signals from the coupler to the modem.
- a telephone line coupler circuit for connecting telephone subscriber equipment to a telephone line, the circuit comprising: ring and tip connector means for connecting to telephone line ring and tip contacts and providing ring and tip signal outputs; a high impedance DC load and a gated line switch connected in series between the ring and tip signal outputs for controllably conducting an “off-hook” current between the ring and tip signal outputs; a transmit opto-coupler means having a transmit signal input and output; means connecting the output terminal to the tip output and to a gate input of the gated line switch; means for controllably providing a low level DC bias signal to the transmit signal input and generating sufficient current on the output to substantially saturate the gated line switch and seize the line; means for providing an outgoing AC signal to the transmit signal input; and AC signal receive means connected to the ring and tip outputs for detecting an incoming AC signal and producing an incoming AC signal output.
- the invention also provides a telephone line coupler circuit for connecting telephone subscriber equipment to a telephone line, the circuit comprising: ring and tip connector means for connecting to telephone line ring and tip contacts and providing ring and tip signal outputs; a high impedance DC load and a line switch connected in series between the ring and tip signal outputs for controllably conducting an “off-hook” current between the ring and tip signal outputs; signal transmit means having a transmit signal input and being connected to the ring and tip outputs for transmitting AC signal; AC communications signal receive means connected to the ring and tip outputs for detecting an incoming AC communications signal and producing an incoming AC communications signal output; and AC ring signal detect means connected to the ring and tip outputs for detecting a telephone ring signal on the telephone line and generating a ringing output signal; wherein: the AC communications signal receive means and the AC ring signal detect means share a common receive opto-coupler device.
- the AC communication signal receive means and the AC ring signal detect means comprise a single band pass amplifier circuit which is switchable between two frequency bands, that is a first frequency band for the telephone ring signal and a second frequency band for received communication signals.
- the band pass filter amplifier is switched between the ring frequency band to the communications frequency band by the line seize signal connected to the means for controllably providing a load level DC bias signal to the transmit signal input of the transmit opto-coupler means.
- the invention also provides a telephone line coupler circuit for connecting telephone subscriber equipment to a telephone line, the circuit comprising: ring and tip connector means for connecting to telephone line ring and tip contacts and providing ring and tip signal outputs; a high impedance DC load and a gated line switch connected in series between the ring and tip signal outputs for controllably conducting an “off-hook” current between the ring and tip signal outputs; a transmit opto-coupler means having a transmit signal input and output; means connecting the output terminal to the tip output and to a gate input of the gated line switch; means for controllably providing a low level DC bias signal to the transmit signal input and generating sufficient current on the output to substantially saturate the gated line switch and seize the line; means for providing an outgoing AC signal to the transmit signal input; AC communications signal receive means connected to the ring and tip outputs for detecting an incoming AC communications signal and producing an incoming AC communications signal output; and AC ring signal detect means connected to the ring and tip outputs for detecting
- the invention also provides a method of isolating and connecting a transmit signal generated by subscriber electronic equipment to a telephone line.
- FIG. 1 is a block diagram of the telephone line coupler circuit according to the preferred embodiment.
- the telephone line coupler circuit comprises a telephone line ring/tip connector providing ring and tip outputs 10 and 11 respectively.
- a diode bridge 12 is provided for providing the correct polarity to the rest of the circuit.
- a receive opto-coupler 16 is connected to the positive ring output of the diode bridge 12 through a capacitor and line seize switch 15 to the negative tip output of bridge 12 .
- a DC line seize load 14 and a line seize switch 15 are connected in series between the ring and tip outputs of bridge 12 .
- a small DC current must pass through the coupler circuit in order for the telephone company central office equipment to consider the line to be in use.
- a transmit opto-coupler 20 has an input consisting of a DC bias signal from a DC bias source 22 and an AC signal component coming from transmit amplifier 24 .
- a comparator circuit is used to block the AC signal in the absence of the DC bias signal and to allow the DC bias signal to pass through in the absence of the AC signal.
- the DC bias voltage from 22 causes the transmit opto-coupler to output a base DC level which saturates the line seize switch 15 to provide the minimum required DC current through load 14 to seize the line.
- the DC bias level is chosen to provide a sufficient output to saturate line seize switch even when the AC component from transmit amplifier 24 is superimposed.
- the AC output from opto-coupler 20 is also fed through a resistance directly to the tip output of bridge 12 .
- a separate pulse dialing input is provided which is ORed with line seize signal 23 .
- line seize signal 23 When the circuit is in the “on-hook” state, line seize signal 23 is low and the band pass filter amplifier 18 is set to amplify AC signals in a frequency range of the telephone ring signal.
- Current from outputs 10 and 11 corresponding to a ring signal pass through ring signal filter 13 across the receive opto-coupler 16 .
- Return current passes through diode 17 .
- the received communication/ring signal output from amplifier 18 produces an AC output corresponding to the ring signal appearing on outputs 10 and 11 .
- the subscriber device connected to the output of amplifier 18 detects the presence of the ring signal and upon deciding to answer, places an output on line seize signal line 23 resulting in amplifier 18 switching to filtering and amplifying frequencies in the communication band and resulting in DC bias source 22 providing a DC bias signal to transmit opto-coupler 20 which causes the line seize switch 15 to be saturated and the line to be seized by passing the required DC current through load 14 . Since the receive opto-coupler 16 is connected to the transmit opto-coupler 20 , a minimum draw of current to place the light-emitting diode of receive opto-coupler 16 in an operational range is achieved. As an AC signal comes into receive opto-coupler 16 , a faithful isolated AC output is generated.
- the line coupler circuit requires only two opto-coupler devices for the purposes of relaying ring signal, communication signal, transmission and seizing the telephone line. While in the preferred embodiment, the band pass filter amplifier 18 is shown as a single block circuit having a single output, it is of course possible to provide two separate filter/amplifier circuits connected to the output of opto-coupler 16 without requiring a connection to line seize signal line 23 to switch between the two filters.
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Telephonic Communication Services (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
- Interface Circuits In Exchanges (AREA)
Abstract
Description
Claims (12)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/570,415 USRE39406E1 (en) | 1995-11-08 | 2000-05-12 | Telephone line coupler |
US11/483,104 USRE42590E1 (en) | 1995-11-08 | 2006-07-10 | Telephone line coupler |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/555,042 US5751803A (en) | 1995-11-08 | 1995-11-08 | Telephone line coupler |
US09/570,415 USRE39406E1 (en) | 1995-11-08 | 2000-05-12 | Telephone line coupler |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US08/555,042 Reissue US5751803A (en) | 1995-11-08 | 1995-11-08 | Telephone line coupler |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US08/555,042 Continuation US5751803A (en) | 1995-11-08 | 1995-11-08 | Telephone line coupler |
Publications (1)
Publication Number | Publication Date |
---|---|
USRE39406E1 true USRE39406E1 (en) | 2006-11-21 |
Family
ID=24215746
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US08/555,042 Ceased US5751803A (en) | 1995-11-08 | 1995-11-08 | Telephone line coupler |
US09/570,415 Expired - Lifetime USRE39406E1 (en) | 1995-11-08 | 2000-05-12 | Telephone line coupler |
US11/483,104 Expired - Lifetime USRE42590E1 (en) | 1995-11-08 | 2006-07-10 | Telephone line coupler |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US08/555,042 Ceased US5751803A (en) | 1995-11-08 | 1995-11-08 | Telephone line coupler |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/483,104 Expired - Lifetime USRE42590E1 (en) | 1995-11-08 | 2006-07-10 | Telephone line coupler |
Country Status (2)
Country | Link |
---|---|
US (3) | US5751803A (en) |
CA (2) | CA2169670C (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070121923A1 (en) * | 2005-09-15 | 2007-05-31 | Tyco Safety Products Canada, Ltd. | Telephone line communication interface |
USRE42590E1 (en) | 1995-11-08 | 2011-08-02 | Pinhas Shpater | Telephone line coupler |
Families Citing this family (35)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR0175447B1 (en) * | 1995-12-26 | 1999-04-01 | 김광호 | Ring Detection Circuit and Method for Wired / Wireless Combined Telephone |
US6480602B1 (en) | 1997-04-22 | 2002-11-12 | Silicon Laboratories, Inc. | Ring-detect interface circuitry and method for a communication system |
US6385235B1 (en) * | 1997-04-22 | 2002-05-07 | Silicon Laboratories, Inc. | Direct digital access arrangement circuitry and method for connecting to phone lines |
US6504864B1 (en) | 1997-04-22 | 2003-01-07 | Silicon Laboratories Inc. | Digital access arrangement circuitry and method for connecting to phone lines having a second order DC holding circuit |
US6587560B1 (en) | 1997-04-22 | 2003-07-01 | Silicon Laboratories Inc. | Low voltage circuits powered by the phone line |
US6498825B1 (en) | 1997-04-22 | 2002-12-24 | Silicon Laboratories Inc. | Digital access arrangement circuitry and method for connecting to phone lines having a DC holding circuit with programmable current limiting |
US6198816B1 (en) * | 1997-04-22 | 2001-03-06 | Silicon Laboratories, Inc. | Capacitively coupled ring detector with power provided across isolation barrier |
US6167134A (en) | 1997-04-22 | 2000-12-26 | Silicon Laboratories, Inc. | External resistor and method to minimize power dissipation in DC holding circuitry for a communication system |
US6442213B1 (en) | 1997-04-22 | 2002-08-27 | Silicon Laboratories Inc. | Digital isolation system with hybrid circuit in ADC calibration loop |
US6430229B1 (en) | 1997-04-22 | 2002-08-06 | Silicon Laboratories Inc. | Capacitive isolation system with digital communication and power transfer |
US6339048B1 (en) * | 1999-12-23 | 2002-01-15 | Elementis Specialties, Inc. | Oil and oil invert emulsion drilling fluids with improved anti-settling properties |
US6408034B1 (en) | 1997-04-22 | 2002-06-18 | Silicon Laboratories, Inc. | Framed delta sigma data with unlikely delta sigma data patterns |
US6137827A (en) | 1997-04-22 | 2000-10-24 | Silicon Laboratories, Inc. | Isolation system with digital communication across a capacitive barrier |
US6389134B1 (en) | 1997-04-22 | 2002-05-14 | Silicon Laboratories, Inc. | Call progress monitor circuitry and method for a communication system |
US6456712B1 (en) | 1997-04-22 | 2002-09-24 | Silicon Laboratories Inc. | Separation of ring detection functions across isolation barrier for minimum power |
US6298133B1 (en) | 1997-04-22 | 2001-10-02 | Silicon Laboratories, Inc. | Telephone line interface architecture using ringer inputs for caller ID data |
US6442271B1 (en) | 1997-04-22 | 2002-08-27 | Silicon Laboratories, Inc. | Digital isolation system with low power mode |
US6359983B1 (en) | 1997-04-22 | 2002-03-19 | Silicon Laboratories, Inc. | Digital isolation system with data scrambling |
US6307891B1 (en) | 1997-04-22 | 2001-10-23 | Silicon Laboratories, Inc. | Method and apparatus for freezing a communication link during a disruptive event |
US6516024B1 (en) | 1997-04-22 | 2003-02-04 | Silicon Laboratories Inc. | Digital access arrangement circuitry and method for connecting to phone lines having a DC holding circuit with low distortion and current limiting |
US6289070B1 (en) | 1997-04-22 | 2001-09-11 | Silicon Laboratories, Inc. | Digital isolation system with ADC offset calibration including coarse offset |
US5870046A (en) | 1997-04-22 | 1999-02-09 | Silicon Laboratories Inc. | Analog isolation system with digital communication across a capacitive barrier |
US6144326A (en) | 1997-04-22 | 2000-11-07 | Silicon Laboratories, Inc. | Digital isolation system with ADC offset calibration |
US6463113B1 (en) * | 1997-06-05 | 2002-10-08 | Compaq Information Technologies Group, L.P. | External signal attenuator for a single-ended transmission line |
US5946394A (en) * | 1997-06-12 | 1999-08-31 | C. P. Clare Corporation | Isolation amplifier with hook switch control |
US6351533B1 (en) | 1998-01-26 | 2002-02-26 | Xircom, Inc. | System and method for protecting devices connected to a telephone line |
US6144733A (en) * | 1998-01-28 | 2000-11-07 | Globespan Semiconductor, Inc. | Ring filter for pots communication system |
US6757381B1 (en) * | 1998-08-13 | 2004-06-29 | Eugene Robert Worley | Design of telephone line interface circuits using a two chip opto-coupler with LEDs integrated onto silicon chips |
CA2397954A1 (en) * | 2000-01-20 | 2001-07-26 | Current Technologies, Llc | Method of isolating data in a power line communication network |
US6958680B2 (en) * | 2000-04-14 | 2005-10-25 | Current Technologies, Llc | Power line communication system and method of using the same |
US6998962B2 (en) | 2000-04-14 | 2006-02-14 | Current Technologies, Llc | Power line communication apparatus and method of using the same |
US7103240B2 (en) * | 2001-02-14 | 2006-09-05 | Current Technologies, Llc | Method and apparatus for providing inductive coupling and decoupling of high-frequency, high-bandwidth data signals directly on and off of a high voltage power line |
US20020002040A1 (en) * | 2000-04-19 | 2002-01-03 | Kline Paul A. | Method and apparatus for interfacing RF signals to medium voltage power lines |
EP1371219A4 (en) * | 2001-02-14 | 2006-06-21 | Current Tech Llc | Data communication over a power line |
US6982611B2 (en) * | 2002-06-24 | 2006-01-03 | Current Technologies, Llc | Power line coupling device and method of using the same |
Citations (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3829619A (en) * | 1972-12-29 | 1974-08-13 | Stromberg Carlson Corp | Telephone ring trip circuit |
US3941939A (en) * | 1974-11-25 | 1976-03-02 | International Telephone And Telegraph Corporation | Electronic ring trip circuit |
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US4282604A (en) * | 1979-04-04 | 1981-08-04 | Jefferson William T | Optical isolation circuit for bidirectional communication lines |
US4292466A (en) * | 1979-08-21 | 1981-09-29 | Siemens Aktiengesellschaft | Circuit arrangement for receiving unipolar DC signals |
US4417099A (en) * | 1980-11-03 | 1983-11-22 | Universal Data Systems, Inc. | Electro-optical isolator circuit for line powered modem |
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WO1994003990A1 (en) | 1992-08-07 | 1994-02-17 | Pascom Technologies Pty. Ltd. | Isolation interface apparatus |
WO1994006215A1 (en) | 1992-09-09 | 1994-03-17 | Michael John Roberts | Communication device connected to an interface circuit employing opto-isolators |
WO1994007319A1 (en) | 1992-09-14 | 1994-03-31 | Agbaje Anozie Uzoma Ulugbo | Telephone line interface |
US5555293A (en) * | 1994-02-04 | 1996-09-10 | Siemens Components, Inc. | Optically-coupled data access arrangement and transhybrid |
Family Cites Families (3)
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US5291545A (en) | 1990-10-02 | 1994-03-01 | Intertex Data Ab | Apparatus and method for determining the state of a telephone line |
US5751803A (en) | 1995-11-08 | 1998-05-12 | Shmuel Hershkovit | Telephone line coupler |
CA2196014C (en) | 1997-01-27 | 2001-05-08 | Reinhart Karl Pildner | Size discriminating dual element pir detector |
-
1995
- 1995-11-08 US US08/555,042 patent/US5751803A/en not_active Ceased
-
1996
- 1996-02-16 CA CA002169670A patent/CA2169670C/en not_active Expired - Fee Related
- 1996-02-16 CA CA002273148A patent/CA2273148C/en not_active Expired - Fee Related
-
2000
- 2000-05-12 US US09/570,415 patent/USRE39406E1/en not_active Expired - Lifetime
-
2006
- 2006-07-10 US US11/483,104 patent/USRE42590E1/en not_active Expired - Lifetime
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US3829619A (en) * | 1972-12-29 | 1974-08-13 | Stromberg Carlson Corp | Telephone ring trip circuit |
US3941939A (en) * | 1974-11-25 | 1976-03-02 | International Telephone And Telegraph Corporation | Electronic ring trip circuit |
US4056719A (en) * | 1975-02-10 | 1977-11-01 | Bell Telephone Laboratories, Incorporated | Two-way telephone transmission system utilizing opto-couplers |
US4101741A (en) * | 1977-03-14 | 1978-07-18 | International Standard Electric Corporation | Line circuit for key telephone systems |
US4203006A (en) * | 1978-04-20 | 1980-05-13 | Prentice Corporation | Direct access coupler |
JPS5586253A (en) | 1978-12-23 | 1980-06-28 | Toshiba Corp | Antiside tone circuit |
US4282604A (en) * | 1979-04-04 | 1981-08-04 | Jefferson William T | Optical isolation circuit for bidirectional communication lines |
US4292466A (en) * | 1979-08-21 | 1981-09-29 | Siemens Aktiengesellschaft | Circuit arrangement for receiving unipolar DC signals |
US4417099A (en) * | 1980-11-03 | 1983-11-22 | Universal Data Systems, Inc. | Electro-optical isolator circuit for line powered modem |
US4436960A (en) * | 1982-01-11 | 1984-03-13 | Bell Telephone Laboratories, Incorporated | Telephone ringing signal generator |
US4558183A (en) * | 1983-10-03 | 1985-12-10 | Cellutron Corporation | Opto-coupler interfacing circuit |
JPS6130847A (en) | 1984-07-24 | 1986-02-13 | Ricoh Co Ltd | Coupling circuit of network control unit |
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WO1994003990A1 (en) | 1992-08-07 | 1994-02-17 | Pascom Technologies Pty. Ltd. | Isolation interface apparatus |
WO1994006215A1 (en) | 1992-09-09 | 1994-03-17 | Michael John Roberts | Communication device connected to an interface circuit employing opto-isolators |
WO1994007319A1 (en) | 1992-09-14 | 1994-03-31 | Agbaje Anozie Uzoma Ulugbo | Telephone line interface |
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Digital Security Controls Ltd. Circuit Diagram DSC 4000 device, Dec. 6, 1995. |
Provisional Spec., AU, David Scott Whitby, Jul. 8, 1992. |
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Reply to Defence to Counterclaim, Court No. T-428-04, Document filed with the Federal Court of Canada. |
Statement of Claim, Court No. T-428-04, Document filed with the Federal Court of Canada. |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
USRE42590E1 (en) | 1995-11-08 | 2011-08-02 | Pinhas Shpater | Telephone line coupler |
US20070121923A1 (en) * | 2005-09-15 | 2007-05-31 | Tyco Safety Products Canada, Ltd. | Telephone line communication interface |
Also Published As
Publication number | Publication date |
---|---|
CA2273148C (en) | 2002-06-25 |
CA2169670A1 (en) | 1997-05-09 |
CA2169670C (en) | 1999-10-05 |
US5751803A (en) | 1998-05-12 |
CA2273148A1 (en) | 1997-05-09 |
USRE42590E1 (en) | 2011-08-02 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: HERSHKOVITZ, SHMUEL, BAHAMAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SHPATER, PINHAS;REEL/FRAME:018447/0583 Effective date: 20020811 |
|
RR | Request for reexamination filed |
Effective date: 20080128 |
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FEPP | Fee payment procedure |
Free format text: PAT HOLDER CLAIMS SMALL ENTITY STATUS, ENTITY STATUS SET TO SMALL (ORIGINAL EVENT CODE: LTOS); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
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FPAY | Fee payment |
Year of fee payment: 12 |
|
B1 | Reexamination certificate first reexamination |
Free format text: THE PATENTABILITY OF CLAIMS 1, 2, 5-7, 9, 11, AND 12 IS CONFIRMED. NEW CLAIMS 13-16 ARE ADDED AND DETERMINED TO BE PATENTABLE. CLAIMS 3, 4, 8 AND 10 WERE NOT REEXAMINED. |
|
CC | Certificate of correction |