JPH0670058A - Circuit, method and apparatus for electric isolation - Google Patents

Circuit, method and apparatus for electric isolation

Info

Publication number
JPH0670058A
JPH0670058A JP5048694A JP4869493A JPH0670058A JP H0670058 A JPH0670058 A JP H0670058A JP 5048694 A JP5048694 A JP 5048694A JP 4869493 A JP4869493 A JP 4869493A JP H0670058 A JPH0670058 A JP H0670058A
Authority
JP
Japan
Prior art keywords
light emitting
emitting diode
phototransistor
digital
telephone
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.)
Withdrawn
Application number
JP5048694A
Other languages
Japanese (ja)
Inventor
Steven Jay Young
スティーブン・ジェイ・ヤング
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.)
Apple Inc
Original Assignee
Apple Computer Inc
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 Apple Computer Inc filed Critical Apple Computer Inc
Publication of JPH0670058A publication Critical patent/JPH0670058A/en
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/20—Repeater circuits; Relay circuits
    • H04L25/26—Circuits with optical sensing means, i.e. using opto-couplers for isolation
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
    • H03K17/78—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used using opto-electronic devices, i.e. light-emitting and photoelectric devices electrically- or optically-coupled
    • H03K17/795—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used using opto-electronic devices, i.e. light-emitting and photoelectric devices electrically- or optically-coupled controlling bipolar transistors
    • H03K17/7955—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used using opto-electronic devices, i.e. light-emitting and photoelectric devices electrically- or optically-coupled controlling bipolar transistors using phototransistors
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/80—Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70, e.g. optical power feeding or optical transmission through water
    • H04B10/801—Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70, e.g. optical power feeding or optical transmission through water using optical interconnects, e.g. light coupled isolators, circuit board interconnections
    • H04B10/802—Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70, e.g. optical power feeding or optical transmission through water using optical interconnects, e.g. light coupled isolators, circuit board interconnections for isolation, e.g. using optocouplers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/0002—Modulated-carrier systems analog front ends; means for connecting modulators, demodulators or transceivers to a transmission line
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
    • H04M11/06—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K2217/00—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00
    • H03K2217/0036—Means reducing energy consumption

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Computer And Data Communications (AREA)
  • Telephonic Communication Services (AREA)

Abstract

PURPOSE: To make the configuration of device for performing electric separation small in size and light in weight by replacing a transformer with an optic/ electronic coupler. CONSTITUTION: Each time a pulse from a computer 20 through a MODEM 22 is received, a 1st LED is flashed. Corresponding to the duration and synchronism of this output pulse, a phototransistor 18 is conducted and an electronic pulse is transmitted through a MODEM 21 to a telephone system 30. The electronic pulse is transmitted from the system 30 to the computer 20 by a similar symmetric circuit. Because of such a system for separating the MODEM 21 and 22 by replacing the optic/electronic coupler with the transformer without using any transformer, the configuration of device for performing electric separation is made light in weight and small in size.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、ディジタル通信の分野
に関し、更に詳しくは、ディジタル・コンピュータを通
信回路網に接続するのに使用される変調／復調装置（モ
デム）に関する。FIELD OF THE INVENTION This invention relates to the field of digital communications, and more particularly to modulation / demodulation equipment (modems) used to connect digital computers to communications circuitry.

【０００２】[0002]

【従来の技術】普通の電話回線を使用してコンピュータ
・システム間の通信を可能にするためモデムを使用する
ことは周知である。モデムは、コンピュータのディジタ
ル情報を受け取り、それを電話回線で伝送できる形式に
変換し、この変換された信号を伝送する。この信号は第
２モデムにより再変換されて、行先コンピュータに送ら
れる。周知のモデムは、電話回線と、モデムを有する他
の回路との間に標準データ・アクセス・アレンジメント
（“ＤＡＡ”）インタフェイスを含んでいる。このＤＡ
Ａインタフェイスは、たとえば雷により生じるサージ電
圧を含む、電話回線における様々な高電圧からコンピュ
ータとその操作者を分離するのに使用される。同時に、
インタフェイスは、コンピュータ・システムから電話機
回路網に電流が流れる可能性を阻止する。周知のインタ
フェイスでは、この電気的分離を行なうのに変圧器を使
用している。2. Description of the Related Art It is well known to use modems to enable communication between computer systems using ordinary telephone lines. The modem receives the computer's digital information, converts it into a format that can be transmitted over a telephone line, and transmits this converted signal. This signal is reconverted by the second modem and sent to the destination computer. Known modems include a standard data access arrangement ("DAA") interface between the telephone line and other circuitry that includes the modem. This DA
The A interface is used to isolate the computer and its operator from various high voltages on the telephone line, including surge voltages caused by lightning, for example. at the same time,
The interface prevents the possibility of current flowing from the computer system to the telephone network. Known interfaces use transformers to provide this electrical isolation.

【０００３】[0003]

【発明が解決しようとする課題】変圧器は電気的分離の
仕事を申し分なく実行することはできるが、いくつかの
問題点を有している。原則的には、どのモデムも、少な
くとも２７００ボルトの過電圧からコンピュータまたは
電話システムのいずれかを分離できなければならない。
変圧器の特性を規定する物理的原理によれば、これだけ
の電圧保護を行なうことができる変圧器は、かなりの大
きさでしかもかなりの重量のものになってしまう。最小
の約１立方インチという寸法でも、スペースおよび重量
が非常に重要な要素である携帯コンピュータにおいて
は、重大な設計上の問題となる。モデムのＤＡＡインタ
フェイス中の変圧器を、変圧器よりも小型で軽量な装置
に置換することにより、周知のモデムをかなり改善する
ことができる。Although transformers can successfully perform the task of electrical isolation, they do have some drawbacks. In principle, any modem must be able to isolate either the computer or the telephone system from an overvoltage of at least 2700 volts.
Due to the physical principles that define the characteristics of a transformer, a transformer capable of providing this much voltage protection would be of considerable size and weight. Even the smallest dimension of about 1 cubic inch is a significant design issue in portable computers where space and weight are very important factors. Replacing the transformer in the modem's DAA interface with a device that is smaller and lighter than the transformer can provide a significant improvement over known modems.

【０００４】[0004]

【課題を解決するための手段】第１実施例では、本発明
は、周知のモデムにおいて使用されている変圧器に置き
換えられる光−電子カプラを有する。入力および出力信
号は、発光ダイオード（「ＬＥＤ」）により光パルスに
変換され、それに伴なうフォトトランジスタは光パルス
を電子信号に再変換する。光−電子カプラは、変圧器よ
りもかなり小さく、軽量で、しかも電圧保護のレベルも
高められる。他の実施例では、光−電子カプラは、単一
集積回路（「ＩＣ」）の一部分である。この集積回路
は、２−４線式ハイブリッド回路、インピーダンス整合
抵抗、リング検出回路、および電子オン・フック・リレ
ーを含んでいる、残りのモデム回路の大部分を内蔵して
いる。SUMMARY OF THE INVENTION In a first embodiment, the present invention comprises an opto-electronic coupler which replaces the transformer used in known modems. The input and output signals are converted into light pulses by light emitting diodes (“LEDs”) and the associated phototransistors reconvert the light pulses into electronic signals. Opto-electronic couplers are much smaller than transformers, are lighter in weight, and offer increased levels of voltage protection. In another embodiment, the opto-electronic coupler is part of a single integrated circuit (“IC”). This integrated circuit contains most of the rest of the modem circuit, including the 2-4 wire hybrid circuit, the impedance matching resistor, the ring detect circuit, and the electronic on-hook relay.

【０００５】[0005]

【実施例】以下、添付の図面に基いて、本発明の実施例
に関し説明する。図１は、本発明の第１実施例を示して
いる。システム１０は、第１ＬＥＤ１２と第１フォトト
ランジスタ１４と、第２ＬＥＤ１６と第２フォトトラン
ジスタ１８と、第１および第２変調／復調回路２１、２
２を有している。コンピュータ・システム２０は、変調
／復調回路２２を介してＬＥＤ１２と第１フォトトラン
ジスタ１４に接続している。コンピュータ・システム２
０は、図１には示されていないが２−４線式ハイブリッ
ド回路を含んでいるモデム回路の一部を内蔵している。
ＬＥＤ１６とフォトトランジスタ１８は、変調／復調回
路２１と第２の２−４線式ハイブリッド回路を介して電
話システム３０に接続している。Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a first embodiment of the present invention. The system 10 includes a first LED 12, a first phototransistor 14, a second LED 16, a second phototransistor 18, first and second modulation / demodulation circuits 21, 2
Have two. The computer system 20 is connected to the LED 12 and the first phototransistor 14 via a modulation / demodulation circuit 22. Computer system 2
0 incorporates a portion of the modem circuit, which is not shown in FIG. 1 but includes a 2-4 wire hybrid circuit.
The LED 16 and the phototransistor 18 are connected to the telephone system 30 via a modulation / demodulation circuit 21 and a second 2-4 wire hybrid circuit.

【０００６】システム１０は入力および出力伝送に関し
て対称的に動作するので、ここでは出力信号の場合につ
いてのみ説明する。ＬＥＤ１２は、コンピュータ２０か
らのパルスを受信するたびにフラッシュする。これら出
力パルスの継続期間と周波数により、フォトトランジス
タ１８は入力パルスと全く同じ周波数でしかも同じ継続
期間、導通する。その後、これら電子パルスは、これら
が電話システム３０に伝送される前にさらに処理され
る。本発明の要素ではないが、適切な光パルスを発生す
るには、周知のコード化技術のいずれかを用いればよ
い。多くのコード化技術には、電圧−周波数変調および
パルス幅変調の２つが含まれている。Since the system 10 operates symmetrically with respect to input and output transmission, only the case of an output signal will be described here. The LED 12 flashes each time it receives a pulse from the computer 20. Due to the duration and frequency of these output pulses, the phototransistor 18 conducts at exactly the same frequency as the input pulse and for the same duration. Thereafter, these electronic pulses are further processed before they are transmitted to the telephone system 30. Although not an element of the invention, any of the well known coding techniques may be used to generate the appropriate light pulse. Many coding techniques include two, voltage-frequency modulation and pulse width modulation.

【０００７】[0007]

【発明の効果】変圧器を光−電子カプラに置き換えるこ
とにより、コンポーネントの大きさや重量を低減する
他、多くの利点が得られる。ファイバ光電話システムの
利用は益々一般的になってきているが、ここに示された
カプラは、１つの過程と１つのコンポーネントで、必要
とされる電気的分離および光信号のファイバ光ケーブル
への伝送を行なうことができる。光−電子カプラは標準
ＩＣのわずかな面積を占めるだけなので、カプラと同じ
ＩＣにモデムの回路の大部分を製造することができると
ともに、モデムのスペースおよび重量を低減することが
できる。さらに、携帯コンピュータにおいては重要なフ
ァクタである電力要求も減少する。一般に、この種のカ
プラは、変圧器分離回路よりも優れた信号−ノイズ・レ
スポンスを有している。最後に、ここに示されたカプラ
は、変圧器の場合よりもかなり安価に製造および設置す
ることができる。このことは現在のコンピュータ市場に
おいて非常に重要な要素である。本発明は、実施例に基
いて説明してきたが、本発明の思想から離れることなく
様々に改変し得ることは当業者には明白であろう。By replacing the transformer with an opto-electronic coupler, there are many advantages in addition to reducing the size and weight of the component. While the use of fiber optic telephone systems is becoming more and more common, the couplers shown here provide the required electrical isolation and transmission of optical signals over fiber optic cables in one step and one component. Can be done. Since the opto-electronic coupler occupies a small area of the standard IC, most of the modem's circuitry can be manufactured in the same IC as the coupler, while reducing the space and weight of the modem. In addition, power requirements, which is an important factor in portable computers, are reduced. In general, this type of coupler has a better signal-noise response than transformer isolation circuits. Finally, the couplers shown here can be manufactured and installed considerably cheaper than in the case of transformers. This is a very important factor in the current computer market. Although the present invention has been described based on the embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit of the present invention.

【図面の簡単な説明】[Brief description of drawings]

【図１】 本発明の第１実施例の概要図である。FIG. 1 is a schematic diagram of a first embodiment of the present invention.

【符号の説明】[Explanation of symbols]

１２ 第１ＬＥＤ １４ 第１フォトトランジスタ １６ 第２ＬＥＤ １８ 第２フォトトランジスタ ２０ コンピュータ・システム ２１ 第１変調／復調回路 ２２ 第２変調／復調回路 ３０ 電話システム 12 1st LED 14 1st phototransistor 16 2nd LED 18 2nd phototransistor 20 Computer system 21 1st modulation / demodulation circuit 22 2nd modulation / demodulation circuit 30 Telephone system

Claims (3)

【特許請求の範囲】[Claims] 【請求項１】 電話機回路網を介してディジタル・コン
ピュータ間のディジタル通信を可能にする変調／復調装
置の電気的分離回路において、 ディジタル・コンピュータに接続し、第１ディジタル電
気パルス情報を第１光情報パルスに変換する第１発光ダ
イオード装置と、 第１発光ダイオードに光学的に結合しかつ電話伝送路に
電気的に接続し、電話伝送路で伝送するため第１光情報
パルスを第２電気パルス情報に変換する第１フォトトラ
ンジスタ装置と、 電話伝送路に接続し、電話伝送路から受信された第３電
気パルス情報を第２光情報パルスに変換する第２発光ダ
イオードと、 第２発光ダイオードに光学的に結合しかつディジタル・
コンピュータに電気的に接続し、ディジタル・コンピュ
ータに伝送するため第２光情報パルスを第４電気情報パ
ルスに変換する第２フォトトランジスタ装置と、 から成ることを特徴とする電気的分離回路。1. An electrical isolation circuit of a modulation / demodulation device for enabling digital communication between digital computers via a telephone network, wherein the first optical electrical pulse information is connected to a digital computer and the first digital electrical pulse information is transmitted. A first light emitting diode device for converting to an information pulse, a first optical information pulse optically coupled to the first light emitting diode and electrically connected to the telephone transmission line for transmission on the telephone transmission line; A first phototransistor device for converting information, a second light emitting diode connected to the telephone transmission line and converting third electric pulse information received from the telephone transmission line into a second optical information pulse, and a second light emitting diode. Optically coupled and digital
A second phototransistor device electrically connected to the computer for converting the second optical information pulse into a fourth electrical information pulse for transmission to a digital computer. 【請求項２】 電話通信ケーブルおよびディジタル・コ
ンピュータに接続した変調／復調装置における電気的分
離を行なう方法において、 ディジタル・コンピュータの出力を第１発光ダイオード
に接続する過程と、 電話通信ケーブルを第２発光ダイオードと第１フォトト
ランジスタに接続する過程と、 ディジタル・コンピュータの入力を第２フォトトランジ
スタに接続し、第１発光ダイオードを第１フォトトラン
ジスタに、第２発光ダイオードを第２フォトトランジス
タに光学的に結合させる過程と、 ディジタル・コンピュータからのディジタル信号を、光
学的に結合した第１発光ダイオードと第１フォトトラン
ジスタを介して電話通信ケーブルに伝送する過程と、 電話通信ケーブルからのディジタル信号を、光学的に結
合した第２発光ダイオードと第２フォトトランジスタを
介してディジタル・コンピュータに伝送する過程と、 から成る電気的分離を行なう方法。2. A method of performing electrical isolation in a telephone communication cable and a modulator / demodulator connected to a digital computer, the method comprising: connecting the output of the digital computer to a first light emitting diode; Connecting the light emitting diode to the first phototransistor, and connecting the input of the digital computer to the second phototransistor, the first light emitting diode to the first phototransistor and the second light emitting diode to the second phototransistor. To the telephone communication cable through the optically coupled first light emitting diode and the first phototransistor, and the digital signal from the telephone communication cable, Optically coupled second light emitting diode Method for performing electrical isolation consisting and transmitting the digital computer, through a diode and a second photo transistor. 【請求項３】 電話通信ケーブルとディジタル・コンピ
ュータに接続した変調／復調装置における電気的分離を
行なう装置において、 ディジタル・コンピュータの出力を第１発光ダイオード
に接続する装置と、 電話通信ケーブルを第２発光ダイオードと第１フォトト
ランジスタとに接続する装置と、 ディジタル・コンピュータの入力を第２フォトトランジ
スタに接続し、第１発光ダイオードと第１フォトトラン
ジスタとを光学的に結合しかつ第２発光ダイオードと第
２フォトトランジスタとを光学的に結合する装置と、 ディジタル・コンピュータからのディジタル信号を、光
学的に結合した第１発光ダイオードと第１フォトトラン
ジスタを介して電話通信ケーブルに伝送する装置と、 電話通信ケーブルからのディジタル信号を、光学的に結
合した第２発光ダイオードと第２フォトトランジスタを
介してディジタル・コンピュータに伝送する装置と、 から成ることを特徴とする電気的分離を行なう装置。3. A device for performing electrical isolation in a modulator / demodulator connected to a telephone communication cable and a digital computer, wherein a device for connecting the output of the digital computer to the first light emitting diode and a second telephone communication cable. A device for connecting the light emitting diode and the first phototransistor, connecting the input of the digital computer to the second phototransistor, optically coupling the first light emitting diode and the first phototransistor, and the second light emitting diode A device for optically coupling a second phototransistor, a device for transmitting a digital signal from a digital computer to a telephone communication cable through the optically coupled first light emitting diode and the first phototransistor, and a telephone Optically connect the digital signal from the communication cable. Apparatus for electrical isolation, characterized in that it consists a device for transmitting a digital computer, via a second light emitting diode and a second photo transistor that.
JP5048694A 1992-02-18 1993-02-16 Circuit, method and apparatus for electric isolation Withdrawn JPH0670058A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US83730992A 1992-02-18 1992-02-18
US837,309 1992-02-18

Publications (1)

Publication Number Publication Date
JPH0670058A true JPH0670058A (en) 1994-03-11

Family

ID=25274129

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5048694A Withdrawn JPH0670058A (en) 1992-02-18 1993-02-16 Circuit, method and apparatus for electric isolation

Country Status (2)

Country Link
JP (1) JPH0670058A (en)
GB (1) GB2264422A (en)

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FR2724797B1 (en) * 1994-09-16 1997-01-24 Perfectionnement Des Materiels OPTOELECTRONIC INTERFACE BETWEEN A TRANSMISSION LINE AND TRANSMISSION AND RECEPTION CHANNELS
DE29505412U1 (en) * 1995-03-30 1996-05-02 Siemens Ag Device for electrically isolated cable break detection in digital transmission links with symmetrical transmission, in particular for digital position transducers
IT1274562B (en) * 1995-05-24 1997-07-17 Bticino Spa ELECTRIC CONNECTION SYSTEM SUITABLE TO TRANSFER DIGITAL SIGNALS BETWEEN TELEMATIC SYSTEMS AND PERIPHERAL ELECTRONIC UNITS

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GB2264422A (en) 1993-08-25

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