US3514852A - Method of making artificial telephone lines impedance matching networks - Google Patents

Method of making artificial telephone lines impedance matching networks Download PDF

Info

Publication number
US3514852A
US3514852A US679764A US67976467A US3514852A US 3514852 A US3514852 A US 3514852A US 679764 A US679764 A US 679764A US 67976467 A US67976467 A US 67976467A US 3514852 A US3514852 A US 3514852A
Authority
US
United States
Prior art keywords
impedance
metalized
strips
strip
contacts
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
Application number
US679764A
Other languages
English (en)
Inventor
Frank Ralph
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.)
International Standard Electric Corp
Original Assignee
International Standard Electric Corp
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
Priority claimed from GB43821/66A external-priority patent/GB1122873A/en
Application filed by International Standard Electric Corp filed Critical International Standard Electric Corp
Application granted granted Critical
Publication of US3514852A publication Critical patent/US3514852A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P3/00—Waveguides; Transmission lines of the waveguide type
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06G—ANALOGUE COMPUTERS
    • G06G7/00—Devices in which the computing operation is performed by varying electric or magnetic quantities
    • G06G7/48—Analogue computers for specific processes, systems or devices, e.g. simulators
    • G06G7/62—Analogue computers for specific processes, systems or devices, e.g. simulators for electric systems or apparatus
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/40—Artificial lines; Networks simulating a line of certain length
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49082—Resistor making
    • Y10T29/49101—Applying terminal

Definitions

  • the characteristic impedance .z of the structure is related to the width and the effective specific resistance of the films and effective capacitance between them.
  • 2 is determined by the relationship between the effective specific resistance and the width of the metalized film.
  • the present invention provides for a standardized construction of metalized films for providing a wide range of z
  • the standardized construction is made with an impedance z z and the required z is achieved by placing the contact strips a specified distance from the ends of the films.
  • the effective capacitance remains virtually the same for a wide range of values of effective resistance.
  • This invention relates to a method of making networks for simulating a non-loaded paired telephone cable, or artificial telephone lines as they are sometimes called.
  • the characteristic impedance 1 of the network at angular frequency w is given by rate of deposition and the latter by the width of the mask aperture through which deposition is eifected.-Neither parameter can be economically modified after deposition and, however uniform the process may be, if either R or b is in error the characteristic impedance will, in general, also be wrong.
  • a method of making a network for simulating a nonloaded paired telephone cable having a characteristic impedance 2 including placing together a pair of resistive metallic film strips, each having a width b and length l, and a dielectric layer, the films being placed one on either side of the dielectric layer, the whole having an impedance z greater than z at an angular frequency to, between the ends of the strips according to the formula where R and C are respectively the effective square (specific) resistance of the strips and the effective specific capacitance between them, and placing in contact with each strip a pair of electrical contacts, the contacts on each strip being placed in from the ends of the strip a distance Kl where K is determined according to the formula
  • R and C are respectively the effective square (specific) resistance of the strips and the effective specific capacitance between them
  • the characteristic impedance z of the basic structure may be equivalent to the characteristics of a telephone line of 2 /2 lb./mile wire.
  • the same strips can be used to make impedances equivalent to lines of 4, 6 /2, 10 or lb./mile wire.
  • Another advantage of this invention is that to nullify variations in manufacturing tolerances for the metalized strips which would lead to variations in 1 for a constant size of strip, the strips can be made with z deliberately larger than 1 and then it is merely a question of measuring the actual z and determining where the contacts must be placed to achieve accurately the required value of 2
  • FIG. 1 is a diagrammatic plan view of a metalized strip with the contacts spaced from the ends thereof;
  • FIG. 2 is a diagrammatic sectional view of the components of an artificial line before winding
  • FIG. 3 is a perspective view of a wound artificial line; and- FIG. 4 is a part sectional view through the wound components in a position indicated by the line H in FIG. 2.
  • the metalized strip shown in FIG. 1 consists of a length of plastic or other dielectric material 10 with a metalized film 11 deposited on one face thereof.
  • the metalized film 11 is slightly narrower than the plastic base, and its dimensions are length l and width b. Two of the metalized strips are required to make one artificial line, and each strip is provided with two electrical contacts 12, 13, the
  • the first step is to calculate the impedance z of the basic metalized strips 10, a, according to the formula
  • the actual values of R and b are determined by measuring a suitable length of metalized strip and C is assumed to be known so that z may be readily determined.
  • the metalized strips must be made so that z is greater than the desired z
  • the length l inches of metalized film required to simulate the L miles of cable of impedance z is determined according to the formula given above.
  • each electrical contact at a distance Kl from each end is then determined, K being given by the formula
  • contact 12 for example, can be moved a short distance x to the right to a position Kl+x from the end while contact 12a is moved a similar distance to the left to a position Klx.
  • d the average diameter of the turns at the position of the contact strips
  • the two contacts will be diametrically opposed.
  • a similar adjustment may be made concerning the outermost pair of contacts to space them one from another, although they may not be moved the same distances as the innermost pair.
  • the important point to note is that provided both contacts of a pair are moved small, equal and opposite distances about the calculated correct position 2:, will not be significantly altered.
  • the characteristic impedance of the network will then be equal to z and the attenuation-frequency characteristic of the network will closely resemble that of L miles of cable of impedance 2,
  • the invention is intended primarily to apply to networks simulating non-loaded telephone subscriber cable over the normal voice frequency range of 300 to 3400 c./s. and for length of l or 2 miles.
  • K such a unit may be made to simulate 1 mile of heavier gauges of cable, even 20 1b. cable, with the characteristic impedance over the frequency range 300 to 3400 c./s. having a return loss, against the ideal value, of not less than 30 decibels.
  • the artificial lines used were for No. 28 A.W.G. (2 /2 lb./mile) cable. As the adjustment was in discrete steps it was not possible to achieve exactly the values of K required for other gauges, but the target values of z corresponding to the actual values of K used are shown on Table H below together with the actual characteristic impedance obtained at various frequencies in the voice frequency range. For convenience in comparison all measurements have been normalized with respect to frequency and relative to a value of l000-j 1000 ohms for the No. 28 A.W.G. cable. The total loop resistance used was 700 ohms and not 680 ohms, and when simulating 20 lb. cable a total of 1100 ohms was used, because the particular unit available for the centre section could not be set below ohms loop resistance.
  • the propagation constant is also modified so as to be equiva lent to approximately the same length of (lower impedance) cable as is represented at the initial impedance z with the contacts at the ends of the winding. More exactly, it the total capacity (equal to lC is made equal to the total capacity of the length of lower impedance line to be simulated, then the propagation constant at voice frequencies of the unit formed by setting the contacts at the calculated distance of Kl from each end will be close to the correct value.
  • a method of making a network for simulating a nonloaded paired telephone cable having a characteristic impedance z including placing together a pair of resistance metallic film strips, each having a width b and length l, and a dielectric layer, the films being placed one on each side of the dielectric layer, the whole having an impedance z greater than z at an angular frequency to, between the ends of the strips according to the formula where R, and C are respectively the efiective square (specific) resistance of the strips and the effective specific capacitance between them, and placing in contact with each strip a pair of electrical contacts, the contacts on each strip being spaced in from the ends of the strip a distance Kl where K is determined according to the formula 2.
  • a method according to claim 1 wherein the resistive metallic film strips are each deposited on a separate dielectric support layer.
  • a method according to claim 2 including the step of winding the two dielectric layers with their associated metallic films into a cylindrical structure with the electrical contacts protruding from the end thereof.
  • a method according to claim 3 including winding a further screening dielectric layer coated on one side with an electrically conducting film together with the two resistive film coated dielectric layers.
  • a method according to claim 4 including the step of making the screening layer extend axially beyond the limit of the resistive films in one direction and coating with metal or otherwise treating the end of the wound structure to short together all the turns of the wound screening layer.
  • a method according to claim 3 including displacing the two contacts at the innermost end of the pair of resistive films by equal and opposite amounts from the calculated position Kl from the end so that when the films are wound into a cylindrical structure the two contacts are angularly disposed from one another.
  • a method according to claim 3 including displacing the two contacts at the outermost end of the pair of resistive films by equal and opposite amounts from the calculated position Kl from the end so that when the films are wound into a cylindrical structure the two contacts are angularly disposed from one another.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Mathematical Physics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Measurement Of Resistance Or Impedance (AREA)
  • Monitoring And Testing Of Transmission In General (AREA)
US679764A 1966-09-30 1967-11-01 Method of making artificial telephone lines impedance matching networks Expired - Lifetime US3514852A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB43821/66A GB1122873A (en) 1966-09-30 1966-09-30 Transmission line
GB50566/66A GB1145524A (en) 1966-09-30 1966-11-11 Impedance matching networks

Publications (1)

Publication Number Publication Date
US3514852A true US3514852A (en) 1970-06-02

Family

ID=10456387

Family Applications (1)

Application Number Title Priority Date Filing Date
US679764A Expired - Lifetime US3514852A (en) 1966-09-30 1967-11-01 Method of making artificial telephone lines impedance matching networks

Country Status (3)

Country Link
US (1) US3514852A (fr)
FR (1) FR93245E (fr)
GB (1) GB1145524A (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4852665A (en) * 1986-12-10 1989-08-01 Schlumberger Technology Corporation Method for monitoring the operations of the rotary drilling of a well

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB544144A (en) * 1939-09-29 1942-03-30 Standard Telephones Cables Ltd Electrical filters
US3160801A (en) * 1958-01-02 1964-12-08 Eastman Kodak Co Wound capacitor and method of making

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB544144A (en) * 1939-09-29 1942-03-30 Standard Telephones Cables Ltd Electrical filters
US3160801A (en) * 1958-01-02 1964-12-08 Eastman Kodak Co Wound capacitor and method of making

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4852665A (en) * 1986-12-10 1989-08-01 Schlumberger Technology Corporation Method for monitoring the operations of the rotary drilling of a well

Also Published As

Publication number Publication date
FR93245E (fr) 1969-02-28
GB1145524A (en) 1969-03-19

Similar Documents

Publication Publication Date Title
Medhurst HF resistance and self-capacitance of single-layer solenoids
US1957538A (en) Electrical network
US2126915A (en) Wave transmission network
US3292127A (en) Closed circuit resistive shielding for multiwinding transformers
US2178653A (en) Building-out unit
US3599122A (en) Filter network including at least one tapped electromagnetic delay line
US2953764A (en) Grid configuration for film type resistor
US3680013A (en) Film attenuator
US2232642A (en) Loading system
US2416683A (en) Wave transmission network
US2381782A (en) Electrical apparatus
US2461061A (en) Equalized delay line
US3594665A (en) Delay lines with added shunt conductance
US2608601A (en) Capacitor
US2943277A (en) Apparatus for producing variable time delay
US2261633A (en) Potential distributing insulator tube and method for making same
US1924840A (en) Method for the compensation of capacity unbalances in the groups of cores of telegraph and telephone cables
US3599125A (en) Thin film resistance attenuator
DE60011882T2 (de) Verfahren zur bestimmung der permeabilität eines magnetischen materials durch die perturbation eines koaxialkabels
US2392790A (en) Electrical transformer and coil
US3555461A (en) Artificial transmission line formed by coiling plural line foils and shorted screening foil
US3320555A (en) Electrical delay line
JPH01106602A (ja) マイクロストリップ線路とその製造方法
US3643234A (en) Read-only memory employing striplines
US3824503A (en) Coupling device and method for simultaneous impedance balancing

Legal Events

Date Code Title Description
AS Assignment

Owner name: STC PLC, 10 MALTRAVERS STREET, LONDON, WC2R 3HA, E

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:INTERNATIONAL STANDARD ELECTRIC CORPORATION, A DE CORP.;REEL/FRAME:004761/0721

Effective date: 19870423

Owner name: STC PLC,ENGLAND

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:INTERNATIONAL STANDARD ELECTRIC CORPORATION, A DE CORP.;REEL/FRAME:004761/0721

Effective date: 19870423