US2914738A - Adjustable correcting networks - Google Patents

Adjustable correcting networks Download PDF

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Publication number
US2914738A
US2914738A US559965A US55996556A US2914738A US 2914738 A US2914738 A US 2914738A US 559965 A US559965 A US 559965A US 55996556 A US55996556 A US 55996556A US 2914738 A US2914738 A US 2914738A
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United States
Prior art keywords
correcting
network
branches
networks
equal
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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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US559965A
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English (en)
Inventor
Oswald Jacques
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.)
Compagnie Industrielle des Telephones SA
Original Assignee
Compagnie Industrielle des Telephones SA
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Filing date
Publication date
Priority claimed from GB51156A external-priority patent/GB793165A/en
Application filed by Compagnie Industrielle des Telephones SA filed Critical Compagnie Industrielle des Telephones SA
Priority to US559965A priority Critical patent/US2914738A/en
Application granted granted Critical
Publication of US2914738A publication Critical patent/US2914738A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/04—Control of transmission; Equalising
    • H04B3/14—Control of transmission; Equalising characterised by the equalising network used
    • H04B3/143—Control of transmission; Equalising characterised by the equalising network used using amplitude-frequency equalisers
    • H04B3/145—Control of transmission; Equalising characterised by the equalising network used using amplitude-frequency equalisers variable equalisers

Definitions

  • equalisation of the" attenuation curves of cable 7 sections with symmetrical or coaxial pairs is normally effected by means of well-known networks: equalisers, artificial lines, correcting networks, etc.
  • adjustable correcting networks of which the attenuation curve can be modified as desired by a change ..of an impedance and even preferably of one or more resistances incorporated in the circuit diagram of the correcting network.
  • Such networks make it possible to compensate thevariations of attenuation as a function of the temperature, as also 7 the residual distortions which may appear after a certain number of amplification sections.
  • Figure 8 shows a correcting network known in the art which can be compared to the one described in Figure 6;
  • Figure 9 is a modified form of the correcting network describedin Figure 6;
  • Figure 10 is a diagram representing the operation of the correcting network according to Figure 9;
  • An antimetric quadripole is a quadripole having a mean characteristic impedance which is constant, i.e., a
  • a cut-all quadripole is a quadripole offering infinite impedance at all frequencies;consequently, a quadripole in which nocoupling exists between the input and output 1 terminals thereof, i.e., the'impedance as seen'from one* of its pairs of terminals is completely different from the impedance disposed between the terminals of the other pair.
  • a lattice-type cut-all antimetric filter is, therefore,
  • Fig. 4 of the above mentioned certificate of addition represents a circuit diagram of a correcting network in a form which is particularly used, and which is reproduced'inattachedFigJ 1.
  • the shunted T therefore has the constant,characteristic im pedance R. r
  • Figure 3 represents acircuit diagram of a shunted T correcting network according to the invention.
  • Figure 4 shows the circuit diagram of network Q appearing in Figure 3;
  • ' g 5 represents correctmg network L work of infinite attenuation carried outinthe form, shown a differential transformer;
  • Figure 6 shows a correcting network as in Figure 3 in which a.4-terminal network Q is inserted for correcting the slope;
  • Figure I is a'diagram representing the operationof I the correcting network according to Figure 6;
  • a shunted'T correcting network according to the invention of which the diagram is shown in attached Fig. 3, has the advantage over the correcting network according to the aforementioned certificate of "addition'49867 or only using, instead of two networks Q and Q a single network Q in a circuit connected onthe one side in shunt with the resistance R and on the other via a resistance R to the primarywinding of a transformer of which the secondary winding is in the shunt branch of the T.
  • the network Q is an antimetric four-terminal net- Z1 and the other branches being composed of the variable resistances R, and R ⁇ , which are so'selected that the product
  • the superior branch of the correcting network: is.
  • the: attenuation of the correcting. network comprises in addition to" the.fixed portion a ,;a portion proportional to At the; frequencies for which E is anoddmultiple of cos' ZB' 1 is ze rci 'and' a equals a whatever the value: given to the parameter of adjustment p: we have pivot points ofitheattenuationcurvea V r l v Choo 11g for Za pure reactance; jX'(w), is'l reduced The pivot points therefore correspond tothe values if of the reduced reactance; there may be any number of them, and the number is reduced to one for an inductance or' a'capacity.
  • R' is e'qual to A II 2R, R that is tinita ns i c nsider o E u i s 12 and to 1'4 cosh a ,
  • the Bode correcting networks give transfer exponents defined by the Formula 16 in which. a and p have the same ineaning (reference attenuation and regulating pa- Qrarneter which in thiscase isthe coefiicient of disadaptation to the input of Q; arid Q but in which I is the transfer exponent (efiective'or on images) of Q and Q acteristic.
  • the reducedresistance I a 1
  • the superior resistance is of 591 ohms, as in the correcting network according to the present invention.
  • resistance in the shunt branch of the T is equal to correcting network comprises 4 inductances and'4 capaci'ties;
  • V tanh tanh 021%(1'207 V
  • the existence'of the two, pivots requires, as the simanda-ratio equal to plest solution, the use of an auxiliarynetwork of which the reactive branches are composed one of a resonant circuit (L, C), and the other of an antiresonant circuit V
  • the elements of the resonant circuit are immediately 1 determined" by: the value ]R ⁇ , of'its'. impedance on the pivots: i r r V 9 gives 'the'diagram of the correcting network,
  • FIG. 11 represents a.correcting network of this kind in the form of a shunted T, R may be infinite and R 7 zero.
  • the general plan of the four-terminal network Q is. given in Fig. 12: this is a lattice with opposite reversed branches, Z
  • branches may be purely reactive, purely resistant or comprise an assembly of reactive and resistant elements.
  • the property of a four-terminal network of this kind to be capable of being substituted for the two fourterminal networks of the Bode type diagrams, by the use of its open-circuit impedances, seen from each pair of terminals, may lead to a saving in the elements used in the setting up of the correcting network.
  • impedance equal to R formed by a symmetrical bridged-T circuit comprising horizontal branches each-having a resistance equal to R, a superior branch in parallel with said horizontal branches having a resistance equal to R an antimetric cut-all lattice-type quadripole with one pair of the terminals thereof connected in parallel with said superior branch and having a characteristic impedance R whereby R is related to R and R; by the equation i RR:12.' t R0 R i 1 a.
  • a correcting network with adjustable attenuation and having a constant characteristic impedance equal to R, formed by a dilferential network equivalent to the T-type comprising a hybrid coil with two identical primary windings and a secondary winding, said two identical 7 two opposite branches with adjustable resistances whose product remains equal to R and two further opposite branches with fixed impedances whose product is equal to R a shunt branch in said difierential network including a resistance R connected across the other pair of terminals of said quadripole, the values of R and R,
  • a transformer having primary and secondary windings, one of said windings being symmetrically connected in one of said horizontal and shunt branches of said network, impedance means symmetrical 1y forming the other of said branches, an antimetric cutall four terminal lattice-type quadripole having infinite attenuation and with a constant mean characteristic impedance, means including a resistance for connecting one pair of terminals of said quadripole to the other winding of said transformer, the other pair of terminals of said quadripole being connected across said impedance means, said quadripole having two branches including adjustable resistances whose product remains equal to the square of the characteristic impedance of said quadripole and two further branches including impedances whose product is also equal to the square of the characteristic impedance of said quadripole.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Filters And Equalizers (AREA)
  • Networks Using Active Elements (AREA)
  • Measurement Of Resistance Or Impedance (AREA)
US559965A 1956-01-06 1956-01-18 Adjustable correcting networks Expired - Lifetime US2914738A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US559965A US2914738A (en) 1956-01-06 1956-01-18 Adjustable correcting networks

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB51156A GB793165A (en) 1956-01-06 1956-01-06 Improvements in adjustable correcting networks
US559965A US2914738A (en) 1956-01-06 1956-01-18 Adjustable correcting networks
FR771813A FR76852E (fr) 1956-01-06 1958-08-04 Perfectionnements aux correcteurs réglables

Publications (1)

Publication Number Publication Date
US2914738A true US2914738A (en) 1959-11-24

Family

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Family Applications (2)

Application Number Title Priority Date Filing Date
US559965A Expired - Lifetime US2914738A (en) 1956-01-06 1956-01-18 Adjustable correcting networks
US818107A Expired - Lifetime US2991433A (en) 1956-01-06 1959-06-04 Adjustable attenuation correcting networks

Family Applications After (1)

Application Number Title Priority Date Filing Date
US818107A Expired - Lifetime US2991433A (en) 1956-01-06 1959-06-04 Adjustable attenuation correcting networks

Country Status (6)

Country Link
US (2) US2914738A (de)
BE (1) BE544310A (de)
CH (1) CH331380A (de)
DE (2) DE1200883B (de)
FR (4) FR1116277A (de)
NL (1) NL97865C (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2991433A (en) * 1956-01-06 1961-07-04 Cie Ind Des Telephones Adjustable attenuation correcting networks
US3122716A (en) * 1961-08-24 1964-02-25 Seg Electronics Co Inc Electrical filter consisting of frequency discriminating section concatenated with all-pass complementary phase correcting section

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2948866A (en) * 1958-10-24 1960-08-09 Cie Ind Des Telephones Adjustable correcting networks

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1732311A (en) * 1926-02-25 1929-10-22 American Telephone & Telegraph Method and apparatus for testing networks
US2044047A (en) * 1935-01-10 1936-06-16 Bell Telephone Labor Inc Wave transmission network
US2070668A (en) * 1935-10-04 1937-02-16 Bell Telephone Labor Inc Wave transmission network

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL36261C (de) * 1929-11-18
US2070688A (en) * 1933-12-30 1937-02-16 Hoover Co Suction cleaner
US2096027A (en) * 1936-01-30 1937-10-19 Bell Telephone Labor Inc Attenuation equalizer
BE524821A (de) * 1952-12-05
NL86023C (de) * 1953-03-16
FR1116277A (fr) * 1956-01-06 1956-05-07 Cie Ind Des Telephones Perfectionnements aux correcteurs réglables
GB793165A (en) * 1956-01-06 1958-04-09 Cie Ind Des Telephones Improvements in adjustable correcting networks
US2948866A (en) * 1958-10-24 1960-08-09 Cie Ind Des Telephones Adjustable correcting networks

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1732311A (en) * 1926-02-25 1929-10-22 American Telephone & Telegraph Method and apparatus for testing networks
US2044047A (en) * 1935-01-10 1936-06-16 Bell Telephone Labor Inc Wave transmission network
US2070668A (en) * 1935-10-04 1937-02-16 Bell Telephone Labor Inc Wave transmission network

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2991433A (en) * 1956-01-06 1961-07-04 Cie Ind Des Telephones Adjustable attenuation correcting networks
US3122716A (en) * 1961-08-24 1964-02-25 Seg Electronics Co Inc Electrical filter consisting of frequency discriminating section concatenated with all-pass complementary phase correcting section

Also Published As

Publication number Publication date
FR76852E (fr) 1961-12-15
FR1116277A (fr) 1956-05-07
BE544310A (de) 1956-01-31
FR76851E (fr) 1961-12-15
FR70150E (fr) 1959-02-03
CH331380A (fr) 1958-07-15
US2991433A (en) 1961-07-04
NL97865C (de) 1961-05-15
DE1224370B (de) 1966-09-08
DE1200883B (de) 1965-09-16

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