US1387210A - Morton -sttltzer - Google Patents

Description

. M. SULTZER. I METHOD AND MEANS FOR CORRECTING IRREGULARITIES IN TRANSMIS S|ON L |NES. APPLICATION FILED DEC- 18, I916. M 1,387,21 O. l I Patented u 9, 1921.

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- MORTON .SULTZER, or BROOKLYN, NEW YORK, AssIGNon To WESTERN ELECTRIC COMPANY, INCORPORATED, or NEW YORK, Y., A conromt'rron on NEW YORK.

'ME'I'HOD AND MEANS r03 CORRECTING IRREGULARITIES IN TRAitsmrssroit-Linns.

To all whom "it may concern Be it known that I. Monrox citizen of the lnited States. resi'din at- Brooklyn. in the county of Kings anditate of XewYork. have invented certain new and useful ln'iprove'ments in Methods and Means tor ('orrectin; Irregularities in Transmission-Lines. of' which the following is a full,

7 clear. concise. and exact description.

This invention relates to a methodand means for correcting irregularities in transmission lines. the object being to provide a method and means for correctingirregularities in transmission lines wherein amultiple condenser may be employed in which the capacity ofany unit may be adjusted with which do not accord with the constants.

out alteriug the capacity valu' s ot' the remainin units.

Although this invention will hereinafter be des ribed in connection 'it-h to ll cables in tele hone systems, it is. to he iinderstoodf tha 1t is not so l1n11ted but maybe used with.-

any suitable electric network. r This inventmn 1s part1cularly adapted for buildingout condensers for use'in telephone circuits made up of associated conductors as i 111 the case oi twlsted pairs nicluded in a the other sections. thus making the-j'cahle non-uniform. Stu-h would he the case when the distance between one end of a standard section and a receiving or transmitting station is unavoidalily lessthan'thelength. of a lhe connecting of thestandard section. end of the standaril section with the station by means of a short section \vould'lnean a non-uniforinity iii the system unless an arti? ticial means is used to increasethe capacity of this short section to the values required. 'lhe necessity of obtaining a loaded telc- Sp'ecification of Letters Patent. Patented -A1tg.

Stnrrznn, a

Application filed December 18, 1916. Serial No. 137,601.

phone system free of non-uniformities liesin the fact that, unless the cable is" quite uni-' form, it cannot be balanced properly by an artificial network, thus tory repeater operation; Q

This increase of capacity" could be added by meansot' bnildin eo'ut condensers of the For various reasons such a large preventing satisfactype described'in the "heeler sultzer Patent 1 No. 1200,0653, datedOctober 3, 1916; but if] they are used, a separate condenser will be required for each capacity .which is to bej "adjusted;

number of condensers, as would be required by the use ofthe above mentioned type for making the electrical constants of a cable f section accord with the constants of the- 2 standard sections and for correcting the capacity unbalance between certam of the, conductors of the SGCiZlOll, would be ob eQ-Q tionable, as; for example, when they were added to the cable at 'a manhol'e whjere the ..75 invention overcomes these objections byproe "vnhng amore compact and effective means available space 'isjnecessar ily limited: This than has hitherto been known, for adding the necesssars capacities to tbe'cableyand 9 for making the final adjustment of the.

for eliminatvalues of the various capacities 111; the capacity unbalance.

In a cable quad eontainingwtwo twisted pairs of conductors. there'are four kinds of, H '85 capacities to be considered, iamely mutual capacity. direct capac ty, "rounded capacity 1 and capacity to groin is meant the capacity between two conducy direct capacity tors when allthe other conductors are: alt-c sent. thatis. the so called geometric capacity 5y mutual capacityiis meant thetotal capacs 7 it v hetweei'rthe two conductorsas used, that it will hetlie sum'of the direct capacity, 4

:hetween the two wires and the additional capac1t v due! to the capacitytof each of theconducto s to some other ob ect or objects;

ltv 'g'rounded capacit is meant the capacity, 1 betweentwo conductors when one of the con-f ,ductors and all other objects in the vicinity Grounded capacity will not.

are g un'd'ed.

be us' l in the "following specification, but

the term "capacity toground as used, willreter to the dn'ect capae1ty of the-conductor 1 under discussion to the cable sheath or other conductors which might/he permanently connected to ground.

.du'ctors may, in general, be neglected. 10

In a cable quad, in general, the necessity does not exist for absolute adjustment of all six of the direct capacities to a high degree of accuracy, but it is preferable that the four of the direct capacities, which enter into the capacity unbalance of a cable, should be relatively adjusted to a high degree of accuracy. By these four capacities is meant the direct capacity between each. wire of one pair, and each of the two wires of the other pair. Even after the units have been accurately adjustedto the values for properly biiilding out the section, it is necessary to make a final adjustment of some in order to obtain this relative adjustment with a high degree of accuracy. Especially is this true in the case of the four capacities-referred to above in connection with the elimination, as far as possible, of cross talk; and they should have values which do not differ from each other by more than a few micro-microfarads.

This invention affords a means for the addition of the desired extra capacity values to a short section of a cable by the addition of two small compactly-built condensers to each cable quad, each condenser containing three units. The :onstructionjof each condenser is such that the value of any unit may be varied without causing any variation in the value of the remaining units. This independent variation may be accomplished by pulling inor out one of the plates of the unit to be varied. The fact that this variation does not affect the other units is due to shielding plates inserted between the units as hereinafter described.

This invention may be better understood by reference to the accompanyingspecification and drawings, 'in whichI ig ire 1 shows a cross-sectional view of a four-wire core or quad of a cable, and the various capacities of such a system'of conductors. Figs. 2 and 3 each illustrate an embodiment of this invention.

Fig. 1 shows a cross-sectional view of a cable quad in which there are four wire con- .ductors, designated by 4, 5, 6 and 7, surro unded by a suitable sheath or covering 18; wires 4 and 5 forming one physical telephone circuit and wiresG and 7 forming the other. If the two conductors of each pair are connected in parallel, each pair may also be considered asa single conductor, so that the two pairs may be used for the so-ealled phantom circuit arrangement. Between any wire and 'each of the other three wires of the quad,

'to the sectioniof a cable quad, as shown in there will be a certain amount of direct ca pacity. Consider that these capacities between the wires of'the quad, represented by Fig. 1, are smaller than those of the standard section, and that condensers 8 to 13 inclusive have been added to the quad to increase them to their proper values. The condensers 14-, 15, 16 and 17 between the various wires and the sheath 18 will be described later.

Figs. 2 and 3 show the two multiple condensers of three units each, whose units are attached to the cable quad. These condensers will be described in detail. In Fig. 2, between clamping arms 19, 19 are insulating material 40 and conducting sheets 20 to 27 inclusive. In Fig. 3, between clamping arms 19, 19 are insulating material 40 and conductingv sheets 30 to 37 inclusive. The sheets 20-21 form the condenser 10; sheets 22-25 inclusive form condenser 9; and sheets 26- 27 form the condenser 12. Corresponding sheets in Fig.3 form the condensers 11, 8 and 13, respectively. As previously stated, assume that these condensers have-been added 4 Fig. 1, to increase the various capacities. Such being the case,conducting sheets 20, 33, 35 and 36 would be connected to'wire4; sheets 27-, 3 1, 32 and 34 to wire 5; sheets 30, 21, 22 and 24 to wire 6 and sheets 37, 23, 25 and 26- to wire 7. Each outer sheet of the two multiple condensers has a. certain ca acity efl'ect to the clamping arm 19, and 1: ese capacities for the outer sheets 20, 30, 27 and 37 have been represented in Fig. 1 by the condensers 14, 1:"), 16 and 17, respectively. These serve to increase the capacities to groundof the wires and to. build them out approxima ely to their proper values for eliminatin the non uniformity, although, 05 being very small, their accurate adjustment is generally unnecessary.

As has been previously stated, it is of the utmost importance that the direct capacities be adjusted to the highest degree of ac- 0 curacy. 'Even when the capacity of each unit is previously calculated and constructed for the proper value, after-the units are placed between the clamping arms, addiif sheet 21 is adjusted, the capacity to ground would be shielded by plate 20, and the ca pacity 9, represented by sheets 22-24 and 23-25, would be shielded from any dis-' turbance by means of sheet 22 which is at the same potential as sheet 21. For, if sheet V 22 were absent, there would 'be electrostatic lines of force between sheets 21 and 23, so' that the ,variation of the effective area ofv sheet 21 would'change the number of lines -latter mentioned lines of 'force will not be varied by movement of 21 as there are no linesbetween sheets 21 and 22-, and so the capacity. of thunit 9 would remain un- (JlIIfIHgQiL, Furthermore, if sheet 22 were not pesent, an increase'in the effective area of slieet.21 would not only affect the capacity of units 9 and 10, but would also increase the capacity between'sheets 20 and 23, or

between wires and 7. But as previously explained, the additional capacity-to be 1n- Iserted between wires 4 and 7 is to be derivedonly from unit 13 of Fig. 3. Hence, this increase in the capacity between sheets 20 and 23would necessitate a corresponding.

decrease to he made in] the value of unit 13 in order, to bring it back to its original value. Thus it is seen that, in the absence of the sheet 22,a variation in the direct capacity valuebet'wecn wires 4 and 6 produces a eta-responding change in the mutual capacity between wires 4 and 7. However, with sheet22 present, the direct capacity of unit 10 may be independently varied.

The plate 22, which-is at the same potential'as the plate that is varied, is shown as a constituentmember of the unit 9 and 'in close proximity to theother plates of said unit, but such need notbe the case as it will periorm 'itsprop'er function 'ofacting, as a shield between the units 10 and 9 by being placed in any suitable position between the units, providing only that it is at the same )oten t-ial as the plate that is to be varied.

11 general. the sheet 22 need not be a membcuoi' either of the units. although it i s shownas such in the drawings. 'lherel'orc,

pacit I "but 1 met atl'ect the capacity of any of the other units. ln the same manner. unit 11 the interposition of a shiclding plate lie-- tween the two adjacent units permits the varlat1ouol' one without affecting the direct capacity ot'arny of the other units.

liy similar reasoning the variation of the cliectivc area of sheet 26 \\'lll change the call lllllt 1.2 between sheets 24) and 27,

may be varied by means of sheet 31 and unit 13 by meausof sheet 36. The :u-ljustment oi there :is considera )ly more insulation bc-, tween the separate units than between the )rotcctin plates 22-425 and plates of each individual unit. This also aids in allowing the independent variation... 1

of the units as it reduces a negligible quanl tity any fringing effect around theedges of the plates. y y l The conducting sheets or plates are pref erably made of copper; although they may be made of tinfoilor other. suitable material.-

The insulating materialmay be of sheets of mica or any otherinsulator. l

Although this invention is explained with I reference to a condens er. having only'three units, it is obvious that theinvention is not so limited, but applies equally as' well; toa. so

condenser having any number of units.

, 'hat is'clalmed. is: o

'1. A unitary multiple condenserstructure comprlsing a plurality of units in such close proximity to each other as, ordinarily to' establish an, electrostatic relation therebetweenfand comprising means for varying the. capacity of one unit without affecting; the capacity of another of said units.

2. A unitary multiple condenser structure comprising a plurality of units, mea'ns t'or varying the capacity of one unit and means i for preventingthe variation of said unit. from affecting the capacity of a neighboring unit, said last mentioned means comprising a protecting shield which cuts off the lines of force between said firstmentioned unit and its neighboring unit.

3. A cable quad comprising a direct capacityanda mutual capacity, and I plurality of conductors, each pair of conductors havin ga a plurality of unitary condenser structures comprlsmg means individualto eachof said structures and inr lependentlof th th f i said structures for varying the direct ca parity between a pa r of said conductors without alt'ecting he mutual capacity .be-

tween auothm pair.

4. unitary multiple condenser structure comprising a plurality of units. each unit being composed of a plurality of conducting sheets separated by a suitable dielectric; said units being separated from each otherj by a metallic shield which serves to cut off the lines-of force to adjacent units. whereby the capacity of a unitmay be varied without alleclmg the capacity of any other of said unitsfi i 5. cable quad composed of a plurality ot conductors. each pair of conductors having.

a' direct capacity and a mutual .capacity..f

and means fol: increasing the direct capacity: between a pair oi said fcoluluctorswithout all'ectingllh'e mutual capacity between other conductors. 'said' means consistin'g of a uni-] tary multiple condenser structure comprising a plurality of units. said units composed ol conducting sheets separated by suitable insulating material. the outer sheet of each unit being at the same potential as the near-. cst sheet ol' the adjacent unit, thcrebyiafi'ording a means for adjusting each unit without fleeting the capacity of any other of saidunlts.

6. A unitary multiple condenser structure containing a plurality of units composed of sheets of conducting and insulating material, and comprising means for varying the ca- 'pacity of one unit without affecting the capacity of another of said units.

7. A unitary multiple condenser .structure, comprising a plurality of units in such proximity that ordinarily they would be 111 inductive relation, and comprlsing means electrically connecting adjacent armatures of different units and maintaining them at the same potential, the area of which is provided by the opposed positions of said armatures being adjustable in amount.

8. A unitary multiple condenser structure containing a plurality of-units in such proximity that ordinarily they would be in inductive relation, and comprising means electrically connecting adjacent armatures of different units to one terminal of the con--' denser so that,the same polarity is represented bythe said armatur'es, the area which is provided by the opposed portions of said armatures being adjustable in amount.

9. A unitary multiple condenser structure composed of a plurality of units each of said units consisting of conducting sheets separated by a suitable dielectric, means for varying one of said: units, and means for 'preventingsaid variation from affecting a neighboring unit, comprising a common terminal for the two outermost coiulucting .sheets of the two neighboring units.

. 10. The method of correcting irregularities in sections of transmission lines which comprises inserting a corrective ii'npedance in a section between the sheath and a wire of said line to bring the value oi the m pedance therebetween to a desired value.

11. Themethod of correcting irregularities in loading sections of transmission lines which comprises inserting in an irregular section a 'corre. ve impedance between the sheath of" said line and a wire therein of such value as to render the irregular section electrically equivalent to a normal section.

ties of loading sections of periodically loaded transmission lines which comprises inserting between the wires of said lines and the sheath in irregular sections a corrective impedance of such value as to rendeig the irregular section electrically equivalent to a normal section. v 13. The methodof correcting'irregularities in loadingsections of periodically loaded transmission lines which comprises inserting between the sheath and the wires in said line in irregular sections a corrective impedanceof such value as to render the 12. The method of correcting irregulari-' irregular sections electrically equivalent to a normal section, and inserting corrective impedance between the wires in said lines for the same purpose.

14. A ftransmission cable comprlsing a wire and a sheath and comprising a plurality of sections one of which is irregular, and a corrective impedance connected between the sheath and wire in said irregular section, of such value as to bring the impedance between the sheath and the wire in said irregular section to a desired value to thereby correct the irregularity,

15.. A transmission cable comprising a wire and a sheath and comprising a .plurality of loading sections, one of which is irregular, and a corrective impedance connected between the sheath and the wire in'said irregular section of such value as to render the irregular section electrically equivalent to a normal section.

16. A periodically loaded transmission line comprising one or more wires and a sheath, and comprising one or more irreguline comprising one or more Wires and a sheath and comprising one or more irregular sections, corrective impedance connected between the sheath and the wires 111 irregular sections, and corrective impedance connected between the wires in said irregular sections, said impedances being of such valueas to render the irregular sections electrically equivalent to normal sections.

1.9. A. transmission cable comprising a.

plurality of wires and a sheath, corrective.

capacities between said wires and said sheath and between said wires.

20. A unitary multiple condenser structurc comprising a. plurality of units in' such proximity to each other that ordinarily they would beinductively related, the mutual capacities between units being of importance,

and said structure comprising conductingmembers arranged for varying the (llIBQlZ' capacity of the unit without afi'ecting the mutual ca iacities between units 21. A unitary multiple condenser struc ture cm'nprising a plurality of units in such proximity to each other that ordinarily they would be inductively related, said structure comprising relatively adjustable conducting I slleets' for varying the direct capacity of'a linit without afiect'ing the mutual ca acities 22. Acitbleqnad comprising two pairsof between units'and having con'siderab ymore insulation betweenthe separate-units than between the armatures oteaoh- 'ihdividual conductors in a sheath and two ij nitary multiple condensers, each condenser including three units, one outside unitof' jbne 'conde'n ser being connected between one conductor of one-pair and one conductor-of the other pair, the other outside unit of said one condenser being connected between the other two conductors, the middle unit of said one' tiple' condensers each condenser including conducting sheets and three condenser units between said sheets, one'outside unlt of one condenser being connected betweenone con ductor of one pair and one conductor of the other pair, the other outside unit of said one condenser being connected between the other two conductors, the middle unit of, v

said one condenser being connected between the two conductors of. said one pair, the

other condenser being correspondingly connected, adjacentarmatures of the different units in each condenser being relatively ad justable and being electrically connected together, the armatures of the units next to said conducting sheets coiiperating with said sheets to' form fouradditional condenser:

:units, and said sheetsvbeing electrically con nected with the sheath.

In witness whereof, I hereunto subscribe my name this 15th day of December, A. D.,

MORTON SULTZER.

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