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Publication numberUS1114409 A
Publication typeGrant
Publication dateOct 20, 1914
Filing dateSep 10, 1914
Priority dateSep 10, 1914
Publication numberUS 1114409 A, US 1114409A, US-A-1114409, US1114409 A, US1114409A
InventorsJames Buckner Speed
Original AssigneeJames Buckner Speed
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Apparatus for correcting disturbances on telephone and other like wires.
US 1114409 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

J. B. SPEED.

APPARATUS FOR CORRECTING DISTURBANOBS 0N TELEPHONE AND OTHER LIKE WIRES.

APPLICATION FILED 11111. a, 1914. nmmwnn SEPT. 10. 1914.

1,1 14,409, Patented 0013.20, 191i 1H5 NORRIS PETERS C0 1 PHOTO iJTH .4 WA "ING DN. D, C.

mtnoao a E I iliane.

To all whom it may concern:

* Ja vrns BUCKNER srnnn, e ase-Year; i f

APPARATUS non coanncrme Bistros-Barrens WIRES.

I Specification oi Letters Patent.

on m ane t AND (Oriana LIKE Patented 20, 1914.

Continuation of application Serial No. 728,385, filed Novembcre, 1912. This application filed March 3, 1914,

Serial No; 822,129. Renewed September 10, 1914. Serial No. 861,138. 1

Be it known that 1, JAMES BUOKNER Srnno, of the city, county, and State of New York, have invented certain new and useful Improvements in Apparatus for Correcting Disturbances on Telephones and other like Wires, of which the following isa specification.

Except as to certain details of circuit arrangement in the transformers 1l-12, in-' cluding the impedance coils 16, this application is a continuation of my application 729,385 filed Nov. 41-, 1912, and is substituted 5 therefor. l My invention.relates to theart of correcting disturbances on telephone and other like Wires, occasioned by the proximityof elec tric power circuits.

1 vfyzinvention consists'in an ap iiaratus for this purpose, the controlling characteristic of which is that it embodies means for sepa rately neutralizing the fundamental fro quency, and harmonics, of the disturbing current, a particular embodiment of said apparatus being, hereinafter described wherein, inconnection with said neutralizing means, there is also employed means for producing an observable manifestation of s the disturbance on the telephone line, for the purpose of facilitating the, Work of correc tion.

These means are-susceptible of many refinements; for example, With regard to the production of the observable manifestation of the disturbance to be corrected, it. is best i that such manifestation be in the form of a visible diagram and furtherthat said diatralizing disturbance, I i have shown one form and arrangement, but'Ido -not confine ,mental of the disturbance. best that the visual representationof, the" disturbance shall be stationary in azimuth, as this is-desirableforthe correction of dismyself thereto, as it may be yaried 'in many particulars to suit good practice, and still be ings:-Figure 1 is a general View, more or less diagrammatic, of my apparatus. FlgQ 1s a'plan View, enlarged, ofthe reflecting disk. I

lis a telephone or telegraph line in which, by reason Of ill'ilJl'OXllllllJY of "an electric power line" 2, disturbances orjtrouble occur.

' A. indicates, as a Whole, an oscilloscope by WlllClI the disturbances inthe line 1 are made visually manifest. Though this niani f festation may. of: any. suitable observable jcharactenl recommend inipractice aforl n of oscilloscope which will give a closed curve or polar type of diagram, in wliichone' revo lutionor 860degi'ees ofjthe diagram 0ccupies the period ofone cycleof the funda- It s, further,

turbances resulting gfrom i'nore than one source of power not o'peratedin" parallel with the others. The oscilloscope A comprises a source of light 3, say, a small electric direction, except in azimuth, said disk carrying a small concave mirror or a reflecting surface 6. This disk is held in the plane of its gimbal rings by a magnetic field produced by the six' pole 'field' magnet 7, the axis of said magnetic field being in the plane of the disk, and said magnetic field rotates synchronously With the fundamental of the disturbance, by reason of being energized by three 3- ph ase circuits, as shown.

A coil of wire 8 is arranged with its axis perpendiculartothe plane of rotation of the .magnetic field, and this coil of Wire iscon-.

nected in any. suitable manner, as, for eX- ample, looped inpwith the'line WirefLas' shown, or a repeating coil may be used, in the usual manner so that said coil is energized by thecurrents in said line Wire. The coil-0f Wire'8 issodisposed With reference to the iron disk 4 and the field magnet 7 nu W bulb. .A, minute iron disk 4 is pivoted in fj gimbals, 5, so aslto be freeto turn in any,

that its effect is to displace, the plane of the iron disk angularly with respect to the'plane of the rotating magnetic field which the field magnet 7 produces As will be seen the fieldinagnet 7is electrically connected with the power wire 2 through the transformer at T, that is to say it is energized from the same power system which is the cause of the disturbance on the line wire 1. It will now readily be understood that because said field magnet 7 is energized from the power wire 2, it follows that the movements of the iron disk 4 and its mirror 6 will always occur at the same position in the circular path of the spot of light, and, therefore, the same diagram will be repeated as many times a second as the frequency of the fundamental of the power circuit, and consequently the disturbance. In order to observe this diagram, the beam of light from the bulb 3. is reflected by the mirror 6 to a ground glass screen 9-, and on this screen the spot of light will only retraverse that portion of its path which is produced by the same. source of disturbance as is operating the rotating field. As this is the case, it follows that the vibrations introduced by the telephone conversation, or, in case of a telegraph wire, by the application of the line battery by the operators key,

while interrupting or adding other vibrations to the disturbance vibratlons, Wlll be practically invisible on the screen 9, since they are not repeated over and over again as are those displacements produced by the disturbing current, which, as before stated, is operating the field magnet 7. Thus by means of an oscilloscope, an observable manifestation of all the electrical disturbance on the line is produced whether caused by electromagnetic or. electrostatic or leakage or atmospheric conduction, said manifestation being a visual one and its diagram being a closed curve as its best type.

The means for the production of another or second disturbance on the telephone line and for regulatingand adjusting the second disturbance in the light of the visible diagram above mentioned, in such manner, that it will effect the desired alterations in the diagram of the disturbance which it is wished to correct, are as follows, in sofar as here illustrated, it being understood as I have before stated that said means represent one form of device which in the present case and for the purposes hereof are electrically typical rather than mechanically specified.

10 are field magnets. There is a plurality of these field magnets and though almost mechanically stationary in the sense that they do not continuously rotate, they, by the use of 3-phase currents, produce rotating magnetic fields, and these field magnets are made so as to be manually shiftable around their axis of symmetry through a rotational angle less than 360 degrees. Corresponding to each of these field magnets are armatures '11 wound for single, three, five, seven, etc.,

phase circuits, only the single, three phase, and five phase armatures being shown, and

these armatures are so arranged that they 11 which are arranged for the production of j fundamental frequency, do not require a itransformer 12.

The leads 13 from the armatures 11 are carried to these transformers through the choking 0011s 16 as shown, so

, that the fundamental frequency of the variousmembers of each polyphase sct neutralize 1 each other and nothing is left 111 the secondary of the transformers except the electromotive force or current which is the same multlple of the fundamental as the number 1 of phases brought into the transformer; for

example, fromthat armature which is wound with three coils for three-phase current, nothing will come out of the transformer into'which these armature leads are taken shiftable around their axis of symmetry, and also that their armatures are movable parah lelto themselves in the direction of the said axis. it now follows that by reason'of the except triple frequency.

1 have stated that the field magnets 10 are plurality of fields, it is possible to produce any of the said multiples of the frequency or the fundamental of the power which is operating said fields, and further that by reason of the mechanical rotative shiftability of said field magnet, each of such frequencies may be varied independently as to phase, and finally, that by reason of the ad- .justability of the armatures in the direction of the axis of symmetry, each of said currents may be varied independently .as to intensity.

In the present illustration, the means for effecting these variations comprise a crank handle lat by which the field magnets 10 are rotatively shifted, and sliding bases 15 on which the armatures move to and from the fields. One of these groups of field magnets and armatures, here shown as the uppermost, is connected up in that part of the complex generating set which is intended to give the variation of phase and intensity of the fundamental of the correction current to be produced. Thus this group puts in the control of the operator the means of varying the phase and intensity of the fundamental component of the complex correction wave or current to be produced. The

other successive groups of field magnets, armatures and transformers. of which there may be 1 any required number, vary the phase and intensity of the different multiples of the fundamental.

It will now be seen that means are provided by the operation of which a second disturbance maybecreated on the line and said second disturbance may be manipulated and. so controlled and adjusted as to attain a complexity and character adapting it to neutralize the first disturbance. This adjustment is effected by the operator'through her deliberate selection and manipulation of the several adjusting devices of the groups of field magnets 10 and armatures 11 to the I The operation of the apparatus as a whole will be better understood by a brief recital of the manner of practically carrying out said operation ina telephone exchange. In any telephone exchange of moderate size there will be found a chief operators desk and a trouble clerks. desk, etc, in addition to the numerous panels of-the large. switchboard which are attended on by the ope'ra tors. I propose to put in another desk, similar in general appearance to the chief operators desk, to be called the correction desk, with a girl operator in charge. This desk may keep a hundred lines or more corrected. Its operation is similar to the chief operators desk, in that the main switchboard girls or operators may all speak to the correction desk and plug any one of their noisy lines in connection with the correction desk. The correction operator on receiving a disturbed line from the main switchboard operator will plug it into a hole of her board, which communicates with one of the correction units, of which there are about a hundred in her desk. Thi correction unit contains, in some form, all of thefapparatus heretofore described, or its equivalents,

that is, the oscilloscope and the complex frequency generating groups .or sets. As soon as she has plugged the line to the cor rection unit, there will appear on the ground-glass screen 9, a clover-leaf shaped figure, that is, one having three principal lobes and cusps, because usually the principal disturbance on telephone lines is of triple the frequency of the fundamental of the power lines. If instead of a clover-leaf figure a heart-shaped figure, with one cusp, is seen, this will indicate that the trouble is principally of the fundamental frequency. As a matter of f'act,neitherof these two figures in its simplest'formj would ever 00- our, the outline of the figure being decidedly wavy. Suppose, however, the figure contains one principal dent, indicating the presence of some of the fundamnetal in the disturbance. Thereupon the operator reaches for that group of field magnets 10 and an matures 11 which concerns the production of the fundamental of the correctioncur rent, and by moving the field rotatively by the crank handle l0,"she will cause the region. of the principal dent in the diagram to be shifted around angularly or in azimuth, while by moving the sliding armature she will change the magnitude of the dent in the diagram as measured radially from its geometrical center. This manipulation will result in the obliteration of any clearly distinguishable onesidedness in the diagram. l/Vhat remainsin the diagram will then be very 'n uch more noticeably three-sided or I, clover-leaf like. She now selects another" group of the complex correction current set and by operating either the field or the an mature, (it makes no difference on which she begins), she will either shift rotationally the three-sided cusps of the oscilloscope figure, or else she will change the magnitude 1 of thethree-sided part,-as measured radially from thecenter; I Between the two shiftings she then obliterates the threeparted irregularity in her diagram. Frequently, thiswill bequite enough to bring the diagramof the oscilloscope to indicate practical silence, but

in cases where the circuit is of more impor tance and greater silence. is required, it may be desirable tocorrect in a similar manner the higher harmonics, a .result attained by. operating other groups of the correction currentfsent.

I claim I .1. An apparatus for the described purpose co1n1')rising means operated by the current in the power line, the proximity of which is the cause of the disturbance on the tele )hone line for aroducin an observable manifestation which is indicative of the dis turbance on said telephone line; means for producing a second disturbance on said telephone line, synthetically out of a plurality of alternating currents whose frequencies are respectively equal to the fundamental of the disturbance and its harmonics: and

means for regulating 'and adjusting said,

alternating currents in their phases and intensities, to effect such alterations'in said observable manifestation as will indicate a condition on jthe telephone line free from, disturbance. y

2. Arrapparatus for the described purpose comprising means operated by the current in the power line, the proximity of which is thecause of the disturbance on the telephone line, for produc ng avisible diagram which is indicative of the disturbance on said telephone line; means for producing a second disturbance on said telephone line, synthetitcally out of a plurality of alternating currents whose frequencies are respectively equal to the fundamental of the ('llS' turbance and its harmonics; and means for regulating and adjusting said alternating currents in their phases and intensities, to effect such alteration in said visible diagram as will indicate a condition on the telephone line free from disturbance.

3. An apparatus for the described purpose comprising means operated by the current in the power line, the proximity of which is the cause of the disturbance on the telephone line, for projecting a beam of light upon a screen. and causing it to traverse a path thereon and so produce a visible diagram indicative of the disturbance on said telephone line; means for producing a s cond disturbance on said telephone line; and means for regulating and adjusting said second disturbance to etiect such alteration in the visible diagram as will indicate a condition on the telephone line free from disturbance.

a. An apparatus for the described purpose comprising means operated by the current in the power line, the proximity of which is the cause of the disturbance on the telephone line, for projecting a beam of light upon a screen and causing it to traverse a path thereon and so produce a visible diagram indicative of the disturbance on said telephone line; means for producing a second disturbance on said telephone line and means capable of selective and several operation for regulating and adjusting said second disturbance to effect such alteration in the visible diagram as will indicate a condition on the telephone linev tree from disturbauce.

5. An apparatus for the described purpose comprising means operated by the current in the power line, the proximity of which is the cause of the disturbance on the telephone line, for projecting a beam of light upon a screen and causing it to traverse and retraverse a closed path synchronous with the fundamental frequency of the disturbance on said telephone line whereby a visible diagram is produced indicative of said disturbance but not of the sound. producing currents on said telephone line; means for producing a second disturbance on said telephone line; and means for regulating and adjusting said second'disturbance to effect such alteration in the visible diagram as will indicate a condition on the telephone line free from disturbance.

6. An apparatus for the described purpose comprising means operated by the. current in the power line, the proximity'of which is the cause of the disturbance on the telephone line, for projecting a beam of light upon a screen and causing it to traverse and retraverse a closed path synchronous with the fundamental frequency of the disturbance on said telephone line whereby a visible diagram is produced indicative of said disturbance but not of the sound producing currents on said telephone line; means for producing a second disturbance on said telephone line; and means capable of selective and several operation for regulating and adjusting said second disturbance to eflect such alteration in the visible diagram as will indicate a condition on'the telephone'line free from disturbance.

7. An apparatus for the described purpose co-mprising a source of light; a movable reflector for projecting a beam of said light; a screen upon which said beam is projected; means affected by the current in the power line, the proximity of which is the cause of the disturbance on the telephone line, to operate the reflector to cause the projected beam to traverse a visible path on the screen, which path is consequently indicative of the disturbance'on said telephone line; means for producing a second disturbance on said telephone line; and means for regulating and adjusting said second disturbance to effect such alteration in the visible path of the beam on the screen as will indicate a condition on the telephone line free from disturbance.

8. An apparatus for the described purpose comprising a source of light; a movable reflector for projecting a beam of said light; a screen upon which said beam is projected; means affected by the current in the power line, the proximity of which is the cause of the disturbance on the telephone line, to operate the reflector to cause the projected beam to traverse a visible path on the screen, which path is consequently indicative of the disturbance on said telephone line; means for producing a second disturbance on said telephone line; and means capable of selective and several operation for regulating and adjusting said second disturbance to eflect such alteration in the visible path of the beam on the screen as will indicate a condition on the telephone line tree from disurbance.

9. An apparatus for the described purpose comprising a source of light; a movable reflector for projecting a beam of said light; a-screen upon which said beam is projected; means aflected by the current in the power line. the proximity of which is the cause of the disturbance on the telephone line, to operate the reflector to cause the projected beam to traverse and retraverse a closed path on the screen synchronous with the fundamental frequency of the disturbance on said telephone line, which path is consequently indicative of the said disturbance but not of the sound producing currents on second disturbance to effect such'alteration v pose comprising means operatedxby the curtoward and from said nagnets, transformtelephone line, for producing a'visible diaphase and intensity of saidsecond disturbmeans for regulating and adjusting the their axis of symmetry, armatulfes' movable said telephone line; means for producing a second disturbance on said telephone llIlG;

and means for regulating and adj ustingsaid second disturbance to ctiect such alteration in the visible path or the beam on the screen as will indicateja condition on the telephone line free from disturbance."

10. An apparatus forthedescribediip un pose comprising a source of light; a movable reflector for projecting a beam ofsaidlight; a screen upon which said beam is projected; means affected by the current in the power line, the proximity of which is the cause of the disturbance on] the telephone line, to operate the reflector to cause the projected beam to traverse and retraverse; a closed path on the screen synchronous with the fundamental frequency of the disturbance on said telephone line, which path is conse-" quently indicative ofthe said disturbance but not of the sound producing currents on said telephone line; means for producing a second disturbance on said telephone line; and means capable'of selective and several operation for regulatingand adjusting said in the visible path of the beam onthe screen as willindicate a condition onthetelephone line free from disturbance. a

11. An apparatus for the described pur rent in the power line, the proximity, of which is the cause of the disturbance on the grain indicative of the disturbance on'zsaid telephone line; means for producing a second disturbance on said telephone line; and means for regulating and adjusting the ance to effect such alteration in the visible regulating and adjusting means comprising field magnets rotatively shiftable around their axis of symmetry, armatures movable ers, and suitable circuit-connections.

12. An apparatus for the described pur pose comprising means operated by the current in the power line, the proximity of which is the cause of the disturbance on the tele'phone line, for producing aivisible diagram indicative of the. disturbancev of said telephone line; meansfor producing a sec-v ond disturbance on said telephone line; and

phase and intensity of said second disturbance to'eflectxsuch alteration in the visible diagram. as will indicate a condition on the telephone line free from disturbance, said regulating and adjusting means comprising selectively and severally operatable groups of field magnets rotatively shiftable around toward 1 and from said magnets, transformi ers, andsuitablecircuit connections. g [l -FAREll)ptl1 2ibll$ fQr the described pur-:

po e o 'np ising'means operated by thepcui rent in the power line, the proximity ct which is theeause-of the d'isturbanceon the telephone line, fore-producing a visible diagram indicative of thedisturbance on "said .telephone line means for producing a sec- 0nd disturbance on said telephone line; and Inean's for i regulating and adjusting the phase and intensity of said second disturb ance to effect such alteration in the vlsible diagrainas will indicate a condition'on the a I telephone line free from disturbance, said regulat ng and ad usting means comprlsing independent v, groups ,OIE field magnets and armatures, the 'magnets being rotatively slnftableparound thelr axis of symmetry and the armatures being, movable to} and from the magnets, thefarmature of one group be-' 111g woundfor alsingle phase circuit, {another for time 'g-phaseQcircuits, another {forfive 5.:phase circuits, and soon, a transformer in electrical connection with the armatureof eachvgroup other t-han-"that forthe single tions for said groups; 1

phase circuit, and'suitable circuit. connec- 14. An apparatusffor the described pur pose, comprising a 'sourceof light a move, 1

able reflector tor, projecting a beam of said light; a screenuponiwhich said beam 1s pros ected; meansafiected by the current in the power line, the proximity of: rwhich is the cause of the disturbance on the telephone l ne, .to operate the reflector to cause the pro ectedbeamto traverse and retraverse a closed *path on the screenj'synchronous with the fundamental frequency of the disturbance on said telephone linewhich pathis con-v sequently indicative of the said disturbance but not of the sound producing currents on said telephone line; meansfor producing a I second disturbance on said telephone line;

and means forregulating and adjusting the phase and intensity of said second dlSllLllb ance to eifect such alteration in" the visible v diagram as'willindicate acondition on the telephone line free fromdisturbance, said regulating andadjusting means comprising independent groups of field magnets and armatures, the magnets beingrotatively shiftablearound their axis ofsymmetryand the armaturesbeing movable to and is from the magnets, the armature of one group being 'wound for 8}SlllglGQPhilSG,C1I'Clllil, another for three 3-phase circuits, another for five 5-phase circuits,- and soom a transformer in electrical connectloniw'ith the armature of eachgroupj otherthan that for the single phase, circuit; and suitable circuit connections for,said groups. e v

,15. An apparatusfor the described purpose COlnPI'lSlIlgHlCELIlSiOPGI'ZllZBd by the ourtelephone line, for producing a visible diagram indicative of the disturbance on said telephone line; means for producing a second disturbance 011 said telephone line;.'and

means for regulating and adjusting the phase and intensity of said second disturb-'- ance to effect such alteration in the visible diagram as will indicate a 'CODClliLlOIi on the telephone line free from disturbance, said regulating and adjusting means comprising independent groups of field magnets'and armatures, the magnets being rotatively shiftable around their axis of symmetry and the ar'matures being movable to and from the magnets, the armature of one group being Wound for a single phase circuit, another for three 3-ph'ase circuits, another for five 5-phase circuits, and so on, a transformer in electrical connection with the armature of each group other than that for the single phase circuit, and suitable circuit connections for-said groups, each of said transformers being characterized by its primary being of as many circuits as the phases of the armature to" which it is connected so that the resultant magnetic 'fiuXin its iron core is of as many timesthe fundamental periodicity as the number of phases for which its primary is Wound, and a slngle secondary circuit in which is developed the said multiple of thefun'daniental frequency. 16. A11 apparatus for the described purpose, comprising a source of light; a movable reflector fo'r projecting "a beam of said light; a screen upon which said beam is projected; means afiected by the current in the power line, the proximity of which is the cause of the disturbance on the telephone line, to operate the reflector to cause the projected beam to traverse and retraverse a closed path on the screen synchronous with the fundamental frequency of the disturbance on said telephone line which path is consequently indicative of the said -disturb' ance but not of the sound producing currents on said telephone line; means for producing a second disturbance on said telephone line; and means for regulating and adjusting the phase and intensity of saidsecond disturbance to effect such alteration in the visible diagram as Will indicate a condition on the telephone line free from disturbance, said regulating and adjusting means comprising independent groups of field magnets and armatures, the magnets being rotatively shifta-ble around their axis of symmetry and the armatures being movable'to and from the magnets, the armature of one group being Wound for a single phase circuit, another for three 3-phase circuits, another for five 5-phase' circuits, and so on, a transformer in electrical connection with the armature of each group other than that for the single phase circuit, and suitable circuit connections for said groups, each of said transformers being characterized by its primary being of as many circuits as the phases v of the armature to which it is connected so that the resultant magnetic flux in its iron core is 'ofas many times the fundamental periodicity as the number of phases for which its primary is Wound, and a single secondary circuit in which is developed the said multiple of the fundamental frequency.

17, An apparatus for the described purpose comprising means for producing a plurality of alternating electromotive forces of the frequencies of the fundamental and the harmonics of the disturbance note of the dis turbance current in a telephone line exposed to an alternating power circuit influence; means for regulating and adjusting said alternating electrom'otive forces individually in both phase and intensity and-means for superimposing said electromotive-forces on the disturbed telephone line and performing said regulation and adjustment under the guidance of an observable manifestation of the condition of disturbance on the said telephone line to the end that the disturbance is nullified.

18. An apparatus for eliminating an un desirable periodic harmonic alternating current element existing in an electric current carrying Wire, which consists in means for producing observable manifestation of the alternating current in said Wire; means for producing the fundamental and several harmonics of the undesirable periodic harmonic alternating current; and means for regulating and adjusting said fundamental in intensity and phase with respect to said undesirable current, and similar means for each of the harmonics of said current, so that a part by part alteration of the observable manifestation of the current in the said Wire may be made, to the end that said undesirable current element may be eliminated.

19. An apparatus for correcting alternating current disturbances on telephone and other like Wires comprising means for producing a second disturbance on said telephone line synthetically out of a plurality of alternating currents Whose several frequencies are respectively equal to the fundamental frequency and harmonics of the disturbing current, and means for separately regulating and adjusting said alternating currents in their phases and intensities, whereby the fundamental frequency and harmonics of the disturbing current are separately neutralized.

20. An apparatus for eliminating an'undesirable periodic harmonic alternating current element existing in an electric current,

carrying Wire which consists in means for produeing the several harmonics of the un- In testimony whereof I afiix my signature desirable periodic'har nonic alternating curin presence of tWo itnesses. rent, and meanst'er separately regulating and adjusting each of the harmonics of the said current, so that a part by part alteration of the current in the said Wire may be WVitnesses: made to the end that the said undesirable MARCELLUS BAILEY, current element may be eliminated. H. B. MARSTON.

JAMES BUGKNER SPEED; 1

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Eatents,

Washington, D. 0.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5267310 *Mar 22, 1991Nov 30, 1993Murata Kikai Kabushiki KaishaControl circuit for automatic elimination of telephone line noise
Classifications
U.S. Classification379/416
Cooperative ClassificationH04M1/74