US1575628A - Telegraph signaling system - Google Patents

Description

IN VEN TOR l Her/ww' ATTORNEY Patented Mar. 9, '1926.y Y Y [UNITED STATES 'PATE-ur f cerros.

JOSEPH HERMAN, OF NEW YORK, N. Y., ASSIGNOR TO AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A CORPORATION OF NEVI YORK.

TELEGRAPH SIGNALING SYSTEM.

Application filed December?, 1923. Serial No. 669,229.

' To all whom t may conce/Mi.: Y

Be it known that I, JOSEPH HERMAN, a citizen of the Republic of Austria, residing at New York, in thecounty of New VYork .and State of New York, have invented certain Improvements in Telegraph Signaling Systems, of which the following is a specifif the removal of bias from a polar relay operating in a telegraph loop or other `open and close circuit.v I It is frequently necessary to take tape records in atelegraph loop circuit and parv ticularly while the subscriber is sending. A polar relay .provided with two balanced 'fwindings is generally used for this purpose. It iswell known to those familiar with the art that-subscribers loop circuits are op.

erated on the open and close principle, viz, when the key is closed current will flow ,through the loop and operate a pole changer at the terminal office by means of which an impulse ofpredetermined polarity will be applied to the line circuit. Upon the opening of the key at the subscribers station current will cease to flow through theloop, and

the pole changer will thereupontransmit an Y.

impulse of opposite polarity over the line circuit. Since it is desirable for the making of these tape records to use a polar relay, and since the circuit'by which such rejlay is controlled operates on the open and close principle and not upon the reversal of polarity principle, it becomes necessary to provide a biasing circuit for the polar relay and to carefully adjust the magnitude of the biasing current so that the armature of the Vrelay will be moved to one of its contacts when current fiows through the loop ycircuit and will be moved kto its other' contact by f virtue of the action of' the biasing winding when current ceases to flow through the loop circuit. j

In order to avoid interference with the subscribers service it has been customary to y. adjust the relative values of the currents in the loop circuit and inthe biasing circuit .only when the loop circuit is'idle, viz, vwhen the subscriber is not transmitting signals thereover. The method adopted consisted inconnecting a meter into each of the two .circuits and adjusting'the biasing circuit "the loop circuit.

until the current therein is one-half that in y Then using such method, it is lnecessary to interrupt the subscriber if the circuit is in us'evat the time or to delay the adjustment of the relay until the subscriber stops' sending.

' It is the object of this inventionto elimi- -nate the disadvantages inherent inl the former. practice so that full and. complete adjustment may be made whileH the subscriber is sending and without interfering with the transmission ofhis signals. i j

This invention will be'clearly understood from the following description whenv read in connection with the attached drawing of which Figure l shows one form of embodiment'of the invention; Fig..2 shows a modification of the polar relay recording circuit which may be Vsubstituted for the similar circuit shown in Fig. l; andFig. 3 shows schematically the arrangement of the wind? ings upon the polar relay set forth in Fig. l. In Fig. l, A representsa Morse subscriber vstation comprising a key l, a line'relay 2 and a sounder 3, which station is connected byv kmeans of the loop l with the pole changer 5 at the terminal station vB. The pole changer 5 has connected therewith a source of potential 6 from which current will iow Vthrough thel subscribers loop whenever thev key l is closed vand will operate the line relay 2 `and also the said pole changer. Connected with the pole changervvis a source of potential 7 by means of which impulses of opposite polarity may be applied through the armature of the pole changer and conductor 8 to the arms'9 of the line circuit with .which are connected the line 10 and the artificial line 1l'. Bridged across the arms; 9 is a polar relay 12 by means of ywhich received impulses cause the operation of Athe Y receiving apparatus which, for thesake of simplicity, is not shown. Since this invention i's. concerned with circuits that operate on the open and close principle, of which receive the plug 14 of the monitoring relay by means of which the tape records heretofore mentioned might be made. It will be seen that when the plug Mis inserted in the jack 13 the contact 15 is opened and the loop circuit is rendered continuous through the loop windings of the polar relay. The circuit of the monitoring relay, normally connected with theloop circuit, comprises two windings 16 and 17, preferably equal, which are adapted to be connected serially with the loop circuit when the arm of the switch 18 is upon the cont-act designated Test. The winding 17 is paralleled by a resistance 19 which is equal to the resistance of winding 17. lVhen the arm of the switch 18 is upon the contact indicated Calibrate, the winding 16 and the resistance 19 will be connected serially in the loop circuit. It is important vto notice that regardless ot the position of the switch' 18 the resistance connected into the loop circuitreniains the same. A third winding 2O"ol1 this relay is connected with the source of potential 21 and a variable resistance 2 2, and these three elements constitute the biasing circuit of this relay. Two other windings 23 and 2li are connected in the manner shown in the drawing with a condenser 25 and resistances 2G and 27, and the circuit comprising these various elements constitutes the vibrating circuit of this relay. This circuit is electrically connected with the armature 2S which is adapted to swing between two contacts connected with sources of potential of opposite polarity. The armature in addition to being connected with the vibrating circuit is connected with a polarized sounder 29'and also with a recording device 30 which may be of any well known type such as a tape-recorder.

The arrangement of the windings upon I the core of the polar relay and the connection of this relay with the operating circuit is shown schematically in Fig. 8. The invention will be apparent from the following description read in connection with Figs. 1 and 3. The monitoring relay should firstv be adjustedmechanicaily sothat its armature 28 will lvibrate `freely between its contacts when the biasing circuit and the circuit' connected with the subscribers loopk are open. Assuming the armature k28 to be on its letthand contact, current will iiow from its positive contact through winding 23 and resistances 26 and 27 to gro-und, and a charging current will alsoiiow through winding 211, condenser 25 and resistance 27 to ground, charging the said condenser. The flow of current through winding 23V will produce a iiuX in such direction as to draw the armature 28 from its left-hand contact. Thereupon, the condenser 25 discharges through the circuit including resistance 26, and windings 23 and 24, the direction of flow being such as to produce iiuX in the same direction as that produced by current from the battery through winding 23. This added impulse quickens the movement oit the armature 28 towards its right-hand contact. As soon as the armature reaches the latter contact the negative pole of theV batteryis connecting with the windings 23 and 24, setting up flux in an opposite direction to that created by the positive pole and causing the armature to move back to its lett-hand contact. The armature will thus vibrate freely so long as the biasing circuit and the circuit connected with theV subscrihei"s loop are open. The biasing circuit is then closed and the relay is connected with the loop circuit by inserting the plug 14 in the jack 13. It is desirable to point out that the currents in the biasing circuit and in the circuit or the windings connected with the loop circuit should be in such directions that the effect produced by the windings of therespective circuits will be opposed to each other. This is clearly shown in Fig. 3. The switch 18 is set upon the vcontact marked Calibrate7 so that the winding 16 and the resistance 19 will be connected with the loop'circuit while signals are transmitted over the loop by operating key 1. The resistance 22 in the biasing circuit is then adjusted until `the armature of the relay vibrates whenever the subscriber transmits a dash, viz, whenever he closes t-he key of his circuit, which vibrationl is indicated by the operation of the polar vsounder 29. lllien this condition has been attained, it will be seen that the eiicctof the biasing winding 2O upon the armature l28 is approximately equal and opposite to the effect oil the winding 16 connected with the subscribers loop. The two eiiects thus neutralize each other and permit the vibrating circuit to control the action of the armature, causing it to vibrate between contacts in the manner before described. If the switch 18 lis now movedy to the contact designated Test, the two windings 16 and 17 will be connected serially with the loop circuit7 and while the current iiowing through the loop is the same as it was when the switch 18 was connected with the contact marked Calibra-te, the eiiect of such current upon the armature 28, viz, the flux produced. is twice as great as before. It will accordingly be seen that when the key 1 is open the biasing winding 20 controls the armature 28 keeping it, for example, against its left-hand contact. As soon as key 1 is closed, current through windings 16 and 17 causes the armature to move to its opposite contact. This is the condition for unbiased 4operation or" the monitoring relay by the signal current in the subscribers loop.

Fig. 2 shows a yvariation of the monitoring relay shown in Fig. 1. In' Fig. 2 there is only one winding 31 connected in series with the loop circuit. The biasing circuit comprises a plurality of-windings 32 vand 33, a(

source of potential 34, a variable resistance 35, a iiXed resistance 37, the magnitude of` which is equal to that of lthe winding 33, and a switch 36 by means of which either the winding 33 or the resistance 37 may be connected into the biasing circuit.l Thev vibrating circuit, similar to that in Figs. 1 and 3, includes the windings 38 and 39, the condenser 40, and resistances 41 and 42.` 'The armature 43 is connected not only with the vibrating circuit but also with the polarized sounder 44 and the recording device 45.

In order to adjust the circuit shown in Fig. 2 so that the current in the biasing circuit may be approximately one-half that which flows through the winding 31, the plug 14 is inserted in the jack 13 while signals are being transmitted from the subscribers station A over the loop circuit. Current will accordingly flow through the winding 31 and will act upon the armature 43 tending, for example, to hold it against the contact shown in the figure. Vith the arm of the switch 36 upon the contact point marked Calibrate, the resistance 35 is varied until the current flowing through the biasing circuit is sufficient to cause the armature 43 to vibrate, which would be manifested by the operation of the polar sounder 44. Under this condition the effect of the current flow through the windings 32 and 33 in series is substantially equal and opposite to the effect of the signaling current through the winding 31 so that the armature is controlled by the vibrating circuit as described in connection with Fig. 1. Since the windings 32 and 33 are substantially similar and equal, the effect of the biasing circuit may be reduced one-half by cutting out the winding 33. This is done by moving the arm of switch 36 to the test contact which connects the resistance v3'? in series with the winding 32 and the other elements of this circuit, and sincev the resistancev of 37 equals that of winding 33 the current flow through winding 32 remains the same as before, but the effect of the biasing circuit is only one-half as great as that of winding 31.

The arrangement shown in Fig. 1 is believed to be the preferable form, because the operating force upon the relay never exceeds the normal operating force. In the ease of the circuit shown in Fig. 2, the operating force during calibration is twice the normal value whenever the subscriber opens his key. This effect may prevent proper adjustment of the relay due to the large amount of residual magnetism. Furthermore, in the case of the arrangement shown in Fig. 1, any mechanical biasing in the relay is neutralized by means of the biasing current. In the case of Fig. 2, however, only one-half the mechanical biasing is neutralized because of calibrating position to vthe test position.

Then the monitoring relay shown, for eX- ample, in Fig. 1, is properly adjusted, the

Aarmature 28 will swing from one contact point to another as the circuit of the subscribers loop is alternately closed and opened. polarity will be connected through the armature 28 with some form of recording device actuated by impulses of opposite polarity connected with the conductor 30. Such recording device might beV a siphon recorder by means of which a tape record of the sig- Vnals transmitted over the subscribers loop might readily be obtained.

Although this invention has been disclosed as embodied in a particular form and arrangement of parts, itis not so limited but is capable of embodiment in other and different forms within the scope of the appended claims.

llVhat is .claimed is:

1. In a telegraph system, the combination with a subscribers loop circuit characterized by the opening and the closing of the circuit for the transmission of signals, of a polarized monitoring relay connected with the said loop circuit having a sectionalized line winding, each section being substantially equal in magnitude to the other and all sections being normally eiectively in series with the said loop circuit, means for substituting for one of said sections a resistance element equal in'magnitude to the said section, a biasing winding having a source of current and current controlling means connected in series therewith, and av vibrating circuit to effect the vibration of the relay armature.

2. In a polarized relay, the combination with an operating winding connected with a line circuit, of a biasing winding having means to vary the current therein, a vibrating circuit arranged to cause the. relay armature to vibrate, the said operating winding being ar anged in two substantially equal parts normally in series, and means to effectively disconnect one of said parts and to substitute therefor a resistance in series with the other-part, the said resistance being substantially equal in magnitude to the disconnected part of the said winding.

3. In a polarized relay,the combination l with an operating circuit comprising two connected windings, a resistance connected with the junction point of the said windings, switching means for effectively connecting into said circuit both of said windings in series, or one of said windings i-n series with the said resistance, a biasing winding having means to vary the current therein, the said operating winding and biasing winding being so poled as to effect the armature of Consequently sources of opposite',

the said relay in opposite manner, and a Vibrating circuit causing the relay :armature to vibrate between its `Contacts when the .Currents in the operating and biasing windings substantially neutralize each other.

4e. The method of ,adjusting for proper operation u polar relay .ot the type defined by Claim 2 connected with a circuit operating on the open yand Close principle, which consists in varying the current flow .in the biasing winding until the eeet thereof on the armature substantially equal and A0ppeeite to the effect produced upon the armature by the line .current flowing` through one or' said line windings in series with :iv re- Sistanoe element of equal magnitudej then eectively 'disconnecting the said resistance from the line circuit and substituting zmother linewlndlng therefor.

In .a circuit of the type defined by claim 20 v2, the method ot' adjusting the polar relay for proper operationwhieh insists in varying the current in the biasing winding` until it neutralizes the ,etleet of the current in the line winding, and detecting the Condition el 25 naine to this specification this 6th day of 30 December 1923.

JOSEPH HERMAN.

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