US2230681A

US2230681A - Method and circuit for telegraphic impulses

Info

Publication number: US2230681A
Application number: US145204A
Authority: US
Inventors: Frischknecht Ernest
Original assignee: Teleregister Corp
Current assignee: Teleregister Corp
Priority date: 1937-05-28
Filing date: 1937-05-28
Publication date: 1941-02-04
Anticipated expiration: 1958-02-04

Description

Feb. 4, 1941.

E. FRISCHKNECHT METHOD AND CIRCUIT FOR TELEGRAPHIC IMPULSES Filed May 28, 1937 4 Sheets-Sheet l IMPULSES RELAY A OPERATED- FIG. 4

42 9.5; RELAY R OPERATED FIG. 5

INVENTOR ERNEST FRISCHKNECHT NEY ATT

Feb. 4, 1941. E. FRISCHKNECHT I METHOD AND C IRCUIT FOR TELEGRAPHIC IMPULSES Filed May '28, 1957 4 Sheets-Sheet 2 FIG.8

nae

INVENTOR ERNEST FR ISCH KN ECHT BY aifi -w AT ORNEY E. FRISCHKNECHT METHOD AND CIRCUIT FOR TELEGRAPHIC IMPULSES Filed May 28, 1957 Feb. 4, 1941. 2,230,681

4 Sheets-Sheet 3 TD FIG. IO 28 FIG. :2

v FIG. I3

INVENTOR ERNEST FRISCH KN ECHT ATTORNEY 1941- V E. FRISCHKNECHT 2,230,681

METHOD AND CIRCUIT FOR TELEGRAPHIC IMPULSES Filed May 28, 1937 4 Sheets-Sheet 4 FIG. l4

LINE3 LINE2 LINE I INVENTOR ERNEST FR SCHKNECHT BY v AT ORNEY Patented Feb. 4, 1941 UNITED STATES PATENT OFFICE METHOD AND CIRCUIT FOR TELEGRAPHIG IMPULSES Application May 28, 1937, Serial No. 145,204

10 Claims.

This invention relates to improved methods and circuits for telegraphic impulses and improved operation of electro responsive apparatus controlled thereby. I

In systems heretofore devised for transmitting and repeating telegraphic impulses by means of repeating relays and the like, the first impulse transmitted by the repeating relays is of shorter length than succeeding impulses of a series of impulses thereby causing failure of the receiving apparatus to operate in response to the first impulse of the series.

In systems for transmitting and repeating telegraphic impulses, which employ repeating relays operating from a constant length signal such as,

of example, the signal received from a transmitting distributor having uniformly spaced transmitting segments to transmit a series of signals, it has been found that the spacing between the first signal and the second signal transmitted by the relays is less than the spacing between the second and all succeeding signals transmitted.

This condition, which is present in an arrangement such as shown in Fig. 5 of the drawings herein, is caused by the relays requiring a longer time to operate when the first impulse of a series is received than when succeeding impulses of the series are received due to the residual magnetism of the relay being near the zero value at the start of the first impulse and at some value considerably above this first value at the start of each of the succeeding impulses. The time required to operate the relay when the first impulse is received is therefore greater than the time required to operate the relay on the succeeding impulses of a series.

Similarly in automatic quotation systems heretofore devised which employ electro magnetic indicator units for posting the quotations, it has been found that these indicator units fail to operate when the first impulse is received due to insuflicient time between the end of the first impulse and the start of the second impulse within 45 which time the armature of the indicator unit must release. This foreshortening of the rest interval between the first impulse and succeeding impulses is caused by the failure of the repeating relays controlling the indicator unit to 50 operate as quickly when the first impulse is received as when successive impulses are received thereby to foreshorten the non-current interval of the indicator unit signal between the first and second impulse.

55 One of the objects of the invention is provision of means for controlling the lengths of outgoing impulses and for maintaining them in uniformly spaced relationship one from the other.

Another of the objects of the invention is the provision of an improved circuit for operating 5 electroresponsive devices by means of a series of impulses whereby the electroresponsive device receives more current during the first impulse of the series than during the succeeding impulses.

Another object of the invention is the provision 10 of means for applying a biasing current to the winding of an electroresponsive device prior to or concurrently with the reception of the first impulse of a series and thereafter removing the biasing current from the device during the re- 15 ception of the first impulse and until all other impulses of the series are received.

A still further object of the invention is an arrangement of circuits comprising a transmitting distributor or the like for initiating a series 20 of uniformly spaced impulses of equal length whereby the series of impulses repeated by the relays of the circuit are all uniform in length and uniformly spaced one from the other.

Other objects of the invention will appear from the following description taken in connection with the drawings in which:

Fig. 1 is a view of a regenerator unit, parts of the frame mechanism broken away.

Fig. 2 is a view of the two armatures employed with one of the relays of Fig. 1, along the line 2-2.

Fig. 3 is a diagram showing the lengths of incomirgg and outgoing impulses of the relays of Fig.

Fig. 4 shows the lengths of incoming and outgoing impulses of the relays of Fig. 6.

Fig. 5 is a circuit of the pair of relays employed with the diagram of Fig. 3.

Fig. 6 is a circuit diagram illustrating one form of the present invention.

Fig. 'l is a diagram of the impulses received from the distributor of Fig. 6.

Fig. 8 shows the current in the indicator units of Fig. 6 when the present invention is not employed.

Fig. 9 shows the current in the indicator units of Fig. 6 in accordance with the present invention.

Fig. 10 shows a circuit in accordance with a modified form of the invention.

Fig. 11 shows the impulses set up by the distributor of Fig. 10.

Fig. 12 shows the current in the indicator units of Fig. when the present invention is not employed.

Fig. 13 shows the current in the indicator units when operated in accordance with the circuit of Fig. 10.

Fig. 14 shows a complete transmitting and repeating system employing the invention.

Fig. 15 shows the current through the winding of the transmitting relay of Fig. 14 as the distributor operates.

Fig. 16 shows the flux in the transmitting relay as the current impulses are received from the transmitting distributor.

Referring first to Fig. 1, there are shown thereon two relays A and AA, the relay A being'provided with at least four pairs of contacts arranged to close as the relay operates. The re lay AA is provided with one or more pairs of normally closed contacts arranged to open as the relay operates, each pair of contacts of the relay AA being operated by an armature individual thereto and so adjusted that one of the pairs of contacts will be opened by the operation of its respective armature before the other of the pair of contacts is opened as the coil of the relay is energized.

Referring next to Fig. 5, there is shown an incoming line L connected to the winding of relay A, the other end of the winding being continued through the break contact and armature l of the relay AA to ground. Assuming that a series of uniformly spaced signals comprising a series of battery impulses, each having 42% closure are applied to the line L, relay A will operate on the first of these impulses to the grounded armature I of relay AA. As the armature 2 of relay A engages its make contact, battery is applied to the winding of relay A from the armature 2,

thereby locking relay A until relay AA is operated. As armature 3 of relay A engages its contact battery is applied to the winding of relay AA causing it to operate. Relay AA is slow to operate however, being restrained somewhat from operation by the spring 4 attached to its armature. The operation of relay AA causes the relay A to release and at its armature 3 open the operating path for the relay AA. As relay A moved its armatures 5 into engagement with the contacts thereof a battery impulse was sent over the lines 6.

The second impulse is now received over the line L, but this occurs so quickly after the release of the relay A that the flux in the core of the coil of the relay A has not diminished to the same value as when the first impulse was received. The relay A will therefore operate quicker on the second impulse than when the first impulse was received. This condition is shown on Fig. 3 which shows a series of uniformly spaced impulses having 42% closure. The operate time of the relay A in response to the first impulse is 17% and for all-succeeding impulses 14%. The impulses delivered by the relay A to the lines 6 are shown to be 63% for the first impulse and 61% for the remaining impulses of the series. It will be noted that the open space between the first and second impulse is 34% and between all other impulses of the series the open space is 39%. This is because the relay AA starts to operate 17% after the first impulse is received and requires 2% longer to operate on the first impulse of a series than on subsequent impulses of the series. When the second impulse is .received, relay AA has its operate circuit closed 1 14% after this impulse is received and operates 2% quicker than during the first impulse due to the residual magnetism remaining in the magnetic core of relay AA at the time the second impulse is received. This results in an open interval of 34% between the first and second impulses retransmitted. When the third impulse is received, the operate circuit of relay AA is closed 14% after the impulse is received, and the relay operates in the same time that it did when the second impulse was received. Since there is a difference of 3% in the operate time of relay A when the first and second impulses respectively are received, this difference of 3% combined with the decrease of 2% in the operate time of relay AA renders the interval between the second and third and succeeding impulses 5% longer than the interval between the first and second impulses of a series. The open space or release time of the electroresponsive apparatus controlled by these impulses is therefore 5% less at the end of the first impulse than at the end of each of the other impulses. The electroresponsive apparatus controlled by these impulses, as for example the indicator unitshown in Patent 2,067,187 granted to Merton L. Haselton on January 12, 1937, depends for operation upon the movement of an armature in one direction as the coil is energized and movement of the armature in the reverse direction by the action of a retractile spring as the coil is deenergized. Should insufficient time be allowed between the deenergization of the coil and the succeeding reenergization thereof, the armature will not fully release and the indicator will fail to operate.

The embodiment of the invention shown on Fig. 6 is a practical solution to the problem of preventing failure of an indicator unit to operate due to the crowding together of the first and second impulses of a series of impulses as in this circuit the first and second impulses have a separation therebetween of substantially the same duration as the separation between each of the following impulses of a series. The circuit of Fig. 6 provides for transmitting to the indicator unit a current impulse of the same strength as the succeeding impulses and maintaining a predetermined residual fiux value in the cores of the indicator units prior to operation of the same in response to the first impulse so that the power developed by the armature of the indicator unit as the first impulse of a series of impulses is received is the same as the power developed by the armature as succeeding impulses of a series of impulses are received. The operation of the system of Fig. 6 will now be described.

The transmitting distributor TD comprises a series of equal length segments 1 connected to battery and uniformly spaced one from the other. As these segments are traversed by the brush 8, a series of battery impulses are transmitted over the conductor 9 to the winding of the relay R a the distributor operates, the circuit being continued through the winding of the relay R to th break contact and armature ll of relay S to ground. The transmitting distributor TD also has a segment l2 unconnected so that as the brush 8 traverses the segments 1, a series of uniformly spaced signals of equal length are transmitted to the relay R, the series being terminated during the time the brush 8 passes over segment I2 of the transmitting distributor. As

the relay R operated and moved its armature [3 into engagement with the contact thereof battery from the armature I 3 of relay R was applied to the winding of relay R to hold the relay operated during part ofthe time the brush 8 was passing from one to another of the segments 1. As armature H of relay R engages the make contact thereof battery is applied to the winding of relay S causing relay S to operate and at its armature remove ground from the relay R, thereby causing relay R to release. Relay S is provided with an adjustable spring |5 whereby the operating time of the relay S may be varied and the output pulse from the relay- R adjusted at will.

The resistance |6 has one end connected to battery and the other end to the conductor 9 whereby a biasing current is applied to the winding of relay R when the relay S is unoperated. This biasing current is of insufficient strength to cause the relay R to operate. Suificient biasing current is maintained through the winding of the relay R however to keep the flux in the magnet core of such a density that the time of operation of the relay R in response to the first impulse of a series is the same as the time of each subsequent operation of the relay R as the remaining impulses of the series are received.

Referring to Fig. 4, the impulses transmitted by the segments 1 of the distributor TD is shown to be 42% and the open period between these impulses is 58%. The operate time of relay R as the first and all others of the series of impulses is received is 9.5% and since the transmitter sends impulses at a uniform rate and the time required to operate the relay R in response to each of these impulses is the same regardless of whether the impulse is the first or any other impulse of a series, the relay R closes its transmitting contacts I! and 8 at uniformly spaced intervals thereby retransmitting impulses to the indicator units II and I2 at a uniform rate. The length of the first impulse transmitted by the relay R is 63% and the open period between the end of the first impulse and the start of the second impulse delivered by the relay R is 37%. The second and all succeeding impulses delivered by the relay R is 61% followed by an open interval of 39%. As the relay S is first required to operate from a fiux value of substantially zero in the core of the winding thereof when the first impulse is received, the operate time of relay S in response to the first impulse is 2% greater than the operate time of this relay as subsequent impulses are received. This condition is the result of the flux in the relay S at the start of the second operation thereof being at a slightly higher residual value than when the first impulse to this relay was received.

The output signal of the relay R therefore is 63% for the first impulse and 61% for all succeeding impulses of a series.

The relay S is provided with an armature |9 having battery connected thereto and normally in engagement with its contact whereby battery from the armature I9 is applied through the resistances 2| and the winding of the indicators U and 12 in parallel during the time the relays R and S are unoperated. The indicators II and 12 are thus normally in a circuit to battery, which circuit includes the resistances 2| and the armature |9 of the relay S. The current flowing through the windings of the indicators II and 12 during the time that relays R and S are unoperated is of suificient strength to set up a flux in the core of the windings of these indicators of such a value that the time required to operate the armature when the first impulse is received is the same as the time required to fully operate the armature when subsequent impulses of a series are received, but the current through the resistances 2| to the indicator units is of insuflicient strength to cause the units to operate until the relay R has operated.

The circuit arrangement of Fig. 6 provides for a decrease in the time required for the armatures of the indicators to fully operate thereby increasing the speed of operation of the indicators. This condition is obtained by adjusting the relay S so that the armature |9 thereof will engage its contact approximately 20% after the contacts of relay R have opened. This arrangement is obtained by the use of two armatures shown in Fig. 2 of the drawings, one of the armatures serving to open the locking circuit for the relay R and the other controlling the current through the resistances 2| in such a manner that the armature |9 engages its contact and causes current to flow through these resistances not sooner than approximately 20% after the contacts of relay R have opened. The armature ll of relay S releases more quickly than the armature i9 due to the force exerted by the retractile spring l5 upon the armature N.

Fig. 7 is a diagram showing the pulses delivered by the transmitting distributor TD of Fig, 6. These pulses for example are shown to be uniformly spaced and having a closure period of 50%, and an open period of 50%.

Fig. 8 is a diagram showing the build up of current in the indicator units II and I2 of Fig. 6 when the armature |9 of relay S is disconnected from battery or otherwise prevented from applying a biasing current to the indicator units prior to their operation.

Referring now to Fig. 9 which is a diagram showing'the current in the indicator units II and I2 in accordance with the circuit of Fig. 6, it will be noted that a value of current y normally flows through the windings of the indicator units when no operating impulse is received and prior to a series of impulses. As the relay R moves its armatures l1 and I8 into engagement with their contacts battery is applied through the resistance 22 to the indicator units thereby to cause them to operate over a circuit including the resistances 2| and 22 in parallel. Twenty-five percent after relay R has operated, the armature IQ of relay S moves away from its normal contact thereby removing battery from one end of the resistances 2| and causing the current in the indicator units to drop to the value at. When the relay R releases after having delivered an impulse of 61% to the 7 indicators the circuit to the indicator windings is open and the current through these windings is zero. Twenty percent later the armature I9 of relay S releases and applies battery through the resistances 2| to the indicator units causing a current to flow through their windings of a magnitude y. After the relay R has released 39% later,relay R again operates to transmit the second impulse of the series of impulses in the indicator units.

It will be apparent from an inspection of the diagram of Fig. 9 and the foregoing description that a current y is applied to the indicator units prior to the first and all other impulses of a series and a current of high intensity is applied to the Winding of the indicator units during the first part of the operating impulse followed by a somewhat lesser value of current as which is subsequently applied to the units before the operating current has been removed. As the relay R releases and current a: is removed, a no'curr'ent period follows after which the biasing current y is again applied to the windings of the indicator units prior to the second operating impulse. The value of the resistances 22 determines the strength of the current 3:, Fig. 9 in the windings of the indicator units II and I2 just prior to the time that the impulse thereto is removed. The current a: may be so reduced in value by the proper selection of the resistances 22 that the flux in the cores of the indicators is of only slightly greater density than the value required to maintain their armatures operated so that when relay R releases, the release time of the armatures of the indicators will be reduced to a minimum.

The advantages flowing from this arrangement will best be understood by consideration of the flux within the coil core of a single indicator unit during an operating cycle thereof. Assuming, for example, that a series of impulses such as those shown on Fig. 7 were delivered to the indicator unit in rapid succession. The first impulse would cause the flux within the core of the unit to be built up from an initial value of substantially zero residual. When the flux has been built up to a certain density within the ferric circuit o the unit the armature begins its movement toward the electromagnet. At the beginning of, the second impulse of the series the flux within the ferric circuit of the unit has not diminished to the initial value and it is desirable therefore to apply an initial current y, Fig. 9, to the winding of the indicator to establish a flux below the value required to operate the unit and to apply a strong operating current at the beginning of each impulse so that the flux may be built up to a density sufiicient to operate the unit with a minimum of delay after the operating impulse is received. The armature therefore starts its movement almost immediately following the reception of the first operating impulse and moves quickly to its fully operated position. During this movement and before the operating impulse is removed, the current through the windings of the indicator is reduced, thereby to lower the flux density in the core of the unit to a value slightly above that required to maintain the armature operated and thereby enable the armature to release with a minimum of delay after the operating current has been removed from the winding of the unit.

The armature of the unit starts to release and during the release stroke thereof the biasing current is again applied to the winding to set up flux in the core so that the armature will respond quickly to the succeeding operating impulse of a series.

Referring now to Fig. 10 which shows a modified form of the invention, battery impulses are transmitted from the distributor TDI as the distributor operates in a manner similar to the operation of the distributor TD. These battery impulses cause the operation of the relay C, the circuit being continued from the winding of relay C to the contact and grounded armature 24 of relay D. As relay C moves its armature 25 into engagement with the contact thereof battery on armature 25 causes the relay D to operate and at its armature 24 open the locking circuit for the relay C, thereby causing relay C to release. Relay C has normally applied thereto a biasing current from battery through the resistance 26, winding of relay C, normal contact and armature 24 of relay D to ground, which biasing current is effective only when relay D is released. The op- 'erate time of relay C, as has been previously explained in connection with relay R, is the same for the first as for the succeeding impulses of a series of uniformly spaced impulses and the relay C therefore at its armatures 21 delivers a battery impulse through the

resistances

28 and 29 to the winding of the indicator units I3. The resistance 29 may be adjusted to obtain the best operation of the indicator I3 as hereinafter described.

The relay C is also provided with an armature 30 the closure of which applies battery to the Winding of relay E from whence the circuit is continued through the winding of relay E and break contact and armature 20 of relay F to ground, thereby causing relay E to operate and lock by way of its armature 3| and make contact thereof to battery. As armature 32 of relay E engages its contact, battery is applied to the Winding of relay F, causing it to operate and at its armature 20 release relay E. Relay E is also provided with an armature 33 and a normal contact so that the resistance 29 is in parallel with the resistance 28 when the relay E is unoperated v movement of the armature 30 of relay C into engagement \m'ththe make contact thereof, armature 33 of relay E was disengaged from its contact and the resistance 29 was removed from the operating circuit of the indicator unit. As the relay C subsequently released, the circuit to the winding of the indicator I3 was opened and the armature of the indicator unit was permitted to release.

The diagram of Fig. 11 shows the impulses transmitted by the relay C as the relay C operates successively. Fig. 12 shows the current in the coil of the indicator unit when the parallel circuit comprising the resistance 29 and the armature 33 of relay E is not employed. It will be noted that the current builds up slowly in the indicator unit under this condition due to the inductance of the coil of the indicator with the result that the flux in the magnet of the unit builds up slowly and the armature does not start its movement until some time has elapsed after the operating impulse is transmitted to the unit.

Fig. 13 is a diagram illustrating how a strong current is first applied to the winding of the indicator unit and subsequently reduced in value before the current impulse is terminated. This first high value of current causes the flux in the unit to build up very rapidly and the movement of the armature to start almost immediately after the current impulse is received. The reduction of the current during the latter part of the impulse causes the resultant flux in the unit to be reduced during the movement of the armature so that as the current impulse is terminated, the

time required for the flux to diminish to a value at which the armature starts to release is substantially zero and the armature releases almost immediately after the impulse has terminated.

As is well known in the operation of electromagnetic devices of this character the pull exerted by the magnet upon the armature for any .given value of flux density is inversely proportional to the square of the distance between the armature and the end of the magnet core. If, for example, the airgap between the armature and the magnet core of the indicator unit with the armature unoperated was three times the distance between the armature and the magnet core with the armature operated, the pull on the armature at the beginning of the operate stroke thereof for any value of flux in the core would be one ninth of the pull exerted by the core on the armature when the armature is in the oper ated position. It is, therefore, a decided advantage to have a flux density in the magnet coil core higher at the beginning of the operate stroke of the armature than when the armature has completed its operate stroke in order that the pull on the armature may be more uniform during the stroke of the armature.

This arrangement results in a faster operation of the indicator unit than has heretofore been possible. It enables the unit to be operated by means of a shorter pulse than heretofore employed and because of the reduced flux in the coil core of the unit at the time the pulsing contacts are opened, the inductance of the unit at this time is decreased and sparking and erosion of the pulsing contacts is reduced thereby prolonging the life and adjustment of the contacts. It also provides for operation of the indicator unit at lower voltages than heretofore employed.

Fig. 14 shows another form of the invention comprising a transmitter TDZ of any suitable type, a pair of transmitting relays G and H, a receiving relay K for repeating the signals received from the relay G and a plurality of line relays L operated thereby. The operation of the relays G and 1-1 will first be described:

As the distributor TD2 engages the first of the connected segments ground is applied to one end of the winding of relay G causing the relay G to operate and at its armature 34 connect battery at one end of the resistance 35, thereby to operate relay H While the brush is in engagement with the first connected segment. It will be noted that with relay H unoperated ground at its armature 36 is connected to the variable resistance 31 and thence to the winding of the relay G, thereby to maintain a residual flux density in the relay G during the time that impulses are not received which is the same order of magnitude, for example, as the flux density at the beginning of the second and all succeeding impulses of a series transmitted by the transmitting distributor TDZ. The relay H is a slow release relay and remains operated While the impulses of a series of impulses are being received and transmitted by the relay G. This relay may be made slow to release by any suitable means as, for example, by the use of a copper slug about the core of the relay or by a suitable resistance 38 connected in parallel with the winding of the relay.

Fig. 15 is a diagram showing the current in the winding of the relay G as the first impulse of a series is received. Referring to Fig. 15, it will be noted that the current 20 flows through the winding of the relay G before the first impulse is received, which current results from the grounded armature 36 of relay H being in circuit with the resistance 31 in series with the winding of relay G. This current is determined by the adjustment of the resistance 31 and. causes the initial flux 1;, Fig. 16, to be maintained in'the core of the electromagnet of the relay G of the' same value as the flux in the core of this relay at the beginning of the second and all subsequent impulses of the series.

As the distributor TDZ transmits the first impulse of a series, the curve toward the left of Fig 15 rises in accordance with the value of current in the winding of relay G as the brush of the distributor crosses the first of the connected segments. The flux in the magnet core of this relay is shown on Fig. 16 immediately below the current wave producing the flux. As the brush of the distributor TD2 crosses this first connected segment, relays G and H operate and as the brush leaves the first connected segment the current in the winding of the relay G drops to zero and the flux in relay G starts to decrease in density until the brush engages the: second of the connected segments of the series at which time the flux density will just have decreased to the initial value c. It is apparent, therefore, that the time required for the relay G to operate and close its contacts after the first pulse is received is the same as the time required after the second and all succeeding impulses of a series of uniformly spaced impulses are received.

If the relay G was operated as a transmitting relay without the biasing current preceding the first impulse, the time required to operate the relay in response to the first impulse received would be greater than the time required to operate the relay as subsequent impulses'o-f the series were received. When the relay G was first required to operate in response to the first impulse of the series the residual flux in the core of the winding would be substantially at zero value, but as the second and succeeding impulses of the series are received, the flux has not diminished to this value and the relay will operate quicker than when the first impulse was received. Since the flux in the relay core reaches the same density at the end of the first impulse as at the end of succeeding impulses of a series and the release time for the relay therefore is the same regardless of Whether the impulse causing the operation of the relay was the first or any other impulse of the series, it is evident that the first of a series of output impulses transmitted by the relay without a substantial value of flux in the core at the beginning of the first impulse is shorter than the succeeding output impulses of the series. Similarly relay K would repeat and additionally foreshorten the first shortened impulse of a series as will relays L, the foreshortening of the first impulse being increased progressively in the relays G, K and L as this signal is repeated by these relays. Thus, if sufficient repeating relays were operated in cascade the first impulse transmitted by the last relay of the cascade would be lost. This condition is a frequent cause of failure of ticker or market quotation apparatus controlled by impulses.

The resistance 31 may be so adjusted that the initial fiuX in the relay G at the beginning of a first impulse of a series is higher in value than the flux at the beginning of the remaining impulses of the series and the time of operation of the relay G therefore as the first impulse is received is less than the time of operation as the remaining impulses are received thereby causing relay G to transmit the first impulse of a series of greater length than the remaining impulses of the series.

As the relay G moves its armature 39 into engagement with the contact thereof battery is applied over the line I to the Winding of repeating relay K during the time the armatures 40 transmit similar impulses to the

lines

2 and 3.

tial flux therein at the beginning of a series of impulses is substantially at zero density and the time required to operate the relays K and L 1 as the first impulse of a series is received is somewhat greater than when subsequent impulses of a series are received. By means of the adjustable resistance 31 the operate time of the relay G as the first impulse is received from the transmitting distributor TDZ may be made sufficiently rapid to increase the length of the first signal transmitted by the relay G and compensate for the delay in the operation of the relays K andL in response to the first impulse received by them so that the relays L will transmit a series of uniformly spaced impulses of equal length without distortion as transmittedby the transmitter TD2.,

For purposes of illustration this invention has been described in connection with a telegraph repeater controlling the operation of a stock quotation system, but it obviously is not so limited, being adapted for use in Various systems for the dissemination of information. Also, the embodiment of the invention may take other specific forms without a departure from the spirit or principles herein described. The present embodiment is therefore illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes within the meaning. and range of equivalency of the claims are intended to be embraced therein.

What is claimed and desired to be secured by U. S. Letters Patent is:

1. In a signaling system, a source of signals comprising a series of uniformly spaced current impulses of equal length, a repeating relay operated thereby, said repeating relay having a plurality of contacts, means for causing said repeating relay to operate within the same time interval after the first impulse of the series is received as when each of the remaining impulses of the series is received and for determining the length of the retransmitted impulses, an indicating device, means for causing the indicating device to operate at a relatively fast rate, said means comprising certain of the contacts of the repeating relay for operating said device over a circuit comprising a first resistance element, a second resistance element normally in parallel circuit with the said first resistance element, and means comprising a relay operated by another contact of the repeating relay for interrupting the circuit through the second resistance element during the time the transmitting contacts are closed whereby the indicating device receives more current during the first part of each operating impulse thereof than during the latter part of the impulse.

2. In a signaling system, a source of uniformly transmitted signals comprising a series of current impulses, a repeating relay controlled thereby, said repeating relay having a biasing current through the winding thereof when the signals are not received, relay means controlled by said repeating relay for interrupting the biasing current during the time the repeating relay is operated and for re-establishing the circuit for said biasing current while the repeating relay is unoperated, adjustable means for controlling said biasing circuit, a transmitting contact on said repeating relay, an indicating device responsive to the operation of said repeating relay, a line including a resistance element connecting said transmitting contact and the indicating device, a second biasing circuit comprising a resistance element, means for maintaining a biasing current through said resistance element and the indicating device when impulses are not received and for interrupting said biasing current to the indicating device during the time when operating impulses are transmitted thereto by the repeating relay and for i e-establishing said second biasing circuit during the time interval between operating impulses.

3. In a system for the dissemination of information, a source of signals comprising current impulses, an indicating device controlled by said signals and operable impulsively step-by-step to different display positions in accordance with the received signals, a relay operated by said signals, means controlled by said relay for controlling the length of the impulses supplied to said indicating device by said source and for applying a biasing current to the indicating device before each of the signals is transmitted thereto and for removing said biasing current while the signal is being transmitted and for subsequently reestablishing said biasing current during the open interval between successive signals to prevent biasing current from being applied to the indicating device during the first portion of the open interval between said signals.

, 4. In a signaling system, a source of signals comprising a series of current impulses, a pair of relays concurrently operable in response to said impulses, a transmitting contact on the first of said relays, adjustable means on the second of said relays for controlling the signals transmitted by the said transmitting contact, an indicator, circuit means including resistance elements for operating said indicator as the transmitting contact is closed, means including said resistance elements controlled by said second relay for applying a biasing current to the indicator prior to and during the first part of each indicator Operating impulse whereby said biasing current augments the current transmitted by the transmitting contact during the first part of the operating impulse and reduces the current through the indicator to a hold value during the latter part of each impulse.

5. In a telegraph repeating system for disseminating information, a pair of repeating relays, a plurality of transmitting contacts on the first of said relays, two armatures on the second of said relays, one of said armatures having adjustalble means for controlling the operation thereof independently of the other armature, means including said adjustable armature for controlling the impulses transmitted by the first relay, a posting device having an operating winding controlled by the transmitting contact of the first relay, a source of biasing current for said operating winding, and means including the other armature of the second .relay for controlling the application of said biasing current to said winding for accelerating the operation of said posting device.

6. In a telegraph quotation system, means for transmitting a series of uniformly spaced telegraphic impulses, a retransmitting relay responsive to said impulses, a baising circuit for said relay including a resistance element, locking means for shunting the resistance element as the relay operates, a pair of contacts on the relay, an auxiliary relay operated by 'said pair of contacts, said auxiliary relay having contact means for interrupting the operating circuit for the retransmitting relay, and means including said biasing circuit and means for adjusting said circuit interrupting means whereby the unoperated time interval for the retransmitting relay between the first and second impulses of the series retransmitted is substantially the same as the unoperated time interval between each other of a pair of successive impulses of the series retransmitted.

'7. Apparatus for operating an electromagnetic indicating device, which comprises means for applying to the device a biasing current of a value to set up a predetermined amount of flux in the device, but insufficient to cause the device to operate, means for applying to the device a signal comprising a value of current of greater strength to cause the device to operate quickly, means for applying another value of current to the device less than the last named value of current, but in excess of said biasing current and having a strength sufiicient to hold the device operated, means for discontinuing the current applied to the device to quickly release the device, and means for thereafter reapplying the first named value of current to the device prior to the reoperation thereof.

8. Apparatus for operating an electromagnetic indicating device, which comprises means for applying to the device a current of a value to set up a predetermined amount of flux in the device, but insufiicient to cause the device to operate, means for applying to the device a signal comprising a value of current of greater strength to cause the device to operate quickly, means for applying another value of current to the device during the time the device is operating less than the last named value of current, but in excess of said first named current and having a strength sufiicient to cause the device to continue operation, means for discontinuing the current applied to the device to quickly release the device, and means for thereafter reapplying the first named value of current to the device prior to the reoperation thereof.

9. In a signaling system, a source of signals comprising a repeating relay for receiving and transmitting a series of substantially uniformly spaced telegraphic impulses, an indicating device controlled by said repeating relay, means for maintaining a flux in the core of the repeating relay prior to the operation thereof in response to the first impulse of the series of the same value as when subsequent impulses are received to operate the repeating relay thereby to maintain the operating time of the relay constant as each impulse is received, means for maintaining the same value of flux in the indicating device as each operating impulse thereof is received from the repeating relay whereby the operating time of the indicating device is the same for each operation of the device and means controlled by said repeating relay for controlling both of said maintaining means.

10. In an electric impulse repeating system, a repeating relay responsive to a series of substantially uniformly spaced incoming impulses, and means for causing said relay to retransmit said impulses with substantially the same interval between the first two impulses of said series as between any other two successive impulses of the series, said means comprising an additional relay means controlled by the repeating operad tion of said first relay for controlling the length of the impulses retransmitted by the first named relay and means comprising a circuit controlled by said additional relay means for applying a biasing current to the winding of said repeating relay prior to and during the reception of at least the first portion of each impulse of the series and for removing said biasing current from the winding of said repeating relay during the operation of said relay means for controlling the length of the impulses retransmitted.

ERNEST FRISCHKNECHT.