US2154623A

US2154623A - Regenerative telegraph repeater

Info

Publication number: US2154623A
Application number: US153878A
Authority: US
Inventors: Fullerton S Kinkead
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1937-07-16
Filing date: 1937-07-16
Publication date: 1939-04-18
Anticipated expiration: 1956-04-18
Also published as: DE716854C; FR840658A; US2154608A; US2154624A; CH215784A

Description

April 18, 1939.

F, S. KINKEAD RE GENERAT I VE TELEGRAPH REPEATER Filed July 16, 1937 INVENTOR ATTORNEY Patented Apr. 18, 1939 v UNITED STATES PATENT OFFICE REGENERATIVE TELEGRAPH REPEATER Application July 16, 1937, Serial No. 153,878

10 Claims. (01. 175-320) This invention. relates to regenerative telegraph repeaters of the start-stop type and more especially to the timing means associated with repeaters of this type. The invention is particularly related to improvements in timing means of the relay type.

In repeaters of this type, vibrating relay circuits are used as timing means in lieu of rotating distributors. One vibrating relay circuit is timed 1 to vibrate once for each impulse of a start-stop signal series, and another relay is timed to vibrate once only for each start-stop series to stop the fast relay circuit at the end of each series. A circuit of this type has been disclosed in United 15 States Patent 1,771,445, issued to Parker-Vemam on July 29, 1930.

It is an object of the invention to provide 2. vibrating relay circuit capable of producing short distinct impulses, of definite length and accugo rately spaced apart.

In accordance with the invention, an unsymmetrical vibrating relay circuit is provided which uses a polar relay in combination with a condenser, the armature of the relay being connected ,5 to a single polarity of potential for control of the oscillations.

In accordance with a further feature of the invention, the relay is permanently biased in one direction, say, toward spacing, and has an oper- 30 ating winding for operation in the other direction, say, toward marking.

In accordance with a further feature, the operating winding is fully energized, say, in spacing position, and quickly interrupts itself by operating the armature to marking position, whereupon a condenser, in charging, continues the operating current for a time, ultimately permitting the biasing means to again operate the relay to spacing position. These operations will then be rea peated at regular intervals. One or the other of the relay contacts is connected to an output circuit for producing accurately timed impulses.

In accordance with another feature of the invention, the repeater circuit includes additional .5 relay means for starting and stopping the timing circuit for each signal series.

The invention will now be described in connection with a specific embodiment comprising a telegraph repeating system such as is illustrated so in the accompanying drawing, to which reference will be made in the following description.

A number of arrows have been applied to the various relay windings in the drawing to make understanding of the operations easier. The ar- 66 rows which are drawn in full lines indicate the direction in which the particular winding tends to operate the relay armature under the particular circuit conditions shown in the drawing, whereas the arrows shown in dotted lines indicate the direction in which the winding will operate 5 the armature under alternate conditions. A double arrow indicates that the winding is more strongly energized than the associated winding marked with a single arrow and thus indicates that the former winding is capable of preventing operation of the relay by the latter winding.

The regenerative repeating system is shown connected between an incoming line circuit LW and an outgoing line circuit LE. Signals incoming over the line west LW operate the receiving relay III which operates the retransmitting relay I I which in turn operates the line relay I2; line relay I2 impresses the repeated signals upon the line east LE.

In this specific embodiment the receiving relay It has a permanent biasing winding and has an operating winding responsive to opening and closing of the line west. The line relay I2 transmits signals into the line east by opening and closing the line. The sources of current are assumed to 95 be located at the distant end of both line circuits. H In case it should be desired to retransmit the signals into line east as polar signals, relay I2 may be omitted and one line conductor of the line east connected to the armature of retransmitting 3U relay II.

The timing circuit comprises the elementary timing relay 20 and the character timing relay 30. Relay 20 normally connects ground through its marking contact to short-circuit the operating windings of relay I I, thereby preventing response by relay II to operations of relay I0. During signaling, relay 20 oscillates in synchronism with signals incoming over line west. For a short interval during each oscillation relay 20 operates to spacing, thereby removing the short circuit for relay II and permitting this relay to respond either to marking or spacing potential at relay IIl. After relay II has assumed its position its winding is again short-circuited and the shortcircuiting current tends to hold the relay in position without chattering. The relay I I may be of a type which has sufiicient remanent magnetism to normally hold the relay firmly against its contacts in either position; however, if desired, one of the operating windings may be disconnected from the operating circuit and connected through a suitable resistance to the armature of the relay for the purpose of self-locking in both positions,

asiswellknown. m

For the purpose of controlling the timing circuits a set of starting relays 40 and 4| are provided. In their normal position these relays apply ground to the operating windings of the timing relays 29 and 36, respectively, thereby locking the latter relays in their marking position and preventing them from oscillating. When the receiving relay ID, in response to a start impulse, operates to spacing, relays 40 and 4| operate to spacing, thereby opening the locking circuits for relays 2i] and 33. In spacing position, relay 40 short-circuits the operating windings of relays 49 and 4| which remain in spacing position in response to suitable biasing means, such as a light spring attached to the armature.

Relays 2D and 30 then commence their cyclic operations, relay 20 with a frequency such that it will complete a cycle once for each incoming impulse of a signal series representing a character, and relay 30 with a. frequency such that it will complete one cycle in a period slightly shorter than the duration of a complete signal series.

The timing relay 2D has fixed biasing means, such as a biasing winding, continuously energized and tending to operate the armature to spacing. The upper operating winding is normally energized over the marking contact of relay 40; the condenser 25 and resistance 26 are short-circuited in this circuit. When relay 40 opens its marking contact, the condenser 25 gradually becomes charged through the operating winding of relay 2B and thus for a time serves to hold this relay to marking. When the charging current has decreased sufficiently, the biasing winding will overcome the operating winding and operate the armature to spacing. At this moment ground at the spacing contact is applied to this circuit. the condenser will be quickly discharged and full operating current will be restored in the operating winding and the relay will quickly operate to marking, again permitting condenser 25 to become charged through the operating winding. Under these conditions the armature of relay 20 will continue to oscillate and will be in its spacing position for only a small fraction of its cycle thus producing highly biased impulses by its contacts. By proper adjustment of resistance 21 this fraction can be varied and by proper adjustment of condenser 25 and resistance 26 the frequency can be adjusted to coincide with the impulse frequency of the signals.

The orienting resistance 28, in causing a. certain potential to be applied to condenser 25, serves to normally establish a certain charge on condenser 25 so that the first operation to spacing by relay 20 will take place after a given interval upon opening of the marking contact of relay 4!] or in other words, upon the arrival of a start impulse over line west. By proper adjustment of resistance 28 the short spacing periods of relay 20 may thus be oriented with respect to incoming signals in such a manner that relay M will be permitted to respond to relay Ill only during that part of each incoming impulse which has least distortion,

Timing relay 30 also has a permanent biasing and its operating winding is normally energized over the marking contact of relay 4|; condenser 35 and resistance 36 are normally short-circuited in this circuit. When relay 4| responds to a start impulse, condenser 35 begins to charge through the operating winding of relay 30, thereby holding the relay to marking. Condenser 35 and resistances 36 and 31 may be so adjusted that the operating current will not be sufflciently reduced to permit the biasing winding to operate the armature to spacing until about the time the last character impulse has been completed and the stop impulse commences. At this time relay 30 goes to spacing and completes a circuit from the armature of relay H to the lower winding of relay 40. If at this time relay happens tube in spacing position relay 4!] will be held in spacing position. However, if relay II should be in marking position relay 4|] will be operated to marking and will stop the cyclic operations of relay 2!]. Relay being in marking position, relay I0 must also be in marking position at this time, so that, when relay 40 operates to marking, relay 4| will be operated to marking and will stop the oscillations of relay 30.

Assuming the arrival of a start-stop signal series over the line west, the operations of the system will be as follows:

Line west and line east normally carry current and all the relays will normally be in the positions shown in the drawing. When a start impulse arrives, line west will be currentless and relay l0 operates to spacing, closing a circuit from battery at its spacing contact through the upper windings of relays 40 and 4|, thereby operating these relays to spacing; these windings will now be short-circuited at the spacing contact of relay 4D and the armatures will be held to spacing by the biasing springs.

When the marking contact of relay 40 opens, condenser 25 begins to charge through the upper operating winding of relay 20; similarly when the marking contact of relay 4| opens, condenser 35 begins to charge through the upper operating winding of relay 30. Due to the orienting adjustment of resistance 28 condenser 25 already had a certain charge, so that, after a compara tively short time, the charging current will be reduced to a Value at which the biasing winding will operate relay 20 to spacing. This will occur shortly before the arrival of the peak or center of the start impulse, at which time relay I is firmly positioned in response thereto. When relay 20 goes to spacing the short circuit at its marking contact is removed from the windings of relay H which now is given a short interval in which to respond to the position of relay I0 and operate to spacing. Immediately after the passing of the peak of the start impulse, relay 20 will return to its marking position, thereby efi'ectively preventing relay H from being disturbed by the next operation of relay I0. Relay 20, as previously explained, receives full operating current in spacing position and, depending upon the value of resistance 21, is quickly returned to marking where it will be held by the charging current from condenser 25.

Relay II in its spacing position causes relay 2 to operate to spacing and thus to send a. start,

relay In just at the time when relay I0 can be expected to be firmly in position. Relay I operates relay l2 correspondingly and a corresponding character impulse will be impressed upon line east.

For each of the five character impulses of the signal series the operations will be repeated as just described ior the first character impulse.

The last impulse, or stop impulse, of each signal series being a marking impulse, it is evident that in those instances where the last, or fifth, character impulse is also a marking impulse, all the transmission relays I0, II and I2 will perform no transition between these two impulses, so that it will be necessary only to time the operations in response to the fifth impulse. This fact is taken advantage of to provide a greater margin for the restoration of relay 30 to marking position near the end of a signaling series, thereby requiring less accuracy in the adjustment of relay 30.

Relay 30 has been held to marking by charging current from condenser until some time after the timing operation of relay 20 in connection with the fifth character impulse; at this moment the charging current is sufficiently reduced to permit the biasing winding to operate relay 30 to spacing. If at this moment relay II is in marking position, whether this be due to the filth character impulse or to the stop impulse, negative battery will be applied over the marking contact of relay II and spacing contact of relay 30 through the lower winding of relayto operate relay 40 to its marking position. Relay 40 now stops the oscillations of relay 20 so that relay I I will be prevented from operating until the next start impulse has been received over line west. The marking potential at relay I0 now operates relay 4| to marking, which in turn causes relay 30 to return to marking, thereby restoring the circuit to normal in readiness for reception. of the next start impulse.

However, if at the time relay 30 was ready for operation to spacing transmitting relay II had been in spacing position due to the reception oi. the fifth character impulse as a spacing impulse, spacing potential would have been applied over the contacts of relays II and 30 to the lower winding of relay 40, thereby holding relay 4!! in spacing position.

When now the stop impulse arrives over line west to operate relay ill to marking, relay 20 will perform its cyclic operation in the same manner as in timing the preceding impulses of this series, and relay II will be allotted a short interval in which to respond to the position of relay I0 and operate to marking, whereupon relay 20 returns to marking position commencing a new cycle. Relay II operates relay l2 and the stop impulse is transmitted over line east.

Relay I I now being in marking position, it will apply marking potential over the spacing contacts of relay 30 to the lower winding of relay 40 which operates and prevents further operations of relay 20. Relay I0 being in marking position, relay 4| will be restoredto marking and will in turn operate relay 30 to marking, thereby reconditioning the circuit for the next signal series.

Reference is made to my application for United States Patent, Serial No. 153,879, filed on even date herewith and relating to the same subjectmatter as the present application.

What is claimed is:

l. A timing circuit comprising relay means having contact means, an operating winding and continuous biasing means, and capacitance means connected to be slowly charged through said winding and to be quickly discharged over said contact means when the charging current is sufilciently reduced for the operating winding to be overcome by said biasing means for operation of said contact means, and said operating winding being energized over said operated contact means to overcome said biasing means and restore said contact means.

2. An impulse producing relay circuit comprising a polar relay having substantially constant biasing means for operating said relay to one position and having a series operating circuit including inductance and capacitance for operation of said relay to its other position and having contact means including contacts connected to said operating circuit for periodically controlling the charging and discharging current through said capacitance means, said contact means being connected to produce highly biased impulses in an output circuit.

3. A polar relay having continuous biasing means for operating said relay into one position, a self-interrupting series circuit including contact means and an operating winding of said relay and a source of unidirectional current for operating said relay into the other position, capacitance means bridged across said contact means to become discharged in said one position and to become charged in said other position to hold said relay in said other position until the charging current has diminished to a predetermined value to permit operation of said relay by said biasing means.

4. An oscillating system as defined by claim 3 further comprising a bridge circuit across said capacitance means including resistance means and starting contact means adapted to complete in normal position said bridge circuit to maintain a holding current in said operating winding and to maintain a limited charge on said capacitance means and to open in the other position said bridge circuit to permit oscillation of said system, said resistance means being adjustable to vary the period between the operation of said starting contact means from normal position and the first operation of said system.

5. An unsymmetrical timing circuit for producing highly biased impulses in an output circuit which comprises a polar relay having contact means, having substantially constant biasing means for operating said relay into one position and having an operating winding for operating said relay into the other position; a series circuit including capacitance means, a source of unidirectional current and said winding for holding said relay in said other position during the greater part of the charging period of said capacitance means; said contact means being connected to bridge, in said first position, said capacitance means to quickly restore said relay to said other position.

6. A self-interrupted relay circuit for producing highly biased impulses comprising a polar relay having continuous biasing means for operating the relay into one position, having contact means, and having a winding connected through coming said biasing means to open said contact means; said start relay means having contact means connected through said start circuit to said winding means to normally hold said first contact means open and to open said start circuit in response to an incoming start impulse; said capacitance means being connected to be charged through said operating winding means for holding said first contact means open when the charging current is heavy; and said first contact means being connected to close a discharge circuit for said capacitance means and to close a circuit for said operating winding means, for quick reopening of said discharge circuit.

8. An impulse producing relay circuit comprising a capacitance circuit, and a polar relay having a winding for operating said relay in one direction, having contacts connected in circuit with said winding and having biasing means for constantly biasing said relay in the opposite direction to close said contacts for energizing said winding characterized in this that said capacitance circuit is connected to be charged through said winding to temporarily hold said relay in said one position.

9. An impulse producing relay circuit comprising a capacitance circuit, and a polar relay having a winding for operating said relay in one direction, having contacts connected in circuit with said winding and having biasing means for constantly biasing said relay in the opposite direction to close said contacts for energizing said winding characterized in this that said capacitance circuit and said winding are serially included in a permanently closed circuit for charging said capacitance circuit through said winding to temporarily hold said relay in said one position.

10. An impulse producing relay circuit comprising a capacitance circuit, and a polar relay having a winding for operating said relay in one direction, having contacts connected in circuit with said winding and having biasing means for constantly biasing said relay in the opposite direction to close said contacts for energizing said winding characterized in this that said capacitance circuit and said winding are serially included in a permanently closed circuit for charging said capacitance circuit through said winding to temporarily hold said relay in said one position and that said contacts furthermore are connected for discharging said capacitance circuit when closed for energizing said winding.

FULLERTON S. KINKEAD.