US2462144A - Pulse receiving and repeating system - Google Patents

Description

Feb. 22, 1949. c. M. THEILLAUMAS 2,462,144

' PULSE RECEIVING AND REPEATING SYSTEM Filed April 12, 1946 I N V EN T 0R. CLEMENT IZ THEILZAUYYAS BYWM/A ATTORNEY.

Patented Feb. 22, 1949 PULSE RECEIVING AND REPEATING SYSTEM Clement M. Theillaumas, Boulogne-Billancourt, France, assignor to Interna ional S'andard Electric Ccrporaiion, New York, N. Y., a corporation of Delaware Application April 12. 1946, Serial No. 661,493

In France March 27, 1945 Section 1, Public Law 690, August 8, 1946 Patent expires March 27, 1965 6 Claims.

This invention relates to improvements in pulse receiving and repeating systems for telecomunication networks using, for example, socalled commercial frequency currents for signaling. Such a system, which may also be adapted directly to voice-frequency signaling purposes by simple modification of the features of construction of some of its circuit elements, is disclosed in my co-pending application Serial N0. 660,269, filed April 6, 1946.

In the pulse receiving and repeating system described in my co-pending application, detection of the incoming signal is effectedv by means of a space discharge tube preferably of the coldcathode type, and pulse repetition is assured through a relay arrangement in the tube plate circuit. The moment of beginning of a pulse is determined by the ionization or lighting-up of the cold-cathode tube which causes the initial energization of a relay. The falling-back of this relay and not the inactivation of the tube determines the end of the pulse train. An auxiliary relay which is caused to be energized by the operation of the first relay effects the inactivation of the tube and also the application to the out-., going line of thecurrent source used to retransmit a signaling pulse train.

For each signaling direction, the pulse-repeating or receiving device comprises a cold-cathode tube fed from the input line through a condensertransformer series circuit and employs a relay arrangement comprising a two-winding retransmitting anode-relay, an auxiliary relay for internal switching, and a slow relay for neutralizing the signal input equipment of the other channel; One of the windings of said anode-relay is energized by signaling current from the input line by means of a rectifier for holding this relay actuated during the period of the incoming signal.

An object of the present invention is to pro-'- vide, in a system of the type'described, additional means for assuring high sensitivity and operating dependability.

Another object of this invention is to provide, in a system of the type described, high-fidelity definition of the duration of a retransmitted pulse train.

A further object of the present invention is to adapt a system of the type described to the employment of ordinary switching relays common in automatic telephony, eliminating the need for slug-fitted relays of the slow-releasing type.

According-to one feature of the invention, retransmission of the repeated signal to the incoming line is prevented by the operation of a.

2 relay contact. According to another feature, the outgoing line is connected to a discharge circuit after the signaling process has been completed.

An example of a circuit illustrating this invention is shown by the single figureof the accompanying drawing, the description of which is as follows:

A commercial-frequency or other signal current coming from the east ionizes the cold-cathode tube TE between cathode 9 and auxiliary electrode 9st through booster-transformer 4 ove the following circuit:

I Wire a from one side of the east input line E to back contacts I of ACE and 2 of COR, condenser 3, primary winding of transformer 4, back contacts 5 of ACE and wire I) to the other side of the east input line.

An incoming signal from the east side input line thus produces a discharge between anode and cathode of TE, and relay AER operates. This relay is energized by current from high tension battery 6 through its right-hand Winding, back contact 1 of auxiliary relay BER, anode 8 and cathode 9 of tube TE, and ground [0.

Relays BER and CER are each equipped with double front contacts. These relays are actuated following the operation of the relay AER closing its front contacts l2 and I3. BER is energized by current through its winding from 24 volt battery ll, front contact l2 of AER and ground I5; and CER by current through its winding from 24 volt battery l4, front contact l3 of AER and ground l5.

Through another double front'contact l6--l| on AER, condenser 3 in series with the primary through the rectifier I9 to keep relay AER operated.

The west side input line W connection with the pulse repeating apparatus is broken through the two reversing contacts 25-2'l of AER and a 50- cycle local source of ringing current S is connected by wires 0 and d to the outgoing west side line for retransmission.

Alternating or pulsating signal current from the east input line is supplied to rectifier l9 which in turn supplies current to the left-hand winding of AER for holding this relay operated during a signaling period. The circuit for the alternating current from the line is, wire a, back contact I of ACE, back contact 2 of COR, front contact E6 of AER, rectifier bridge l9, primary winding of transformer 4, back contact of ACE, wire b; and rectified current from rectifier I9 then energizes the left-hand holding winding of AER as stated above.

Relays BER and GER have been energized by the closing of contacts i2l3 on AER. Relay BER upon being energized breaks the plate circuit of tube TE at its contact 1 and grounds the control electrode 9:1: at its frontcontact 2|. Relay CER. upon being energized short-circuits its low resistance left-hand Winding through a front contact 23 which makes it slow to fall back and allows it to hold during a pulse train. Through two other front contacts 24, 28, it short-circuits the mid-points of the differential transformers 20 terminating the respective east and West side transmission lines. This inactivates the respective grid circuits of the amplifiers which serve as a coupling between the two channels. Finally, through a reversing contact 22, CER breaks the west-side input circuit at anadditional point and prepares a line-discharge circuit for the westside transmission channel.

When the incoming signal ceases, relay AER falls back, as the rectified signal current flowing through the left-hand holding winding of the relay ceases, and disconnects the supply of current energizing relays BER at 12 and CER at I3. Relay BER is slightly delayed in falling back by a rectifier cell 26 shunting a fraction of its winding-while relay CER is much longer delayed in opening its front contacts. During the time elapsing between the falling back of AER and that of GER, the west-side line is discharged over the circuit comprising wire 0, back contact 21 of AER, front contact 22 of CER, BOO-ohm resistance and wire 11. After the falling back of CER, the device is ready to receive and retransmit a new pulse.

Main relay AER, auxiliary relay BER and slow blocking relay CE'R operate in sequence as their respective windings are energized; and as their respective windings are deenergized their armatures fall back in successive sequence with suitable time delays as pointed out above in the description of the'circuits in which they operate.

As auxiliary relay BER operates with a slight delay retransmission is corrected to a certain degree for an accidentally short incoming signal. A perfect correction is not necessary here because of the fact that a cold-cathode tube operates under theactionof a very brief signal. The delay obtained is equal to the time required for good operation of end receivers.

The operation of the repeater for a west-side incoming signal is similar and consequently need not be described in detail.

The limits of use of the system in a practical operating example are as follows:

The alternating or pulsating pulse signal, on arrival must have a voltage greater than or equal to '12 volts, the optimum desired voltage is 18 volts 6 volts; the tube supply voltage is 130 volts 15 volts with the possibility of using a lower voltage by simply changing a resistance; in the case of a 4-wire terminating set system, for example, by the joint use of the 48 volt battery and the +70 volt battery.

The auxiliary relay and the slow relay are fed under 24 volts with possibility of feeding under 48 volts by the mere addition of a resistance.

While I have shown and described a particular embodiment of my invention, it will be apparent to those skilled in the art that variations and. modifications thereof may be made without departing from the underlying principles of the invention. I, therefore, desire the following claims to include within the scope of my invention all such substitutions and variations whereby substantially the results of my invention may be obtained by the use of substantially the same or equivalent means.

What is claimed is:

1. A pulse receiving system for telecommunication networks comprising a cold-cathode tube, a transformer having its secondary connected to the input of said tube and its primary arranged to receive an incoming signal, a relay having a winding connected in the anode circuit of said tube, a rectifier bridge having a pair of opposite junction points connected across a winding of said relay, and normally open relay contacts connected in series with the other pair of junction points of said bridge, arranged to connect said other pair of points across the signal input upon ionization of said tube.

2. A pulse receiving system for telecommunication networks comprising a cold-cathode tube, a transformer having its secondary connected to the input of said tube and its primary arranged to receive an incoming signal in series with a condenser, a two-winding relay having a first winding connected in the anode circuit of said tube, a rectifier bridge having a pair of opposite junction points connected across the second winding of. said relay, front contacts associated with said relay and connected in series with the other pair of junction points of said bridge, arranged to connect said other pair of junction points in shunt with said condenser and part of said primary winding, and means for breaking the anode circuit of said first relay winding subsequent to ionization of said tube.

3. A pulse receiving system for telecommunication networks comprising, in combination, a cold cathode tube, a transformer having its secondary connected to the input of said tube and its primary arranged to receive an incoming signal, a condenser in series with said primary, a twowinding'anode-relay having a winding connected to the tube anode and energized upon activation of said tube, a rectifier bridge having a pair of opposite junction points connected across a winding of said anode-relay, front contacts of said anode-relay connected to the other pair of Junetion points of said bridge in shunt with said condenser and part of said primary winding, an auxiliary relay having a winding connected in series with front contacts of said anode-relay and a source of energy arranged to energize said auxiliary relay, said auxiliary relay having back contacts connected in the anode circuit of said anode-relay, and front contacts and a circuit connecting the latter front contacts across the input of the tube, arranged to short circuit said input when the auxiliary relay is energized.

4. A pulse receiving system for telecommunication networks comprising in combination a cold cathode tube, means for impressing an incoming si nal upon said tube and thereby causing ionization thereof, a first relay, means for energizing the first relay when said tube is in operation,

means for maintaining said first relay in operation after the tube operation is terminated, a second relay, means for energizing the second relay when the first relay is energized, means including a back contact of the second relay for terminating the operation of the tube when the circuit relay is energized, means for maintaining said second relay in energized condition after release of the first relay, a third relay, means for energizing the third'relay when the first relay is energized, a signal output circuit, means including a back contact of the third relay for rendering the output circuit inoperative when the third relay is energized, and means for maintaining the third relay in energized condition after release of said first and second relays.

5. A pulse receiving system for telecommunication networks comprising a cold cathode tube, two transmission channel circuits each terminated by a differential transformer, means for impressing an incoming signal upon said tube and thereby ionizing the tube, a first relay, means for energizing the first relay when the tube is in operation, means for maintaining said relay in energized condition for the duration of the signal, a second relay, means for energizing the second relay when the first relay is energized, means including a back contact of the second relay for terminating the operation of said tube when the second relay is energized, a third relay, means for energizing the third relay when the first relay is energized, means including a back contact of the third relay for disconnecting the outgoing transmission channel, and switching means operated by energization of said first relay for short circuiting the respective mid-points of said difierential transformers.

6. A pulse receiving system for telecommunication networks comprising a cold cathode tube, two transmission channels, a differential transformer terminating each channel, means for impressing an incoming signal upon said tube and thereby ionizing the tube, a first relay, means for energizing the first relay when said tube is in operation, a second relay, means operative when the first relay is energized for placing said tube out of operation, means for delaying the release of the second relay after release of the first r lay, a third relay, means operative when the first relay is energized and including a back contact of the third relay for disconnecting the outgoing channel, means including front contacts of said third relay for short circuiting the respective midpoints of said differential transformers and means for delaying the release of said third relay after the release of said first and second relays.

CLEIVIENT M. THEILLAUMAS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,070,900 Harris Feb. 16, 1937 2,222,248 Blount Nov. 19, 1940

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