US847777A - Telephonic repeating circuit and apparatus. - Google Patents

Description

PATENTED' MAR. 19, 1907.

F. E. DE P. D' HUMY. TBLEPHONIG REPBATING CIRCUIT AND APPARATUS.

APPLICATION IILBD JUNE 26. 1906.

2 SHEETS-SHEET 1.

No 847,777. PATENTED MAR. 19, 1907. P. E. DE F. DHU'MY. TELEPHONIG RBPEATING CIRCUIT AND APPARATUS..

APPLICATION FILED JUNE 26, 1906.

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. I 2 SHEETS-SHEET 2.

' transmission in either direction at the will of articulation from the receiver. Attempts TED s'rA'rEs PATENT OFFICE.

Specification of Letters Patent.

TELEPHONIC .REPEATING CIRCUIT AND APPARATUS- Patented March 19, 1907.

Application filed June 26,1906. Serial No. 323,482.

To all whont it may concern:

Be it-known that I, FERNAND EMILE DE FAUCHEUX DiIUMY, a citizen of the United States, residing at Englewood, in the county of Bergen and State of New Jersey, have invented certain new and useful Improvements in Telephonic Repeating Circuits and Apparatus, of which the following is a specification, reference being had to the drawings accompanying and forming part of the same.

One of the most 'serious'difiiculties met with in telephonic transmission over lon circuits is the unavoidable attenuation o the current, due to well-known causes, thereby rendering the action on the distant receiving instruments correspondingly weak. To remedy this drawback, it'has been proposed to divide the circuit in'to comparatively short sections and to repeat or reproduce the current-waves in one section after another from the transmitting end of the system to the receiving end witha fresh source of current and correspondin 1y amplified waves in each section. It is oi course desirablein fact, it is practically essentialthat such a system be reciprocal-that is, operative for.

the arties usin the line and not in one direction only. umerous systems based on this plan have been roposed but so far as I am aware none of t ese numerous attempts has been productive of practical results. The use of relays with two line-circuits, as commonly employed, is productive only of a sustained hum or shriek in the instrument, due to the fact that waves relayed from one line into the other are relayed back into the first, then again into the second, and back into the first, and are thus tossed back and forth at the rate of the vibrating'attunement of the relays. Furthermore, any reciprocal repeater which sends waves back into the originating or sending circuit causes distortion of the original wavesto a greater or less degree,for the reason that the relay armature or diaphragm possesses a certain inertia whichcauses' it to lag sl i htly behind the waves which actuate it. onsequently any waves which the relay sends into the originating-circuit will be slightly in arrear of the original waves, producing resultant distorted waves, which are carriedto the second linecircuit and reach the receiving end thereof in their distorted form, thereby'seriously impairing the distinctness or clearness of the which are in series with their appropriate line-circuits the other differential windings are put in series with artificial-line loads having resistance, capacity, and inductance equal to the transmission-circuit.v Hence although the system referred to is actually reciprocal in operation it fails to produce the results for which a repeating system is intended, for the addition of the artificial lines, through which the new currents must flow, brings each circuit, in effect, up to the orignal total length of the line efore it was di.

vided.

I have therefore been led to devise my present invention, which has for its chief object to provide, first, a reciprocal repeating system in which the direction of transmission is changed at the will of the parties using the line by the mere act of speaking into the transmitter without the use of automatic switches; second, a system in which amplified current-waves are sentinto the second or receiving line circuit, but not in the first or originating line circuit also; third, a system in which reciprocal operation may be obtained with or without differentially-wound relays, but without attenuating the-current by an artificial line in series with the receiving-line.

The nature of the invention by which these objects are attained will be more readily understood from a description of the preferred embodiments, which are illustratedin the annexed drawings, wherein Figure 1 is a diagram showing the preferred form. Figs. 2 and 3 are diagrams showing modifications.

Referring now to Fig. 1, R and R. indicate two microphone relays of any suitable type, with the usual local circuits L L, but havingtheir receiving magnets wound differentially, as indicated at 1' r and r 1*", respec- .IIO

tively. C C are the east and west tel ephonecircuits, respectively, in which are the windings t t of transformers T T. The other windings t t of these transformers are in ductance, and capacity equalto its respective line-circuit C or C. a

The operation of the system will now be readily understood. If a voice-current be produced in thetelephone-circuit C, corresponding current will be induced in the transformer T, in the winding t thereof, flowing through the differential winding 1' of the relay R, and thence dividing to the ground through windings i and t of transformers T and T respectively. The diaphragm of the relay is thereby actuated in eorres 0ndence with the current-waves in the tele onecircuit and causes fresh, stronger, an inde-' pendent but exactly similar'current-waves to be set up in the winding t of transformer T These current-waves flow to the relaymagnet R, where the current divides and flowsin opposite or neutralizing directions on account of the equal loads on the two branches of the magnet-Winding. Part of the currentthus divided flows to transformer T and artificial line A and thence to ground, while the other part flows to groundthrough the winding t (which now becomes a primary) of the transformer T. The fresh strong current in the primary t induces similar'current-with corresponding waves in the other winding t, (now the secondary,) which current-waves are propagated to the telephone in circuit G At the same time no effect is produced on the relay local circuit Lcand telephone-circuit C, since therelay R" is not affected. Consequently the voice wave's originating'in line C are reproduced in line C, inductively through transformer T,electromechanlcally and inductively through relay R, and inductively through transformer T, and that without affecting in any way the original waves in circuit C. Conversely, by an exactly similar operation voice-waves I in circuit C are reproduced in circuit C.

Fig; 2 shows a slightly-different arrangement in regard to the differential relays. In this case the relay-transformers are each provided with two secondaries t and t", which are connected to the appropriate differential windings of the other relay instead of a's'i'ngle secondary connected at the neutral point of the other relay magnet winding.

ays being secured by means of-the trans-- formers T T, whose windings. t t are connected at their middle points with the windings fit respectively, of transformers T T.

In this case current induced in transformerwinding t, for example flows to the middle point of transformer-winding t, where it divides, half flowin to ground through the transformer T an the other half flowing to ground by way of the artificial line A. The current induced in the other winding of transformer T actuates the relay R The current thereby induced in the latters transformer-winding t flows to the middle point of the winding 25 of the transformer T and dividing there flows equally through the two halves, one of which includes the transformer T, and causes the current to be induced or repeated in line-circuit C, while the other half includes (inductively) the balancing-Circuit or artificial line A. The currents in the two halves of winding 6, however, ai'e. in .opposite directions, and hence neutralizeeach other so far as any effect on the other winding of the transformer is conoerned. Conse uently the relay R although not di erentially wound, is nevertheless unaffected, and likewise the originating-circuit C. In the same way currents originating in line-circuit C will he reproduced in the other without affecting the relay R From the foregoing descri 7tl01'1 it will be seen that the s stein in loot forms is fully reciprocal wit out the use of automatic switches, the direction of transmission being changed at will b the 'act of speaking into the transmitter o the receiving-station, and that the amplified current-waves are produced only in the receiving-circuit C or C, as the case may be, and not in the originating circuit. There can therefore be no deforming of the original waves, with consequent impairment of clearness at the receiving end of the system, nor can current-waves be thrown back and forth between the two circuits, with the objectionable humming or singing. It will also be seen that the currents produced in the transformers T T divide at the differential devices. which, as explained above, may be either rela s or transformers, half of the current in uencing inductively the transmission line-circuit through transformer T or T, as the case may be, and the other half inductively influencing the respective artificial line, thereby bringing the two influencing-circuits into multiple relation with each other. The consequent attenuation of the current in such an arrangement is only that due-to the natural loss'or straightening effect in the transmission-circuits, which loss is much less than would result in a series relation.

It is to be understood, of course, that the arrangements herein described are merely typical of the invention, which may be emtem, in combination, a telephone-line consisting of independent sections, repeating devices having differential windings, portions of their windings being in inductive relation to respective sections of the telephone-line, and artificial-line loads in inductive relation to other portions of the windings of the repeating devices, as set forth.

3. In a telephonic repeating .system, in combination, atelephone-line consisting of independent sections, a device having differential windings, one ofthe differential windings being connected inductively with one of the line-sections, means for producing in the said differential device currents correspond ing to currents in the other line-section, and an artificial-line load connected inductively with another winding of the differential device, as set forth.

4. In a telephone repeating system, in combination, a telephone-line consisting of independent sections, a device having differential windings, one of the differential windings being connected inductively with one of the line-sections, an artificial-line load connected inductively with another winding of the differential device, and a circuit in inductive relation to the other line-section and connected to the neutral point of the winding of the differential device, as setforth.

5. In a telephonic repeating system, in combination, a telephone-line consisting of independentsections, a relay having a differentially-wound receiving-magnet, one of the differential windings being connected induct-' ively with one of the line-sections, an artificial lin.e load connected inductivel with the other differential winding of the re ay receiving-magnet, and a circuit in inductive relation to the other line-section and adapted to produce currents in the relay corresponding to currents in the said line-section as setforth.

.6. In a telephonic repeating system, in combination, a telephone-line consisting of independent sections, a relay having a differentially-wound receivinganagnet, one of the differential windings being connected inductively with one of the line-section's, anartificial-line'load connected inductively with the other differential winding of the relay receiving-m agnet, and a circuit in inductive relation to the other line-section and connected to the neutral point of the windings of the relay receiving-magnet, as set forth.

7. In a telephonic repeating system, in

combination, a telephone-line consisting of independent sections, a relay having a differentially-wound receiving-111agnet, one of the differential windings being connected inductively with the one of the linesections, means for producing in the said differential device currents corresponding to currents in the other line-section, and an artificial-line load connected inductively with another differential winding of the relay receiving-magnet, as set forth.

8. In a reciprocal telephonic repeating system, in combination, a telephone-line con sisting of independent sections, repeating-relays having differentially-wound receivingmagnets, portions of the differential windings' being in inductive relation torespective sections of the telephone-line, and artificialline loads in inductive relation to other portions of the differential windings of the relay receiving-magnets, as set forth.

'9. In a reciprocal telephonic repeating system, a divided telephone-hne, repeating-relays having differentially-wound receivingmagnets, and artificial-line loads, the said artificial-line loads and the sections of the responsive to currents originated in its respective line-section and. unresponsive to currents produced by it in the other line-section,- as set forth.

12'. In a telephonic repeating system, a relayhaving a differentially-wound receiving magnet inductively connected with'a transmission-line and an artificial line, as set forth.

FERNAND EMILE DE FAUCHEUX IYHUMY.

Witnesses:

STURGES S. DUNHAM, THOS. J. BYRNES.

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