US1652549A - Carrier-wave telegraphy - Google Patents

Description

Dec. 13, 1927. 1,652,549

P. l. WOLD CARRIER WAVE TELEGRAFHY Original Filed Sept. 30, 1919 2 Sheets-Sheet l I //7ve/7/0r: Pe/er l Vo/d.

Dec. 13, 1927. 1,652,549

P. I. WOLD CARRIER WAVE TELEGRAPHY Original Filed $ept. so, 1919 2 Sheets-Sheet 2 llllllllrllllv Pe/er VVo/G Af/ja Patented Dec. 13, 1927.

UNITED STATES 1,652,549 PATENT OFFICE.

PETER I. WOLD, 0F SCHENECTADY, NEW YORK, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

OARRIER-WAVE TELEGBAPHY.

Application filed September 30, 1919, Serial No. 327,435; Renewed Kay 14, 1927.

The present invention relates to distant control of apparatus by waves of electrical energy for signaling or other purposes. A particular object of the invention is to provide method and means whereby a receiving operator in a simplex or a multiplex wave transmission system may give an indication to a sending operator during the progress of the transmission.

In an application of Burton W. Kendall, Serial No. 334,682, filed October 31, 1919, there is described a wave transmission system adapted for signaling, in which it is necessary for the receiving operator to keep his F key closed in order to receive signals and to enable the sending operator to hear his own signals. With the receiving operators key open, as in breaking in, neither operators receiver responds to further actuation of the sending operators key, and the system so far as the operators are concerned is therefore analogous to the Morse closed circuit system. To the same extent the present invention may be said to resemble the open circuit Morse system in that the receiving operator may break in on his sending operator by depressing his key and holding it closed, the key when not sending being open at its front contact.

A better understanding of the invention may be had from the following detailed description of an embodiment of the invention, taken in connection with the drawing, of which Fig. 1 is a schematic circuit diagram of a system according to the invention, and

2 and 3 show modifications of the system of Fig. 1.

Referring first to Fig. 1, stations S and S are adapted for independent two-way communication over the line 1 with stations S and S respectively. Other similar stations may be associated with the line 1 and may be adapted for selective intercommunication. Stations S and S are not shown in detail in the drawing since they are similar to S and S which are shown and are below described in detail.

Line 1 is provided with nets 2 and 3 for balancing for all the transmitted frequencies, and with line coils 4 and 5 for coupling the sending and receiving sets in balanced relation to one another. For transmission to the line 1, stations S and S feed into the branch 6 which contains coils 7 inductively related to the line coils 4, and for receiving from the line 1, stations S and S are associated with the branch 8 which is bridged across the line. Stations S and S have similar branch circuits 9 and 10 respectively.

Stations S and S have generators 11 and 12 respectively which produce waves of the same or different frequencies, preferably of slightly diiferent frequencies to permit of easier selections between transmissions in the opposite directions.

By actuating key 13 at station S for transmitting signals, the generator 11 is connected for different intervals to the circuit 14, which may be tuned, if desired, to the generator frequency. Circuit 14 is coupled to circuit 15 also tuned to the frequency of generator 11.. The wave trains thus sent out from the generator 11 are impressfd through the coils 7 and 4 upon the Because of the conjugate arrangement of the net and coils 4 and 7, the wave from generator 11 does not pass into circuit 8, but after traversing the line it passes into branch 10 across which are the tuned branches 16, 17 etc. Branch 16 is tuned to the frequency of the wave from generator 11, and this wave is therefore selectively transmitted to the tuned circuit 18, which is coupled to the branch 16 as shown and is also tuned to be selective to the wave from generator 11. Circuit 18 is connected through the normally closed back contact of double-point key 19 to the input terminals of the amplifier A from which the wave passes in amplified form to the detector D By the well-known action of the detector each wave train received over the line is converted into a more or less continuous current in the output of the detector and is thus rendered capable of actuating relay 20. Relay 26 therefore responds to the actuation of the distant sending key 13 and may, by a local circuit as indicated, control any desired type of receiver, such as the usual sounder.

To transmit from station S to S key 19 is actuated and at its front contact closes the circuit of generator 12 and causes the transmission of a wave from source 12 through circuits 21 and 22, preferably tuned, through branch 9 and to the line 1. At station S this wave is selected by the tuned branch 23, and the key 13 being in its normal or up position, the wave is impressed through the resonant circuit 24 upon the amplifying and detecting circuit comprising A and D by which the wave 15 enabled to actuate relay 25 in the manner indicated in connection with detector 1),.

In addition to each transmitters control of the distant receiver, provision is made whereby the sending operator hears in his own receiver the signals which he is transmitting. For this purpose in the system of Fig. 1, coil 26 is included in the circuit 1 1 so that when the key 18 is depressed energy is fed from generator 11 through coil 26 and through coil 27 coupled thereto and ineluded in the input circuit of detector D so that relay 25 is actuated by this energy. This method of producing side tone in the 'local receiver is especially adapted for use with staggered carrier frequency, in which case the circuits 23 and 24 are selective of a frequency or of frequencies different from that of generator 11. The wave from generator 11 is made to affect relay 25, however, by being impressed upon the input circuit of the detector D over a path which does not include the selective circuits 23 and 24-. In a similar manner, when the key 19 at station S is depressed the distant relay 25 will be actuated and, by virtue of the coupling 27, the local relay 20 will also be actuated.

If during the transmission from station S to S for instance, the operator at S wishes to break in on the sending operator, the key 19 is depressed and is held down, where-- upon a continuous wave from generator 12 is thrown on the line. When the key 13 is on its back contact, i. e., between signals, the circuit 24. is connected to the input terminals of amplifier A The wave incoming from generator 12 is, therefore, impressed on amplifier A and the sending operator hears in his local receiver reverse signals as well as the signals transmitted by him. With proper adjustment of the contacts of key 13 and the receiving circuit, the relay 25 could be made to keep the receiver continuously in. the marking condition, whether that be the open or closed condition, by the alternate application of energy from generators 11 and 12, and the sending operator would cease to hear his si nals entirely.

The presence of side tone by virtue of the coupling 26, 27 or similar means, it should be noted, is not necessary to the provision for breaking in. If there is no side tone, the sending operator does not hear his own signals. If the receiving operator depresses his key, however, the sending operator hears signals the reverse of those being sent by him in his local receiver, due to the closure between signal elements of his key 13 at its back contact. In either case he is notified of the fact that the receiving operator has his key 19 depressed. The sending operator therefore stops sending and releases his key 13 which is held in its up or normal position, thus placing his receiver circuit under control of the distant operators key so that signals may be received from the distant station S In similar manner, stations 5, and S and other intercommunicating stations if provided may be arranged for similar cooperation with each other over the line 1, it being understood that the generators for transmitting and the receiving circuits in stations S and S and other stations employ frequencies different from those used by stations S and S and each other. In other respects the stations may be alike.

' In Fig. 2, a different manner of producing side tone in the local receiver is shown. No special circuit is used for transferring en ergy from generator 11 to the receiving circuit, but the line 1 and net 2 are adjusted for a slight unbalance so that when energy from generator 11 is impressed on the line through coils 7 and 4 a portion of its passes into branch 8, since, on account of the unbalanced condition, circuit 8 is no longer bridged across points of equal potentials with respect to the wave from generator 11.

In case the same frequency is used for transmission in both directions over the same channel of line 1, a simple tuned circuit, such as 23 in Fig. 1, would serve to select the wave from generator 11 as well as that from generator 12. However, if a different frequency is used for transmission to station S from that generated by generator 11, it is necessary to use a selecting circuit in branch 8, which will pass both the transmitting and receiving frequencies. The hand filter 28 is shown for that purpose, and it is so proportioned as to pass waves that are impressed on branch 8 either from the local generator 11 or from a distant station S so that relay 25 is actuated by either wave. This filter comprises tunin'g elements, such as inductance or capacity or both, in series with the branch circuit and in shunt of the branch. For details as to the design and construction of such a filter the United States patent to G. A. Gampbell, No. 1,227,113, granted May 22, 1917, may be consulted.

By depressing key 13, which in this instance may be a single-point key, current from generator 11 is thrown onto line 1. At the distant station S the incoming current will be transmitted" through a band filter which may be entirely similar to 28. After being amplified, the received current is detected, as described in the case of Fig. 1, to cause actuation of the receiver similar to relay 20 of Fig. 1. At the same time, as above explained, some ofthe energy being transmitted from generator 11, by virtue of the unbalance of the conjugatelyassociated coils 4: and 7, will pass into branch 8, will be selectivelytransmitted by filter 28, and will actuate relay 25. In order to simplify the drawing the necessary amplifying and detecting devices are not shown in Fig. 2. The

'wave of different frequency from the transmitter of station S is also selectively transmitted by} the filter 28 and hence, as in the case of Fig. 1, both the local and the distant receivers are controlled by signal trains supplied to the line at either station. The mutilation of the signals in the local receiver during transmission, or the continued energization of the receiving relay, or the silencing of the receiver as heretofore indicated will be a notification to the sendmg operator of a break signal from the distant station. At station S a band filter 29 is indicated which may be adapted to pass both the transmitted and received waves for station S In both of the arrangements thus far shown a single net 2 has been used to balance the line 1 for all the transmitted frequencies. In Fig. 3 a net 30 and a branch 31 are provided for each two-way channel. The band filter 32, which may be siimlar to the filter 28 above described, selectively passes between the line 1 and station S all'the frequencies transmitted from and to that station.

By depressing key 13 the wave from generator 11 is impressed on the line 1 through branch 31 and filter 32, and a portion of the energy is transmitted through coil 33 and coupling 27' to the detector D so that relay 25 is actuated in accordance with the outgoing signals. Incoming waves from the distant station S pass through coupling 34. to the amplifying and detecting circuit and actuate relay 25 as before. Instead of using the coil 33 and coupling 27, these elements might be omitted and the net 30 adjusted for a slight unbalance so that some of the output energy from generator 11 would be fed through coupling as to the local detectingcircuit.

The invention has been disclosed with par ticular reference to signaling, but it is equally adapted for distant control of apparatus of any desired nature. Also the waves employed may be radiated waves, instead of waves conducted over a line.

The invention is not to be limited either by the particular circuit arrangements as a whole as they have been illustrated and described or by the specific details, but only by the scope of the appended claims.

What is claimed is:

1. A signaling system comprising two stations connected by a transmission medium, a transmitter and a detector at each of said stations, the transmitters at different stations being arranged to transmit difl'erent frequencies, and means controlled by each of said transmitters for rendering said detectors selectively responsive to each of said transmitters actin alone.

2. A s1gn ing system having stations, 8. transmission medium for the transmission of waves between said stations, a transmitter at one station for transmitting a wave of given frequency, a receiver at said station, a transm1tter. at another station for trans mitting a wave of a substantially difi'erent frequency, a selective circuit between said receiver and said medium for selectively transmitting the wave of different frequency to cause the actuation of said receiver independently of the wave produced at the local transmitter, and means to cause the actuation of the receiver by waves from the local transmitter independently of said selective circuit.

3. A line having a high frequency channel for two-way transmission of signals between stations, a transmitter and a receiver for said channel at each station, means for balancing said line for the transmitted and received high frequencies, and means whereby the receiver at each station is responsive to the transmitter at that station acting alone, and selectively responsive to said transmitter at another station acting alone.

4:. A signaling system comprising two stations connected by a transmission medium, a transmitter and a detector at each of said stations, the transmitters at different stations being arranged to transmit different frequencies, and means controlled by the transmitter at each of said stations for rendering the detector thereat alternately responsive 'to the local and distant transmitters acting alone.

5. In a two-way wave transmission system, a line for conveying a plurality of waves of different frequencies, transmitters and receivers for said line, selective receiving circuits associated with each of said receivers, means inluding balancing nets for said line for associating said transmitters and receivers with said line, each transmitter comprising means for impressing wave trains upon said line and upon a local one of said receivers, and means operative between the transmission of said wave trains for rendering said receiver responsive to a wave received over said line.

6. Asignaling system comprising a plurality of stations connected by a transmission medium, a transmitter and a receiver at each of said stations, a selective receiving circuit at each of said stations normally associated with the receiver thereat, and means controlled by each of said transmitters for disassociating the respective receivers from their receiving circuits and for simultaneousl rendering said receivers responsive to tile local transmitter independently of the local selective receiving circuit.

7. A two-way wave transmission system comprising a plurality of stations, a source of waves, a selective circuit and a receiver at each station, connections for impressing a received-wave from another station upon the selective circuit at one station to actuate selectively said receiver, andiconnections for actuating the receiver at the same station by impressing the wave from said source thereupon independently of said selective circuit.

8. In a two-way wave transmission system, the method which comprises controlling a receiver by either the local or a distant transmitter acting independently and shifting the said control from one to. the other of said transmitters between each two signal elements in order to permit the receiving operator to break in on the transmitting operator.

9. In a two-way Wave transmission system, the method which comprises transmitting currents of frequencies individual to each transmitter, controlling a-receiver by either the local or a distant transmitter acting independently and shifting the said control from one to the other of said transmitters between each two signal elements.

10. In a two-way wave transmission system having stations, a transmitter'at each station for transmitting currents of frequencies individual thereto, a receiver at each station controlled both by the local and a distant transmitter, said local and distant transmitters each exerting its control by supplying currents of substantially different frequencies and means for actuating the receiver at each station by each signal element transmitted by the local transmitter independ-' ently of said distant transmitter and for placing said receiver under control of said distant transmitter between each two of said signal elements.

11. A signaling system comprising a plurality of stations connected by a transmission medium, means at each station for transmitting a wave of a distinctive frequency, a receiver at each of said stations, means to cause the selective actuation of said receivers by the wave transmitted from only one of the other stations, and means controlled by the transmitting -means at each of said stations for rendering the receiver thereat unresponsive to incoming Waves and for rendering said receiver responsive to waves from the local transmitter.

12. A signaling system comprising two stations connected by a transmission medium, a normally open circuit including a source of current at each of said stations, a selective receivin circuit and a receiver at each of said stations, a coupling between said normally open circuit and said receiver, and a key at each of said stations adapted in one position to connect the receiver with the selective receiving circuit thereat, and in another position to close the normally open circuit to supply current to said transmission medium and to said receiver.

13. A two-way wave transmission system comprising a plurality of stations, a source of waves, a selective circuit and a receiver at each station, a key adapted in one position to associate said receiver with said selective circuit whereby to impress received waves from another station upon said receiver, and means adapted in another position of said key to connect said receiver in circuit with the local source of waves independently of said selective circuit.

14. A two-way wave transmission system comprising a plurality of stations connected by a transmission medium, a source of waves of distinctive frequency at each station, a selective receiving circuit and a receiver at eaclLof said stations, said receiving circuits being tuned to the frequency of the waves transmitted from only one of the other stations, a key at each of said stations adapted in one position to associate the receiver with the selective circuit thereat whereby to impress received waves of predetermined frequency upon said receiver, and means adapted in another position of said key to connect the local source of waves in circuit with the receiver independently of the selective receiving circuit thereat.

15. A signaling system comprising a line,

a plurality of stations associated therewith,

PETER I. WOLD.

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