US2047900A - Multiple signaling system - Google Patents

Description

Jul 14, 1936. w. BRUCKEL 2,047,900

' MULTIPLE SIGNALING SYSTEM Original Filed May 27, 192av L llnf T RECTIFIER I I -TRANSHITTER oc RECTIFIER Inventor: Waldemar Brl'jckel,

His Attorney.

Patented July 14, 1936 UNITED STATES 2,047,900 MULTIPLE SIGNALING SYSTEM Waldemar Briickel, Berlin, Germany, assignor to General Electric Company, a corporation of New York Application May 27, 1929, Serial No. 366,139. In Germany July 14, 1924. Renewed November 19 Claims.

My present application is a continuation in part of my former application, Serial No. 40,606, entitled Multiple signaling systems, filed June 30, 1925, issued June 21, 1932, as Patent No. 1,863,829. and assigned to the same assignee as my present application;

My present invention relates to signaling systems, and more particularly to multiplex signaling.

It is well known that a multiplex utilization of a wire signaling or remote control may be accomplished by effecting the individaul remote operations by alternating currents of difierent frequencies as in alternating current multiplex telegraphy. The number of connections which may be established and operated without interference'over one continuous wire is limited by, the range of frequency which is practically available on the particular wire. Limitations of this nature often arise when a number of different signals are to'be transmitted over one continuous wire-from one station to several other stations. In such cases the total number of signals to be transmitted determines the number of different f so ing to the use of modulated high frequency waves.

The high frequency waves serve to connect the transmitter with the individual receiving stations while-the modulated frequencies serve to separate the individual signals supplied to any one receiving station from one another.

fine novel features which I believe to be charac eristic of my invention are set forth with particularity in the appended claims.- My invention itself, however, both as to its organization and method of operation together with future objects and advantages thereof will best be understood by reference to the following specification taken in connection with the accompanying drawing in which Fig. 1 shows diagrammatically a transmitter associated with a plurality of transmission lines. Fig. 2 shows a receiving station associated with one of the transmission lines and Fig. 3 shows certain modifications of the receiver together with means for producing a return signal to indicate that the transmitted signal has been properlyreceived.

Referring to the drawing, I have indicated at I a high frequency oscillation generator or tube connected to a high frequency oscillating output circuit 2 which may be adjusted for various wave lengths by means of a plurality of condensers 3. The connection of any desired condenser with the tube may be effected by means of relays 4. controlled from a remote point, or in any manner desired. The high frequency oscillating tube I may be influenced in its operation by means of a special grid'which is connected to an additional tube or modulator 5. As in the case of tube I, there is connected to this additional tube a low frequency oscillating output circuit 6 which may include condensers I which are' adapted to be connected in circuit by means of relays 8.

If a relay 4 and a relay 8 are operated, a particular high frequency oscillation is produced it is connected. All of these circuits thus offer 20 high impedance to all of the carrier frequencies other than the one to be transmitted over the particular line. of any particular frequency is confined to the desiredpower line over which signaling on the respective frequency is effected, and is prevented from becoming distributed over the other lines of the power system where it is not utilized. Thus waste of the carrier energy in extraneous channels of the power line is avoided, and desired economy in (he transmitting equipment is effected.

The high frequency wave produced by the transmitter reaches the corresponding receiving station at the other end of wire II and excites a high frequency oscillating circuit M by way of a resonant connection l2 and inductive coupling In this way the carrier energy I3; These oscillations are rectified and amplified by a receiving tube I5 which is continuously in circuit. With pure high frequency waves, a pure direct current is obtained in the primary of transformer l1, while with modulated high frequency waves a direct current with superposed alternating current of the modulation frequency is obtained there. The direct current component excites a relay It by which the current sources for the other tubes are connected. The superposed signal bearing alternating current, on the other hand, appears in the secondary winding of transformer l1 and is supplied to the grid of the next amplifier tube 18. Oscillating circuits 19 are connected in the plate circuit of tube l8 and are tuned to the individual modulation frequencies. These circuits may contain the actual output relays for the circuits of the individual intended signals. The relays may be thermal or soft iron relays, or any type desired.

Additional rectifier tubes may be connected with the individual oscillating circuits for the purpose of converting the alternating current into direct current, andin order to make it feasible touse a directcurrent relay as the output relay, the advantage of this arrangement being that a very accurate and rapid effect may be obtainedwhere precise manipulations are desired. Such an arrangement is shown in Fig. 3 in which each of the tuned circuits! are shown as connected to the input circuit of a rectifier IS, the output circuit of which includes a relay 20 which may be used for signal purposes.

I have also shown in Fig. 3 of the drawing, means whereby a signal may be transmitted back to the station including the apparatus shown in Fig. 1 in response to a signal received at the receiving station.

In Fig. 3, I have represented at 2| a transmitter which is arranged to be energized through a circuit 22 whenever any one of the relays 20 is energized. It will be seen that this circuit is completed through the middle contacts of any of the relays 20, these contacts all being connected in multiple. Also when any relay 20 is energized by means of its upper contacts, a circuit is completed from the side of the corresponding tuned circuit I9 opposite the connection of that circuit to ground to the modulating circuit of the transmitter 2 I, one side of which may also be grounded as indicated at 23'. If this transmitter be of the type shown in Fig. 1 this connection will extend to the grid of the four-element discharge device which is shown connected to the condenser 1. In this way the carrier wave which is transmitted to the signaling station may be modulated with the same frequency which modulates the received carrier wave. Thus returned signals may then be received at the transmitting station of Fig. 1 by means 24 similar to'that shown in Fig. 2 indicating that the transmitted signal has been correctly received at the receiving station.

What-I claim as new and desire to secure by Letters Patent of the United States is: v

1. In a signaling system, a plurality of transmission lines adapted and arranged to transmit currents of different frequencies, a common high frequency generator connected to all of said lines, means for varying the frequency of said generator thereby to supply current having any of the frequencies transmitted by said lines, means for modulating the currents supplied by said generator with any one of; a plurality of additional frequencies, and a receiver connected to each line,

each receiver being responsive to the frequency transmitted by the respective line, and a plurality of circuits associated with each receiver, each of said circuits being responsive to a different one of said additional frequencies.

2. In a signaling system, a transmitter comprising a high frequency generator, means for varying the frequency of said generator, a modulator cooperating with said generator, means for varying the frequency supplied by said modulator, a plurality of transmission lines, connections between said lines and said generaton'said connections including a plurality of tuned circuits, a plurality of receivers associated with said transmission lines, said tuned circuits being tuned to wave with signal current, means included in said receiver for rectifying the received high frequency wave to obtain said signal current, an amplifier for the received signal current obtained by said last means through rectification of the received high frequency wave and means for controlling the energization of said amplifier in response to the intensity of unidirectional current resulting from the rectification of said received high frequency wave modulated with said signal current which is amplified by said amplifier.

4. In a signal system, a sending station, a remote station, means for transmitting from the sending station a carrier wave, means for selectively modulating-said carrier wave with any one of a plurality of different predetermined frequencies, a receiver for said carrier wave in the remote station, means associated with said receiver responsive to any of said modulations for initiating the transmission of a carrier wave back to the sending station, means for modulating said last-mentioned carrier wave with currents having a, frequency dependent upon the frequency of the received modulation, and means in the sending station responsive to said signal wave to indicate the response at the remote station.

5. In a signal system, a sending station, a remote station, means for transmitting from the sending station a carrier wave, means for selectively modulating said carrier wave with any one of a plurality of different predetermined frequencies, a receiver for said carrier wave in the remote station, means associated with said receiver responsive to any of said modulations for initiating the transmission of a carrier wave back I to the sending station, means for modulating said the frequency to which the respective receivers respond, each of said receivers being responsive to a high frequency current of a different fre- '7 transmitting to' said receiver a high frequency 'wave, means for modulating said high frequency last mentioned carrier wave with current having the frequency of the received modulation, and means at the sending station to indicate the response at the remote station.

6. In a high frequency signaling system, a transmitting station and a receiving station, a detecting device and amplifying device in the receiver circuit, a relay in the circuit of said detecting device adapted to close the power circuits for the amplifying device during reception of the desired radio carrier wave and to open said power circuits when no such carrier wave is being received.

7. In a high frequency signaling system, a transmitting station and a receiving station, a detecting device and amplifying device in the received circuit, a relay in the output of said detecting device adapted to operate on a change in current through the detecting device when the desired carrier wave is beingreceived and thereby control the power supplied to the amplifying device.

' thermionic detector in the receiving circuit, am-

plifier tubes forthe output of said detector, a relay in the output circuit of the detector adapted to maintain the power circuits subsequent to the detector closed during the reception of the deleast one connected with power and connecting the first named tubes to the power source automatically upon and by the change in current in a connectedtube due to the receipt of the radio message to be received.

11. In a radio signaling system, a radio receiving station comprising vacuum tubes supplied with power from a local source, means for connecting at least one of said tubes permanently to said power source, means for'connecting or disconnecting some of said tubes from said power source, the last-named means being controlled upon and by change in space current in a connected tube on receipt of signal current to connect the disconnected tubes.

12. A high frequency receiver including a first portion and a second portion, said first portion being normally in condition to. respond to high frequency waves and normally to supply waves resulting from reception of said high frequency waves to said second portion, said second portion being normally disconditioned for response to said resulting waves and means responsive to the intensity of said waves received in said first portion to condition said second portion for response to said resulting waves supplied thereto by said first portion whenever the intensity of said waves received in said first portion exceeds a predetermined value.

13. In a high frequency signalingsystem, a

, receiving station, a thermionic detector in the receiving station, an amplifier tube for the output of said detector, means responsive to receive high frequency waves to maintain the circuit subsequent to the detector in operative condition during reception of the desired carrier wave and to disable said circuit upon reduction of said carrier below a, predetermined value.

14. In a high frequency signaling system, a receiver having an amplifier, said amplifier, during'desired reception of signal bearing currents, being in condition for normal amplification of said signal bearing currents, an electron discharge device responsive to currents bearing the same signals as those amplified by said amplifier, and means connected in circuit with said electron discharge device and responsive to said currents bearing the signals amplified by said amplifier to interrupt operation of said amplifier injvresponse to a reduction in the level of received high frequency wavesto a value'above zero.

- 15. in combination, a signal receiver having a high frequency input circuit and an output circuit, a channel for signal bearing alternating currents between said input circuit and said output circuit, means normally to discondition said output circuit 'for' response to said signal bearing currents, said means being responsive to the intensity of currents received in said input circuit bearing signals to be transmitted through said channel to condition said output circuit for response to said currents when said intensitymined value.

an output circuit providing a signal controlled potential, means responsive to said potential for de-energizing said signal indicating means, and means associated with said de-energizing means whereby it is rendered responsive only to signals 5 having a definite minimum amplitude.

17. The combination, in a high frequency receiver, of an input circuit upon which high frequency oscillations modulated with low frequency oscillations are received, an output device, a transmission channel between said circuit and said output device, said channel including means to demodulate said received high frequency oscillations to reproduce said low frequency oscillations and to supply said low frequency oscillations to said output device, said channel comprising two portions, one of said portions being maintained continuously in condition for the transmission of current therethrough and including means responsive to the intensity of said received high irequency oscillations modulated with said low frequency oscillations which are supplied through said channel to said output device for operating a control device when said intensity of the received oscillations exceeds a predetermined value, and said second portion being normally disconditioned for the transmission of'current therethrough, and means to condition said second portion when said control device operates.

18. The combination, in a high frequency rechannel and means are maintained in condition for response of said output device to said low frequency oscillations reproduced from said received high frequency oscillations except when said received high frequency oscillations have intensity less than a predetermined value when said con-- dition for response is interrupted.

19. The combination, in a high frequency re ceiverof an input circuit upon which high frequency oscillations modulated with low frequency oscillations are received, an output device, a channel between said input circuit and said output device, said output device being responsive to said low freqency oscillations, means in said channel to demodulate said high frequency oscillations to reproduce said low frequency oscillations, means to supply said reproduced low frequency oscillations to said output device, said first means being maintained normally in condition to demodulate said received high frequency 60 oscillations and said second means being normally disconditioned for transmission of the low frequency oscillations reproduced therefrom to said output device, and means responsive to the intensity of said received modulated high frequency oscillations to condition said second means for transmission of the low frequency oscillations reproduced by said first means to said output device when said intensity exceeds a predeter- WALDEMAR nniicm.

Images