US1397432A - Signaling system - Google Patents

Description

C, v. LOGWOOU.

SIGNALING SYSTEM.

APPLICATION flLED JUNE I6. 1917. 1,397,432,, ,latented Nov. 15, 1921,

C. V. LOGWOOD.

SIGNALING SYSTEM.

APPLlQATlON FILED JUNE 16, 1917.

Patenwd Nov. 15 192% ,2 SHEETS-SHEET 2.

CHARLES "l7. LOG- 001), OF NEW] YORK, N. Y.

SIGNALING SYSTEM.

Specification of Letters Patent.

Patented Nov. 15,1921.

Application filed June 16, 1917. Serial No. 175,131.

To all whom it may concern:

Be itknown that l, CHARLES V. Loewooo, a citizen of the United States, residing at New York, in the county and State of New York, have made a certain new and useful Invention in Signaling Systems, of which the following is a. specification.

This invention relates to signaling systems. The object of the invention is to provide a signaling system which is simple in construction and arrangement and efficient in operation. A further object of the invention is to provide a signaling system particularly adaptedfor use in wireless communications. A further object of the invention is to provide a circuit arrangement which will operate a signaling 'device upon the receipt of received signals. A further object of the invention is to utilize the arrangement above described for automatic switching from transmitting to receiving system for use in connection with telephony or telegraphy. Further objects of the invention will appear more fully hereinafter.

The invention consists substantially in the construction, combination, location, relative. arrangement of parts, and circuit connections employed, all as will be more fully hereinafter set forth as shown by the accompanying drawing and finally pointed out in the appended claims.

Referring to the drawing Figure 1 is a diagrammatic view of a circuit arrangement embodying my invention.

Fig. 2 is a similar view showing one application ofmy invention wherein automatic switching from receiving'to transmitting is secured.

The same part is designated by the same reference numeral wherever it occurs throughout the several views.

Multiple step amplification by means of an audion is now well known in the art, and it among the special purposes of my present invention to provide means for paralyzing the last audion of amultiple step amplification immediately upon the receipt of an incoming signal and to utilize the paralyzation of the last amplifier to operate a relay which in turn operates a signal device.

Referring to the drawing I show in Fig. 1 the usual receiving system comprising an antenna 1 connected to earth 9- through the usual inductance 3 and capacity 4.. The re i-cived signals are led to the first audion 5 of the multiple step amplifier to the input grid electrode 6 thereof through the usual transformer well known in the art. The audion 5 delivers to the second step amplifier audion 7 which in turn delivers to the third step audion 8 through the usual circuits well known in the art. The respective filaments 9 of the audions are connected in common to source of current 10 to be heated thereby. The impulses received by audion 5 are transmitted fromthe plate electrode 11 to the regulation second step amplifier transformer 12 to the grid electrode 6 of the audion 7, and likewise the plate electrode 11 of the audion 7 transmits its amplified impulses to the transformer 13, which is a special transformer preferably one having an iron core three-quarters of an inch in diameter and four inches long of approximately 4,000 turns of number 36 copper wire wound the full length of the core, constituting the primary coil. The secondary coil preferably has two sections, each section of approximately one and one-half inches in diameter and one and one-half inches in length, surrounding the primary winding. The secondary coil preferably has about 30,000 turns and preferably of No. 4:0 enamel wire. The amplified impulses transmitted from the second step audion 7 to the transformer 13 are received by the grid 6 of audion 8. The secondary of coil 12 feeding into the audion 7 .is preferably open circuited, while the secondary of coil 13 is preferably connected to the common lead of filament 9 through a condenser 14. Connected between the primary of the transformer 12 and the common lead of the filaments 9 is a source of current such as the battery 15, so connected that the positive terminal is connected to the plate 11. Likewise a battery 16 is connected between the primary coil of transformer 13 and the common lead of the filaments 9 so that its positive pole is connected to the plate 11 of audion 7. Likewise a battery 17 is connected between the plate 11 of audion 8 and the filaments of the respective audions 5, 7, and 8. A 'resistance 18, preferably variable as shown, is connected between the grid 6 and the filament 9 of the third step audion 8 which forms a leak for leading ofi the negative change from the grid. 6 of that audion. The amount of current supplied to the respective filaments 9 from the source 10 is controlled by the resistances 19 as is well known.

it is well known in three step amplifica- .tion when the slightest impulse enters the first step audion the third step will paralyze so that it is impracticable to use this system of three step amplification as an amplifier of pulsating current of any strength unless a leak path is provided so that the negative charge on the grid electrode of the last amlifier can be led from the grid electrode.

t is the common practice to provide leak paths from the grid in both the second and third step amplifiers solely for this purpose. Where heretofore the paralyzing of the audion of the last step of amplification has been deemed to have disadvantages and etforts have been made extensively to overcome the same, it is among the special purposes of my present invention to utilize the paralyzing of the last step amplifier to perform useful work, such for example as a calling device which will call an operator immediately upon the receipt of the first signal. It is obvious that normally current flows through the wing circuit of audion 8 and through the relay 20 back to the filament, but any slight impulse relayed from the transformer 21 of the first step audion 5 will paralyze audion 8 and prevent this current flow. In this'instance the relay 20, which in the form shown and merely for the purpose of illustration, I show as a polarized relay, operates to cgntrol an auxiliary circuit, and it is solely for this purpose, namel of increasing the charge on the grid of au ion 8 to paralyze the audion that the specially constructed transformer 13 is employed, but it is obvious that a specially constructed transformer is not necessary and my invention therefore is not to be limited thereto. The operation of the system is exceedingly simple, signals are received by antenna 1, and are transmitted through t ansformer 3 to the detector, which, purely for the purposes of illustration I show in tlfi form of a crystal detector 23, and are thence transmitted through'transformer 21 to the nultiple step amplifier whereby the received signal is amplified through its respective steps many times and a negative charge of considerable magnitude is thrown on the grid 6 of audion 8, thereby causing current to stop flowing through the polarized relay 20 to operate the arm 25 and close the circuit of any signaling device, such for example as a bell-26 fed from current source such'as a battery 27. -Consequently it will be seen that. immediately upon the receipt of a'signal'the paralyzing of the last step audion'operates to supplycurrent to a relay to operate the same to render operative a si rial-indicating device.

. ith but slight modification this inven- "tion can be utilized to automatically switch a transmitting circuit to a receiving circuit, and for this purpose I have shown one application ofmy invention to such an arrangement in Fig. 2. In this instance I employ "the. antenna 29 connected to the earth 30 through the capacity 31 and inductance 32 for the transmitting circuit, and the antenna 29 connected to the earth 33 through inductance 34 for the receiving circuit. The antenna 29 is automatically switched between the two circuits 32, 31, 30 and 34, 33 by the action of a relay 35 and armature 36, which relay 35 is controlled by the circuit which in turn is controlled by the paralyzing of the last step audion 8. A microphone transmitter 37 fed from the source such as battery 38 leads to the transformer 39 which feeds to the transformer 40 of the first step audion 5 and the signals thus received are delivered to the audion 7 and from there to the audion 8 in the usual and well known manner, all as has been hereinbefore de scribed. The high negative charge on the grid of audion 8 causes the polarized relay 20 to operate to open the normally closed circuit of battery 41 relay 42 and thence to return through the armature 43 controlled by the polarized relay, and likewise the circuit controlling the relay 35. The opening of this circuit deenergizes the relay 42 and allows its armature 45 to establish the circuit between the contacts 46 and 47. Likewise the deenergizing of the magnet 35 allows its armature 36 to establish circuit connection with the sending antenna system 32, 30. At the same time the sound currents generated by a microphone 37 are transmitted through the coil 50 to the, grid of audion 100 51 which isincluded in the circuit of the usual audion transmitting system 52 which is the usual system employed for transmission and comprises generally the filament gridand plateelectrodes, the grid and fila- 105 ment electrode being connected by inductance 53, capacity 54, which inductance 5 is associated with inductance 32 of the antenna earth system. It is seen that the armature 36 controls the transmitting circuit and unless circuit connection is established between 46 and 47 the oscillion system is inoperative. The grid electrode of audion 52 is provided with a leakage path for its excessive negative charge to the filament of the audion 51, which filament is otherwise completely insulated from the remaining electrodes of the audion. In other words the receivedrimpulses transmitted to the audion 51 from coil 50 control the os- 12C cillating circuit of audion 52 in accordance with the degree of leak from the grid of audion 52. This is accomplished by controlling and neutralizing the positive and negative charges in the audion 51 by the voice as Wlll be readily understood. When the operator ceases to speak into the microphone 37 the paralyzed condition of audion 8 disappears, thereby allowing the polarized relay 20 to close the circuit of the respective V operator ceases to speak before the system.

spealrin menace relays l2 and 35 which is the one instance operates to open the transmitting circuit, and in the other instance to switch the an tenna to its receiving circuit. This is the normal condition of the apparatus and its normal condition is retained until signals are again sent in the transmitter 87.

The leak path formed by the varied resistance 18 connected between the grid and filament of the audion 8 serves the purpose of allowing the high charge on the grid to leak therefrom when the operator ceases in the traninitte'r, and this again places't e audion in normal condition. By varying this resistance, or rather by adjusting it, the paral zed condition of the audion can be control ed at will with respect to the length of time it remains paralyzed. Thus it can be readily adjusted to allow say from five to ten second to lapse after the will be switched automatically to the reoeiving circuit. Likewise it can be adjusted to act almost instantly upon the completion of an expression or clause. It is obvious, however, that any desired control may be thus effected. 1

It is obvious that while I have shown this system as an automatic switching arrangement in connection with, radio telephony my invention is not to be limited or restricted thereto, as with but slight modification ap' parent to one skilled in the art the radio telegraph system may be employed. 1 have not shown the receiving system but merely the traniormer 34- leading to the same as any receivin system well known in the art may be cmp oyed, but

Having now set forth the objects and na ture of my invention, what I claim as new and useful, and of my own invention, and desire to secure by Letters Patent, is,

l. The combination with a receiving circuit and transmitting circuit, provided with a common antenna, a switch normally connecting said antenna to said receiving circuit, a relay controlling said switch, an andion, a s gnaling device associated with said audiona id with said transmitting circuit, means actuated by the operation of said ggg signaling device for paralyzing said audion, and mean operated thereby for actuating said relay to operate said switch.

2. The combination with a receiving circuit and a transmitting circuit, provided with a common antenna, a switch normally connecting said antenna to said receiving circuit, a relay controlling said switch, an audion, a signaling device associated with said audion and with said transmitting circuit, means actuated by the operation of said signaling device for impressing a large negative charge on the grid electrode of said audion, and means operated thereby for actuating said relay to operate said switch.

3. in an automatic signaling system, an antenna normally in circuit relation with a receiving system, a normally open-circuited transmitting system, a source of sig nals, an audion associated therewith, and mean controlled by said source of signals for impressing a large negative charge on the grid electrode of said audion, and means operated thereby for closing the transmit tin circuit and connecting the antenna to said transmitting system.

4. in an automatic signaling system, an antenna normally in circuit relation with a receiving system, a normally open-circuited transmitting system, a source of signals, an audion associated therewith, and means controlled by said source of signals for paralyzing said audion, and means operated thereby for closing the transmitting circuit and connecting the antenna to said. transmitting system.

5. The combination with an antenna, of a receiving system and a transmitting system associated therewith, one of said systems being normally connected to said antenna, an audion, means controlled by the paralyzing oi the audiontor automatically connecting said antenna to the other oi said systems and. simultaneously breaking the connection between said antenna and the system normally connected thereto.

in testimony whereof I have hereunto set my hand on this oist day of May A D, 1917.

Images