US1971605A - Signaling system - Google Patents

Description

Aug. 28, 1934.

DETECTOR '2 I5 I35 l4 12. 2,2. 24-

ANT.

v. M. GRAHAM- 1,971,605

SIGNALING SYSTEM Filed Nov. 10, 1931 LEI BY :gRGIL M :gRAHAM A OR Y FI LZ;

FFEQE. I

res "Pr- 7 1,971,605 SIGNALING SYSTEM Virgil M. Graham, Rochester, N. Y., assignor to Strcrnberg-Carlson Telephone Manufacturing Company, Rochester, N; Y., a corporation of 1 New York Application November-1o, 1931, Serial No. 574,065

' 12 Claims. (01. 250-20)- This invention relates to signaling systems and Referring to Fig. 1, 6 designates an antenna or more particularly to radio receiving systems. other signal collector which is linked to the input It has been proposed to provide an automatic circuit of aradio frequency amplifying stage insensitivity control device or compensating means cluding the screen grid vacuum tube 7. The outin a radio receiver whereby incoming signals of put of this radio frequency amplifying stage is varying signal strength are reproduced as subcoupled to a first detector including the vacuum stantially uniform audio signals. 7 It is Well known tube 8. As is well known, this detector and oscilthat in such an automatic sensitivity control delator 9 functions to translate the incoming sigvice, rectifying means is provided whereby the nal at radio frequency into a predetermined inter- 10 carrier, Wave component of an incoming signal is mediate frequency. The output circuit of the derectified to apply a regulating potential to the tector 8 is coupled to the input of an intermediate control grid of at least one of the vacuum tubes in frequency amplifying stage including the screen a high frequency amplifying portion of the radio grid vacuum tube 10, the output of which amreceiver. Such a rectifier has usually taken the plifying stage is coupled by means of a trans 15 form of a three-electrode vacuum tube which is former 11 to the input circuit of a second detector physically independent from the detector tube including thefive element screen grid tube 12. or frequency translating device of the radio re- This tube includes a plate or anode 13, a screen ceiver. p v 14, a control grid 15, acathode l6, and a heater 17.1 In order to obtain a similar result, it hasalso This second detector may be considered as com- 20 been proposed to use certain of the electrodes of a prising a portion operating to translate the am- 5;- multi-electrode vacuum tube for translating an plified radio signal into audio frequencies and a incoming signal either at radio frequency or at an second portion serving to rectify the carrier comintermediate frequency into a signal ataudio freponent of the amplified signal, all "of which willquencies and to utilize otherelectrodes of this tube be further pointed out. The first portion of the to rectify the carrier component of the incoming detector comprises the input network including signal for the purpose of providing a controlling the control grid 15, condenser 18, secondary windpotential for regulating the automatic sensitivity ing 19 of the transformer 11, resistor 20, the upper in the amplifier portion of the radio'receiver. In portion of resistor 21, and the cathode 16, and. 511611 an arrangement h weve the translation also the output network of the detector connecting to of the incoming signal at radio frequencies or the screen 14, inductance 22, the upper portionof 8 intermediate frequencies into audio frequencies by the potentiometer 23, primary winding of the the rectifier or translating device, has been effectaudio transformer :24, to the positive terminaloof s WithOut any p fi v o e t ct y the 180 volt source, through t is source to groundspeaking, without any translationgain. a ed conductor 25, and thence to the cathode 16. It

In accordance with the present invention, it is will be noted that a resistor 26 connects the con- 0 proposed to use a multi-electrode vacuum tube trol grid 15 to the grounded conductor 25, so that With-certain of its electrodes n i in as a the control grid is maintained at a predetermined rectifier of ms Carrier wmllonent 0f t e incoming negative potential with respect to the cathode. signal in order to develope a regulating potential It is well known that this type of the detector, in] 'celtain of the high q y pl fyi g addition-to translating the incoming signal from staeesof a radio iv w y he en itivity radio frequency into audio frequency, effects this of a radio receiver is automatically adjusted otranslation with a substantial translation gain comp n t f r v y n n mi si nal tr n h more commonly referred to as amplification.

and to employ certain other electrodes of this Thesecond portion of the detector i cludes 45 device to translate the incoming signal from either the network connecting the anode 13, the secradio frequencies or intermediate frequencies into ondary winding 19 of the tr n I audio frequencies and this translation is effected si t r 20, and the upperxportion 0f r sistor 21 with a material increase in signal gain popularly to the cathode 16.v It will be readily recognized referred to as fl w that this portion of the detector constitutes a Fora clearer understanding of the invention, truerectifier which functions to translate the reference isimade t0 draWiTflg in' wh h Fig. 1 carrier component of the radio signal into pulsatis. a diagrammaticshcwing of a radio receiver in ing direct current, the audio component of which cluding the present invention, and Fig. 2 repreis filtered out by the networks including the consents a. modified form of second detector which densers 27, 28, 29 and 30 into substantially direct may be substituted for thatshown in Fig. 1. g current. This direct current flowing through the It is well known that such a change in the biasing potential on the control grid of a vacuum tube in an amplifying stage serves to' changethe amplification effected in such a stage in accordance with such changing potential. Similarly,

this biasing potential is applied over conductor through resistor 36 and the secondary transformer winding 37, to the control grid 39 .of

the vacuum tube 8 in the first detector. This biasing potential likewise regulates the amplification effected in the first detector. While this regulating potential has been disclosed as applied to the control grids of two vacuum .tubes of a radio receiver, the invention is not limited to such a specific arrangement, but the desired sensitivity control may be effected in one or more vacuum tube stages in accordance with the degree of control desired. 5

The output circuit of the second detector previously described as including the primary Winding of the audio transformer 24, is coupled by means of this transformer to an audio stage including two vacuum tubes 40 and 41 which are connected in opposition, or as more commonly referred to, in push-pull. The output of this audio stage is linked by means of an audio transformer 42 to a loud speaker LS which may be of any well-known type.

The circuit diagram of the present disclosure with the exception of the loud speaker and a suitable power device for supplying the A current or heating current as well as the 180 volt course,

.represents the detailed circuits of a radio reing condensers which have their rotor units 'mounted on a single adjustable shaft to efiect a ceiver. However, these circuits have not been described in detail but are shown to give a proper setting for the invention. It will be understood however, that condensers 43, 44 and 45 are tunproper tuning of the radio receiver.

In Fig. 2 there is shown a modified form of second detector which may be substituted for the circuit network of Fig. 1 included between the broken lines. This form of second detector like that previously referred to, effects the translation of the amplified radio frequencies or intermediatefrequencies into the audio frequencies with a substantial translation gain. While the: previously mentioned detector effects detection by so called plate rectification, that effected in the circuit network in Fig. 2 is of the type referred to as grid detection. In the operation of this circuit network, amplified incoming signals ateither radio frequencies or intermediate frequencies are introduced throughthe transformer 11 into the input circuit of the second detector including the five-element vacuum tube 12. This .input circuit may be described as including the cathode 16, the secondary winding 19 of the transformer 11, which winding is bridged by the condenser 52, resistor 53, grid leak. 54 and grid condenser55 in paralleL'and control grid,15..

The output circuit of this detector includes the screen 14, inductance 56, primary winding of the transformer 24, through the 180 volt source, ground conductor 25 and thence through resistor 53, secondary winding 19 to the cathode 16. This output circuit is linked by the transformer 24 to the audio amplifier including the vacuum tubes tending from the anode 13, resistor 5'7, ground conductor 25 and thence to the cathode 16. The rectified carrier wave flowing through the resistor 57 develops a drop in potential which is applied through the resistor 31 and the conductor 35 to the control grid or grids of one or more of the amplifying stages preceding the second detector in a manner already described in connection with Fig. 1. The capacitor 58 co-operates with the resistor 57 to filter out the audio component of the rectified carrier wave and the resistor 31 with the condenser 59 serves further to filter out any undesired audio component.

While the present invention has been shown as incorporatedinaradioreceiver of the superheterodyne type, it is equally applicable to other type of radio receivers including those of the tuned and untuned radio frequency types. From the foregoing it will be understood that applicant has invented a detector in which a portion thereof translates an incoming signal into audio frequencies' with a substantial translation gain and in which a portion of the detector develops a regulating potential which is utilized to control automatically the sensitivity of a radio receiver whereby substantially uniform signal volume is de- 1.1.!

Veloped.

WhatI claim is:

1. In a radio receiver utilizing a single heated source of electron emission fora plurality of electron paths, the method of reproducing radio frequency signals into perceptible condition at-uniform volume which comprises, amplifying said signals above audibility, translating said amplified signals into audio frequency signals .with'a substantial translation gain through one of said electron paths, rectifying a component of said amplified signals through another of said paths,

utilizing said rectified signal component in regulatingthe amplification of the signals above audi-' n bility, and translating said audio frequency sigll";

nals into perceptible condition.

2 In a radio receiver utilizing a single heated source of electron emission for a plurality of electron paths, the method of reproducing radio frequency signals into perceptible condition at uni- I.

form volume which comprises, amplifying said signals above audibility, translating said amplifled signals into audio frequency signals with a substantial translation gain through one of said electron paths, rectifying a component of said I1;-

amplified signals through another of said'paths,

filtering said rectified component to eliminate a substantial pulsating component therefrom, devel'oping from said rectified and filtered component a regulating'potential, utilizing said po- .1

tential to regulate the amplification of signals above audibility, and translating said audio frequency signalsinto audible signals.

3. In a radio, receiver including an amplifier having means to regulate the degree of amplifica- I 5 tion to be effected therein determined by a biasing potential, and a detector of the electron dis-' charge type utilizing a single heated source of electron emission fora plurality of electron paths,

the method of reproducing radio frequency siggamete rceetitr ceiieitgen at endees-weenie h mifaiageisnaiaatcve armss ente ta ners-rangeanswe er/re readers fr'e de lower n -sew l's'ii u tilizliif anourer eie t o i eirri'e'atv veesmp a ameesesaz spmeesigs isg asses g laureates-retri ve ridnlii'oliien't td difi- M velop a biasing otential, applyifi g sai wfiiasiifg 10 potr'i-tiisl t'd re ate' t'li e'signal amplification effected above audible frequencies, and translating said audio frequency signals into perceptible condition. 4. In a radio receiver including an amplifier provided with means to regulate the degree of amplification to be effected therein as determined by a biasing potential, and a detector of the electron discharge type utilizing a single heat/ed source of electron emission for a plurality of elec- '20 tron paths, the method of reproducing radio frequency signals into perceptible condition at uniform volume which comprises, amplifying signals above audibility, utilizing one electron path to translate said amplified signals into audio fre- 25 quency signals with an appreciable translation gain and utilizing another electron path to rectify the carrier wave component of the amplified signal, employing said rectified carrier Wave component to develop a biasing potential, and applyfifiing said biasing potential to said amplifier to regulate the amplification effected therein, and translating said audio frequency signals into perceptible condit receiver including an amplifier typ 1;. g a l0 emission for a plura 1 method of reproducing 1' into perceptible conditiion at uniform volume which comprises, amplifying said signals above audibility, developing electron emission from said source, utilizing a portion of said electron emission in one path to translate said amplified signal into audio frequency signals and to amplify the same, utilizing another portion of said electron emission in another path to def i velop a rectified current corresponding to the carrier wave component of said first-mentioned amplified signals, employing said rectified current to generate a biasing potential, utilizing said biasing potential to regulate the amplification of said 35 first-mentioned signals, and translating said audio frequency signals into perceptible condition 6. In a radio receiver, an amplifying stage including a vacuum tube operating to amplify signals at frequencies above audibility, a detector (lei-Z having a vacuum tube provided with a first electrode, a second electroda'a third electrode, and a cathode, an input circuit for said detector linked to said amplifier, said input circuit including said cathode and one of said electrodes, an output circuit including said cathode and another of said electrodes, a rectifier circuit including a portion of said input circuit, an additional one of said electrodes and P r said cathode, said rectifier circuit serving to recti fy the carrier component of said amplified signal, means for developing a potential according to said rectified carrier component, and means for utilizing said potential to control the amplification efiected in said amplifying stage.

'7. In a radio receiver, an amplifying stage inest . l nlked to saidianiplifier by a transformer, said saiuaiir iiryilig sta efny wtransrerme sare mput i iiicmcing ear ssumes ne seeonuary tieiiep'saie tiiii'd said first e letrbde thr odgnanapaMt for biasing said third electrode, an output circuit including said second electrode and said cathode, a resistor in said input circuit, and means for applying a negative potential developed by said resistor to control the amplification effected in said amplifier.

8. In a radio receiver, an amplifying stage, including a vacuum tube operating to amplify signals at frequencies above audibility, a detector having a vacuum tube provided with electrodes including an anode, a screen, a control grid and a cathode, an input circuit for said detector linked to said amplifier by a transformer, said input circuit including said cathode, the secondary winding of said transformer, a grid leak and a grid condenser in parallel and said control grid, an output circuit for said detector including said screen and said cathode, a rectifier circuit including said cathode, a portion of said input circuit and said anode, means in said rectifier circuit for developing a potential varying in accordance with the rectified current therein, and means for applying said potential to the control grid of said amplifier.

9, In a radio receiver, an amplifying stage includingravacuum tube operating to amplify sigaudibility, detector yided with "electrodes ee'n, a control grid and Te i a athodefa input circuit including said cathode, the secondary winding of said transformer, a grid leak and a grid condenser in parallel and said control grid, an output circuit including said screen and said cathode, a rectifier circuit including said cathode, a portion of said input circuit and said anode, said input circuit including a capacitance bridged across the terminals of said secondary winding to tune said input circuit, means in said rectifier circuit for developing a potential varying in accordance with the rectified current therein, and means for applying said potential to the control grid of said amplifier.

l0. Ina radio frequency signaling system, means for amplifying signals at frequencies above audibility, means including one heated electron source for translating said amplified signals into audio frequency signals with a substantial trans.- lation gain, means including said heated electron source for rectifying a component of said amplified signals, means controlled by said rectified signal component and including a portion of said amplifying means for regulating the amplification effected by said amplifying means, and means for reproducing said audio frequency signals into perceptible form.

11. In a radio frequency signaling system, means for amplifying signals at frequencies above audibility, means including one heated electron source for translating said amplified signals into audio frequency signals with a substantial transnal component, means controlled by said filtered quencysianals with. fiu anfla re s at n ain, means includingsaidheated electron source 101;- z eofl-fylngn compenent of-sglql gmplifled; signals; cqp-trplled, by said ,rectifled' signal, component fqn-pqntrolling the biasing of 'sa 1d-a .mp1i-; fying ;4-mea r ls whereby the amplification eiiected: by-saisi am lit ms me n regulated, d a for reprodueingus aidnqqdio frequency signals intoperceptible form, t I j 1 1,971,605Q-Vi'rgil Graham,- Roch August 28 -3 Disclaim d M rz'zmberg-0arlson Telephonii-Mr1n 3min pateIg-ereby enters 131115 dl sclauner as to laims 3, 4, 6, 10, 1 and 12 fsaid [Ofiicial Gazette April 21, 1986.]

quencysianals with. fiu anfla re s at n ain, means includingsaidheated electron source 101;- z eofl-fylngn compenent of-sglql gmplifled; signals; cqp-trplled, by said ,rectifled' signal, component fqn-pqntrolling the biasing of 'sa 1d-a .mp1i-; fying ;4-mea r ls whereby the amplification eiiected: by-saisi am lit ms me n regulated, d a for reprodueingus aidnqqdio frequency signals intoperceptible form, t I j 1 1,971,605Q-Vi'rgil Graham,- Roch August 28 -3 Disclaim d M berg-arlson Telephonii-Mr1n 3min pateIg-ereby enters 131115 dl sclauner as to- laims 3, 4, 6, 10, 1 'and 12 fsaid [Ofiicial Gazette April 21, 1986.]

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