Патент USA US2411605код для вставки
Nov. 26, 1946. R„ Q_ WEBB ELECTRICAL CIRCUITS Filed Feb. 25, 1945 2,411,605 2,411,605 3 4 nator tubes 25 should preferably be provided with two control grids which are nearly equally eñ’ec tive in controlling the plate current flowing through the tubes. For this purpose, tubes of the electrode 31 may now be represented by the vec tor 0_30, and the voltage applied to the control electrode 39 may be represented by the vector 0_3?. As was the case in connection with the vector series of curves of portion (a) of the iig general character such as pentagrid converters may be used. The secondary Winding 29 of the transformer ure, the plate currents flowing through the tubes 25-and 21 naturally are still proportional to the 2| is suitably tuned by means of the tuning ca pacitor 3|, and output energy from this resonant vector sums of the two grid voltages which are rep resented by the vectors 0_39 and O-24, on the one hand, and O--32 and 0_24 on the other hand, so that now it will be seen that the result 'ant vectors are indicated by the vectorO--SS as secondary circuit consisting of the inductance of the secondary winding 29 of the interstage transformer 2| and the tuning capacitor 3| is fed by way of the conductors 33 and 35, respec representing the output from the tube 25, and tively, to the #l control grids 31 and 39 of the the Vector 0_38 as representing the output from discriminator tubes 25 and 21, respectively. 15 the tube 21. The second control grid 4| and 43 of the tubes It thus can be seen that for a condition where 25 and 21, respectively, are tied together, pref erably by the conductor 45, and -excited directly Ythe frequency is increased, unequal plate cur blocking condenser and functioning in substan tially known manner. The resistor element 5| serves to connect the biasing source, convention ally represented by the battery 53, to bias the the tube 21, whereas for a decrease in the input grids 4| and 43 to a suitable place as an operat ing point -within the region of plate current cur driven positive with respect to the cathodes by reason of the bias obtained thereon through the rents result, and the flow of these currents from the plate or anode |1 of the driver tube I5 through the load resistors 55 and 61 produces by way of the coupling condenser 41 and conduc 20 useful output variations. In the case where the tor 49, with the condenser 41 constituting a frequency is increased, it can be seen that the output from the tube 25Vbecomes greater than for frequency, the opposite'condition will take place. Since the grids of the tubes 25 and 21 are never vature. The plate or anode battery 55 supplies biasing source 53, it can be seen that these tubes not only the operating voltage for the plates 51 represent a load of substantially infinite imped and 59 of the tubes 25 and 21, respectively, but 30 ance on the resonant circuit and the result is that also supplies the operating voltages for the the output characteristic approaches more close screen electrodes 6| and E3 of these same tubes. ly the phase shift curve of the resonant circuit Variations in resultant output energies iiowing alone. _ through the tubes 25 and 21 are derived as use In the modified arrangement of Fig. 3, provi ful plate .current variations in accordance with sion has been made for a discriminator circuit the voltage drops produced through the resistors which is particularly adapted for operation with 65 and 61, which voltages are made available at in the audio frequency range. To this end, in put signals are applied at the input terminals 13, 15 and then serve to energize the primary wind the terminal points 69 and 1|, respectively. Considering the operation of the circuit here inabove explained, reference may be had to Fig. 40 ing I9' of the interstage transformer 2|', which 2, wherein the curve (a) represents a condition when the circuit arrangement of Fig. l is in bal is n_ow shown particularly as an audio frequency transformer, in order to energize the secondary ance, so that the vectors O-Zß and O-22 rep winding indicated as 29’. The general arrange resent the voltages applied to the control elec _ment of the tubes 25 and‘21 is somewhat similar trodes 31 and 39, respectively. It is, of course, 45 vto that shown by Fig. l with the control elec apparent that each of these voltages is 90° out trodes or grids 31 and 39 being energized by con of phase with respect to the voltage represented nection to the outer terminalsrof the transform by the vector O-24 which represents that volt er secondary 29', and the grids 4| and 43 being age which is applied to the parallelly connected parallelly connected and thus energized co-phas grids 4| and 43, which shift in voltage is due to ally, as well indicated with reference to the ar the resonant transformer action of the interstage rangement of Fig. 1. transformer 2|, and naturally the currents In connection with the arrangement of Fig. 3, however, it will be noted that the grids 4| and 43, while connected together, now connect by drawn by the plates or anodes 51 and 59 vof the tubes 25 and 21 willV then be represented as being proportional to the vector sums of the grid volt ages O~-20 and O--24, on the one hand, and 0_22 and 0_24 on the other hand, so that these may ¿be represented now by the vectors 0_25 and 0_28, respectively. way of a conductor 11 to an intermediate point 19 representing the junction of the serially con nected capacitor 8| and‘resistor 83, which to gether are connected in parallel with the trans Thus, the out puts `'from tubes 25 and 21 are equal for this con dition, and a balanced condition is obtained with no useful output at terminals 59 and 1|. Referring now more particularly to curve (b) of .Fig..2, it will be seen that a condition has been represented when the applied frequency has been raised in value, for instance, so that now the Vvoltages appearing at the control electrodes 31 and 39 will no longer be represented by vec l former secondary 29’. Y 60 In connection with the operation of the c_ir cuit shown by Fig. 3, reference will now be made to the vector analysis represented by the vectors of Fig. 4. Referring to Fig. 4, and ñrst topor tion (a) thereof, it will be seen that the vector O-44 represents the voltage applied to the grid electrodes 4| ~and 43 which are parallelly con nected and that -such voltage will be 90° out 'of phase with the voltages represented by the vec tors which are 90° out of phase with respect to tors O-40 and O--42, respectively, whenY the ap the voltage represented by the vector O--24 as 70 plied frequency is such that the capacitive re applied to the control electrodes or grids 4| and actance of the condenser 8| is equal to the resist 43, but, due to the characteristics of the resonant circuit consisting of the transformer secondary 29and» the capacitor 3|, a phase shift has oc curred so that the voltage applied to the QOntrol ance of the resistor 83. f I As `was above explained, the plate currents now ing from the tubes 25 and 21 are proportional to the vector sums of the grid voltages, that is, 2,411,605 _ for instance, thev grid voltageïOä-Mappearing on the grid 4| and the grid voltage 0*-40 appear two signal actuated-- controlîelectrodes, A»meansQfor » supplying vfrequency‘modulated signal energy in 180° -out-of-phase relationship to one control electrode element of each tube, means for sup ing on the grid- 31 of the tube 25 willf produce a plate current which is» proportional tothe vsui-ns of these voltages which can be represented by the . vector O-Mì, or likewise, the platecurrent flow ing through-the tube 21 on vconditions wher-ey the plying ’thev frequency modulated» signal energy cophasally upon a second control electrode ele ` ment of each tube with thesuppiied signal energy normally shifted 90° in phase relativeto the signal voltages on the grids 39 and 43 are 90° out of phase may be representedby the vector O--48. In this formand under these condi-tions, a 'bal' anced condition is obtained, Vas explained by ref-‘ erence to Fig. 2(a) . A , However, let it be supposed that- the applied energy supplied to the' first control` electrode ele iov ment of each tube, ' and' phase shifting means . comprising a serially connected capacity and re sistance element operative upon a shift inY the frequency of the suppliedv signal energy for al' tering the relativ-e vphase differences of the sig frequency is increased.` Then it can’be seen that the> voltage representedv by the vector O-M that l5 nal energy applied to the first and second con trol electrode elements of each tube to produce is applied toA the grids 4'! and 43 begins> to llag thereby output energy of varying magnitudes and occupies now a portion represented as Of---54 from each tube. _ as in vectorY series (li), but the voltageshereto 2. A detector circuit comprising a pair of mul fore represented as OL-ílil andI O=-`42 by the vec* tor series (a) occupy the vsame relative position ‘ tielectrode thermionic devices each havingV a plu rality of input and control circuits and a single and are now represented >by vector series (b) as 0_50 and O-52, respectively. Under such cir cumstances, it is apparent that the plate cur rents flowing from the tubes 25 and 21 are now no longer equal, but to the contrary, are unequal and are proportional now tothe vectors O>--56 and O»--58, with that represented by the vector Ote-58 being larger than O---56. for the degree of phase shift introduced by reason of thevolt ages applied to the grids `¿H and' d'3.' It therefore becomes apparent that when the audio frequency is either raised or lowered,`the plate currents from the tubes 25 and 21 become unequal, and that one plate current is increas ing while the other is decreasing. The result is that voltage drops are produced across the resis tors 65 and 61 which now become useful in pro output circuit, .means to supply frequency modu lated signalling voltages to one like input circuit of each of said devices with a phase variancev of 180° in the energy supplied to each ofV the said input circuits of the tubes, means to supply the frequency modulated signalling voltages to the second input circuits of the said tubes cophasally, means including a serially connected capacity and resistance element for supplying voltage to the last named input circuitsl of the tubesl with a 90° phase shiftA relative to the voltage sup plied to the first named input circuits for condi tions of equilibrium, means t0 produce phase var iances from the normal 90° phase 'difference be- tween the voltages applied to the said two input circuits of each of the tubes upon frequency changes in the supplied signalling voltages, and viding output variations. It, of course, might be an output circuit responsive to the said 90° phase apparent that the general arrangement of the shift variances in the voltages supplied to the iiff) condenser and resistor serially connected could said input circuits. be replaced by other reactive combinations in 3. A detector circuit comprising an energy order to provide the desired effects, and then transfer means having outer terminals whereat, suitable tuningsuch as shown, for instance, by upon excitation, Voltages are developed which Fig. 1 might be applied across the transformer . are out-of-phase with respect to each other, a secondary 29’ as there indicated also. center tap connection to the said energy trans While the invention has been described in such fer means, a series circuit connected in shunt a manner that one signal is placed upon one con with the said energy transfer means and between trol electrode and the other signal is placed upon the outer terminals thereof, said series circuit the other control electrode of each tube, it, of comprising a resistance and a capacity element 50 course, will be apparent that the input signals in of which the capacitive reactance of the condenser the normal 90° phase relationship may be ap is equal to the resistance of the resistor at a pre~ plied to either of the control electrodes where determined output frequency of the said energy the parameters or geometry of the tubes 25 and transfer means, an voutput connection at the 21, for instance, are such that either of the con junction point ofthe said resistance and con 55 trol grids 31 or lêl, on the one'hand, and 39 and denser elements whereby, for predetermined im 43 on the other hand are equally effective in con pressed frequency values on the said energy trans trolling the electron flow between the cathode ' fer means, a voltage is developed between the said and anode elements of thetube. Under such center tap connection and the output connection circumstances it is apparent Vthat one signal to the junction of the condenser and resistor 60 might be applied to one control electrode and which is 90° out-of-phase relative to each of the the other signal applied to the other control voltages developed between the said center tap electrode interchangeably, and consequently the connection and the outer terminals of said energy connections to each of the tubes might be dif transfer means and at other frequencies the said ferent but only so long as each control electrode 65 voltage developed between the said center tap is equally effective in its operation. Y connection and the junction of the said resistance Other modifications naturally will become ap Vand condenser shifts closer or farther away from parent and suggest themselves at once to those the said normally out-of-phase voltages at the skilled in the art in the light of the invention set outer terminal of the said energy transfer means. forth by the following claims. Y 4. A 'detector circuit including a pair of therm Having described the invention, what is claimed 70 ionic tubes each having an output electrode and 1s: at least two signal actuated control electrodes, 1. A circuit for detecting frequency modulated means for applying frequency modulated signal signal energy comprising a pair of thermionic ling voltage in 180° out-of-phase relationship to tubes each having an output electrode element like signal actuated control electrode elements of 75 connected to a common load circuit and at least I2,411,605 7 8 each of the said tubes, an electrical network com prising a series combination of a resistance ele -ment and a capacity element connected between said last named electrodes, said capacity and re sistance elements being of such size that at a pre determined frequency the capacitive reactance of the capacity element is equal to the resistance of the' resistance element, a connection to second like signal actuated control electrode elements of said tubes from the junction point of said capacity predetermined ~impressed frequency the signal voltages applied to the two said input circuits of and resistance elements whereby, at a normally predetermined impressed frequency, the signal voltages applied to the two said control electrodes of the said tubes are 90° out-of-phase relative to each-other, and at other frequencies the phase angle between the two said applied voltages in creases and decreases in proportion to changes in frequency. 5. A detector circuit including a pair of therm ionic tubes each having an output circuit and at least two signal actuated input circuits, means for applying frequency modulated signalling voltage in 180° out-of-phase relationship to like input circuits of each of the said tubes, an electrical net WOI‘k Comprising a series combination of a re the said tubes are 90° out-of-phase relative to each other, and at other frequencies the phase angle between the two said applied voltages in~ creases and decreases in proportion to changes in frequency and output voltages proportional to frequency changes are developed in the said out put circuits. ' 6. A detector circuit including a pair of therm ionic tubes each having an output electrode ele ment and at least two signal actuated control electrodes, input connections to apply normally 180° out-of-phase voltages to a first like control electrode element of each tube, a phase shifting network comprising a serially connected capacity element and a resistance element connected loe tween said first named like control electrode ele ments, a connection from each of the second like control electrode elements of each tube to the junction point of'said serially connected1 capac ity and resistance elements whereby, for condi tions When the resistance of the said resistance element is equal to the capacitive reactance of the capacity element, a voltage is applied to the second like control electrode elements which is 90° out-of phase relative to the first supply voltage and for other frequency values of impressed energy the relative phase difference varies substantially pro sistance element and a capacity element connected .in shunt with sai-d last named input circuit, said capacity and resistance elements being of such size that, at a, predetermined frequency, the ca pacitive reactance of the capacity element is equal 30 portionally, thereby to produce output energy to the resistance of the resistance element, a con from the two said output electrode elements which nection between the second like input circuit of is proportional to the change in frequency applied. said tubes and the junction point of said capacity and resistance elements, whereby at a, normally RICHARD C. WEBB.