US2121103A - Frequency variation response circuits - Google Patents

Frequency variation response circuits Download PDF

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US2121103A
US2121103A US45413A US4541335A US2121103A US 2121103 A US2121103 A US 2121103A US 45413 A US45413 A US 45413A US 4541335 A US4541335 A US 4541335A US 2121103 A US2121103 A US 2121103A
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frequency
circuit
circuits
tuned
potential
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US45413A
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Stuart W Seeley
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RCA Corp
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RCA Corp
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Priority to NL79628D priority Critical patent/NL79628B/xx
Application filed by RCA Corp filed Critical RCA Corp
Priority to US45413A priority patent/US2121103A/en
Priority to DER97596D priority patent/DE685380C/de
Priority to NL52037D priority patent/NL52037C/xx
Priority to GB28373/36A priority patent/GB489094A/en
Priority to DER99029A priority patent/DE706234C/de
Priority to US184926A priority patent/US2233751A/en
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • H03J7/02—Automatic frequency control
    • H03J7/04—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
    • H03J7/042—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant with reactance tube
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R25/00—Arrangements for measuring phase angle between a voltage and a current or between voltages or currents
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D3/00—Demodulation of angle-, frequency- or phase- modulated oscillations
    • H03D3/02—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal
    • H03D3/06—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal by combining signals additively or in product demodulators
    • H03D3/08—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal by combining signals additively or in product demodulators by means of diodes, e.g. Foster-Seeley discriminator

Definitions

  • My present invention relates to high frequency variation response circuits, and more particularly to frequency response networks of a type utilizing changes in phase relations of primary and secondary circuit' voltages which occur in coupled tuned circuits when the applied high frequency energy departs fromresonance with the tuned circuits.
  • each mistuned circuit of the discriminator network is connected to a rectifier, and as the applied frequency departs from resonance with the desiredoperating frequency, the center frequency of the mistuned circuits, either one or the other of the mistuned rectifiers becomes operative to derive a direct current from the applied signal energy.
  • Another important object of the present invention is to provide a method of, and apparatus for, obtaining differential direct current potentials, or currents, whose magnitude and polarity are determined by the amount and the sign, re-
  • An additional object of the invention is to provide a frequency discriminator network wherein tor sum potentials of the primary and secondary voltages may be realized, one maximizing above and one maximizing below the center frequency, which latter frequency is the common resonant frequency of the primary and secondary circuits, and rectifiers being utilized to rectify those sum voltages in such a manner that the resulting direct current voltages are added in opposition; thus the sum of the direct current voltages will be zero at resonance, and the sum will be some real value whose polarity will depend upon the sign of the frequency departure when the applied frequency departs from resonance.
  • Still other objects of the invention are to utilize the frequency variation response network of the present invention in the demodulator stage of a system adapted to receive amplitude-modulated, or frequency-modulated, carrier waves, and wherein the demodulator networks are not only adapted to produce voltages corresponding to the modulation voltages, but also produce direct current voltages to regulate the gain of carrier wave amplifiers, and the frequency of the local oscillator of the receiving system, when the latter is of the superheterodyne type.
  • Still ⁇ other objects of the invention are to improve generally the simplicity and efllciency of high frequency variation response networks, and more especially to provide such networks in a simple and economical manner which will not only be reliable in operation, but readily manu- I ment for analyzing the fundamental principle underlying the invention,
  • Fig. 2 illustrates a frequency discriminator network embodying a practical form of the inven tion
  • FIG. 3 graphically illustrates the mode of ation of the arrangement in Fig. 2,
  • Fig. 4 is a circuit diagram of a superheterodyne receiver embodying the invention.
  • Fig. 5 is a modification of the demodulator network of the receiver of Fig. 4 when employed to receive frequency-modulated carrier waves
  • Fig. 6 shows still another application of the present invention.
  • Fig. 1a circuit arrangement for analyzing, and visually indicating, the fundamental principle underlying the present invention.
  • the functioning of the present invention depends upon a predetermined phase relationship which exists between the potentials of coupled tuned circuits.
  • the action depends upon the fact that when a pair of resonant circuits are coupled, and each circuit is tuned to the same operating frequency, then a 90 phase difference exists between the potentials across the coupled circuits.
  • the phase angle between these potentials varies as the frequency of the energy applied to the coupled circuits departs from resonance therewith.
  • Fig. 1 there is shown a pair of coupled resonant circuits P and S; the circuit P is tuned to a desired frequency by shunt condenser I, while circuit S is tuned to the same frequency by condenser 2.
  • the high frequency waves which are to be applied to the double tuned network PS are derived from a source 3 of high frequency waves; and the source may be, for example, a signal generator capable of generating waves having a frequency of about 465 k. 0.
  • Such a source includes a device enabling it to be adjusted in frequency so that the frequency of the waves can be varied; and those skilled in the art are fully aware of such devices.
  • An amplifier 4 is ,used to amplify the waves from source I prior to impression upon circuit P.
  • the numeral 5 designates an oscilloscope of a well known type; the deflector plates being denoted by numeral 0, and the fluorescent screen thereof bearing numeral 1.
  • each of circuits P and S is tuned to a predetermined frequency of source 3, say 465 k. c., and waves of that frequency are impressed on amplifier 4 by source 3.
  • a circular pattern 8 will form on the screen 1. This circle was observed to increase, or decrease, in diameter as the amplitude of the waves from source 3 increased, or decreased, respectively. Again, as the frequency of the waves generated by source 8 varied, the shape of pattern 8 was observed to change. The dotted ellipse 8 denotes the appearance of the pattern shape when the frequency of the impressed waves is varied.
  • the degree of coupling between P and S determines whether or not the major axis of the ellipw will exceed the diameter of circle 8. Thus, if the coupling is adjusted to critical value, or over, the major axis will be greater as the applied frequency departs from resonance.
  • the shape of the pattern on the screen 1 is dependent on the phase relations of the voltages applied to plates 6 by circuits P and S. Changes in amplitude ofi, or on, resonance only varies the size of the pattern. Further, a change of impressed frequency of! resonance with circuits P and S will result in an appreciable change in the form of the pattern 8.
  • the oscilloscope 5 then, demonstrates in a visual manner the effect of the applied frequency on the phase relation between the potentials across P and S, and proves that for applied frequencies other than the resonant frequency of circuits PS the voltages across these two circuits are not in time quadrature.
  • the primary tuned circuit is designated by numeral III, and is connected in the plate circuit of an amplifier II.
  • a source I2 of high frequency waves is connected to impress such waves on the input electrodes of amplifier H.
  • the secondary tuned circuit I3 is resonated to the frequency of circuit III.
  • the high alternating potential side of circuit III is connected condenser IE to a center tap on" coll I l/of circuit 13, the coil M and coil 15 being magnetically coupled.
  • the condenser l6 merely 'servesto isolate the direct current plate potential (from source, 3) of the primary circuit, and 'its'reactance is, small enough tobe disregarded as far as the frequency of operation is concerned.
  • the ioutput load comprises resistors I 9 and 20, .of like magnitudal,connectedin-series between the cathodes of the diode 'rectifiers, a condenser 2
  • resistors 19 and 20 are connected to the centertap on the coil l4 through a radio frequency choke 22.
  • the dotted line curve in Fig.3 designates the difierence inscalor maginitrides-of' the potentials E; and E2, assuming the latter are rectified and added in oppositiong ItWill beobserved from 'Fig. 3 thatat 'th resonant f 'fiquer cy of the primary and s ecabove conditions. ,This does not mean thata larger. secondary with the same prlmary,or a different'valueot coupling, would not give a greater number of volts per cycle change in the primary plus one half the secondary sum, but in such event 5 the resultant itself wouldbegreater. Circuit, or other, requirements might necessitate an exceedingly low tuned primary impedance; in which case a much higher ratio would be in order.
  • Fig. 2 an embodiment of the present invention, .wherein there is obtained differential direct current potentials (or currents) whose magnitude and polarity are determined by the amount and the sign, respectively, of the difierencebetween an applied frequency and a certalnfflctitious frequency.
  • a measure of the sensitivit may he the developed direct current volts, or amperes per cycle of frequency deviation, per volt applied'to' the grid of the tube whose plate circuit contains the primary l5.
  • this quantity will bea tunet vtion of the rate of change, with frequency, of the dii ference between the magnitudes of the input potentialsto-the two detectors ll and -I8, or the slope of curve E1 E2,( l ig. 3).11 these magni- .tudesv are plotted against frequency .difi erence (both positive'and negative) the curves willln- 'tersect on the zero abscissa-ordinate with slopes equal but opposite in sign, as shown in Fig. 3.
  • the response network shown in Fig. 2 shows one specific manner for combining the direct current output potentials, or currents, of. the rectifiers I! and I 8 to produce the differential effect. It is to be clearly understood, however, that detectors of the plate rectification type may be used instead of the rectifiers -shown. In that case a differential winding would be placed between the two plates of the detector tubes; and the magnetic field of the differential winding will then be zero at resonance, and in opposite Thus, detected output currents would be addedv in opposition.
  • the response network of Fig. 2 is capable of many circuit applications.
  • the diodes l1 and i 8 need not be separate tubes, but may be disposed within a common tube envelope, as in the 6H6 type tube. Where the waves from source I 2 are modulated carrier frequencies, the condenser 2
  • the resistances of the series resistors l9 and 20 may be between 0.5 and 1.0 megohm, and it is further pointed out that the radio frequency choke coil 22 is optional. However, if this choke coil is used, then; is desirable that the condenser 23 be used. If the resonant, or center, frequency is applied to the grid of the amplifier tube H, the voltages E2 and E1 will be equal. These voltages are rectified by the diodes I1 and I8, and direct currents will flow into resistors 19 and 20 in opposite directions with respect to ground. Thus, the net direct current potential produced by the two voltage drops between the cathode side of resistor i9 and ground is equal to zero.
  • Fig. 4 illustrates one such use wherein a superheterodyne receiver utilizes the response network for a triple function.
  • the received signals are demodulated; automatic volume control (AVC) voltage is provided from the demodulated signals; and automatic local oscillator frequency control (AFC) voltage is also derived from the demodulated signals.
  • AVC automatic volume control
  • AFC automatic local oscillator frequency control
  • the receiver is of a conv the broadcast range of 550 to 1500 k. c.
  • the receiver may comprise the usual signal collector A followed by a tunable signal amplifier 30.
  • the amplified signals are fed to a first detector Ii which has a tunable input circuit 32, local oscillations being impressed on the detector II by a local oscillator.
  • the latter may be of any desired type; it is shown as comprising a triode 38, of the 6F7 type, which has a tunable circuit 34 connected between its control grid and cathode.
  • Direct current blocking condenser 35 is connected between the high alternating potential side of circuit 34 and the grid, while a grid leak resistor 30 is connected between the grid and cathode.
  • the rotors of the variable tuning condensers of the amplifier 30, first detector II and oscillator 33 are mechanically coupled for uni-control tuning adjustment.
  • the plate of tube 33 is reactively coupled, as at M, to the circuit N to produce local oscillations. Any well known method of transmitting the local oscillations to the mixer, or first detector, ll may be used. For example, the oscillations may be impressed upon the cathode of the detector 3
  • the plate circuit of the mixer tube includes circuit 31 which is tuned to the operating I. F., for example 465 k. c.
  • Any well known device may be electrically associated with the local oscillator to maintain the oscillator tuning tracking properly so as to keep the I F. value constant over the receiver tuning range. Such a device, for example, comprises condensers in series and shunt with the oscillator tuning condenser, and the condensers being properly chosen for the ,required function.
  • the I. F. energy in circuit 21 is amplified through amplifier 18 containing one, or more,
  • the input circuit 39 being coupled to circuit 31 and being tuned to the operatmg I. F.
  • the amplified I. F. energy is impressed upon the network including the two rectifiers.
  • This network is constructed substantially the same as that shown in Fig. 2. For this reason corresponding elements will be designated by the same numerals, but differentiated by prime notations.
  • the primary circuit I is tuned to the I. F. of 465 k. c., and is magnetically coupled to the secondary tuned circuit l3, tuned to the same I. F.
  • the high alternating potential side of the circuit I is connected through blocking condenser It to the midpoint of coil I4.
  • has a low impedance at the operating I. F., and in general it is desirable that it be low at useful modulating frequencies.
  • the junction of resistors l9 and is connected to ground through condenser 23', and the audio and AVC voltages are taken off at this point.
  • the junction point 40 is connected to the subsequent audio utilization network through an audio coupling reactance II.
  • the AVC voltage is impressed on the stages'whose gain is to be regulated by a lead l2.
  • the latter is connected to the signal grid circuits of the amplifier 3
  • Those skilled in the art are fully aware of the manner of operating of the AVG circuit; this acts to regulate the gain of the controlled tubes in a sense to maintain the carrier amplitude at the circuit i3 substantially uniform despite carrier amplitude variations at collector A.
  • the differential direct current potential for the AFC function is taken from the cathode side of resistor, 19'.
  • the lead 44 is connected, through filter "resistor sacrum t e cathode side" of'rfelsistor'lil' to thegrid 46 of 'thefreduency control tube 41, The latter maybe 'a 'pentode of thfe 6F? type and is"then”the"pentode section or the tube whose triode section is oscillator 33.
  • the plate isconn'ected by lead 50 to the high alternating" potentialside ofjclrcuit' 34.
  • Direct current potential of proper magnitude is supplied reshaping "from a positive potential source FB
  • Direct "current blocking condenser 5l' is connected 1nser1es'w1tnine' -cou 34" of circuit 34.
  • Tlie'ble'eder' 4 1"'i's connected between +3 and ground.
  • Theinitialfbias for grid' '46 is provided bythc bleder section 49"; high frequency by-pass condenser 50' being shunted across section 49.
  • the resistor 53 may have a magnitude'of the orderof20;000 ohms; and condenser iz may have a value of'0;0002"mfd.
  • the grid 46 of tube41 is connected to the junction of resistor 53 and condenser 52 through condenser 5'4.
  • the point 40 is a potent source'of "audio voltage to's'upply the following audio network (which may comprise one, or more st "ges oi audio amplification followed by a re- 'd1 i t :e'r)',' and no'other audio detector is necrect current voltage taken off between and ground has'the p'roperpolarity for U on. This'potential will bear the same ratio to the developed?
  • the connections between the plate circuit of tube 41 and oscillator-circuit aresuch that a negative capacity is reflectedjacro'ss (the oscillator circuit. p
  • the tube 41 produces a negative capacity effect on the oscillator circuit.
  • the magnitude of this negative capacity is, of course, a function of the mutual conductance of tube 41.
  • the receiver may be of a type using a combined oscillatornrst detector network in place of independent circuits. In such a case, a pentagrid converter tube is used, as is well known.
  • the frequency control circuit actuated by the AFC voltage may be replaced by other types of networks which will accomplish the desired results.
  • networks disclosed by C. Travis in application Serial No. 19,563, filed May 3, 1935 may be used.
  • a choke must be included in any external connection to the point 40.
  • the receiving system shown in Fig. 4 can be employed to receive frequency-modulated carrier waves. That is to say, the frequency variation response network shown embodied in the system of Fig. 4 can be utilized in connection with detecting frequency modulated waves.
  • Fig. 5 thereis only shown, in order to preserve simplicity of disclosure, the portion of the response network between the primary circuit i0 and the audio frequency network. It will be observed that the networks are substantially similar except for the following changes.
  • the condenser 2l' when receiving frequency modulated waves, is given a magnitude which is sufilciently small to by-pass energy of intermediate frequency, but is small enough not to shunt the audio frequency currents.
  • the condenser 23' is replaced by condenser 23", and the latter is connected in shunt with resistor is.
  • the audio voltage component of the recti- -In the case of a receiver of frequency-modulated waves the AFC network will be of particular advantage since it is especially desirable in such reception to keep the oscillator circuit resonant to that frequency which will result in the operating I. I". when a desired station is tuned in.
  • detection of the frequency-modulated waves is accomplished without the utilization of mistuned rectifier circuits, which are tuned to opposite sides of the operating carrier frequency, a method which has been employed heretofore.
  • the primary circuit I0 is tuned to the same carrier frequency as the secondary circuit ii. and the audio voltage at point 40' varies in polarity and magnitude in dependence upon the frequency departure corresponding to the modulation applied to the carrier wave.
  • Fig. 6 Another use for the frequency variation response network shown herein is illustrated in Fig. 6.
  • Conventional, and well understood, circuit networks are conventionally represented in the circuit arrangement of Fig. 8.
  • the numeral 00 represents the transmitter oscillator which may be considered as operating, for example, at 1000 k. e.
  • the usual monitoring oscillator operates at a frequency of 1,000.5 k. 0.
  • Fig. 6 designates any desired type of filter network which can pass energy of 500 cycles.
  • the 500 cycle energy is impressed upon the frequency response network which comprises the primary winding 03. which is coupled as shown to the secondary winding.
  • the primary and secondary windings may be of the iron core type, and are tuned to the 500' cycle frequency.
  • the diode rectifier I has its anode connected to the high potential side of the secondary winding, and the cathode of rectifier is connected to.the low potential side of the secondary winding through a scrim path which includes resistor 60, resistor 01 and the cathode to anode space current path of diode rectifier 00.
  • An alternating current by-pass condenser 00 is connected in shunt with resistors 60 and 01, and the visual indicating device 10 is connected in shunt -with condenser 00.
  • Condenser 0! prevents resistor 61 from being short circifited.
  • the condenser 03' could be placed, if desired, between ground and the low potential side of resistor 01.
  • the indicator [0 may be an ammeter which is properly calibrated to indicate departures as low as 0.1 cycle of! the 500 cycle input energy. It is possible to generate a voltage of 10 volts across the meter 10 to indicate a one cycle variation. It will be recognized that this indicating network is very sensitive, particularly at the frequency variations which are required in transmitter practice.
  • a primary resonant circuit connected to a source of high frequency waves, said circuit being tuned to a desired frequency
  • a secondary resonant circuit including a coil tuned to the same frequency, means for reactively coupling said circuits, means for connecting the high alternating potential side severalq te ewt rim r-z 91 1 m. #0 he m min n thetaor the secondary circuitj'means'foi 'rectuym g the notent mt. the w end of.
  • connections -between the primary" and sec ondary circuits ' such that two alternating currentf potentials of lilge polarity exist between the ends o f'the' secondary circuit and thelow poten ⁇ ua end of the primary, jdnef of isaid'potent'ials maximizing above f'the operatin frequency, and one maximizing below the latter, means'for rectify n' the antennas; mea s r 'a'fldit c th resulting" directjcurrent voltages in' Opposition, means for deriving fromsaid last-named means a'voltagecorresponding to the modulation of the received waves, and another voltage varying in magnitude with the waveamplitude.
  • a frequency response network comprising a primary circuit which is tuned to the saidcarrier' frequency, a secondary circuit in-' 'cluding "a coil tuned to the same carrier frequeney; saidjprimary and secondary circuitsbein'g reactiyely coupled, means for connecting the high alternating potential side of the primary circuit to" the mid-point of thesecondary' circuit coil whereby two' alternating current potentials of like polarity existfbetween the opposite sides of the secondary circuit and the low potential sides of' the primary circuit, one of said alternating potentials manimizin'g above said carrier frequency, i andthe other maximizing" below the latter fre-;
  • thelen e' ti e iniefinedia-ief 'r re'actiyely coupling s'aidcir fli's'ticiiuit being coupled-to tn l egp oipt of the s'econd respnant circuit "coil, means for rectifying the alternating potentialspf like, polarity atjthe twc ends of said second'jresonantcircuit with ,re-.
  • high frequency energy applied to the primary circuit departs from resonance with said coupled circuits, for varying the frequency of one of said sources in a sense to correct said departure.
  • a superheterodyne receiver adapted to receive frequency-modulated carrier waves, and which receiver includes, in addition to. a first detector, local oscillator network including a frequency determining element, intermediate frequency amplifier and audio frequency transmission network, a detection network comprising a primary circuit, tuned to the intermediate frequency, coupled to the output of the intermediate frequency amplifier, a secondary circuit, tuned to the intermediate frequency, reactively coupled to said primary circuit, a path of low impedance to the intermediate frequency energy connected between the high alternating potential side of said primary circuit and the mid-point of the secondary circuit, a diode rectifier having its anode connected to one side of said secondary circuit, a second diode rectifier having its anode connected to the other side of said secondary circuit, a resistive impedance connected in series between the cathodes of said two diodes, means for connecting the mid-point of said resistive impedance to said first named mid-point, an audio frequency transmission path connected to one side of said resistive impedance, the opposite side of said impedance being at
  • an electron discharge tube having its space current path connected in shunt across said tunable oscillation circuit, an electrode in the space current path of said last named tube connected to have said derived direct current voltage impressed on it, a reactive path, including a resistor in series with a condenser, connected in shunt with said space current path and said tunable oscillation circuit, and means for impressing the alternating current potential developed across said reactive path condenser upon the electrode disposed in said space current path whereby variation of the direct current voltage of said electrode will result in a variation of the effective reactance in said tunable oscillation circuit.
  • a second resonant circuit tuned to the same frequency, said circuits being reactively coupled, a source of waves coupled to the first circuit, a pair of diode rectrosers, one of the diodes having its anode connected to a point of high alternating potential on the second circuit, the other diode having its anode connected to a point of relatively low alternating potential on the second circuit, a resistive impedance connecting the cathodes of said diodes, means establishing a point of said second circuit intermediate said two points at the potential of the high alternating potential side of the first circuit, means esta an intermediate point of said impedance at said first intermediate point potential, and means for utilizing direct current voltage developed across said impedance by the rectification action of the diodes.
  • a second circuit tuned to the same frequency, said circuits being reactively coupled, a source of alternating current coupled to the first circuit, a pair of diode rectiflers, one of the diodes having its anode connected to a point of high alternating potential on the second circuit, the other diode having its anode connected to a point of relatively low alternating potential on the second circuit, a resistive impedance connecting the cathode: of said diodes, means establishing a point of said second circuit intermediate said two points at the potential of the high alternating potential side of the first circuit, means establishing an intermediate point of said impedance at said first intermediate point potential, and a visual current indicator means for utilizing direct current voltage developed across said impedance by the rectiiication action of the diodes.
  • a superheterodyne receiver of the type provided with a local oscillator having a tank circuit tuned to a desired frequency, a network utilizing oscillations from the oscillator and producing a beat frequency, a first resonant circuit tuned to the beat frequency, a second resonant circuit tuned to the same beat frequency, said beat circuits being reactively coupled, a pair of diode rectifiers, one of the diodes having its anode connected to a point of high alternating potential on the second circuit, the other diode having its anode connected to a point of relatively low alternating potential on the second circuit, a resistive impedance connecting the oathodes of said diodes, means establishing a point of said second circuit intermediate said two points at the potential of the high alternating potential side .of the first circuit, means establishing an intermediate point of said impedance at said first intermediate point potential, and means, responsive to the direct current voltage developed across said impedance by the rectification action of the diodes, for automatically a
  • a second circuit tuned to the same frequency, said circuits being reactively coupled, a source of intermediate frequency energy coupled to the first circuit, a pair of diode rectifiers, one of the diodes having its anode connected to a point of high alternating potential on the second circuit,the other diodes having its anode connected to a point of relatively low alternating potential on the second circuit, a resistor connecting the cathodes of said diodes, means including a condenser establishing a point of said second circuit intermediate said two points at the potential of the high alternating potential side of the first circuit, a condenser of low impedance to intermediate frequency current connected in shunt with said impedance, means establishing an intermediate point of said impedance at said first intermediate point potential, and means for utilizing direct current voltage developed across said impedance by the rectification action of the diodes.
  • a second resonant circuit tuned to the same frequency, said circuits being reactively coupled, a source of waves including an amplifier coupled to the first circuit, a pair of diode rectifiers, one of the diodes having its anode connected to apoint of high alternating potential on the second circuit, the other diode having its anode connected to a point of relati Iely low alternating potential on the second circuit, a pair of series resistors of equal value connecting the cathodes of said diodes, means establishing a point of said second circuit intermediate said two points at the potential of the high alternating potential side of the first circuit, means establishing the junction point of said resistors at said first intermediate point potential, and means for utilizing direct current voltage developed across said resistors by the rectification action of the diodes.
  • a second circuit tuned to the said frequency, said circuits being reactively coupled, a source of waves coupled to the first circuit, a pair of diode rectiflers, one of the diodes having its anode connected to a point of high alternating potential on the second circuit, the other diode having its anode connected to a point of relatively low alternating potential on the second circuit, a resistive impedance connecting the cathodes of said diodes,
  • a second resonant circuit tuned to the same frequency, said circuits being reactively coupled, a source of waves coupled to the first circuit, a pair of diode rectifiers, one of the diodes having its anode connected to a point of high alternating potential on the second circuit, the other diode having its anode connected to a point of relatively low alternating potential on the second circuit, a resistive impedance connecting the cathodes of said diodes, means establishing a point of said second circuit intermediate said two points at the potential of the high alternating potential side of the first circuit, means establishing an intermediate point of said impedance at said first intermediate point potential, means for utilizing direct current voltage developed across said impedance by the rectification action of the diodes, said last means comprising a network provided with a frequency determining circuit, and a direct current voltage connection being connected between one end of the impedance and said frequency determining circuit for frequency adjustment of the latter.
  • a second resocoupled to the first circuit a pair of diode rectifiers, one of the diodes having its anode connected to the high alternating potential side of the second circuit, the other diode having its anode connected tothe low alternating potential side of the second circuit, a resistor connecting the cathodes of saiddiodes, one end of the resistor being at ground potential, means establishing the mid-point of said second circuit at the potential of the high alternating potential side of the first circuit, means connecting the mid-point of said resistor to said first mid-point, and. a direct current voltage path connected to the ungrounded end of the resistor for utilizing direct current voltage developed across the resistor by the rectification action of the diodes.
US45413A 1935-10-17 1935-10-17 Frequency variation response circuits Expired - Lifetime US2121103A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
NL79628D NL79628B (xx) 1935-10-17
US45413A US2121103A (en) 1935-10-17 1935-10-17 Frequency variation response circuits
DER97596D DE685380C (de) 1935-10-17 1936-10-16 Einrichtung zur Umsetzung der Abweichung einer Frequenz einer Wechselspannung von einer Normalfrequenz in eine sie nach Graesse und Richtungssinn kennzeichnende Gleichspnung
NL52037D NL52037C (xx) 1935-10-17 1936-10-16
GB28373/36A GB489094A (en) 1935-10-17 1936-10-19 Improvements in or relating to superheterodyne wireless receivers
DER99029A DE706234C (de) 1935-10-17 1937-04-03 Empfaenger mit selbsttaetiger Scharfabstimmung
US184926A US2233751A (en) 1935-10-17 1938-01-14 Frequency variation indicator circuit

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US45413A US2121103A (en) 1935-10-17 1935-10-17 Frequency variation response circuits

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US2121103A true US2121103A (en) 1938-06-21

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US184926A Expired - Lifetime US2233751A (en) 1935-10-17 1938-01-14 Frequency variation indicator circuit

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DE (2) DE685380C (xx)
GB (1) GB489094A (xx)
NL (2) NL52037C (xx)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2425999A (en) * 1943-12-20 1947-08-19 Gen Electric Signal portraying apparatus
US2433361A (en) * 1940-01-20 1947-12-30 Submarine Signal Co Method and apparatus for echo ranging
US2444651A (en) * 1944-11-30 1948-07-06 Rca Corp Shaping circuit for cathode beam tubes
US2447098A (en) * 1943-06-28 1948-08-17 Stanolind Oil & Gas Co Signaling system
US2477570A (en) * 1945-01-05 1949-08-02 Russell A Berg Radio relay system
US2483314A (en) * 1941-08-16 1949-09-27 Hartford Nat Bank & Trust Co Superheterodyne receiver comprising automatic frequency control
US2495023A (en) * 1945-05-03 1950-01-17 Paul B Sebring Discriminator circuit
US2501368A (en) * 1944-03-25 1950-03-21 Emi Ltd Frequency stabilized relay for frequency-modulated oscillations
US2527523A (en) * 1944-08-11 1950-10-31 Farnsworth Res Corp Frequency control system
US2541067A (en) * 1944-11-30 1951-02-13 Sperry Corp Frequency responsive device
US2543256A (en) * 1948-05-20 1951-02-27 Rca Corp Diversity receiver for multiplex frequency shift tones
DE817926C (de) * 1949-01-27 1951-10-22 Philips Nv Frequenzmodulationsvorsatzgeraet fuer einen Rundfunkempfaenger
US2620439A (en) * 1947-11-05 1952-12-02 Gen Electric Noise balancing circuits
US2692947A (en) * 1951-05-11 1954-10-26 Sperry Corp Locator of inflection points of a response curve
DE1002817B (de) * 1954-10-05 1957-02-21 Gen Electric Phasendemodulator
US2904675A (en) * 1953-10-21 1959-09-15 Philips Corp Frequency demodulator
US8526817B2 (en) 2012-01-24 2013-09-03 Harris Corporation Communications device with discriminator for generating intermediate frequency signal and related methods
US8620158B2 (en) 2012-01-24 2013-12-31 Harris Corporation Communications device with discriminator and wavelength division multiplexing for generating intermediate frequency signal and related methods
US8879919B2 (en) 2011-09-09 2014-11-04 Harris Corporation Photonic communications device with an FM/PM discriminator and related methods
US9063067B1 (en) 2010-11-17 2015-06-23 Alvin P. Schmitt Moisture sensing devices

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE938386C (de) * 1941-04-01 1956-01-26 Heinz Fleck Dr Gleichrichter mit Gegenkopplung auf einen vorgeschalteten Verstaerker
DE943955C (de) * 1942-01-18 1956-06-07 Telefunken Gmbh Auf Frequenzaenderungen ansprechende Schaltungsanordnung
US2434914A (en) * 1942-04-21 1948-01-27 Standard Telephones Cables Ltd Frequency indicating cathode-ray oscilloscope
US2523341A (en) * 1943-11-02 1950-09-26 Int Standard Electric Corp Vibrating device
US2457136A (en) * 1943-12-08 1948-12-28 Int Standard Electric Corp Arrangement for frequency measurements
DE898036C (de) * 1944-01-04 1953-11-26 Svenska Aktiebolag Gasaccumula Vorrichtung zum Messen von Phasenwinkeln, beispielsweise fuer die Bestimmung einer Funkpeilrichtung
NL70931C (xx) * 1945-06-14
DE977658C (de) * 1945-09-07 1968-01-25 Rca Corp Detektor fuer phasenwinkelmodulierte Traegerfrequenzspannungen
US2648979A (en) * 1946-08-09 1953-08-18 Seismograph Service Corp Transducer testing apparatus
US2655036A (en) * 1947-10-01 1953-10-13 Gen Motors Corp Frequency modulated torsional vibration analyzer
NL82934C (xx) * 1949-05-13
US2613271A (en) * 1950-04-07 1952-10-07 Rca Corp Tuning indicator for frequency shift telegraphy
US2688726A (en) * 1951-01-11 1954-09-07 Northrop Aircraft Inc Phase-amplitude-frequency measuring system
DE921389C (de) * 1951-12-06 1954-12-16 Sueddeutsche Telefon App Umschaltbarer UEberlagerungsempfaenger fuer AM/FM-UEbertragungen
DE949242C (de) * 1952-03-16 1956-09-13 Blaupunkt Werke G M B H Zweign UEberlagerungsempfaenger fuer frequenzmodulierte Schwingungen mit automatischer Scharfeinstellung
BE532476A (xx) * 1953-10-12
US2835803A (en) * 1953-10-12 1958-05-20 Esther Marion Armstrong Linear detector for subcarrier frequency modulated waves
DE976553C (de) * 1954-10-28 1963-11-14 Telefunken Patent Empfaenger fuer Telegrafie-Nachrichten mit Frequenzumtastung
US3015776A (en) * 1957-02-09 1962-01-02 Sud Atlas Werke G M B H Indicating fluctuations in frequency and amplitude

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2433361A (en) * 1940-01-20 1947-12-30 Submarine Signal Co Method and apparatus for echo ranging
US2483314A (en) * 1941-08-16 1949-09-27 Hartford Nat Bank & Trust Co Superheterodyne receiver comprising automatic frequency control
US2483889A (en) * 1941-08-16 1949-10-04 Hartford Nat Bank & Trust Co Superheterodyne receiver with automatic frequency control
US2447098A (en) * 1943-06-28 1948-08-17 Stanolind Oil & Gas Co Signaling system
US2425999A (en) * 1943-12-20 1947-08-19 Gen Electric Signal portraying apparatus
US2501368A (en) * 1944-03-25 1950-03-21 Emi Ltd Frequency stabilized relay for frequency-modulated oscillations
US2527523A (en) * 1944-08-11 1950-10-31 Farnsworth Res Corp Frequency control system
US2541067A (en) * 1944-11-30 1951-02-13 Sperry Corp Frequency responsive device
US2444651A (en) * 1944-11-30 1948-07-06 Rca Corp Shaping circuit for cathode beam tubes
US2477570A (en) * 1945-01-05 1949-08-02 Russell A Berg Radio relay system
US2495023A (en) * 1945-05-03 1950-01-17 Paul B Sebring Discriminator circuit
US2620439A (en) * 1947-11-05 1952-12-02 Gen Electric Noise balancing circuits
US2543256A (en) * 1948-05-20 1951-02-27 Rca Corp Diversity receiver for multiplex frequency shift tones
DE817926C (de) * 1949-01-27 1951-10-22 Philips Nv Frequenzmodulationsvorsatzgeraet fuer einen Rundfunkempfaenger
US2692947A (en) * 1951-05-11 1954-10-26 Sperry Corp Locator of inflection points of a response curve
US2904675A (en) * 1953-10-21 1959-09-15 Philips Corp Frequency demodulator
DE1002817B (de) * 1954-10-05 1957-02-21 Gen Electric Phasendemodulator
US9063067B1 (en) 2010-11-17 2015-06-23 Alvin P. Schmitt Moisture sensing devices
US8879919B2 (en) 2011-09-09 2014-11-04 Harris Corporation Photonic communications device with an FM/PM discriminator and related methods
US8526817B2 (en) 2012-01-24 2013-09-03 Harris Corporation Communications device with discriminator for generating intermediate frequency signal and related methods
US8620158B2 (en) 2012-01-24 2013-12-31 Harris Corporation Communications device with discriminator and wavelength division multiplexing for generating intermediate frequency signal and related methods

Also Published As

Publication number Publication date
US2233751A (en) 1941-03-04
GB489094A (en) 1938-07-19
DE706234C (de) 1941-05-21
NL52037C (xx) 1942-03-16
NL79628B (xx)
DE685380C (de) 1939-12-16

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