US2492184A - Polyphase oscillator - Google Patents

Polyphase oscillator Download PDF

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Publication number
US2492184A
US2492184A US613979A US61397945A US2492184A US 2492184 A US2492184 A US 2492184A US 613979 A US613979 A US 613979A US 61397945 A US61397945 A US 61397945A US 2492184 A US2492184 A US 2492184A
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US
United States
Prior art keywords
tube
grid
control
tubes
frequency
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US613979A
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English (en)
Inventor
George T Royden
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STC PLC
Federal Telephone and Radio Corp
Original Assignee
Standard Telephone and Cables PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to BE470920D priority Critical patent/BE470920A/xx
Priority to NL66753D priority patent/NL66753C/xx
Priority to US249184D priority patent/USB249184I5/en
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to US613979A priority patent/US2492184A/en
Priority to GB5134/47A priority patent/GB627630A/en
Priority to ES0178724A priority patent/ES178724A1/es
Application granted granted Critical
Publication of US2492184A publication Critical patent/US2492184A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B5/00—Generation of oscillations using amplifier with regenerative feedback from output to input
    • H03B5/20—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising resistance and either capacitance or inductance, e.g. phase-shift oscillator
    • H03B5/22—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising resistance and either capacitance or inductance, e.g. phase-shift oscillator active element in amplifier being vacuum tube
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03C—MODULATION
    • H03C3/00—Angle modulation
    • H03C3/02—Details
    • H03C3/09—Modifications of modulator for regulating the mean frequency
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03C—MODULATION
    • H03C3/00—Angle modulation
    • H03C3/10—Angle modulation by means of variable impedance
    • H03C3/24—Angle modulation by means of variable impedance by means of a variable resistive element, e.g. tube

Definitions

  • This invention relates to the generation of polyphase e1ectric-power,-.and more-in particular to a polyphase oscillation generating system wherein the frequency of oscillation maybe varied as desired.
  • An object of this invention is to provide a polyphase oscillator whose frequency -may be varied as desired in a dependable and efiicient manner.
  • a further object'is to provide such a system which is.;adaptable for use, for example, in-a frequency modulation system where the center frequency may-becontrolled for monitoring purposes.
  • Theinventionv accordingly consists in the teaturesiof construct-ion, combinations of elements, arrangements of parts .and i in the several steps and relation-and orderof each of the same to one or more of the others, all as will be illustrativelydescribed-herein, and the scope of the application of which will be. indicated in the following claims.
  • Figure 1 is a-simplified circuit diagram showing one embodiment of the invention.
  • Figure 2 is similar toF-igure -1, but shows another embodiment ofthe invention.
  • a polyphase oscillator whose frequency may be variedprecisely as desired in response to some control effect.
  • polyphase oscillation may be utilized advantageously in certain frequency-modulated radio equipment.
  • a polyphase source of electric power is provided wherein the frequency is'varie'd by electronic means to permit such a rapid response.
  • a-three-phase system in which inherently the phase angle between the phases is maintainedconstant and the frequency is varied bythesimple procedure of changing a control potential applied to a plurality of electronic devices. This is achieved by changing the impedance of. certain elements of agroup of phase shift circuits whereby the frequency of oscillais inherent-in this. circuit.
  • a three-,phasecircuit shown in simplified 'for-m wherein.thefilament andplate supply circuits for the .various tubes. .are omitted, and wherein :a ⁇ three-phase radio-lfrequency .power outputis -surnpliedath, B,land-IC. .This circuit.
  • .Resistors 34,42 and 50 are..connected to the positive side of ,a. suitable source ofhighpotentialdirect current, the negative.side...of whichis connected to cathodes 38, J46 and .54 through ground.
  • Grids 31, 4.5 and 453 .of the control .tubes 36, .44 g and -52 are connected together andito. one terminal .55 .of a .suitable control potentiaLEm, .the other terminal 56 of which is connected to ground and thence to cathodes 38, 46 and 54.
  • each of the oscillator tubes I, 2 and 3 is connected to provide one of the three phases of the polyphase output and each tube exerts a control influence upon the tube of the next phase so that the three phases are held in their exact 120 relationship.
  • the control effect by each tube upon the tube of the next phase is exerted through an interstage phase shift circuit, there being three such circuits which are identical in components, characteristics and operation.
  • the phase shift circuit by which tube I controls tube 2 is formed by capacitance and resistance connected in series, the capacitance being supplied by a condenser l6 and there being a series resistance circuit to ground formed in part by resistors 25 and 26.
  • the remainder of the resistance circuit is formed by two additional connections to ground which are from juncture 3
  • grid 8 is connected to ground through resistor 25 to juncture 3
  • control tube 36 may be considered as an equivalent fixed resistor, the value of which is equal to the internal impedance of the tube, so that in fact resistors 25, 2B and 34 and control tube 36 may be considered as being a single resistor which connects grid 8 to ground and which forms the resistance component of the phase shift circuit.
  • the value of this single resistance component is such with respect to condenser [6 that at the normal frequency of operation there is a 60 phase shift on grid 8 with respect to plate ID. This 60 phase shift between plate In and grid 8 combines with the 180 phase shift produced in the vacuum tube 2 between grid 8 and plate II to produce the net phase shift desired between the two tubes.
  • the 60 phase shift is subtractive with respect to the 180 phase shift of the tube, and thus there is a net phase shift of 120, but if the 60 phase shift is considered as additive with respect to the 180 phase shift of the tube, the net phase shift is 240; and with either the additive or subtractive relationship the desired net effect is obtained.
  • oscillator tube 2 controls oscillator tube 3
  • oscillator tube 3 controls oscillator tube I.
  • plate II of tube 2 is connected to grid 9 of tube 3 through an interstage phase shift circuit formed by condenser I1, resistors 21, 28 and 42 and control tube 44; and, plate I2 of oscillator tube 3 is connected to grid 1 of oscillator tube I through an interstage phase shift circuit formed by condenser I8, resistors 23, 30 and 50 and control tube 52.
  • Each of these two phase shift circuits operates the same as the circuit connecting plate I and grid 8, and, during operation, each phase maintains the next phase in its proper relationship, and any tendency for one phase to deviate from this relationship is automatically corrected.
  • Control tubes 36, 44 and 52 have been considered as having a normal grid bias on their grids so that they act as fixed resistors. However, when there is a control signal at Em, the grid bias of each of these grids is changed with the result that the internal impedance or equivalent resistance of each of the control tubes is changed. Thus, for example, a change in the grid bias of grid 31 changes the equivalent resistance of control tube 36 and thus changes the effective resistance connecting grid 8 of oscillator tube 2 to ground. This tends to cause a change in the phase shift produced by this phase shift circuit because the phase shift depends upon the relative values of the capacitance of condenser I6 and the effective resistance connecting grid 8 to ground.
  • the three oscillator tubes I, 2 and 3 control each other, and, therefore, the phase shift relationship between phases does not change, but rather the frequency of oscillation changes in such a manner as to maintain the desired fixed phase shift relationship between phases.
  • the simple action of changing the grid bias of control tubes 36, 46 and 52 changes the frequency of oscillation of the oscillator system. For example, if the control signal Em increases, the impedances of tubes 36, 46 and 52 decrease; then a higher frequency is necessary in order to maintain the phase shift at the oscillator tube grids and the circuit therefore oscillates at this higher frequency. Conversely, a reduction in the control signal Em causes a reduction in the oscillating frequency.
  • the components of the circuit are such as to permit operation within the frequency range desired so that a dependable source of polyphase oscillation is provided.
  • more than three phases may be provided by adding additional oscillator tubes and interstage phase shift coupling circuits, it being understood that due consideration must be given to obtaining trolled in accordance with a control signal Em,
  • This second control infiuence may be for monitoring purposes so that the normal frequency of oscillation is regulated by a direct current voltage and then the control signal Em exerts a frequency modulating effect to make the system oscillate at frequencies above and below the normal frequency.
  • Oscillator tubes 51, 58 and 59 correspond to tubes I, 2 and 3, respectively, and in addition to the elements of tubes I, 2 and 3 (which are correspondingly numbered), tubes 51, 58 and 59 are provided with screen grids 30, 6
  • Grid 63 of tube 51 is connected to the juncture 69 of a condenser 10 and a resistor 1
  • Juncture .69. is also connected to the positive side of w-batterwlfi tiie riegative side of which..- is: connected; toeanode 61*.
  • grid 64 of tube 58 is connectedeatytheejuncturer 13 to one sideofa groundedcondenser I4, 2.
  • the monitoring control referred to above is provided by effecting a change in the basic effective resistances of the three interstage phase shift circuits. Accordingly, resistors 34, 42 and 58 are replaced by three monitor control vacuum tubes BI, 82 and 83. These tubes have, respectively, plates 84, 85 and 86, grids 81, 88 and 89 and cathodes 98, 9
  • Grids 81, 88 and 89 are connected together and to the plate 93 of a vacuum tube 94 which has a cathode 95, a, control grid 96 and grids 91 and 98.
  • Plate 93 is connected to the juncture 99 between a pair of voltage divider resistors I88 and ml, which are connected in series and form a voltage divider between the positive terminal and the grounded negative terminal of a source of direct current.
  • Grid 99 is connected to the juncture I82 of a condenser I83 (the other side of which is grounded) and a resistor I84 which has its other side connected to the positive side of a source of direct current, the negative side of which is grounded.
  • Control grid 96 is connected to one terminal I85 of a monitor control potential Ec, the other terminal I86 of which is connected to the grounded cathode 95.
  • potential Ec is a direct current potential, and its value controls the current flow through tube 94.
  • tubes lfl 82 and 83 i$ireadilyrcohtroll% I
  • possibltembbdinients maye situtad' the mechanical featuresiiofstiieaabove invention a and; as the artshereinzdescribedniiightibe: variedt in: various -partsaall without departing .fromithee scope of the inventionait'isiztoirbei un'derstood:thati alt n iatte'r hereinabove -se forth; on showrriirttlie accompanyingdrawing oebe interpreted?
  • each of said amplifier stages is represented by a vacuum tube having a cathode, a plate and a plurality of grids, further comprising means for limiting the amplitude of oscillations generated by the system, said last means including a diode anode placed in each of said tubes adjacent the cathode thereof, an impedance connected to each cathode whereby the cathode potential will vary with the current through the tube, means for biasing said diode anode to a potential more negative than that of the associated cathode except upon occurrence of amplitudes above a predetermined limit, a condenser shunting said diode anode, said cathode and said impedance, and means connecting said diode anode to one of the grids of one of said tubes.
  • each stage comprises a pentode tube and wherein the diode anode of each stage is connected to the screen grid of the preceding stage.
  • a polyphase oscillation generating system comprising a plurality of amplifier stages, a plurality of non-resonant phase shifting networks cyclically interconnecting said stages and composed of capacitive and resistive impedance means, the resistive impedance means of each of said networks including a pair of triodes, means connecting the plate of one triode of each pair to the cathode of the other triode, a condenser forming part of said capacitive impedance means connected to said plate and said cathode, a source of space current connected across said two triodes in series, means for grounding the cathode of said one triode at least for the frequencies in the operating range of the system, means for applying a signal potential to the grid of said one triode whereby the operating frequency of the system may be modulated, and means for applying a control potential to the grid of said other triode whereby the mean operating frequency of the system may be varied.
  • each of said amplifier stages is represented by a vacuum tube havin a cathode, a control grid, a screen grid and a plate, the plate of each stage being coupled to the control grid of a succeeding stage over a respective one, of said phase shifting 15 networks, further comprising means for limiting the amplitude of oscillations generated by the system, said last means including a diode anode placed in each of said tubes adjacent th oathode thereof, a resistor connected between each cathode and ground, means for biasing said diode anode to a potential more negative than that of the associated cathode except upon occurrence of amplitudes above a predetermined limit, a condenser shunting said diode anode, cathode and cathode resistor, and means connecting the diode anode of each stage to the screen grid of the preceding stage.

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  • Amplifiers (AREA)
  • Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
  • Particle Accelerators (AREA)
US613979A 1945-09-01 1945-09-01 Polyphase oscillator Expired - Lifetime US2492184A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
BE470920D BE470920A (de) 1945-09-01
NL66753D NL66753C (de) 1945-09-01
US249184D USB249184I5 (de) 1945-09-01
US613979A US2492184A (en) 1945-09-01 1945-09-01 Polyphase oscillator
GB5134/47A GB627630A (en) 1945-09-01 1947-02-21 Polyphase frequency modulators
ES0178724A ES178724A1 (es) 1945-09-01 1947-07-02 Mejoras en sistemas generadores de oscilaciones

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US613979A US2492184A (en) 1945-09-01 1945-09-01 Polyphase oscillator

Publications (1)

Publication Number Publication Date
US2492184A true US2492184A (en) 1949-12-27

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US249184D Pending USB249184I5 (de) 1945-09-01
US613979A Expired - Lifetime US2492184A (en) 1945-09-01 1945-09-01 Polyphase oscillator

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US249184D Pending USB249184I5 (de) 1945-09-01

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US (2) US2492184A (de)
BE (1) BE470920A (de)
ES (1) ES178724A1 (de)
GB (1) GB627630A (de)
NL (1) NL66753C (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2633534A (en) * 1950-02-01 1953-03-31 Bell Telephone Labor Inc Variable frequency oscillator
US2675523A (en) * 1950-10-20 1954-04-13 Fisk Bert Phase modulation keyer
US2714697A (en) * 1953-04-02 1955-08-02 Donald C Small 3-phase, rc, variable voltage, variable frequency oscillator for electric motor
US2971165A (en) * 1958-09-12 1961-02-07 Genisco Inc Multi-phase oscillator with amplitude stabilizing means
US3141139A (en) * 1961-12-26 1964-07-14 Bell Telephone Labor Inc Direct-coupled transistor oscillator having variable source impedance for controlling frequency
US3831112A (en) * 1972-12-27 1974-08-20 Proximity Devices Voltage controlled sweep oscillator
US3918008A (en) * 1972-12-27 1975-11-04 Proximity Devices Voltage controlled sweep oscillator

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1745559A (en) * 1924-12-01 1930-02-04 Schrack Eduard Electron-discharge-tube generator
US1972535A (en) * 1930-05-14 1934-09-04 Robert M Page Polyphase relaxation circuit oscillator
US2024489A (en) * 1932-01-08 1935-12-17 Rca Corp Circuit arrangement for generating or amplifying electric oscillations
US2055090A (en) * 1933-02-23 1936-09-22 Rca Corp Electrical oscillation generator
US2236985A (en) * 1939-10-28 1941-04-01 Gen Electric Oscillator
US2321269A (en) * 1941-11-21 1943-06-08 Rca Corp Frequency modulation
US2373437A (en) * 1940-02-15 1945-04-10 Emi Ltd Twin-discharge tube oscillator

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1745559A (en) * 1924-12-01 1930-02-04 Schrack Eduard Electron-discharge-tube generator
US1972535A (en) * 1930-05-14 1934-09-04 Robert M Page Polyphase relaxation circuit oscillator
US2024489A (en) * 1932-01-08 1935-12-17 Rca Corp Circuit arrangement for generating or amplifying electric oscillations
US2055090A (en) * 1933-02-23 1936-09-22 Rca Corp Electrical oscillation generator
US2236985A (en) * 1939-10-28 1941-04-01 Gen Electric Oscillator
US2373437A (en) * 1940-02-15 1945-04-10 Emi Ltd Twin-discharge tube oscillator
US2321269A (en) * 1941-11-21 1943-06-08 Rca Corp Frequency modulation

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2633534A (en) * 1950-02-01 1953-03-31 Bell Telephone Labor Inc Variable frequency oscillator
US2675523A (en) * 1950-10-20 1954-04-13 Fisk Bert Phase modulation keyer
US2714697A (en) * 1953-04-02 1955-08-02 Donald C Small 3-phase, rc, variable voltage, variable frequency oscillator for electric motor
US2971165A (en) * 1958-09-12 1961-02-07 Genisco Inc Multi-phase oscillator with amplitude stabilizing means
US3141139A (en) * 1961-12-26 1964-07-14 Bell Telephone Labor Inc Direct-coupled transistor oscillator having variable source impedance for controlling frequency
US3831112A (en) * 1972-12-27 1974-08-20 Proximity Devices Voltage controlled sweep oscillator
US3918008A (en) * 1972-12-27 1975-11-04 Proximity Devices Voltage controlled sweep oscillator

Also Published As

Publication number Publication date
ES178724A1 (es) 1947-09-01
USB249184I5 (de)
BE470920A (de)
NL66753C (de)
GB627630A (en) 1949-08-12

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