US2441964A - Compensating circuit - Google Patents

Compensating circuit Download PDF

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Publication number
US2441964A
US2441964A US536302A US53630244A US2441964A US 2441964 A US2441964 A US 2441964A US 536302 A US536302 A US 536302A US 53630244 A US53630244 A US 53630244A US 2441964 A US2441964 A US 2441964A
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US
United States
Prior art keywords
voltage
circuit
source
resistor
oscillator
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
US536302A
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English (en)
Inventor
Donald D Grieg
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
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to US536302A priority Critical patent/US2441964A/en
Priority to GB13359/46A priority patent/GB611568A/en
Priority to FR930580D priority patent/FR930580A/fr
Priority to CH259967D priority patent/CH259967A/de
Priority to ES175485A priority patent/ES175485A1/es
Application granted granted Critical
Publication of US2441964A publication Critical patent/US2441964A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K7/00—Modulating pulses with a continuously-variable modulating signal
    • H03K7/08—Duration or width modulation ; Duty cycle modulation
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
    • G05F1/10—Regulating voltage or current
    • G05F1/46—Regulating voltage or current wherein the variable actually regulated by the final control device is dc
    • G05F1/52—Regulating voltage or current wherein the variable actually regulated by the final control device is dc using discharge tubes in series with the load as final control devices

Definitions

  • This invention relates to electrical circuits and more particularly to such circuits utilizing electron control tubes such as pulse modulator circuits. f
  • lIt is accordingly anobject of the present Yinvention t0 provide means for-compensating for the effect of supply voltage fluctuations in circuits including electron discharge devices.
  • Fig. 1 is a circuit diagram of one form of time modulator incorporating the principles of the present invention
  • Figs. 2A, 2B and 2C are curves usefulin explaining the operation of the circuit of Fig. l;
  • Fig. 3 is a circuit diagram of a modification of the f form of the invention illustrated in Fig. l.
  • Fig. 1 a source of unregulated voltdivider 2 through a connnection 5.
  • the output of the oscillator will vary in proportion to the value of the voltage supply, or, in other words, the voltage output of the oscillator 3 will vary linearly with respect to a variation in the voltage from source I.
  • a modulating circuit generally indicated at 6 is coupled to the oscillator 3 by means of trans- ⁇ former 'I having a primary coil 8 and two secondary coils 9 and I0.
  • the primary coil 8 of the transformer 'l forms part of the plate tank circuit of the oscillator 3.
  • the two secondary coils 9 and Il) have their outer terminals respectively connected to the grids II and I2 of two triodes I3 and I4, which as shown, may be enclosed in a common envelope.
  • the plate voltage for the anodes of triodes I3 and I4 is supplied from an adjustable tap I5 on voltage divider 2 over a common connection I6.
  • each of secondary windings 9 and I0 of transformer 'I are connected to the ends of the primary winding of an audio transformer Il.
  • the midpoint of this primary Winding is grounded.
  • the voltage for the speech circuit portion of the modulator 6, including microphone I8 and the secondary winding of transformer Il, is derived across voltage divider 2 by means of a third adjustable tap I9.
  • the biasing circuit includes a cathode resistor connected between the cathode 2! of tube I4 and ground,V
  • resistor 2&1 a further resistor 22 connected between the upper terminal of resistor 2&1 and the cathode 23 of triode I3.
  • a Kpair of conventional by-pass condensers 2li. and. zii respectively shunt, the resistor 2E! and 2,2- to ground.
  • V Resistors 2li and 22 are so chosen that the bias between grid l2 and cathodeZ'I oftriode Iii, on one hand, and thebia-s between Vgrid ⁇ Il and cathode 23 of triode I3, on the otherhand;willA be substantially equal on opposite sides of; the Vcut-ofpoint 2l' as indicated.v inrFig. 2A. Y
  • the wave produced by' oscillator 3' is applied through transformerI-to the twosecondary wind-V ings aand Hi.V This makes the outer-terminal of winding 9 180 out of phase with the outer Vterminal ofwindingI; Thus thewave-'of oscillatort, will be applied on grids; I-I; and I2 one inverted in phase with respect tothe other. 1
  • waves 2c and 29 areshown; for illustration purposesas triangular in shape, it; wi-,llbe understood, of course, that they will be sinusoidal from oscillator 3. Ii desired', the input waves may be made triangular by suitable-Shaper circuits.
  • the amplitude ofV the, wave output from oscillator 3- has decreased proportionally, tha-tris,A to Vtwo-thirds of itswforinervalue.
  • the projection of waves 28a, 29a against the new operating curve is similar in the output curve of Fig. 2A as-was j the spacing of the corresponding points along the axis 3ft.
  • a suitable clipping and differentiating circuit can be provided in the output ofl modulator so that'the peaks at points Sii; 3l, 32 and 33 will be transformed into a train of pulses havingl the spacing representedby suchpoints.
  • sinusoidal waves are used at the input, the peaks are in the form of ⁇ cusps which when clipped provide sharp pulses;
  • Points 3&3, 3i, 3Z'Vand3g31wl1 assume new positions 36a, 3io, 32u and 33a; the amplitude ofV waves a'will be decreasedV considerably from its input value, and wave 2go will not be passed toany degree.
  • the time displacement of points Sila, Ela, 32a and33a will varygconsiderably with respect to the-original spacingas shown in'Fig.' 2A.
  • the outputofthe modulator 6 will be distorted' to a very considerable degree so as to reduce the delity of transmission.
  • Fig. 2C Retains the newoperating curve 36 ci Fig. 2B, but the biases on triodes i3 andY I have each dropped one-thirdinvalue, 'and' have shifted to new position- 35u-and-v 31'611. It'should be emphasized that the change in the value of biasesu, 35a is proportional tothe'voltage fluctuation in source lila, and consequently tothe change in current in the plate circuit.
  • Fig.r2C also illustrates theeffect of projecting-the"reduced amplitude waves 23a. ⁇ and 29d-Y symmetrically disposed on Ytheir new biases 34a and 35a. respectively, against the new operating curve 36. It will be seen that while the amplitude ci the resulting output sig- V nalis reduced the pointsof intersection of output Theaudio modulating 4circuit including microphone i8, land trai'isforrner i?
  • Condensers 24 and 25 should be large enough to smooth pulsations in the cathode circuit across resistors 29 and 22.
  • the audio modulation through transformer l1 will vary proportionally to the amplitude of the base wave from oscillator 3.
  • the relative modulation of the base wave by the audio wave will remain constant regardles-s of variation in voltage from source I.
  • Fig. 3 illustrates a modification of Fig. l ein# ploying an additional resistor 37 connected between junction point 38 on lead I6 and the top terminal of resistor 22.
  • This additional resistor 31 is of a high value, and acts to produce the desired bias voltage across resistors 2li and 22 independently of the operating conditions of tri ⁇ odes I3, I4.,
  • This modication of Fig. 3 maintains a constant D. C. potential across resistors 20, 22 regardless of the A. C. current through triodes I3 and I4.
  • a separate load resistor 39 is preferably employed between the output of the triodes and connection point 38.
  • a biasing arrangement for producing an initial differential bias on the two devices and While maintaining said ⁇ differential Varying the mean bias of said devices to compensate for variation in the Voltage of said source comprising a first biasing resistor connected in series between the cathode of one of said electron discharge devices and the negative -side of said source of potential, and a second biasing resistor connected at one end in series with said first resistor to the negative side of said source oi potential and at its other end to the cathode of the other of said electron discharge devices.
  • a time modulation system further including an arrangement for translating mechanical signals into electrical signals, means for coupling said arrangement in pushpull to the grids of said electron discharge devices, and a circuit for supplying said arrangement with potential from said source of potential.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Automation & Control Theory (AREA)
  • Amplifiers (AREA)
US536302A 1944-05-19 1944-05-19 Compensating circuit Expired - Lifetime US2441964A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US536302A US2441964A (en) 1944-05-19 1944-05-19 Compensating circuit
GB13359/46A GB611568A (en) 1944-05-19 1946-05-02 Improvements in or relating to electric pulse time modulators
FR930580D FR930580A (fr) 1944-05-19 1946-07-12 Perfectionnements aux circuits électriques compensateurs
CH259967D CH259967A (de) 1944-05-19 1946-09-24 Anordnung zur Erzeugung von elektrischen Impulsen, bei welcher der Einfluss von Speisespannungsschwankungen auf die Abstände der Impulse mindestens angenähert kompensiert ist.
ES175485A ES175485A1 (es) 1944-05-19 1946-10-26 Mejoras en sistemas de circuitos de compensación

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US536302A US2441964A (en) 1944-05-19 1944-05-19 Compensating circuit

Publications (1)

Publication Number Publication Date
US2441964A true US2441964A (en) 1948-05-25

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
US536302A Expired - Lifetime US2441964A (en) 1944-05-19 1944-05-19 Compensating circuit

Country Status (5)

Country Link
US (1) US2441964A (fr)
CH (1) CH259967A (fr)
ES (1) ES175485A1 (fr)
FR (1) FR930580A (fr)
GB (1) GB611568A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2888849A (en) * 1955-09-14 1959-06-02 Humphrey Electronic musical instruments
US2975366A (en) * 1946-03-27 1961-03-14 Donald R Young Pulse width discriminator

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1541311A (en) * 1923-02-07 1925-06-09 Western Electric Co Vacuum-tube circuits
US1789364A (en) * 1925-11-28 1931-01-20 Rca Corp Method and means for combining and for eliminating frequencies
US1996378A (en) * 1931-12-21 1935-04-02 Charles J Hirsch Hum elimination
US2009070A (en) * 1931-11-28 1935-07-23 Telefunken Gmbh Power supply means for vacuum tubes
US2037267A (en) * 1928-07-04 1936-04-14 Telefunken Gmbh Power supply network for thermionic tubes
US2039113A (en) * 1931-12-01 1936-04-28 Telefunken Gmbh Amplifier circuits
US2078245A (en) * 1933-06-19 1937-04-27 Telefunken Gmbh Modulation and frequency stabilization
GB468959A (en) * 1935-01-15 1937-07-15 Fernseh Ag Improvements in or relating to methods of modulating carrier waves
US2174154A (en) * 1936-05-06 1939-09-26 Rca Corp Ultra high frequency transmitter
US2184571A (en) * 1938-05-27 1939-12-26 Rca Corp Modulation system
US2185874A (en) * 1935-08-12 1940-01-02 Telefunken Gmbh Arrangement for amplitude modulation
US2223430A (en) * 1938-01-25 1940-12-03 Rca Corp Modulation system

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1541311A (en) * 1923-02-07 1925-06-09 Western Electric Co Vacuum-tube circuits
US1789364A (en) * 1925-11-28 1931-01-20 Rca Corp Method and means for combining and for eliminating frequencies
US2037267A (en) * 1928-07-04 1936-04-14 Telefunken Gmbh Power supply network for thermionic tubes
US2009070A (en) * 1931-11-28 1935-07-23 Telefunken Gmbh Power supply means for vacuum tubes
US2039113A (en) * 1931-12-01 1936-04-28 Telefunken Gmbh Amplifier circuits
US1996378A (en) * 1931-12-21 1935-04-02 Charles J Hirsch Hum elimination
US2078245A (en) * 1933-06-19 1937-04-27 Telefunken Gmbh Modulation and frequency stabilization
GB468959A (en) * 1935-01-15 1937-07-15 Fernseh Ag Improvements in or relating to methods of modulating carrier waves
US2185874A (en) * 1935-08-12 1940-01-02 Telefunken Gmbh Arrangement for amplitude modulation
US2174154A (en) * 1936-05-06 1939-09-26 Rca Corp Ultra high frequency transmitter
US2223430A (en) * 1938-01-25 1940-12-03 Rca Corp Modulation system
US2184571A (en) * 1938-05-27 1939-12-26 Rca Corp Modulation system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2975366A (en) * 1946-03-27 1961-03-14 Donald R Young Pulse width discriminator
US2888849A (en) * 1955-09-14 1959-06-02 Humphrey Electronic musical instruments

Also Published As

Publication number Publication date
ES175485A1 (es) 1946-12-01
CH259967A (de) 1949-02-15
FR930580A (fr) 1948-01-29
GB611568A (en) 1948-11-01

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