GB1320451A - Linear analogue to frequency converter - Google Patents

Linear analogue to frequency converter

Info

Publication number
GB1320451A
GB1320451A GB1320451DA GB1320451A GB 1320451 A GB1320451 A GB 1320451A GB 1320451D A GB1320451D A GB 1320451DA GB 1320451 A GB1320451 A GB 1320451A
Authority
GB
United Kingdom
Prior art keywords
bridge
frequency
impedance
oscillator
measuring
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
Application number
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.)
Cheeseman K A
Original Assignee
Cheeseman K A
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 Cheeseman K A filed Critical Cheeseman K A
Publication of GB1320451A publication Critical patent/GB1320451A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03C—MODULATION
    • H03C3/00—Angle modulation
    • H03C3/36—Angle modulation by means of light-sensitive element
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/18—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using conversion of DC into AC, e.g. with choppers
    • 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
    • H03B5/26—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 frequency-determining element being part of bridge circuit in closed ring around which signal is transmitted; frequency-determining element being connected via a bridge circuit to such a closed ring, e.g. Wien-Bridge oscillator, parallel-T oscillator
    • 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
    • H03C3/26—Angle modulation by means of variable impedance by means of a variable resistive element, e.g. tube comprising two elements controlled in push-pull by modulating signal

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Temperature Or Quantity Of Heat (AREA)
  • Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)

Abstract

1320451 Impedance measuring bridge: measuring non-electric variables K A CHEESEMAN 22 Dec 1971 [27 Jan 1971] 3284/71 Headings G1N and G1U The out-of-balance signal from a bridge 1, 2, 3, 4 which includes at least one frequency dependent impedance, is rectified and amplified 8 and used to adjust the frequency of a Wien bridge oscillator 9 providing a constant amplitude supply to bridge, whereby if an unknown impedance is connected either across one arm or in series with one arm of the bridge the frequency of the oscillator when balance is attained will be proportional to the unknown impedance. As shown the circuit includes a linearizing circuit 5, and the frequency of the Wien bridge oscillator is determined by photo-cells 14, 15, and a lamp 16. However, mechanically switched resistors, or capacitors or thermistors could also be used. The unknown impedance may be resistive, e.g. a thermistor for measuring temperature which would be connected in series with bridge resistor 3, or capacitive e.g. from a displacement or liquid level transducer which would be connected across the bridge capacitor 4.
GB1320451D 1971-01-27 1971-01-27 Linear analogue to frequency converter Expired GB1320451A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB328471 1971-01-27

Publications (1)

Publication Number Publication Date
GB1320451A true GB1320451A (en) 1973-06-13

Family

ID=9755436

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1320451D Expired GB1320451A (en) 1971-01-27 1971-01-27 Linear analogue to frequency converter

Country Status (1)

Country Link
GB (1) GB1320451A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4472968A (en) * 1981-11-11 1984-09-25 Smiths Industries Public Limited Company Capacitive fluid-gauging probes and systems

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4472968A (en) * 1981-11-11 1984-09-25 Smiths Industries Public Limited Company Capacitive fluid-gauging probes and systems

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Legal Events

Date Code Title Description
PS Patent sealed
PLNP Patent lapsed through nonpayment of renewal fees