US3683344A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Displacement-electric signal converter
Assignee: Yokogawa Electric Corp
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Filing: 1970-07-14
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Granted: 1972-08-08
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Expires: 1990-07-14
Abstract
Abstract A displacement-electric signal converter having a pair of displacement detecting elements the impedances of which vary in accordance with a displacement, a rectifier including a bridge circuit, first and second capacitors, an oscillator for supplying AC current to the displacement detecting elements, a circuit for controlling voltage for the oscillator, and amplifier for amplifying current flowing through the second capacitor. In this case, the output signal is supplied to a load through a transmission line of a DC electric power source for the amplifier.
Inventors
- 👤 Bunjiro Saito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:46
CPC Classifications
G; G08; G08C; G08C19/00; G08C19/02; G08C19/06; G08C19/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
280 words
A displacement-electric signal converter comprising: a pair of displacement sensing means connected in series and having impedances which are differentially changed in accordance with a mechanical displacement; a rectifier circuit consisting of a plurality of diodes connected as a bridge circuit, said series-connected pair of displacement sensing means being connected between the input terminals of said bridge circuit, first and second capacitors, said first capacitor being connected between the output terminals of said bridge circuit, said second capacitor having means connecting one end to the connection point of said pair of displacement sensing means and its other end connected to one of the output terminals of said bridge circuit; a current corresponding to the difference between the impedances of said pair of displacement sensing means being obtained from said first capacitor; a current corresponding to the sum of said impedances being obtained from said second capacitor; an oscillator with its output side coupled to said pair of displacement sensing means for applying A. C. current to said pair of displacement sensing means; a differential amplifier circuit with one input terminal connected to said second capacitor, the other input terminal of said differential amplifier supplied with a constant voltage and the output side of said differential amplifier connected to said oscillator for providing the electric power source voltage for said oscillator to maintain substantially constant current flowing through said second capacitor; a second amplifier to which the voltage across both terminals of said first capacitor is supplied for amplifying current flowing through said first capacitor; and a means including a D. C. electric power source of said second amplifier for transmitting the output signal of said second amplifier to a load.
Claim 2
Dependent Claim
280 words
A displacement-electric signal converter comprising: a pair of displacement sensing means connected in series and having impedances which are differentially changed in accordance with a mechanical displacement; a rectifier circuit consisting of a plurality of diodes connected as a bridge circuit, said series-connected pair of displacement sensing means being connected between the input terminals of said bridge circuit, first and second capacitors, said first capacitor being connected between the output terminals of said bridge circuit, said second capacitor having means connecting one end to the connection point of said pair of displacement sensing means and its other end connected to one of the output terminals of said bridge circuit; a current corresponding to the difference between the impedances of said pair of displacement sensing means being obtained from said first capacitor; a current corresponding to the sum of said impedances being obtained from said second capacitor; an oscillator with its output side coupled to said pair of displacement sensing means for applying A. C. current to said pair of displacement sensing means; a differential amplifier circuit with one input terminal connected to said second capacitor, the other input terminal of said differential amplifier supplied with a constant voltage and the output side of said differential amplifier connected to said oscillator for providing the electric power source voltage for said oscillator to maintain substantially constant current flowing through said second capacitor; a second amplifier to which the voltage across both terminals of said first capacitor is supplied for amplifying current flowing through said first capacitor; and a means including a D. C. electric power source of said second amplifier for transmitting the output signal of said second amplifier to a load.
Claim 3
Dependent Claim
24 words
A displacement-electric signal converter as claimed in claim 1 in which said pair of displacement sensing means consist of a pair of differential inductors.
Claim 4
Dependent Claim
23 words
A displacement-electric signal converter as claimed in claim 1 in which said pair of displacement sensing means consist of a pair of capacitors.
Claim 5
Dependent Claim
68 words
A displacement-electric signal converter as claimed in claim 1 in which said second amplifier is a second differential amplifier one input terminal of which is supplied with voltage across said first capacitor and the other input terminal of which is supplied with a feedback voltage, said second differential amplifier controlling a load current to make the voltage difference between said voltages applied to its input terminals substantially zero.
Claim 6
Dependent Claim
59 words
A displacement-electric signal converter as claimed in claim 1 which comprises a circuit for comparing current passing through said second capacitor with a reference current and controlling the electric power source voltage of said oscillator in accordance with the difference between said currents, and a third amplifier employing a blocking oscillator for amplifying current passing through said first capacitor.
Claim 7
Dependent Claim
33 words
A displacement-electric signal converter as claimed in claim 1 which further includes a range change circuit connected in parallel to said first capacitor for changing the range of voltage across said first capacitor.
Claim 8
Dependent Claim
43 words
A displacement-electric signal converter as claimed in claim 6 in which said range change circuit includes a plurality of circuits each comprising a resistor and a switching element connected in series, and each of said circuits connected in parallel with said first capacitor.
Claim 9
Dependent Claim
34 words
A displacement-electric signal converter as claimed in claim 4 which includes a zero point adjusting circuit which adjusts the zero point of the converter by controlling the feedback voltage from said second differential amplifier.
Claim 10
Dependent Claim
22 words
A displacement-electric signal converter as claimed in claim 8 in which said zero point adjusting circuit consists of a variable resistor element.
Claim 11
Dependent Claim
28 words
A displacement-electric signal converter as claimed in claim 5 in which a means is provided for changing the range by varying a feedback current of said blocking oscillator.
References Cited (Backward Citations)
US3456132A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-08 | 1976-02-07 | 1976-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-08 | 1980-02-07 | 1980-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-08 | 1984-02-07 | 1984-08-08 | $7700.00 | Window Closed / Lapsed |