EP0105120A2
Expired / Lapsed
EP
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Method and apparatus for measuring signals from differential sensors
Assignee: International Business Machines Corp
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Filing: 1983-08-02
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Granted: —
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Expires: 2003-08-02
Abstract
Abstract Method and apparatus for measuring the signals from a transducer. The signals are processed to form a differential component normalized by a summation component such that common changes to the sensors response characteristic are compensated. The sensors performance at the limits of the sensing range is also improved by the summation signal.
Inventors
- 👤 Rudolf Heinz Barsotti
- 👤 Arthur Wesley Grove
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 11:13
CPC Classifications
G; G01; G01D; G01D3/00; G01D3/02; G01D3/021; G01D5/00; G01D5/12; G01D5/14; G01D5/24; G01D5/241; G01D5/2417; G11; G11B; G11B15/00; G11B15/56; G11B15/58
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
99 words
A method for compensating first and second sensors having a capacity which varies in accordance with a sensed condition, said sensors having a common connection to a source of a.c. signals, and first and second signal supplying connections comprising; rectifying first and second signals from said first and second signal supplying connections, whereby first and second d.c. voltages are produced; combining said first and second d.c. voltages to provide a bias signal; and applying said bias signal to said common connection whereby a composite signal voltage is applied to each of said sensors for weighting said response characteristic. "
Claim 2
Independent Claim
99 words
A method for compensating first and second sensors having a capacity which varies in accordance with a sensed condition, said sensors having a common connection to a source of a.c. signals, and first and second signal supplying connections comprising; rectifying first and second signals from said first and second signal supplying connections, whereby first and second d.c. voltages are produced; combining said first and second d.c. voltages to provide a bias signal; and applying said bias signal to said common connection whereby a composite signal voltage is applied to each of said sensors for weighting said response characteristic. "
Claim 3
Dependent Claim
14 words
The method of claim 1 further including the step of inverting said bias signal.
Claim 4
Dependent Claim
126 words
Measuring apparatus including first and second capacitor sensing means (Cl, C2), each having a common side receiving a signal, and a pair of remaining sides producing a signal voltage V 1 and V 2 , and further including an arrangement compensating for changes in said capacitor sensing means response characteristic said arrangement comprising: means (16, 17) for rectifying each of said signal voltages to produce first and second d.c. signal voltages (Vt l , vt 2 ) and means (25, 26, 28, 29) for applying the summation Va of said dc signal voltages to said capacitor common sides whereby said capacitor is biased at a level proportional to the reciprocal of V 1 + V 2 , compensating for any common changes in said response characteristic.
Claim 5
Dependent Claim
126 words
Measuring apparatus including first and second capacitor sensing means (Cl, C2), each having a common side receiving a signal, and a pair of remaining sides producing a signal voltage V 1 and V 2 , and further including an arrangement compensating for changes in said capacitor sensing means response characteristic said arrangement comprising: means (16, 17) for rectifying each of said signal voltages to produce first and second d.c. signal voltages (Vt l , vt 2 ) and means (25, 26, 28, 29) for applying the summation Va of said dc signal voltages to said capacitor common sides whereby said capacitor is biased at a level proportional to the reciprocal of V 1 + V 2 , compensating for any common changes in said response characteristic.
Claim 6
Dependent Claim
78 words
The apparatus of claim 3 wherein said means for applying the summation of said first and second d.c. voltages comprises: first and second resistors (25, 26) having first ends connected to receive one of said d.c. voltages; a differential amplifier (28) having an inverting input connected to the remaining resistor ends and a non-inverting input connected to a reference voltage (Vr) whereby a summation signal is produced from said first and second d.c. voltages and said reference voltage.
Claim 7
Dependent Claim
23 words
The apparatus of claim 3 further comprising a differential amplifier (23) for combining said d.c. signal voltages to produce an output voltage (Vo).
Claim 8
Dependent Claim
27 words
The apparatus of claim 3 further comprising means for subtracting said first and second differential voltages V 1 , V 2 whereby a measurement signal is produced.
References Cited (Backward Citations)
No citation records indexed.
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