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Patent Searching and Data


Title:
OSCILLATION TYPE SENSOR DETECTION CIRCUIT
Document Type and Number:
Japanese Patent JP2004108848
Kind Code:
A
Abstract:

To provide an oscillation type sensor detection circuit having no trouble factors for converting it into an ASIC by minimizing current/voltage converting operation and mainly using computing operation with a current signal for simplifying the circuit.

The oscillation type sensor detection circuit amplifies an AC electromotive force signal from an oscillation type sensor having a natural oscillation frequency which is changed depending upon a physical quantity to be measured and applies the amplified output as an excitation signal for the oscillation type sensor to cause self-oscillation. It comprises a voltage/current conversion circuit for converting the AC electromotive force signal into an AC current signal, a current/voltage conversion circuit for converting a first current signal proportional to the AC current signal into a voltage signal, a gain control conversion circuit for inputting the voltage signal and supplying the excitation signal to the oscillation type sensor, an absolute value circuit for generating a second current signal proportional to the absolute value of the AC current signal, and an integration circuit for inputting the second current signal to generate a third current signal for controlling the gain of the gain control conversion circuit.


Inventors:
TAKAMUKAI YAYOI
Application Number:
JP2002269415A
Publication Date:
April 08, 2004
Filing Date:
September 17, 2002
Export Citation:
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Assignee:
YOKOGAWA ELECTRIC CORP
International Classes:
G01L9/00; G01L13/02; (IPC1-7): G01L9/00; G01L13/02