Detection circuit for non-common mode voltage strain bridge signal

Abstract

A detection circuit for a non-common mode voltage strain bridge signal is applied to engineering technical fields in a wind tunnel aerodynamic test such as balance signal detection and measurement onmoment, pulling pressure, acceleration and the like, belonging to the signal detection technical field. The detection circuit is characterized by comprising a symmetric precision excitation power supply, an instrumentation amplifier, a strain bridge and the like, wherein, the symmetric precision excitation power supply is used for supplying excitation voltage with symmetric positive and negative poles for the strain bridge so as to eliminate common mode voltage applied to the poweramp instrumentation amplifier; the relative effective signal can be generally reduced by 40dB to 80dB; and the instrumentation amplifier with high input impedance performs differential amplification on the measurement signal output by the bridge to generate an electrical signal which facilitates to be measured. The detection circuit has the advantage that: the bridge outputs non-common mode voltage, which can improve signal measurement accuracy by fully utilizing high common mode rejection ratio property of the instrumentation amplifier.

Description

technical field

[0001] The non-common-mode voltage strain bridge signal detection circuit is used in the engineering technology fields such as balance signal detection in wind tunnel aerodynamic tests and torque, tension pressure, acceleration measurement, etc., and belongs to the signal detection technology field. Background technique

[0002] Usually, the bridge detection circuit is powered by a single power supply, and there is a common-mode voltage at the bridge output, which will have a negative impact on the measurement signal and cause signal distortion. The non-common-mode voltage strain bridge signal detection circuit is powered by a positive and negative symmetrical excitation power supply to eliminate the common-mode voltage applied to the instrumentation amplifier in the subsequent stage, and can make full use of the high common-mode rejection ratio characteristics of the instrumentation amplifier to improve the signal. Measurement accuracy. Contents of the inv...

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