Detection circuit for pressure sensor of aeroengine

Abstract

The invention provides a detection circuit for a pressure sensor of an aeroengine. The pressure sensor is electrically connected with an AD converting unit through a sensor loop detection unit and an input instrumentation amplifier respectively. Voltages of four detection resistors of a Wheatstone bridge of the pressure sensor are input to the instrumentation amplifier U2; the instrumentation amplifier U2 transmits a collected voltage value to the AD converting unit; the loop detection unit detects voltage drops of detection points on the four detection resistors of the Wheatstone bridge, the voltage drops are operationally amplified through an operational amplifier on the loop detection unit and then are transmitted to the AD converting unit, and a CPU of an electronic controller of the aeroengine judges faults of the detection points of the Wheatstone bridge of the pressure sensor according to an output voltage value of one loop detection circuit and the voltage obtained after AD conversion through the AD converting unit. The detection circuit has the advantages that the voltage is stable and reliable, output voltage ripples are very small, test accuracy is high, and a millivolt voltage difference value of P3 voltage output is not affected. The actual test shows that the maximum error is not greater than 0.05bar.

Description

technical field [0001] The technology is applicable to the detection circuit of the pressure sensor of the Huygens balanced bridge composed of the strain resistance, especially the detection circuit of the pressure sensor of the aeroengine. Background technique [0002] With the development of integrated circuits and semiconductor technology, semiconductor force-sensitive sensors based on the piezoresistive effect of semiconductor materials have appeared, and silicon piezoresistive pressure sensors have been obtained due to their advantages of small size, high performance, and low cost. widely used. However, the resistance value of the bridge formed by diffusion technology is easy to change with the temperature, and the piezoresistive coefficient of the piezoresistive element has a large negative temperature coefficient, which easily causes the dispersion of the resistance value and the temperature coefficient of resistance, resulting in the thermal sensitivity drift of the ...

AI Technical Summary

Problems solved by technology

The normal working current of the pressure sensor is generally 5 ~ 10mA. If there is a fault such as an internal short circuit of the pressure sensor or a damaged sensor line, it is easy to damage the power supply circuit of the pressure sensor of the engine electronic controller.

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