Piezoelectric acceleration sensor signal conversion circuit excited by current source

Abstract

The present invention provides a piezoelectric acceleration sensor signal conversion circuit excited by a current source, comprising a bias voltage module and a signal conversion regulation module. The circuit provided by the invention has a self-reference voltage provided by a precise voltage source, and the self-reference voltage is divided by a resistor so as to generate a quiescent operating point of an insulated gate field-effect tube; and alternating quantities of electric charges are overlaid on the quiescent operating point, the electric charges are changed to current through the insulated gate field-effect tube, and voltage signals corresponding to the alternating electric charges are obtained through conversion of the resistor. With good stability of the temperature, simple structure of the circuit, few elements and low cost, the circuit provided by the invention is easy to regulate the quiescent operating point of the conversion circuit, may work without impressed voltage sources, and is provided with the same interface and only two wires for inputting and outputting signals, therefore facilitating to connect with external circuits and improving the reliability. Moreover, the current signals flow within the interface so as to be used for a long distance measurement, therefore having a great extensive value in use.

Description

technical field [0001] The invention relates to a circuit for converting the high input impedance of the sensor into a low input impedance in the field of piezoelectric acceleration sensor detection, realizing the conversion of the output charge of the sensor, and the conversion of the current to the voltage signal. Background technique [0002] The piezoelectric acceleration sensor uses the piezoelectric effect to measure non-electric physical quantities such as vibration and impact. For example, in the field of magnetic suspension bearings, the piezoelectric acceleration sensor is used to obtain the data after the rotor is excited by the hammer, and analyze the model of the rigid body of the rotor. State mode; In the non-destructive testing technology of forestry trees, the piezoelectric acceleration sensor picks up the mechanical stress wave vibration waveform of the knock, detects and calculates the propagation speed of the stress wave to analyze the elastic modulus of th...

AI Technical Summary

Problems solved by technology

Although the input resistance between the gate and source of the junction field effect transistor can reach more than MΩ, it is not very high; the gate-source voltage of the amplifier circuit is negative in static operation, it is difficult to adjust the static operating point, and the junction field effect The temperature stability of the tube is not as good as the insulated gate field effect tube, and the static operating point will drift

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