Strain sensor simulator

Abstract

The invention discloses a strain sensor simulator which comprises a sensor interface, a precision resistance network, a common mode voltage switching circuit, an output signal generating circuit, a DA switching circuit, a reference voltage generating circuit, a control system and a temperature sensor. The sensor interface, the precision resistance network, the common mode voltage switching circuit and the output signal generating circuit are connected in sequence. The reference voltage generating circuit is connected to the sensor interface, the common mode voltage switching circuit and the DA switching circuit. The control system is connected to the temperature sensor and the DA switching circuit. The DA switching circuit is connected with the output signal generating circuit. The sensor interface is connected with an external measuring instrument. The reference voltage generating circuit generates a positive and negative reference source voltage of the DA switching circuit according to the voltage output by the common mode voltage switching circuit and the positive voltage output by the sensor interface. The DA switching circuit generates a DA output voltage according to the positive and negative reference source voltage and a set digital quantity, and then generates an output analog signal together with the voltage output by the common mode voltage switching circuit. The output analog signal is output to the external measuring instrument through the sensor interface.

Description

technical field [0001] The invention relates to a strain sensor simulator, in particular to a high-precision resistance strain sensor simulator. Background technique [0002] When producing, overhauling, and inspecting various measuring instruments that use the output of strain gauge sensors as input signals, it is usually necessary to use a high-precision regulated power supply as a standard signal to measure various errors of the instruments. On the one hand, the price of the high-accuracy regulated power supply is relatively expensive; on the other hand, the high-accuracy regulated power supply must be used in conjunction with a high-accuracy voltmeter, which is not convenient for on-site use. Therefore, in the process of production practice, it is often necessary to use sensor simulators to test and test measuring instruments. [0003] An existing sensor simulator such as figure 1 As shown, the voltage at the dividing point of the precision resistor network is used as ...

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Problems solved by technology

[0004] However, although the existing sensor simulator circuit eliminates the influence of the common-mode voltage on the zero point, the output signal of the DAC circuit affects the value of the common-mode voltage after passing through the operational amplifier, resistor R5, and resistor R3, so that only at the zero point When the common mode voltage is the partial pressure of R1 and R2 on the input positive and negative voltages, the effective output of the signal is not linear with the set value of the DAC, so that there is a systematic error between the set value and the actual output value

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