Passive thermal resistor sensor signal simulation circuit

Abstract

The invention belongs to the field of sensor signal simulation, and relates to a thermal resistor sensor signal simulation circuit. The passive thermal resistor sensor signal simulation circuit comprises a digital-to-analog conversion chip, a first operational amplifier, a second operational amplifier, a third operational amplifier, a gear-shifting switch, a plurality of capacitors and a plurality of resistors, wherein the gear-shifting switch is connected with the reference end of the digital-to-analog conversion chip through a voltage follower circuit, and the feedback end and the output end of the digital-to-analog conversion chip are sequentially connected with a filtering circuit and a proportion amplification circuit formed by the operational amplifiers in series. Resistor signals output by the passive thermal resistor sensor signal simulation circuit have the physical characteristics of a real resistor, are strong in band load capacity and are free of interference of subsequent circuits; in addition, digital signals can be linearly converted into thermal resistor signals in a given manner to be continuously output, the output precision is high, and the output range can be adjusted by the gear-shifting switch.

Description

technical field [0001] The invention belongs to the field of sensor signal simulation and relates to a thermal resistance sensor signal simulation circuit. Background technique [0002] At present, there are mainly two methods for thermal resistance sensor signal simulation, the first method can be found in figure 1 , the circuit is composed of a limited number of resistors (R1, R2, ..., Rn) in series, and a program-controlled relay switch (K1, K2, ..., Kn) is connected in parallel to each resistor. When the program-controlled relay switch is closed, the corresponding resistance is in a short-circuit state, so the output resistance of the circuit is the sum of the resistance values ​​corresponding to the program-controlled relay in the off state. The disadvantages brought by this method are obvious. The output resistance value is discrete, and the precision is too low to output a continuous thermal resistance signal that meets the resolution requirements, and there is distu...

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Problems solved by technology

Although the output resistance value of this method is continuous, it does not have the physical characteristics of real resistance, and the load capacity is weak. As long as the load end circuit has current input to the precision resistance, it will cause interference to the circuit.

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