Double-channel analog/digital combined variable gain data acquisition device

Abstract

The invention relates to a double-channel analog / digital (A / D) combined variable gain data acquisition device. The device comprises a primary amplifying and conditioning circuit, two parallel amplifying circuits, an A / D conversion module and a digital control module, wherein the output ends of the primary amplifying and conditioning circuit are separately connected with the input ends of the two parallel programmable amplifiers in a two-way parallel programmable amplifier circuit; the output ends of the two parallel programmable amplifiers are separately connected with the corresponding inputchannels of the A / D conversion module; the A / D conversion module is connected with the digital control module; and the digital control module reads the sampling value which is through A / D conversion and sends a control signal to control the A / D conversion process and change the gains of the programmable amplifiers. The acquisition device can be used to increase the dynamic range and span of measurement, ensure the sampling accuracy of weak signals and large-range signals and realize high-speed and high-accuracy data acquisition; and the method is more suitable for the detection of the analog of which size is unknown and variation range is wider.

Description

technical field [0001] The invention relates to a data acquisition device for dynamically adjusting the gain of an amplifying circuit in advance according to the changing trend of signals, and belongs to the technical field of data acquisition. Background technique [0002] In a measurement system, some signals can vary widely. For these measured signals with large and small changes, if the amplifying circuit adopts a fixed gain, it will often cause that the signal cannot be well matched with the range of the A / D converter within a certain range of the signal. For example, for weak signals, the amplifying circuit needs relatively large gain to meet the range requirements of the A / D converter and realize accurate measurement. But for the measured signal with relatively large amplitude, if a larger gain is still used, the signal will exceed the range of the A / D converter after amplification, and correct measurement cannot be realized. [0003] Therefore, in order to achieve ...

AI Technical Summary

Problems solved by technology

This not only causes the loss of effective information and affects the accuracy of data acquisition, but also requires a circuit stabilization process for gain changes, which increases additional waiting time, thus restricting the speed of data acquisition. For some applications that require high-speed acquisition This unfavorable factor is particularly obvious in applications

Therefore, for some high-precision, high-speed data acquisition, this conventional device for changing the gain cannot meet the needs

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