Minitype resistance measurement system

Abstract

The invention relates to the technical field of low-current source resistance measurement, in particular to a minitype resistance measurement system which comprises a single chip microcomputer. The minitype resistance measurement system is characterized in that a signal a output end of the single chip microcomputer is connected with an input end of a D / A converter, an output end of the D / A converter is connected with an input end of a controllable low-current source, an output end of the controllable low-current source is connected with a tested small resistor, voltage dropping of the tested small resistor is used as output to be connected with an input end of a high-signal-to-noise-ratio programmable amplifier, an output end of the high-signal-to-noise-ratio programmable amplifier is connected with an input end of a low pass filter, an output end of the low pass filter is connected with an A / D converting input end of the single chip microcomputer, a signal b output end of the single chip microcomputer is connected with an address input end of a channel selector, so that different resistance connecting parts are selected to change the magnification times of the high-signal-to-noise-ratio programmable amplifier, through close matching of the controllable low-current source and the high-signal-to-noise-ratio programmable amplifier, the problem of resistance temperature rising in existing high-constant-current-source scheme measuring is avoided, and accuracy of low resistance measurement is improved.

Description

technical field [0001] The invention relates to the technical field of resistance measurement of small current sources, in particular to a tiny resistance measurement system. Background technique [0002] At present, the measurement of tiny resistance has long been a difficulty in electronic measurement. In practical engineering applications, the traditional method is to measure the resistance of the loop by using the DC double-arm bridge method. Although this method has high sensitivity, it is mainly used in laboratory measurements because the current is too weak and must be done manually. In 2003, Li Weibo of Huazhong University of Science and Technology and others proposed a method of measuring resistance with a constant current source, and measuring a small resistance with a DC constant current. The idea is: use a DC constant current to pass through a small resistance, collect data after signal conditioning, and then output show. Since the current of the usual DC cons...

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Problems solved by technology

[0003] The purpose of the present invention is to avoid the defects of low measurement efficiency and poor precision in the prior art and provide a tiny resistance measurement system, which effectively solves the problems of the prior art through the close cooperation of the controllable small current source and the high signal-to-noise ratio program-controlled amplifier. existing problems

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