Low direct current clamp-shaped measuring device

Abstract

The invention discloses a low direct current clamp-shaped measuring device, which belongs to the technical field of electrotechnics, solves the problems of low sensitivity and precision when the existing current sensing device is used for measuring industrial tiny direct current, and is used for accurate measurement in the field of low direct current industry with reliable and stable operating structure. The measuring device comprises a sensor head, a modulation transformer, a band-pass filter, a phase sensitive demodulator, a direct current amplifier and a power amplifier, wherein the sensor head is annular, and comprises a first half ring detection core and a second half ring detection core in an upper half ring U-shaped detection core as well as a third half ring detection core and a fourth half ring detection core in a lower half ring U-shaped detection core. After the upper and lower half ring U-shaped detection cores are assembled, the overall magnetic shielding core is placed in an annular half cavity formed by shielding layers on two sides, and a feedback winding is wound outside the annular magnetic shielding core. The measuring device can realize accurate measurement of industrial tiny direct current; and the sensor head has a clamp-shaped structure, so that the measuring device is high in measurement sensitivity and accuracy and is suitable for industrial application.

Description

technical field [0001] The invention belongs to the field of current measuring equipment in electrotechnical technology, and more specifically relates to a clamp-type measuring device for small DC current. Background technique [0002] "Instrument Technology and Sensors" published a paper "Magnetic modulation type DC small current active sensor" published on pages 9-11 of the 10th issue in 2008. The main points and key parameters of excitation source circuit, magnetic modulation circuit and signal processing circuit are analyzed and introduced, and the opening type small current sensor is proposed, which can improve its resolution and measurement accuracy by processing the iron core section into a zigzag shape. The paper has certain reference value, but the analysis of the circuit and the method of processing the iron core into a zigzag shape is very limited. Because for the DC small current clamp type, that is, the open type measuring device, the key technology is whether ...

AI Technical Summary

Problems solved by technology

Although the permalloy material has the advantages of high magnetic permeability, the defect that the magnetic permeability of the iron core is mechanically cut and the opening is severely reduced is also very prominent; and the silicon steel sheet is cut and opened After that, there will be no serious drop in magnetic permeability, but its own magnetic permeability is not high

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