DC comparator

Abstract

A DC comparator comprises a pair of openable and closable main iron cores, an exciting coil and a secondary feedback coil which are wound outside the main iron cores, and a signal processing circuit,wherein the signal processing circuit comprises a modulation circuit, and a demodulation circuit, a signal amplification circuit and a signal feedback circuit which are connected in sequence; the mainiron cores are wrapped with a multiferroic material thin film; and the multiferroic material thin film is connected with a zero setting circuit. According to the DC comparator, the main iron cores are wrapped with the multiferroic material thin film, the zero setting circuit is connected with the multiferroic material thin film, and the magnetic conductivity of a ferromagnetic layer (the multiferroic material thin film) is changed by loading a voltage to a piezoelectric layer in the multiferroic material thin film, so that the asymmetry of the main iron cores is inhibited, the zero point problem caused by the asymmetry and difference of the iron cores is fundamentally solved, and the precision of the DC comparator is improved.

Description

technical field [0001] The invention belongs to the technical field of current measurement, in particular to a DC comparator. Background technique [0002] As a calibration instrument for DC current, the DC comparator needs to have high precision, and the zero point size of the DC comparator limits the precision of the small range of the DC comparator to a certain extent. A DC comparator is generally modulated by two or more magnetic cores. Due to the asymmetry and differences between each iron core, zero points will appear. The asymmetry and difference of the iron core can only be reduced as much as possible through quality control during the production of the iron core, but it cannot be completely avoided. How to solve the difference and asymmetry of the iron core becomes a The main problem that restricts the zero adjustment and accuracy of the DC comparator. [0003] figure 1 The circuit schematic diagram for the DC comparator, such as figure 1 As shown, the currently...

AI Technical Summary

Problems solved by technology

However, this adjustment method does not fundamentally solve the zero point problem caused by the difference and asymmetry of the iron core itself, and because the difference of each iron core is inconsistent, the compensation point and compensation method of each instrument need to be adjusted. Debugging one by one, the cost of manpower and time is high. At the same time, because one or more zeroing circuits need to be added, the system variables will increase, which will affect the stability of negative feedback under certain conditions.

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