Closed-loop magnetic balance Hall current sensor

Abstract

The invention discloses a closed-loop magnetic balance Hall current sensor with small zero point drift and fast response speed. The Hall element is connected to one end of the compensation coil through the amplifier circuit, and the other end of the compensation coil is connected to the load resistance Rm. The amplifier circuit is provided with an operational amplifier IC1 and a power amplifier composed of triodes Q1 and Q2. The Hall element passes through The resistor R1 is connected to the negative input terminal of the operational amplifier IC1, the Hall element is connected to the positive input terminal of the operational amplifier IC1 through the resistor R2, and the output of the power amplifier is fed back to the negative input terminal of the operational amplifier IC1 through the zero adjustment circuit FH1.

Description

technical field [0001] The invention relates to a closed-loop magnetic balance Hall current sensor, in particular to a closed-loop magnetic balance Hall current sensor with small zero point drift and fast response speed. Background technique [0002] At present, the known Hall current sensors are all based on the principle of the Hall effect, and there are two types: an open-loop direct measurement type and a closed-loop magnetic balance type. Due to the low accuracy and slow response speed of open-loop direct-measurement Hall current sensors, closed-loop magnetic balance Hall current sensors are often used in wind power, DC motor drives, battery power supplies, and welding machine power supplies. The existing closed-loop magnetic balance current sensor is provided with a magnetic ring, and a primary current input wire is placed in the center of the magnetic ring, and a Hall element and a compensation coil are arranged on the magnetic ring. The Hall element is connected to o...

AI Technical Summary

Problems solved by technology

The closed-loop magnetic balance current sensor has the advantages of high precision and short response time, but in environments with harsh climate conditions (such as wind power systems), the zero point drift is large, especially the zero point drift caused by high temperature and low temperature is particularly serious, resulting in overall The stability and consistency of the system are not good, which seriously affects the accuracy of the system operation, causes system malfunction, and even damages the equipment.

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