What is the principle of current sensor?

Magnetic material: What is the principle of the current sensor?
Two basic principles of current sensors. the

With the continuous development of science and technology, the current power supply equipment is becoming smaller and more compact, and incorporates many new technological achievements. Such as switching power supply, hard switching, soft switching, voltage regulation, linear feedback voltage regulation, magnetic amplification, NC voltage regulation, PWM, SPWM, EMC, etc. The continuous development and advancement of electric power technology is directly driven by practical needs. In order to realize the automatic detection and display of the current, it has an automatic protection function under dangerous conditions, such as over-current, over-voltage, etc., and has a high intelligent control function. Power supply technology with functions such as inductive detection, inductive sampling, and inductive protection has gradually become a development trend. Inductors that detect current or voltage have gradually become a trend in China, and are gradually favored by the majority of power supply designers. the
Generally speaking, the role of the current sensor is to take samples, that is, to convert the current of the circuit under test into a voltage value through electromagnetic induction or resistance, and then convert the dedicated ADC into a digital signal for analysis. The core controller can adjust the flux of the FET according to the detected signal, thereby changing the current value of the controlled circuit. the
operating mode. the

Using Hall magnetic balance principle (closed loop) and Hall direct measurement (open loop). the

1. Open-loop current sensor principle: use high-quality magnetic core to gather the magnetic flux generated by the original current IP current in the magnetic circuit, the Hall element is fixed in the small air gap, and the flux is linearly detected. After special circuit processing, the Hall voltage output by the device is consistent with the original side wave, and the output voltage conforming to the original side wave is obtained. the

2. The magnetic balance current sensor, also known as the compensation sensor, is the magnetic field generated by the measured current Ip on the magnetic gathering ring, and the magnetic field generated by the current is compensated by the secondary coil, so that the Hall device is in a state of zero magnetic flux. the
The specific working process of the magnetic balance current sensor is: when the main circuit current passes through the magnetic field generated by the magnetic field gathering ring, it is induced to the Hall device on the Hall device through the magnetic field gathering ring, and the generated signal output drives the corresponding power tube and conducts, thereby obtaining Compensation current Is. This current generates a magnetic field through multiple turn groups, which is opposite to the magnetic field generated by the measured current, compensating the original magnetic field and gradually reducing the output of the device. There is no increase in Is when the number of turns is equal to the magnetic field generated by Ip. At this time, the Hall device acts like zero magnetic flux and can be balanced by Is. Any change in the measured current will upset this balance. When the Hall device generates a signal, the magnetic field is out of balance. After the energy is amplified, the secondary coil immediately generates a corresponding current to compensate for the unbalanced magnetic field. The time from magnetic unbalance to unbalanced rebalance is less than 1 microsecond, which is a dynamic process. the