1、34Hall Current Sensor and Its ApplicationIn the modern society, the information demand is huger and huger, and sensors play an important role in the information acquisition. They can turn all kinds of physical information, according to certain rules, into measurable electrical signal. Based on the c
2、hanges of electrical signals we measured, and the related physical information relationship, we can gain the measured physical information changes or size.According to the working principle of the sensor, we can divide the sensors into many types, such as photoelectric sensor, charge sensors, potent
3、ial type sensor, semiconductor sensor, the electricity sensor, magnetic sensor, resonant sensor, electric chemical formula sensor etc.Hall sensor is the use of hall element based on the Hall effect principle, which can concert the physical information, such as current, magnetic field, the displaceme
4、nt, pressure, etc, into electromotive force output. It belongs to the potential type sensor. At present, this kind of sensor is mainly hall integrated circuit and the core unit is based on the Hall effect, which is made through the integrated circuit technology. So it is not only a kind of integrate
5、d circuit, but a kind of magnetic sensor.According to the actual application, this article is mainly about the hall current sensor.1. Hall effectWhen we place a metal or semiconductor wafer in a magnetic field, and if there is a current through it, it will produce electromotive force in the perpendi
6、cular direction of the electric and magnetic field, calling this kind of physical phenomenon Hall effect.Figure 1 Hall effect principle diagramUnder the action of the Lorentz force generated in the magnetic field, the carrier of energized semiconductor chip, deflect and accumulate respectively on bo
7、th sides of the chip, thus forming a electric field, called the Hall electric field. Hall electric field produces electric field force which is contrary to the Lorentz force, hindering carrier to continue to pile up, until the hall electric field force equal with the Lorentz force. At this time, it
8、will set up a stable voltage on both sides of the chip, and this is the hall voltage.2. Hall current sensorAlong with the urban population and the expansion of the construction scale of the city, and the increasing of all kinds of electric equipment, power consumption is bigger and bigger. The power
9、 supply equipment of the city often overload , while power environment becomes more and more bad, the test to the power being more and more serious. Thus, the problems in the power supply come out more and more apparently . Now, small power supply equipment has been combined with more and more new t
10、echnology. For example, switch power supply, hard switch, soft switch, parameter voltage regulator, linear feedback voltage regulator, magnetic amplifier technology, numerical control pressure regulation, PWM, SPWM, electromagnetic compatibility, etc. The actual demands directly promote power techno
11、logy development and progress. In order to detect and display current automatically, and the automatic protection function and more advanced intelligent control when the harm such as over current, over voltage occurs, the power supply technology with sensing detection, sensing sampling and sensing p
12、rotection becomes a trend. Sensors of detecting current or voltage, called Hall current sensor, come into being, and quickly become the favorite of the designers of the power supply in our country.2.1 The performance characteristics of Hall current sensorHall current sensor has superior performance,
13、 and it is a kind of advanced electric detecting element, which can isolate the main circuit loop and electronic control circuit. It has all the advantages of transformers and shunts, and at the same time, overcomes their disadvantages (transformer can be only applied to the power frequency measurem
14、ent, 50 Hz; shunt is unable to do isolation measurement). Using the same one hall current sensor module detecting element not only can test AC, but also can detect DC, even can detect transient peak. It has the following performance characteristics. Measure the arbitrary waveform current, such as DC
15、, AC, and even to transient peak parameters measurement; High precision. General Hall current sensor modules precision in the work area is higher than 1%, and the precision is suitable for any waveform measurement; The linearity is better than 0.5%; Good dynamic performance. The dynamic response tim
16、e of general Hall sensor module is less than 7s, and the tracking speed di/dt is above 50A/s; Working band wide. It can work in the frequency range from 0 to 20 KHZ very well; Strong overload ability. Wide measurement range（010000A）; High reliability. The average trouble-free working is more than 5 x 10000 hours; Small size, light weight, easy to install and it will not bring any loss to the system.In view of the above high performan
