Hall effect is a kind of magnetoelectric effect. This phenomenon was discovered by Hall (AH Hall, 1855-1938) in 1879 when he studied the conductive mechanism of metal. Later, it was found that semiconductors, conductive fluids, etc. also have this effect, and the Hall effect of semiconductors is much stronger than metals. Hall elements made using this phenomenon are widely used in industrial automation technology, detection technology, and information processing. aspect. The following Xiao Bian introduces Hall sensor function and Hall sensor characteristics.
The role of Hall sensors
1, displacement measurement
Can be used for displacement measurement, the linear Hall sensor is placed in the middle of the two oppositely placed permanent magnets of the same polarity. At this point, this point can be regarded as the displacement zero point, and the magnetic induction intensity is zero. When the sensor is displaced to â–³Z on the Z-axis, the sensor will have a voltage output, and the size of the displacement and the voltage at this time are directly proportional.
2, force measurement
If the parameters such as pressure and tension are taken as displacement, we can measure the magnitude of the pressure and tension, and can use this principle to make a force sensor.
3, angular velocity measurement
A magnet is usually attached to the periphery of a non-magnetic material disk. When the Hall sensor approaches the periphery of the disk, the disk will rotate one rotation and the Hall sensor will output a pulse at the same time. Using this principle, the rotation can be measured. The number of turns, if you insert a frequency meter in it, you can measure the speed of rotation.
Hall sensor classification
1, linear Hall sensor
The linear Hall sensor consists of a Hall element, a linear amplifier and an emitter follower, which outputs an analog quantity.
2, switch Hall sensor
Switch Hall sensors consist of regulators, Hall elements, differential amplifiers, Schmitt triggers, and output stages that output digital quantities. Hall sensors used in mobile phones are micropower switching Hall sensors.
Hall sensor features
1, Hall sensors can measure arbitrary waveforms of current and voltage, such as: DC, AC, pulse waveform, and even the measurement of transient peaks. The secondary current faithfully reflects the waveform of the primary current. The common transformer is not comparable to it, it is generally only suitable for measuring 50Hz sine wave.
2. The electrical insulation between the primary circuit and the secondary circuit is completely insulated. The insulation voltage is generally 2KV to 12KV, and the special requirement is up to 20KV to 50KV.
3, high precision: in the working temperature area accuracy is better than 1%, the accuracy is suitable for any waveform measurement. The common transformer is generally 3% to 5% accurate and suitable for 50Hz sinusoidal waveforms.
4, good linearity: better than 0.1%
5, dynamic performance is good: response time is less than 1μs tracking speed di/dt is higher than 50A/μs
6, Hall sensor module This excellent dynamic performance provides a key foundation for improving the performance of modern control systems. Compared with ordinary transformer's response time is 10-12ms, it can not meet the needs of the development of the work control system.
7. Work frequency bandwidth: The accuracy is 1% in the frequency range of 0-100kHz. Accuracy is 0.5% in the 0-5kHz frequency range.
8, measuring range: Hall sensor module for the system product, current measurement up to 50KA, voltage measurement up to 6400V.
9, strong overload: When the primary current overload, the module reaches saturation, can automatically protect, even if the overload current is 20 times the rated value, the module will not be damaged.
10. The module is small in size, light in weight and easy to install. It will not cause any loss in the system.
11. The "capacitance" between the primary and the secondary of the module is very weak. In many applications, the various effects of the common-mode voltage are usually negligible. When the high voltage changes of several kV/μs are reached, the module has its own Shielding function X-ray machine maintenance.
12. The module's high sensitivity makes it possible to distinguish weak signals on "high components", for example, to distinguish a few milliamperes of AC components from a few hundred amps of dc components.
13, high reliability: failure rate: λ = 0.43 ╳ 10-6 / hour
14. Strong resistance to external magnetic fields: The error caused by a magnetic field generated by a current twice the operating current (2Ip) at a distance of 5-10cm from the module is less than 0.5%, which is resistant to external magnetic fields for most applications. Interference is sufficient, but interference with very strong magnetic fields should take appropriate measures.
Editor's summary: The function of the Hall sensor and the characteristics of the Hall sensor are introduced here, and we hope to help everyone. If you want to know more related information, you can pay attention to this website information.
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