Hall sensor is a magnetic field sensor made based on the Hall effect, widely used in industrial automation technology, detection technology, and information processing.

The Hall coefficient measured through Hall effect experiments can determine important parameters such as the conductivity type, carrier concentration, and carrier mobility of semiconductor materials.

Due to the small potential difference generated by Hall elements, they are usually integrated with amplifier circuits, temperature compensation circuits, and voltage stabilizing power supply circuits on a single chip, known as Hall sensors. Hall sensors, also known as Hall integrated circuits, have a smaller appearance.

A certain type of Hall sensor

Advantages and Applications of Hall Sensors

At present, Hall devices can withstand certain vibrations and operate within the range of -40 ℃ to -150 ℃. They are fully sealed and free from water and oil pollution, and can fully adapt to the harsh working environment of automobiles.

Hall sensors can measure currents and voltages of any waveform, such as DC, AC, pulse waveforms, and even transient peak values. The secondary current faithfully reflects the waveform of the primary current. Ordinary transformers are incomparable, as they are generally only suitable for measuring 50Hz sine waves

There is good electrical isolation between the primary and secondary circuits, with an isolation voltage of up to 9600Vrms;

High accuracy: The accuracy is better than 1% in the working temperature range, which is suitable for measuring any waveform; Hall switch device has no contact, no wear, clear output waveform, no jitter, no rebound, and high position repetition accuracy (up to μ M level).

Wide bandwidth: The rise time of a high bandwidth current sensor can be less than 1 μ s； However, the bandwidth of the voltage sensor is relatively narrow, usually within 15kHz. The rise time of the 6400Vrms high-voltage voltage sensor is about 500uS, and the bandwidth is about 700Hz.

Wide measurement range: current measurement can reach 50KA, voltage measurement can reach 6400V.

Solid structure, small size, light weight, long service life, easy installation, low power consumption, high frequency (up to 1MHz), vibration resistant, and not afraid of pollution or corrosion from dust, oil, water vapor, and salt mist.

The above diagram is a typical Hall sensor application for positioning - two magnets on a wheel pass through a Hall effect sensor. The wheel shown in the diagram has two equally spaced magnets, and the voltage on the sensor will peak twice in one cycle.

Usually used to measure the speed of wheels and axles, such as on the ignition timing (timing) or tachometer of an internal combustion engine. It is used in brushless DC motors to detect the position of permanent magnets.

Hall sensors are widely used in facilities requiring isolation and detection of current, such as variable frequency speed regulation device, inverter device, UPS power supply, communication power supply, electric welding machine, electric locomotive, substation, numerical control machine tool, electrolytic plating, microcomputer monitoring, power grid monitoring, as well as emerging solar energy, wind energy, subway track signal, automotive electronics and other fields.

Main characteristic parameters of Hall sensors

As mentioned earlier, a Hall sensor is a magnetic field sensor made based on the Hall effect, and its main characteristic parameters include the following categories.

(1) Input resistance R

The DC resistance between the two excitation current terminals of the Hall sensor element is called the input resistance. Its value ranges from a few ohms to a hundred ohms, depending on the components of different models.

As the temperature increases, the input resistance decreases, resulting in an increase in input current, which ultimately causes a change in the Hall sensor potential. To reduce this impact, Z uses a constant current source as the excitation source.

(2) Output resistance R

The resistance between the potential output terminals of two Hall sensors is called the output resistance, which has the same order of magnitude as the input resistance. It also changes with temperature. Choosing an appropriate load resistor is easy to match, which can reduce the drift of the water potential caused by temperature to Z.

(3) Z large excitation current I - Hall sensor parameters

Due to the fact that the potential of the Hall sensor increases with the increase of the excitation current, it is always desired to use a larger excitation current of 1M in applications. However, as the excitation current increases, the power consumption of the Cheng Er element increases, and the temperature skin of the element increases, resulting in an increase in the temperature drift of the Hall sensor's tunnelling potential. Therefore, each model of several devices has a corresponding Z excitation current, which ranges from a few milliamperes to several hundred milliamperes.

(4) Sensitivity K

(5) Z high magnetic induction intensity BM - Hall sensor parameters

When the magnetic induction intensity exceeds BM, the nonlinear error of the Hall sensor's potential will significantly increase, with a Tesla (T) of several thousand Gauss (Gs) (1Gs=104T).

(6) Equipotential potential

At the rated excitation current F, when the external magnetic field is zero, it is an error caused by the geometric size asymmetry of the four electrodes.

(7) Hall sensor potential temperature coefficient

The value of 6M is generally the open circuit voltage between the output terminals of the zero knife Hall sensor, which is called the unequal potential. When used, the bridge method is often used to compensate for the unequal potential. Under the action of a certain magnetic induction intensity and excitation current, the percentage of change in the Hall sensor potential for every 1 degree Celsius temperature change is weak, which is the Hall sensor potential temperature coefficient, which is related to the material of the Hall sensor components.