The Hall sensor effect, discovered in 1879 by Edwin Herbert Hall, is transforming our everyday lives. It measures magnetic field variations with impressive precision. Today, these sensors are everywhere, from cars to smartphones and household appliances.

Hall-effect sensors operate by Lorentz force, generating a voltage proportional to the magnetic field. Their small size, around 10 mm², and thickness of 0.5 mm make them ideal for a variety of industrial applications. They can measure speed, position, proximity and even electrical current without direct contact.

Hall-effect sensors are characterized by their reliability and long service life. They have no moving parts, ensuring long life and resistance to harsh conditions. Their affordable cost also makes them very attractive to many industries.

Key points to remember

  • Hall-effect sensors measure magnetic field variations
  • They use the principle discovered by Edwin Herbert Hall in 1879
  • These sensors can be found in cars, washing machines and telephones.
  • They offer long service life and withstand harsh conditions
  • Hall-effect sensors are more economical than mechanical switches
  • They can measure high currents without opening the circuit
  • An external 5V power supply is generally required

Introduction to the Hall effect and its industrial applications

The Hall effect, discovered by Edwin H. Hall in 1879, revolutionized the measurement of magnetic fields. This discovery paved the way for numerous applications in modern industry. The Hall probe has become an essential tool for the precise measurement of magnetic fields in a variety of sectors.

Historical discovery

Edwin H. Hall observed that an electric current flowing through a conductor subjected to a magnetic field generated a perpendicular voltage. This voltage, known as Hall's voltage, is proportional to the intensity of the magnetic field. This discovery laid the foundations for modern magnetic field sensors.

Importance in the industry

Hall-effect sensors have become indispensable in many industrial sectors. They enable non-contact measurement of position, displacement, speed and electrical current. These sensors are particularly appreciated for their precision and reliability in harsh environments.

Main applications

In the automotive industry, Hall-effect probes are used to detect the position of rotating shafts in gearboxes. In electronics, they are used to measure currents in frequency conversion systems. In robotics, these magnetic field sensors play a crucial role in the precise positioning of robotic arms.

Physical principle of the sensor hall effect

The Hall effect, discovered in 1879 by Edwin Herbert Hall, forms the basis of today's non-contact sensors. This phenomenon is crucial to understanding the operation of position sensors, which are essential in industry.

Lorentz force and electron behavior

The Lorentz force plays a central role in the Hall effect. It acts on charge carriers in a conductor, where an electric current and a perpendicular magnetic field are present. This force deflects electrons, causing a separation of charges in the material.

Hall voltage generation

The separation of charges, caused by the Lorentz force, generates an electrical voltage, the Hall voltage. This voltage is measurable and varies according to the intensity of the applied magnetic field. Semiconductor materials such as silicon or gallium arsenide are chosen for their high sensitivity to this effect.

Interaction with the magnetic field

The interaction between electric current, magnetic field and material structure is essential for the efficiency of a Hall-effect sensor. The sensitivity of the sensor depends on the mobility of the charge carriers in the material. This property enables non-contact sensors to detect the position of magnetic objects with great precision, without the need for physical contact.

Hall-effect position sensors offer a reliable and precise solution for a wide range of industrial applications. They are used in fields ranging from automotive to embedded systems.

Hall-effect sensor components and structure

A Hall-effect sensor consists of several crucial components. At the center is a thin conductor through which an electric current flows. This core, a magnetic transducer, is subjected to a perpendicular magnetic field. This generates a measurable Hall voltage.

The plastic housing protects the internal components. It also facilitates sensor integration. Basic sensors, such as the US1881, come in a TO92 package with three pins. These pins are used for power, ground and signal output.

More advanced sensors can have up to eight legs. They offer additional features. For example, some models include a built-in amplifier to boost the output signal. Others incorporate an analog-to-digital converter for direct compatibility with digital systems.

Hall-effect proximity sensors can be unipolar or bipolar. Unipolar sensors, such as the US5881, respond to a single magnetic pole. Bipolar sensors, such as the US2882, detect both poles, offering greater flexibility of use.

For more complex applications, 3D sensors like the MLX90333 enable precise position detection in all three axes. These sophisticated devices integrate several sensitive elements and advanced processing circuits in a single, compact package.

Technical specifications and performance

Hall-effect sensors are characterized by their outstanding technical performance. They play a crucial role in many motion detection systems. They combine precision and reliability in a unique way.

Magnetic sensitivity range

A Hall-effect switch offers magnetic sensitivity from 0.75 to 1.72 mV/Gauss at 5V. This wide range ensures accurate detection of even the weakest magnetic fields. This guarantees outstanding efficiency in a wide range of applications.

Supply voltage and consumption

These motion sensors operate with a supply voltage of 4.5V to 6V. Their low power consumption of around 9 mA makes them ideal for embedded systems and portable devices.

Operating temperatures

The robustness of Hall-effect sensors is reflected in their wide operating temperature range. They operate from -20°C to +85°C, ensuring stable performance in a wide range of environments. This feature makes them particularly suitable for industrial and automotive applications.

Output resistance of 50 ohms and thermal stability of 0.03% per °C enhance their reliability. Their accuracy, ranging from 0.5% to 1% for currents up to 10 kA, makes them highly effective measurement tools.

Hall-effect sensor types available

The range of Hall-effect sensors is vast, meeting a multitude of industrial needs. They fall into distinct categories, each designed for specific uses.

Linear and digital sensors

Hall-effect sensors fall into two main categories: linear and digital. Linear sensors transmit a voltage proportional to magnetic intensity. The latter transmit a binary signal above a defined magnetic threshold.

Unipolar and bipolar sensors

Polarity is a criterion for distinguishing Hall-effect sensors. Unipolar sensors, such as the TLE4905L, respond to a single magnetic pole. Bipolar sensors, such as the TLE4935L, detect both poles. The TSH188CX is an example of a bipolar latching sensor, while the TSH253CX is omnipolar.

Rotary and position sensors

Specialized sensors are available to measure rotation or position. The KMZ10B and SAS241S2, for example, are designed for these applications. Littelfuse offers customization options, allowing the addition of connectors or modification of wire size.

The diversity of Hall-effect sensors enables us to meet the requirements of every industrial sector. From the SS41 range to ultra-compact analog models, these devices offer flexible, efficient solutions for magnetic sensing.

Applications in the automotive industry

The automotive industry relies heavily on hall-effect sensors to boost vehicle safety and performance. These magnetic field sensors are essential in many vital systems.

In the safety sector, Hall-effect sensors are used in anti-lock braking and traction control systems. They measure wheel speed with the utmost precision. This enables rapid intervention in the event of loss of grip.

For engine control, the hall sensor detects the position of the crankshaft and camshaft. This data is crucial for optimizing fuel injection and ignition. They improve performance and reduce fuel consumption.

Hall-effect sensors are also used to enhance comfort. They detect the proximity of doors and windows, as well as the control of electric seats. Their reliability and resistance to extreme conditions make them ideal for these applications.

The AH39xxQ series, specially designed for the automotive industry, demonstrates the evolution of these sensors. Qualified to AEC-Q100 Grade 0, it offers a wide voltage range and enhanced protection against electrostatic discharge. It meets the stringent requirements of the automotive sector.

Use in embedded systems

Hall-effect sensors are essential in embedded systems. They offer compact, reliable solutions for a wide range of applications. These non-contact position sensors are indispensable.

Motor control

In BLDC motors, Hall-effect sensors detect the position of the rotor. This information enables precise rotation control. This ensures efficient, stable operation. Household appliances and industrial equipment benefit from this technology to optimize their performance.

Current measurement

Hall-effect sensors measure current without direct contact. They generate a voltage proportional to the intensity of the magnetic field. This non-invasive method is very useful in sensitive electronic devices and power management systems.

Position detection

As position detectors, these sensors excel in automotive applications. They monitor crankshaft position to improve engine performance. In smartphones, they detect screen rotation, adapting the display to the device's orientation.

The integration of Hall-effect sensors in embedded systems offers significant advantages. Their small size makes them easy to fit into tight spaces. Their reliability and precision make them essential components for industrial automation. They improve production efficiency and equipment safety.

Advantages and limitations of Hall-effect sensors

Hall-effect sensors are characterized by their non-contact design, guaranteeing long life and reliability. They are resistant to contaminants such as dust and water, making them suitable for harsh environments. This robustness makes them particularly useful in harsh conditions.

Their ability to detect static and variable magnetic fields makes them indispensable in many industrial applications. Their sensitivity and linearity enable precise measurements, even under a wide range of conditions. This makes them versatile and reliable tools.

However, Hall-effect sensors have their limitations. Their sensitivity to temperature can affect performance, requiring compensation. Parasitic magnetic fields can also interfere with measurements, requiring appropriate shielding or filtering.

Their limited bandwidth makes them less suitable for high-frequency applications. Charge carrier concentration affects linearity. In addition, an offset component in the output and a voltage of inductive origin may require additional adjustments to ensure accurate measurements.

Installation and maintenance

Installation and maintenance of Hall-effect sensors are essential for their optimum operation. These devices, such as hall-effect switches and motion sensors, require meticulous attention. This applies to both installation and maintenance.

Installation procedures

Hall-effect sensors should only be installed by qualified personnel. These non-intrusive sensors can be easily integrated into existing circuits. It is crucial to check the voltage supply (3.3 V DC) and avoid vibrations. Sealing and correct mounting position are essential to optimize performance.

Calibration and settings

Regular calibration is crucial to maintaining sensor accuracy. These Hall-effect motion sensors detect flow rates from 50 ml/min to 2.5 L/min. They operate between 5 and 1 degrees. A test bench enables electrical and non-electrical checks, verifying operation, accuracy and thermal stability.

Preventive maintenance

The service life of a Hall-effect sensor is around 50,000 hours. To prolong this, we recommend regular cleaning of the system. Avoid electrical impact and overpressure. Hall elements are encapsulated to protect against moisture. Regular maintenance of the assembly line, including machine cleaning and replacement of wearing parts, ensures optimum performance.

Syscom-Prorep solutions for Hall-effect sensors

Syscom-Prorep stands out as a leader in the integration of Hall-effect sensors for industry. The company offers a complete range of solutions, tailored to the specific needs of each customer.

Range of products available

Syscom-Prorep presents a variety of Hall-effect sensors, including linear and digital models. These sensors are designed to operate in extreme conditions, with a temperature range from -40°C to +80°C. Their rugged construction includes a UL-746C-certified plastic housing and an IP66 waterproof rating.

Technical support and services

The Syscom-Prorep team provides comprehensive technical support for the installation and maintenance of Hall-effect sensors. Their expertise covers calibration, adjustment and preventive maintenance, ensuring optimum device performance.

Customized solutions

Syscom-Prorep develops customized solutions integrating Hall-effect sensors. These solutions can include NB-IoT connectivity options, long-life 4000 mAh Li-SOCl2 batteries, and anti-theft features. The company works with partners such as Opto 22 and Raltron to create complete automation and frequency control systems.

Conclusion

Hall-effect probes have transformed the measurement of magnetic fields, bringing unprecedented precision to many sectors. These devices, essential for analyzing materials, especially semiconductors, have revolutionized the field. Their ability to measure a wide range of parameters, from position to speed to current, makes them indispensable.

In the automotive industry, their importance is undeniable, notably for ABS braking systems and fuel level indicators. Their use also extends to computer hard disks. Unlike reed sensors, Hall-effect probes are characterized by their compactness and high-frequency performance.

The choice between these technologies depends on the requirements of each application. Reed sensors are distinguished by their energy efficiency and robustness under extreme conditions. Hall-effect sensors, on the other hand, are characterized by their versatility. This technological variety opens the way to exciting advances, promising a future rich in innovation for magnetic field sensors.

FAQ

What is the Hall effect?

The Hall effect, discovered by Edwin H. Hall in 1879, is a physical phenomenon. It occurs when a magnetic field passes through an electrical conductor. This creates a voltage perpendicular to both the current and the magnetic field.

How does a Hall-effect sensor work?

A Hall-effect sensor detects the presence or intensity of a magnetic field. The application of a magnetic field generates a voltage. This voltage is proportional to the intensity of the magnetic field, enabling magnetic changes to be measured or detected.

What are the main applications for Hall-effect sensors?

Hall-effect sensors play a crucial role in the automotive industry. They are used for ABS braking systems and engine control. In electronics, they enable non-contact current measurement. They are also essential in robotics for position detection. What's more, they are present in many household appliances and industrial equipment.

What are the advantages of Hall-effect sensors?

Hall-effect sensors offer several advantages. They are compact, durable and precise. They operate without contact and are affordable. What's more, they are resistant to dust and moisture, making them suitable for a wide range of industrial applications.

Are there different types of Hall-effect sensors?

Yes, there are several types of Hall-effect sensors. There are linear and digital sensors, unipolar and bipolar, as well as rotary and position sensors. Each type has unique characteristics, adapted to specific applications.

How do I install and maintain a Hall-effect sensor?

Installing a Hall-effect sensor means aligning it correctly with the magnetic field to be measured. Maintenance includes regular checks on alignment, electrical connections and calibration. It is crucial to follow the manufacturer's instructions for installation and maintenance, specific to each model.

What is the typical operating temperature range of a Hall-effect sensor?

The operating temperature range of Hall-effect sensors varies from model to model. It generally ranges from -40°C to +150°C. Some specialized sensors can operate in more extreme temperature ranges.

Can Hall-effect sensors measure electric current?

Yes, Hall-effect sensors are frequently used for non-contact current measurement. By detecting the magnetic field generated by an electric current, they can accurately measure current intensity without interrupting the circuit.

What's the difference between unipolar and bipolar Hall-effect sensors?

A unipolar sensor responds to a single magnetic pole (north or south), while a bipolar sensor can detect both poles. Bipolar sensors are often used in applications requiring more precise detection of direction or position.

Does Syscom-Prorep offer customized solutions for Hall-effect sensors?

Yes, Syscom-Prorep offers customized solutions for Hall-effect sensors. The company can tailor its products to specific customer requirements. It provides technical support and services to ensure optimal integration in a variety of industrial applications.

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