Hall Effect Sensor

Hall Effect Sensors: A Brief History & Explanation

Over 100 years since the discovery of the Hall effect, sensors using this technology are common today and their applications are diverse. In fact, Sensor Solutions alone offers thousands of unique magnetic field sensors. Find out more about the Hall effect as we explore its history and its relevance to modern industry.

The Hall effect was named for Edwin H. Hall, who discovered in the late 1800s that it was possible to measure a transverse voltage in the presence of a magnetic field on an electrical current. For example, when an electrical current is passed through conductive or semi-conductive material while exposed to a perpendicular field of magnetic flux, the negative charge carriers are deflected to one side, while the positive charge carriers move to the opposite side. The difference in potential across this plane is the Hall voltage. A Hall effect sensor effectively converts this transverse voltage produced from the magnetic field to an electric signal. Though Hall's discoveries were well received in his day, it wasn't until the last 30+ years that they would be fully utilized with the help of supporting technologies in numerous applications, from use in our everyday living, to large-scale factories and production lines.

There are two basic types of Hall effect sensors: threshold devices and linear devices. More subtypes and configurations for each kind exist, but we will just describe a brief, functional overview. Threshold devices are the digital, on/off type of sensors, while the linear devices are the analog output sensors. For example, counters or proximity switches are types of threshold sensors. The sensor is configured to switch on or off when the field strength crosses a certain threshold. Linear devices, or analog Hall effect sensors can produce a Hall voltage proportional to the strength of the surrounding magnetic field. However, to make this voltage useful in most applications, supporting technologies such as an amplifier are usually required. It was the development of the supporting technologies in the last few decades that really launched the use of the Hall effect magnetic sensors on a larger scale.

Today, Hall effect sensors are used in proximity switching, monitoring speed, positioning, direction, and more. These sensory devices are used in a wide range of industries, including computer technologies, automotive and aircraft, medical equipment, industrial and agricultural equipment, and mass production lines, to name a few. The use of these technologies not only helps in the actual function of everyday devices, but also provides and tracks data, or indicates changes or anomalies within a greater system. Hall effect sensors can help act as protection for your machinery or devices, signaling when something requires immediate attention to help prevent problems from escalating down the line. Designing Hall effect sensors for these types of early detection and even safety preventatives can save you time, money, and energy from having to constantly check over or review your systems.

Hall effect devices are also beneficial with their long lifespan, high repeatability, and quick output generation. They are sold state sensors with no moving parts, and they are fairly inexpensive to produce. Hall effect devices can also survive a broad temperature range. Their practicality and versatility can serve any industry with vast numbers of applications. They help keep your devices or operations running smoothly and effectively at all times.