While many types of sensors are used to measure electrical currents, the volume or flow of liquids or gases, or even changes in pressure or humidity in the atmosphere, there are also sensors that have more specific but equally important roles in machine and equipment operation. A good example of these specialized devices can be found in Hall effect sensors.
What is the Hall Effect?
The Hall effect is named after its discoverer, Edwin Hall. He found that within a system that includes an electrical conductor begin transverse to an electric current, a magnetic field will develop that is perpendicular to the electric current.
This creates a voltage difference, which is known as the Hall voltage. However, different components within the system, such as different types of electrons or metals, creates different levels of variance between the positively charged electrons and the negatively charged electrons, resulting in a very effective way to measure the magnetism of the system.
This is important because it is the combination of the electrical current and the magnetic field generated that can be used to create movement within an electrical system. Different types of devices from loudspeakers to headphones and virtually anything operating with an electric motor relies on the Hall effect.
How it Works
Most commonly the Hall effect sensors are essential to monitor the voltage and maintain a steady flow through the system. In a very simple explanation think of a straight line of electrons moving through a system in a straight line, which won’t create any movement.
Then, by creating a magnetic field, this causes them to arch or move away from that straight line. When this happens, one side of the system becomes more heavily saturated with electrons, creating a difference between the positive and negative voltage, and resulting the ability to create movement within the system.
The most common and least costly option to measure this voltage change is through electronic Hall effect sensors that are very small and can have a variety of different appearances based on the specific use requirements. They are accurate and effective and are readily available through most electronic stores and online retailers.
Typically, Hall effect sensors are used to measure distance, proximity, or positioning, but they can also be used to determine speed through positioning measurements over time. They can be used in all types of alarm systems or in notification systems and, since all they need is a magnetic plate on the other component, they are a low-cost option for many applications.