A Hall effect sensor is a transducer that detects the presence of a magnetic field. It works on the principle of the Hall effect, which was discovered by Edwin Hall in 1879. The Hall effect is the production of a voltage difference (Hall voltage) across an electrical conductor when a magnetic field is applied perpendicular to the current flow.
Hall effect sensors are commonly used in various applications, including:
Proximity Detection: They can detect the presence of ferrous (magnetic) objects, making them useful in applications like proximity switches.
Speed Measurement: In some cases, Hall effect sensors are used to measure the speed of rotating objects with magnets attached, such as in wheel speed sensors for automotive applications.
Current Sensing: Hall effect sensors can measure the current in a conductor without physical contact. They are used in current sensors and current transformers.
Position Sensing: In combination with magnets, they can be used for position sensing, such as in rotary encoders and linear position sensors.
Brushless DC Motors: Hall effect sensors are often used to determine the rotor position in brushless DC motors, allowing for precise control of the motor.
Magnetometers: They can also be used in magnetometers to measure the Earth's magnetic field for navigation and compass applications.