A basic magnetic speed sensor, also known as a magnetic pickup or magnetic proximity sensor, is a type of speed sensor used to measure the rotational speed of a target object equipped with a ferromagnetic material. These sensors are widely used in various applications, such as automotive, industrial, and machinery systems.
Here's a general description of how a basic magnetic speed sensor operates:
Principle: The sensor operates based on the principle of electromagnetic induction. When a ferromagnetic target, such as a gear or a toothed wheel, rotates in close proximity to the magnetic speed sensor, it induces changes in the magnetic field, which the sensor can detect.
Construction: The magnetic speed sensor consists of a magnet or a coil surrounded by a protective housing. The sensor is typically mounted in close proximity to the rotating target. The target, in turn, has a series of evenly spaced ferromagnetic elements (such as teeth) on its surface.
Magnetic Field Variation: As the ferromagnetic elements on the rotating target pass by the magnetic speed sensor, they create fluctuations in the magnetic field around the sensor. These variations generate a corresponding electrical signal within the coil of the sensor.
Signal Output: The electrical signal produced by the coil is typically an alternating current (AC) voltage signal with a frequency proportional to the rotational speed of the target. The faster the target rotates, the higher the frequency of the output signal.
Signal Processing: The output signal from the magnetic speed sensor is processed by the control system or an electronic module. The system can convert the frequency of the signal into actual speed values (RPM - Revolutions Per Minute) through calibration and calculations.
Applications: Magnetic speed sensors find applications in various fields. In the automotive industry, they are used in vehicle speedometers and transmission systems to determine vehicle speed. In industrial settings, they are used in monitoring and controlling the speed of rotating machinery like motors, generators, and conveyor belts.
Overall, magnetic speed sensors are simple and reliable devices that provide an effective way to measure rotational speed in many mechanical systems. Their ease of installation, durability, and accuracy make them a popular choice for speed measurement in a wide range of applications.