Motor Hall Effect Sensor Magnetic Ring

Hall-effect magnetic rings are frequently used in brushless motors and certain fixed-speed motors. In the brushless motor industry, they are also referred to as Hall-sensing poles. This is because Hall-sensing magnetic rings are typically multipolar rings (featuring multiple N and S poles). Their operating principle relies on the interaction between the ring's multiple magnetic poles and the Hall element to detect the motor's rotational speed and efficiency. The motor's operation can then be controlled based on the signals provided by the Hall-sensing magnetic ring.

Hall-effect magnetic rings do not require exceptionally strong magnetism. As long as multiple poles are arranged to provide pole signals to the Hall element, the Hall element can receive signals and function normally. Therefore, Hall-effect magnetic rings are predominantly made of ferrite material (typically sintered or molded ferrite). These ferrite rings offer stable magnetism with distinct magnetic poles that deliver stable pole signals to Hall sensors. This makes them widely used in speed measurement applications. Depending on brushless motor requirements, both axial multipole and radial multipole magnetic rings are available. The surface magnetic flux density of these rings is typically around 1000 Gauss—neither too strong nor too weak—sufficient to provide signals to Hall sensors without interfering with the motor's own magnetic circuit operation.

However, due to differences across industries, specialized terminology for these products varies. terms like Hall-effect magnetic rings, multipole sensing rings, Hall-effect magnetic poles, radial sensing rings, and radial multipole ferrite rings are used. Yet, upon examining product usage, most are confirmed as Hall-effect magnetic rings. Radial multipole ferrite Hall-effect magnetic rings, with their low cost and stable magnetic properties, are extensively applied in brushless motors, stepper reduction motors, and similar products.