China Neodymium And Ferrite Magnets Manufacturer & Supplier 
The electronic gear shifter is commonly used in electric vehicles and some intelligent transmission systems. The gear-shifting sensing mechanism inside typically employs permanent magnets to work in conjunction with Hall sensors, enabling gear identification, transmission control, and position detection. This article primarily introduces the sensing magnets used here, including their working principles, materials, and functions.
The working principle of the induction magnet used in electronic shifters is based on physical phenomena such as electromagnetic induction and the Hall effect. At its core lies a multipole magnet (primarily ring-shaped). Taking a common 8-pole magnetic ring as an example, eight magnetic poles are evenly distributed around the circumference in an alternating N-S-N-S pattern, with each pole corresponding to a 45-degree angle. The magnetic ring is fixed to the knob base and rotates synchronously with driver operation. Multiple Hall sensors or magnetic encoder chips are installed at fixed positions beneath the magnetic ring, typically requiring at least two sensors with a 90-degree phase difference to form an orthogonal configuration. As the knob rotates, the sensors sequentially pass over different magnetic poles, outputting periodically varying sine and cosine signals. By detecting the signal amplitude, phase, and zero-crossing points, the control unit precisely calculates the knob's absolute angular position. Different gear positions (P, R, N, D, S, etc.) correspond to preset angular intervals. When the knob rotates into a specific interval and remains stationary, the system identifies that gear position as selected.
Product is an injection molded multipole ring magnet.
In terms of materials, sintered ferrite and injection-molded ferrite are primarily used, with some applications also employing injection-molded neodymium iron boron. All these materials require molds. Among them, injection-molded magnets can be formed as a single piece, offering excellent impact resistance. They are magnetized using a multi-pole magnetization method.
Regarding function, the primary role of magnets is to generate a magnetic field. Here, the sensing magnet serves the same purpose—providing detectable magnetic field changes that enable the Hall sensor to detect the gearshift action.
The above covers the relevant details about sensing magnets for electronic shifters. Our company specializes in motor magnets and possesses numerous molds for injection-molded and bonded multi-pole magnetic rings. If you require samples or a quote, please provide dimensions and technical specifications.
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