How many poles does the disc magnet in the sensor section typically have?

In various position detection and speed feedback applications, the shapes of magnets commonly used in conjunction with sensors are mostly circular, ring-shaped, and hollow cylindrical. Some netizens have asked how many poles are typically found in the circular magnetic pieces of the sensor part?

Actually, the number of poles of a circular magnetic sheet is not fixed, but rather determined by application needs, resolution requirements, and the type of sensor it is paired with. It can have as few as 2 poles or as many as hundreds of poles.

In conventional applications, 2-pole circular magnetic pieces are the most basic and widely used form. Structurally, they typically feature a symmetrical distribution of one N pole and one S pole (either axially or radially magnetized). This approach is commonly used for simple Hall switch speed measurement or position trigger detection. Its advantages include low cost, simple processing, and stable magnetization. However, its resolution is relatively low, typically outputting only one complete signal cycle per revolution, making it suitable for applications where precision is not critical.

Sensor circular magnet

When applications demand higher resolution, circular magnetic sheets are magnetized with 4, 6, or 8 poles. As the number of poles increases, the number of signal cycles generated per revolution also increases, thereby enhancing detection accuracy.

In precision positioning or magnetic encoder systems, high-pole count magnetic rings with 8 or more poles, even 32 or 64 poles, are increasingly employed. These rings have smaller pole pitches, necessitating stringent requirements for the magnetization equipment and consistency of magnetic properties.

The above is an introduction to the circular magnetic pole of the sensor part. The core depends on the resolution requirements, speed range, and sensor type. For specifications and quotations, please contact our website customer service.

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