Magnetic Ring Encoder | Circular Encoder | Ring Encoder Working Principle

A magnetic ring encoder is a commonly used position sensor that determines position by measuring magnetic field changes. Its working principle relies on magnetic materials responding to field variations.

Typically a magnetic ring encoder has two parts: a fixed magnetic ring and a sensor mounted on the moving object. The ring, made of magnetic material, generates a field; the sensor—often a Hall element or magnetoresistive sensor—measures field variations.

As the object moves, the ring and its magnetic distribution move too; the sensor converts field changes into electrical signals to determine position.

Magnetic ring encoders operate in two modes: absolute and incremental. In absolute mode, the ring’s field distribution maps uniquely to absolute positions, allowing the system to recover exact position after power loss. In incremental mode, the field is periodic, reporting relative position changes and requiring a reference point at startup.

Magnetic ring encoders offer high precision and resolution, good stability and repeatability, fast response, and low latency, making them suitable for high-speed motion control.

In summary, magnetic ring encoders measure magnetic field changes to determine position and are widely used in machining, automation, and robotics for accurate motion control.