How does a magnetic ring work?

When talking about how a magnetic ring works, you can imagine it as a circle that performs "magic." It can transmit information without directly touching other parts.

The Invisible "Magnetic Ruler"

Internal Structure: Although the magnetic ring looks plain on the surface, even resembling black rubber, its interior is evenly divided into many small squares.
Alternating Polarity: Each small square is a miniature magnetic pole. These positive (N) and negative (S) poles are arranged in a line, one after another, around the circle. This is like having an invisible "scale" etched onto the ring.

Generating Signals Through Movement

Rotating with the Wheel: When the machine or wheel rotates, the magnetic ring installed on it also rotates rapidly.
Passing the Sensor: Next to the magnetic ring, there is usually a "receiver" (i.e., a sensor). As the magnetic ring rotates, its positive and negative poles alternately "pass" in front of the sensor.

Magnetic Field Fluctuations Become Data

Sensing the Magnetic Field: The sensor is very sensitive and can feel the magnetic field constantly "pushing" and "pulling."
Translating Magnetic Pulses: When a positive pole passes, the sensor generates one signal; when a negative pole passes, it generates another signal.
Calculating Speed: The faster the magnetic ring rotates, the higher the frequency of these signal pulses. The computer can accurately determine how many rotations the wheel has made and its rotational speed by counting how fast these signals are pulsing.

Why use this method?

Contactless Transmission: Because there is no physical contact between the magnetic ring and the sensor, there is no friction loss, resulting in a very long lifespan.
High Accuracy: This method of generating signals through alternating magnetic poles is much more accurate than older mechanical gears, and can even detect very subtle changes in speed.

Tip: What can interfere with it?

Iron Filings are the Enemy: Because it is magnetic, if small iron particles from the road surface adhere to the magnetic ring, it's like smearing mud on the "scale," preventing the sensor from reading the correct signal. Powerful magnets: If you bring a very strong magnet close to it, it might disrupt the alignment of the magnetic poles, causing it to malfunction.