Magnetic Sensors

Magnetic Sensors: Definition, Working, Uses, and Benefits

Magnetic sensors are a popular type of sensing device found in small vehicles, including electric bicycles. They operate by detecting changes in the magnetic field generated when a magnet is in close proximity, allowing them to measure the vehicle’s speed, direction, and acceleration.

Uses of Magnetic Sensors

The primary use of magnetic sensors in electric bicycles is for pedal-assisted speed control. The pedal assist systems measure the rider’s pedaling rate and adjust the motor’s output accordingly, enabling riders to maintain a comfortable cadence while traveling at higher speeds than possible with standard pedal power. Additionally, magnetic sensors can also be used to monitor the bike’s battery life, assist with parking, remotely unlock the bike, or control LED lights or audio systems.

Working Principle of Magnetic Sensors

Magnetic sensors operate on a simple principle. They use two magnets – one fixed and one moving – to produce an alternating electric current that can be measured by a Hall effect sensor. The frequency of this current changes depending on how fast and far apart the magnets move, providing useful information about the bike’s speed and acceleration.

Benefits of Magnetic Sensors

  • Provides increased accuracy compared to traditional analog tachometer designs, delivering real-time readings that are precise to nearly 0.1km/h. This allows riders to have greater control over their riding experience.
  • Requires low maintenance due to their high durability in extreme conditions, making them suitable for rugged off-road trails and city streets.
  • Ideal for electric bikes as they can work efficiently with e-bike power systems, providing precise speed readings that can optimize pedal-assist performance.


In conclusion, magnetic sensors are an essential component of electric bicycles, providing accurate speed and acceleration data that enables pedal-assisted speed control. They offer several benefits, including increased accuracy, durability, and low maintenance requirements, making them an ideal choice for e-bike power systems.