To calculate the speed and the mileage when riding a bicycle, a speedometer is used. A spoke mounted magnet activates a Reed Sensors sitting at the fork.
The signal is transmitted to the bicycle computer which calculates speed an mileage with the number of wheel turns (means Reed Sensor activations) and
the wheel diameter.
Modern buildings use automatic blinds
to provide shadow and heat protection. These blinds a very prone to fast winds and storms.
A wind meter uses a fan with a magnet and a Reed Sensor to calculate the current wind speed and to automatically draw the blinds up if the wind speed exceeds a certain level.
Electric motors of e-bikes and pedelecs are supporting the deployed body power in subject to the current speed. The current speed is measured with a spoke mounted magnet and a Reed Switch at the fork.
Each wheel turn activates the Reed Switch, the motor control united counts activations and multiplies them with the wheel diameter. Additional motor power is set free according to the measured speed.