Wiegand sensors in large numbers

Wiegand sensors can be used as proximity switches in different ways. If, for example, the object to be detected is magnetized by itself or equipped with one or more small permanent magnets, the Wiegand sensor reacts as soon as the object comes so close that the polarity is reversed and the voltage pulse is generated. This effect can be used to precisely record and measure linear or rotary movements, for example. 

Alternatively, the Wiegand sensor can also be installed as a proximity switch between a set of permanent magnets. If an iron or steel object comes too close to it, the magnetic field immediately around the Wiegand sensor is distorted to such an extent that the polarity is reversed and the current pulse - and thus the alarm signal - is triggered.