Hall-Effect Sensors

When a magnetic field is applied perpendicular to a charged plate, the electrons move to one side - creating a potential between the sides. This is termed the “Hall Effect” after Edwin Hall who discovered it in 1879. The charge between each side can be used to measure the field or operate a switch (after amplification). The output of Hall-effect sensors can be either analogue or digital (by adding a Schmitt trigger to the circuit). The analogue types are often used in precision laboratory instruments while the digital types find many applications as limit switches in CNC machines, 3D printers and factory automation.