HallSensor

HallSensor, or Hall effect sensor, is a device that detects magnetic fields using the Hall effect. It typically consists of a thin conducting layer through which a bias current flows; when a magnetic field is present perpendicular to the layer, charge carriers are deflected, producing a transverse Hall voltage. The Hall voltage is measured and conditioned to provide either an analog output proportional to field strength or a digital switch output that toggles when the field crosses a threshold.

There are two common forms: linear (analog) Hall sensors, which output a voltage roughly proportional to the magnetic field, and switch-type Hall sensors, which provide a binary on/off signal around a specified trip field. Some devices include integrated signal conditioning and temperature compensation, and outputs can be ratiometric to the supply voltage or in digital formats such as open-collector or push-pull.

Key performance parameters include sensitivity (volts per magnetic field unit), temperature stability, offset, linearity, supply voltage range, and bandwidth. The sensing element is typically made from silicon or other semiconductor materials, and many designs use a magnetic flux concentrator to boost sensitivity.

Applications include non-contact measurement of speed and position in automotive wheel speed and crank/cam sensors, brushless DC motor commutation, industrial position sensing, current sensing, and proximity sensing. Benefits include lack of mechanical wear, compact size, and fast response; limitations include temperature drift, offset, and dependence on external magnetic fields.

The Hall effect was discovered by Edwin Hall in 1879, and modern Hall sensors integrate the sensitive element with conditioning circuitry to provide practical sensing solutions.