Magnetoresistive sensors are very small components that are designed to sense an applied magnetic field. Because no electrical contact is required, the sensor can operate across a relatively large air gap. To make embedding possible, magnetoresistive sensors are designed to be small and operate on very little power.
The magnetoresistive effect is fairly straightforward: an applied magnetic field can change the resistance of an electrical conductor that permeates. The resistance increases or decreases depending on the orientation of the field lines about the direction of current flow. This anisotropic magnetoresistive sensor (AMR) can be contrasted with the Hall Effect sensor. In general Hall, effect sensors operate over shorter distances and are less accurate than AMR sensors. However, AMR sensors cannot detect full 360-degree rotation of the magnetic field where Hall Effect sensors do.
There is a wide range of applications for magnetoresistive sensors, most of which revolve around detecting the position or presence of an object. A magnetoresistive sensor can be embedded in a medical cabinet drawer to identify if it is in the open or closed position. A treadmill can use the magnetoresistive sensor as a type of dead-man switch, deactivating the treadmill if the safety key is removed. Read more Read less