Sensors, referred to as contactless sensors, can be used to detect the position of a sensed object without contacting the sensed object. Contactless sensors include magnetic sensors, inductive sensors, and capacitive sensors.
Magnetic sensors include Hall-effect sensors and magneto-resistive (XMR) sensors. Where, magnetic sensors are used in sensors, such as position sensors, speed sensors, motion sensors, and proximity sensors in automotive, industrial and consumer applications.
Usually, in Hall-effect sensors, current flows through a Hall-effect sensing element or plate and a magnetic field perpendicular to the current flow deflects charge carriers due to the Lorentz force. The deflected charge carriers create a Hall voltage perpendicular to both the magnetic field and the current flow. This Hall voltage can be measured and is directly proportional to the magnetic field.
XMR sensors include anisotropic magneto-resistive (AMR) sensors, giant magneto-resistive (GMR) sensors, tunneling magneto-resistive (TMR) sensors, and colossal magneto-resistive (CMR) sensors.
Often, position sensors are two state switches, where the position sensor switches from one state to another state based on the distance that the sensed object is from the sensor. If the sensed object is closer to the sensor, the position sensor is in one state and if the sensed object is further away from the sensor, the position sensor is in another state. The position sensor, detects that the sensed object is in one of two regions. However, multiple position sensors are needed to detect that the sensed object is in one of more than two regions. This leads to an increase in the number of sensors and wiring, which increases system costs.
For these and other reasons there is a need for the present invention.