Hall sensors are among the most widely used sensor types today. Now available on click boards.
BI HALL click is a bipolar Hall effect switch, meaning it's sensitive to both magnetic poles:
It outputs a HIGH logic level when exposed to a south pole magnetic field, and a LOW logic level when exposed to a north pole magnetic field. When you remove it from a magnetic field, the logic level stays in its previous state.
After Hall current click, this is our second click board utilizing the Hall effect, with two more on the way. So it's worth recalling the basics:
Electrons traveling through a conductor are diverted from their straight path when exposed to a perpendicular magnetic field. A voltage develops across the conductor. A small voltage, measured in miliVotls. Still, Edwin Hall managed to detect it in his lab in Baltimore in 1879, and the effect is named after him.
Hall sensors have several distinct advantages: their sensitivity is not impeded by dirt or dust. Since the measurement is contactless, they're also not subject to mechanical wear and tear.
Hall sensors are used in cars, consumer electronics, industrial machines—anywhere where there is a moving magnet or a magnetic field.
The bipolar sensor is especially suited for applications where alternating north and south poles are used to ensure switching. For example, to measure rotary speed by utilizing a ring magnet.