What is a Magnetic Sensor? from AutomationDirect

Magnetic sensors are the unseen force behind much of today's technology. From small sensors that ensure your smartphone's screen rotates correctly, to those enabling the precise functioning of industrial robots, these sensors play a pivotal role in our daily lives. So, what is a magnetic sensor? A magnetic sensor detects magnetic fields and converts this information into electrical signals. This capability allows it to monitor position, proximity, motion, and even the direction of an object. One of the most common types is the Hall Effect sensor. Discovered by Edwin Hall in 1879, it operates on the principle that when a magnetic field is applied perpendicular to a current-carrying conductor, it induces a voltage—the Hall voltage—transverse to the current. (Wired) These sensors are used in a wide range of applications! In automobiles, they monitor wheel speed for anti-lock braking systems. In smartphones, they detect the device's orientation, ensuring your screen displays correctly. Industrial robots rely on them for precise position sensing, enhancing automation efficiency. But Hall sensors aren’t the only variation. Other types include reed switches that open or close circuits when exposed to a magnetic field and magneto-resistive sensors, which change their electrical resistance in response to magnetic fields. At AutomationDirect, we carry magnetic proximity sensors that are based on magneto-resistive technology. GMR or Giant Magneto Resistive Effect technology has measuring cells consisting of resistors with several extremely fine, ferromagnetic, and non-magnetic layers. Two of these GMR resistors are used to form a conventional Wheatstone bridge circuit which produces a large signal proportional to the magnetic field when a magnetic field is present. A threshold value is defined, and an output signal is switched via a comparator. These sensors are used for non-contact position detection beyond the normal limits of inductive sensors. These can detect magnets through walls made of non-ferrous metal, stainless steel, aluminum, plastic, or wood. We also offer position switches for our NITRA pneumatic cylinders. Cylinder position switches can be used in pneumatic systems to determine cylinder position, cycle count, or confirm the operation. Superior to reed switches, these reliable solid-state switches have no moving parts for longer life and are designed for use with cylinders with magnetic pistons. Cylinder position switches are mounted directly on the cylinder body and detect a permanent magnet attached to the end of the piston through the cylinder housing. Technological advancements have produced more compact, sensitive, and energy-efficient sensors. These innovations are paving the way for smarter electronics in more responsive automation systems. For all your industrial automation needs, and more information on our full lineup of sensors, visit us today at AutomationDirect.com! Click here to learn more about our sensors. Click here for more videos.