Touchless Rotary Sensors White Paper
Product Announcement from Novotechnik U.S., Inc.
A new generation of touchless position sensors solves a number of new problems while simplifying existing on-line control applications by providing design engineers with an opportunity to reduce implementation and maintenance costs. This technology can solve problems from measuring through materials to existing shaft alignment issues.
Novotechnik's new generation of touchless sensors utilize a magnetic field Hall Effect element. The Hall Effect is the production of a potential difference (the Hallvoltage) across an electrical conductor in which an electric current flows in the presence of a magnetic field. The direction of the potential difference is perpendicular to both the magnetic field and the current.
In a touchless position sensor, a permanent magnet attached to the rotating shaft is used as a position marker. The orientation of the magnetic field is captured using an integrated circuit. The analog output represents the calculated angle.
Since the rotating shaft with the position marker is separate from the sensor,these touchless systems are ideal for applications that require an extended maintenance-free life, mounting flexibility, or transmissive measurement through air or non-magnetic materials.
Touchless angle sensors are also ideal in applications where torque must be kept to a minimum, for example devices used to measure wind direction or dancer arm applications (e.g. wiring, textile, and printing). In the past this application required expensive sensors with special bearings to dampen torque to levels as low as 0.002 to 0.003 Ncm. Since there are no axial or radial forces to adversely affect the accuracy or the life of touchless sensors, they are ideal for demanding applications. There's no friction and no mechanical parts to wear out. As a result, Novotechnik touchless angle sensors have unlimited mechanical lifetimes.In contrast to conventional low-torque angle sensors that require an intricate manufacturing process and expensive materials, touchless sensors are simpler to manufacture and consequently less expensive.