Dynapar Magnetic Encoder Overview
The heart of an encoder is the way that it provides information – that’s the encoder engine. An encoder engine takes the positional and speed information and then supplies the signal that is sent to the application.
The engine type is categorized by the method that the control information is determined. There are two major categories:
- Optical Encoder engines, both masked and phased array
- Magnetic Encoder engine
The differences in the way that a magnetic encoder and an optical encoder gather information lead to performance differences in different operating environments. Understanding how an optical and magnetic encoder work can help determine what kind of encoder is best suited to your application.
The Technology of Magnetic Encoder Engines
An optical encoder uses light (optics) to identify unique positions for the encoder. A magnetic encoder uses the same principle to determine a position as an optical encoder, but it does it using magnetic fields rather than light.
With a magnetic encoder, a large magnetized wheel spins over a plate of magneto-resistive sensors. Just as the disk spins over the mask to let light through in predictable patterns, the wheel causes predictable responses in the sensor, based on the strength of the magnetic field. The magnetic response is fed through a signal conditioning electrical circuit.
The number of magnetized pole pairs on the wheel pole, the number of sensors, and the type of electrical circuit all work together to determine the resolution of the magnetic encoder.
The key to using magnetism as the element to produce a signal is that it is unaffected by very demanding environments – including dust, moisture, and extreme temperatures, and shock.
Magnetic Encoder Applications
A magnetic encoder is designed to output reliable digital feedback in the most demanding and harshest of application environments. Applications for this technology usually require broad temperature specs, high shock and vibration resistance, robust sealing, and contaminant protection all while focusing on output signal reliability, easy installation, and downtime reduction. Popular applications for magnetic encoders include position and velocity feedback in Steel, Pulp, Paper, & Lumber mills.
Dynapar's most-popular Magnetic Encoder products:
NorthStar RIM Tach NexGen line of digital tachometers
NorthStar SLIM Tach 56
Check out our broad selection of encoders and resolvers at http://www.dynapar.com/Products_and_Solutions/