Tiny encoder makes waves

Inductive encoders operate by tracking reactionary current-flow resistance (to nearby material) in one or more coils. However, there are drawbacks to simple inductive encoders, such as the temperature dependence of their soft iron or ferrite. External magnetic fields can also push their material's permeability to well below the saturation point. One alternative is ironless inductive encoders. These far more accurate sensors have long been featured in large motors, but have not been produced for micromotors until now, according to sources at maxon motor, Fall River, Mass. The company has invested in the development of these miniaturized encoders, and the result is the MILE (maxon's Inductive Little Encoder), an inductive encoder in which eddy currents generate contrast. It is possibly the smallest of its kind in the world. The new encoder delivers 64 pulses at up to 120,000 rpm and has three channels. Suitable applications include medical technology, robotics, and industrial applications in harsh environments. For more information, visit www.maxonmotorusa.com.