Tachogenerator having a magnetoresistance stator coil

摘要

A tachogenerator has a magnetoresistance film coil formed on a stator surface along a circular path concentric with a rotor axis. The coil has a spatially periodic structure, with multiple spaced-apart lateral components series connected with longitudinal components. The stator surface is opposite to a rotor surface having multiple equiangularly spaced magnetic pole faces with alternately opposite polarities. Current passed through the coil develops voltage variations. Undesirable small voltage variations resulting from manufacturing tolerances are averaged to zero at the coil output terminals.