Considerations of output voltage waveform on magnetic linear encoder for artificial heart using linear pulse motor

Abstract

Sinusoidal output voltage waveforms have been considered on magnetic linear encoders which are used to detect a displacement of a mover on an artificial heart using a linear pulse motor. The magnetic linear encoder needs to be miniature, able to detect a small displacement and able to control speed. A new idea using the tooth of a mover has been developed to detect the displacement by using a small magneto-resistive element which is capable of high frequency response. Obtained results are as follows: (1) the magnetic linear encoder for the linear pulse motor was considered and clarified as a structure and a principle operation; (2) the sinusoidal output for the magnetic linear encoder was formatted with the output waveform of 29.9 mV and a distortion factor less than 10%; and (3) it was found that a bias gap of maximum output voltage was not dependent on the tooth pitch of the linear pulse motor mover when the detecting gap was fixed.