Detecting Velocity on a Linear Moving Object by Induction Electromotive Force

Abstract

It is tried to develop the Induction Electromotive force type Velocity Detector (IEVD) that detects directly velocity of linear moving objects. The IEVD can directly detect velocity with high resolution, without contact on an object and dosen't give any effect on the object. The IEVD detects electromotive force in proportion to velocity from the pararell electrodes on belt-shape resistor film. The IEVD is constructed with resistor film with two pararell eloctrodes, magnets and yoke moving with an object and some electric circuits. The circuit of detector is simply constituted with electric adder circuit, amplifier and low-pass filter.
From simulation on electric circuit about resistor film, error of IEVD is low when resistivity of resistor film is high and resistivity of electrodes on resistor film is low. From experiment, it becomes clear that output of IEVD is in proportion to velocity of standard detector. For more large output voltage, some resistor films are put in layer and magnet is made wider.