The Hall effect multiplier: A contribution to analog multiplier technology.

Abstract

A purely electronic four-quadrant analog multiplier of wide bandwidth and good accuracy has always been an unobtainable goal to the electrical engineer. With the availability of intermetallic compounds commercially, there has been a renewed interest in the use of Hall effect for multiplying two quantities together. Starting with the classical theory of Hall effect and magnetoresistance, this thesis carries on by comparing those materials that lend themselves to Hall effect multiplication. Due to the ease in obtaining indium arsenide (InAs) wafers commercially, a Hall element was selected which was embodied in a magnetic core of grain oriented silicon steel. In chapter III intrinsic errors, or those errors associated with the Hall element, are rigorously discussed. Several compensation schemes have been suggested to reduce these errors; some of which are incorporated in the final multiplier design. Chapter IV continues on by analyzing the Hall generator errors. These errors, associated with the Hall element in connection with its magnetic circuit, originate mainly because of the nonlinearities of the magnetic core. In essence chapter V is concerned with those errors introduced externally in putting the Hall effect to use. Finally in chapter VI the experimental results of the practical Hall effect multiplier are outlined. The accuracy of the prototype multiplier has been found to be of the order of 0.5% with an effecti7e bandwidth of 680 cps.