The Hall-effect compass

Abstract

Recent work on semi-conductors has led to materials in which the Hall effect in the earth's magnetic field is strong enough to form the basis of a simple electrical compass. The theory of the device is briefly presented and expressions derived for the voltage and power output, and the ultimate sensitivity obtainable. The comparative merits of various semi-conductors are shown in tabular form; this information should be useful also for other devices based on the Hall effect.