This article describes a little-known technique for multiplying, dividing and otherwise manipulating AC and DC signals using flux-variable resistors (magneto-resistors) in a novel bridge configuration. The basic magneto-resistance bridge forms a four-quadrant multiplier, but with the aid of operational amplifiers, provides 0.1% linearity in squaring, square-rooting, modulating, mixing, demodulating, rectifying, and related applications. Read full article