Abstract: A generally figure-of-eight transformer core carries first, second and third toroidal windings spaced along its central leg and is formed with magnetic shunts across the gaps between central and outside legs in the planes between windings. A capacitor is connected across the second winding of value so that it coacts with the effective leakage reactances provided by the magnetic shunts so that the output load current provided by the third winding is directly proportional to the input voltage applied across the first winding independently of the load impedance and with low distortion, even in the presence of high harmonic content in the input voltage and a nonlinear load impedance.