Paul Acarnley is Professor of Electric Drives at the University of Newcastle upon Tyne, UK. His interest in stepping motors started at Leeds University, with a Ph.D. on the torque-producing capabilities of variable-reluctance stepping motors, and continued at Cambridge University, with work on new closed-loop and microprocessor-based control techniques. Besides stepping motors, Paul Acarnley's research interests include the application in electric drives of methods for estimating and controlling speed, rotor position, flux, torque and temperature. He is a Fellow of the IET.