A digital hysteresis loop experiment

A toroid with primary and secondary windings is used as a transformer to generate magnetic hysteresis curves. The primary winding is driven by a signal generator, which induces an alternating voltage in the secondary winding. Both input and output voltages are captured using a digital storage oscilloscope and processed to generate and display a hysteresis curve. We show such curves are representative of the material used as the transformer core. Data acquisition and processing steps are presented in a manner suitable for use in an undergraduate laboratory or lecture demonstration.