In this Demonstration, a 50 Hz variable-amplitude voltage is applied to an ideal saturable inductor (with no hysteresis) to determine the corresponding magnetizing current waveform. The voltage-current curve is drawn using the arctangent function. Two parameters are used to adjust this nonlinear relationship: the amps-volts reference factor, which acts as a scale factor for the current, and the saturation level, which indicates the voltage level at which saturation becomes more evident. The current plot is displaced half a cycle (0.010 s) because of the inductive nature of the circuit.