In this simulation the square-wave source (1 ms period, 40% duty, 10% rise/fall) makes each element respond in its characteristic way: the resistor current follows the source almost exactly (i = v/R), so you see a square-like current that is essentially in-phase with the voltage. The inductor current cannot change instantly — it smooths the waveform into ramps and rounded peaks as it stores and releases energy (voltage impulses at edges produce gradual changes in i = (1/L)∫v dt). The capacitor c

Square Wave Using an Operational Amplifier #electronics | Electronics Byte