A vibratory amplitude controller for vibratory mechanisms such as vibratory feeder having an addition to our parts container, electromagnetic drive unit operated from an AC current source for imparting oscillatory motion to the parts container. The controller includes a sensing means for sampling the electromagnetic drive unit currents during a specific predetermined interval each AC current cycle to produce a vibratory amplitude representing signal means responsive to the vibratory amplitude representing signal controls the amount of power delivered from the AC current source electromagnetic dive unit to maintain a desired vibratory amplitude under varying load and AC line voltage conditions.
