Method and apparatus for controlling electromagnetic parts feeder

An apparatus for controlling an electromagnetic parts feeder, comprising:

• a vibrating unit provided with an electromagnet that vibrates at a predetermined frequency;
• a bowl adapted to discharge parts accommodated therein by means of said vibrating unit;
• a driving circuit for driving said electromagnet;
• a control unit for outputting a driving signal to said driving circuit to cause a predetermined driving and temporarily idling the driving of said electromagnet at every predetermined driving cycles of said electromagnet;
• a signal detecting means for detecting a waveform of a signal obtained from a coil of said electromagnet by its electromagnetic induction during a period of said idling;
• a phase difference detecting means for detecting a phase difference between the waveform of said signal obtained by said signal detecting means and a waveform of said driving signal of said driving circuit;
• and
• a vibration controlling means for controlling vibration of said electromagnet based on the phase difference obtained by said phase difference detecting means.