A non-directional frequency generator capable of minimizing frictional noise generated due to a mechanical rotation mechanism, including: a plurality of brushes connected with a direct current power source; and a commutator which converts a direct current waveform inputted from one of the brushes into an alternating current waveform by a rotational movement thereof, having a groove formed on an outer circumference thereof slanted inward to the commutator so as to reduce friction with the brushes during the rotation thereof.