Patent ID: 7010978

Claim:
An electrically operated tuning fork apparatus, comprising: a tuning fork having a base and a pair of tines, said tines having tips remote from said base and formed of or including material in which a magnetic field can be induced; an electrical coil having a substantially linear longitudinal axis within said coil, at least a portion of both tines of said tuning fork being located within said coil and parallel to said axis, with no portion of said coil being located between the tines of said tuning fork; and a position sensor to provide a signal indicative of the position of said at least one tine so that the tuning fork can be maintained at resonance; whereby at least one of said tines can be vibrated relative to the other of said tines by passing a varying current through said coil to thereby induce mutually repulsive magnetic fields in said tines essentially transverse to said tines.