POWER TOOTHBRUSH WITH ADJUSTABLE OPERATION

The system changes frequency of the toothbrush to adjust the amplitude of motion of the brush portion of the toothbrush. The change in frequency occurs either manually or automatically. In the manual embodiment, the user, via a switch and internal circuitry, can adjust the operating frequency of the toothbrush which results in a change of amplitude to a value which is most comfortable to the user. In the automatic mode, the resonant frequency of the toothbrush is determined upon initiation of the operation of the toothbrush. The resonant frequency value is then offset by a selected amount, usually higher than the resonant frequency; this offset frequency is the operating frequency of the toothbrush.