Brushhead replacement indicator system for power toothbrushes

摘要

A system for determining when the brushhead portion of a power toothbrush should be replaced. The system includes a piezoelectric transducer for detecting oscillations of the brushhead. The piezoelectric transducer produces an output signal which is used to drive a counter which accumulates the total number of such oscillations. When the total number of oscillations reaches a preselected number, which is representative of typical use of the toothbrush for a predetermined amount of time, e.g. six months, a signal is produced which drives an alarm indicator, the action of which is recognizable by the user of the toothbrush.