United States Patent: 5784742, Giuliani, et al.
Toothbrush with adaptive load sensor
Issued: July 28, 1998
An electric toothbrush (10) with an adaptive load sensor (12) is disclosed. The toothbrush of this invention includes a brush head (16) that is vibrated by a drive assembly (18). The load sensor monitors the current drawn by the drive assembly to determine the mechanical load to which the toothbrush is exposed. The load sensor assembly produces an adaptive threshold signal that represents the instantaneous maximum pressure load. If the sensed load voltage exceeds the adaptive threshold signal, the load sensor assembly de-energizes the drive assembly and generatesan alarm signal so as to give the user a warning that the toothbrush has been excessively loaded.
Inventors: Giuliani; David (Mercer Island, WA), McMahon; Ryan W. (Seattle, WA), McInnes; James Christopher (Seattle, WA)
Assignee: Optiva Corporation (Bellevue, WA)
Appl. No.: 08/494,322
Filed: June 23, 1995
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