Electric toothbrush with motor energised by plate capacitor

摘要

An electric toothbrush (2) or other device which is used for only short periods e.g. 3 mins has a motor (3) which is energised by a plate capacitor (4) having gold surfaces. A mains supplied sealed charging station (1) has a primary induction coil (7) which interacts with a secondary coil (6) in the base of the toothbrush (2) and charges the capacitor (4) rapidly via a series connected rectifier unit (5). The normal exponential discharge rate of the capacitor (4) is modified by an electronic voltage regulator (9) which optimises the transfer of the available capacitive energy over the period of use.