Abstract: A control system for a bidirectional switch (20) is described, formed of a pair of MOFSET power transistors (210, 220) connected in anti-series, i.e. source to source or drain to drain. This control system includes means (50) allowing the state of conduction of the power transistors to be controlled, one or the other of these transistors being able to be set to the “OFF” state in order to assure the interruption of a current through the bidirectional switch (20). This control system includes coupling means (SWCPL, 510) enabling the gate of the power transistor at the “ON” state to be coupled at least temporarily with the gate of the power transistor at the “OFF” state when the bidirectional switch is switched on. This has the advantage of allowing, on the one hand, the use of high control voltages assuring a reduction in the series resistance of the power transistors, and, on the other hand, the bidirectional switch to be quickly switched on.

Abstract: An apparatus equipped with a battery, such as an electrical toothbrush, receives from a charging device a charging voltage which adapts to the charged condition of the battery and on whose over-discharging is correspondingly small. On the one hand the apparatus comprises a series circuit between a capacitor and a diode which is connected to the charging device parallel to the battery, wherein the diode is arranged in the forward direction. On the other hand in series to the battery there is arranged an electronic switch which periodically for a short time interrupts the charging procedure of the battery. In each case during such an interruption the charging apparatus is unloaded and its voltage increases jump-like by which means the capacitor can be charged via the diode. In each case with a closed switch, i.e.