| 摘要 |
A cordless electrical appliance is provided with an adapter unit and the two of them can be rested upon a base unit. The base unit has contacts connected to a supply voltage, and includes an appliance-current path with appliance-current-path contacts, and an auxiliary-current path with auxiliary-current-path contacts. The base unit includes a step-down transformer whose primary is connected across the voltage-supply contacts and whose secondary is connected in the auxiliary current path. The auxiliary current path includes a relay winding which controls a relay switch in the appliance-current path. Both the adapter unit and the base unit are provided with grounding devices. The adapter unit is likewise provided with appliance-current-path contacts. When the appliance with its adapter unit is seated upon the base unit, in a particular predetermined position, the appliance-current-path contacts of the two units engage, and connecting means on the adapter unit bridge the auxiliary-current-path contacts of the base unit, thereby energizing the relay winding and closing the relay switch in the appliance-current path, and the grounding devices of the two units become electrically connected to each other.
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