An adapter unit for adaptively supplying a portable radio telephone with power.

摘要

A portable radio unit (200) used with an adapter unit (1) having a hands-free circuit (70) and for adaptively supplying the portable radio unit with electric power. The hands-free circuit is activated in response to a contact between a connecter (T92, T62) of the portable radio unit and a connecter (T91, T61) of the adapter unit in the event that the portable radio unit is in a communication state when it is attached to the adapter unit. When the portable radio unit is not powered by its rechargeable battery (100) attached thereto or is not in a communication state when it is connected to the adapter unit, the first power supply circuit (40) of the adapter unit supplies the rechargeable battery of the portable radio unit. When the portable radio unit is in the communication state when it is connected to the adapter unit, the second power supply circuit (30) of the adapter unit supplies the portable radio unit through the rechargeable battery.