| 摘要 |
A battery pack (1), for use with a portable radio-receiving apparatus or radio-telephone such as a cellular telephone, comprising a plurality of rechargeable batteries (3) housed in a box (2) engageable with the apparatus or telephone and a call alert system (5) capable of detecting an incoming call signal and generating an alerting vibration. The call alert system (5) comprises an electronic circuit (6) generating a vibration by means of a micromotor (7) having an eccentric mass (7a). When the telephone replies to an incoming call, the electronic circuit (6) detects either an RF signal coming from the telephone or an electrical absorption signal through the batteries (3). Even if the portable telephone does not have a vibrating call alert system, the user does not need to change the telephone and buy a new one, but simply need to replace the existing battery pack. |
