| 摘要 |
This invention includes an adaptor for use with a master-slave telephone system. The system comprises at least one slave telephone and a master control telephone for selectively controlling the application of telephone signals. The adaptor of this invention comprises means for determining when the master controlling telephone is on hook and not in use, the adaptor disables the slave telephone. The determining means comprises a switch operative in a first state for connecting the telephone line to the slave telephone and in a second mode for disconnecting the telephone line from the slave telephone, and a sending means adapted to be connected to the slave telephone to sense the presence of a telephone signal passing along the telephone line and derived from the master control telephone, whereby upon sensing the presence of the telephone signal, said adaptor supplying the telephone signal is applied to the slave telephone. |
