| 摘要 |
<p>PURPOSE:To eliminate a battery having being required for memory backup and dial number write by using a telephone line as a power supply so as to apply the memory backup and dial number write. CONSTITUTION:When a mode designation switch 5 designates the write mode and the handset is hooked off in this state, an on-hook signal is inputted to a HOOK terminal of a selection signal generating circuit 4. That is, the circuit 4 is set to the write mode. In this case, since the hook switch 3 is turned on, a switch element 8 is turned on and a current is supplied from a telephone line 1 to the circuit 4 via the 1st power supply circuit 13. Thus, the write to the dial memory 40 is applied by the current supplied from the telephone line 1 via the 1st power supply circuit 13. Thus, the battery is not required.</p> |
