| 摘要 |
<p>An automatic telephone call unit is used to produce a sequence of operations and to monitor the sequence, and avoid incorrect calls. It can also compose selected telephone numbers and transmit prerecorded messages. The unit has a recorder which may receive either a signal from an oscillator when the line is cut-off, or a series of modulated pulses during a call. The pulses are initiated by the dial during the start of the call. A microphone and an amplifier are used to record messages onto the tapes of the recorder. The unit also has a call timing circuit to limit the time of calls, and a line adaptor circuit to inject into the line the spoken message.</p> |
