| 摘要 |
The answering cycle of a telephone answering device is initiated by a solid state circuit responsive to a ringing signal. The rectified ringing signal charges a triggering capacitor to a level sufficient to turn on a controlled rectifier. Conduction of the controlled rectifier effectively connects an inductor as a load across the telephone line, and biases on a transistor to switch power to the motor, amplifier and other components of the answering device. At the end of the answering cycle the controlled rectifier is turned off, thereby unloading the telephone line and disconnecting power from the answering device. Operation of the answering device is inhibited when insufficient tape remains for recording additional incoming messages.
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