| 摘要 |
PURPOSE:To start the normal operation without any hindrance even at the power supply OFF and reapplication such as power failure by supplying a control voltage stored at application of power to a voltage controlled crystal oscillator and opening the frequency control loop for nearly 30min until the oscillator is made stable. CONSTITUTION:A control voltage generating circuit 7 and a timer circuit 9 are connected between a control amplifier 8 and a voltage controlled crystal oscillator 6. The control voltage generator 7 controls an output frequency of the voltage controlled crystal oscillator 6, the control voltage in this case is converted into, e.g., a digital signal and written in a storage circuit including a RAM at any time. This requires low power consumption, then the circuit does not lose storage and is operated for a long period by a small-sized battery even at power interruption. When the power supply is cut off during the normal operation and the power is applied again, the circuit 7 supplies the control voltage stored before the interruption of power to the voltage controlled crystal oscillator 6. The timer circuit 9 connects the control amplifier 8 and the control voltage generating circuit 7 cut off so far after nearly 30min elapse from the application of power. |
