| 摘要 |
<p>A synchronizing circuit comprising a control loop for controlling the frequency and the phase of an oscillator. For the automatic adjustment of the oscillator the central frequency is determined, i.e. a frequency for which the control loop has optimum hold and pull-in properties. A signal having a given frequency is applied to the signal input of the loop. An adjustment signal which is applied to the oscillator is changed incrementally until the control signal generated by the control loop becomes equal to a reference value. The instantaneous word value of the converter is stored in a store. In normal operation, this value which corresponds to the central frequency is applied to the oscillator after digital-to-analog conversion, the control loop being operative for controlling the oscillator.</p> |
