| 摘要 |
PURPOSE:To stabilize the frequency by providing a temperature detector, a storage device, a CPU and a synthesizer supplying a control signal to an oscillator together with other control signal. CONSTITUTION:The temperature detector 1 detects the ambient temperature of the oscillator, an analog digital converter 2 converts the output into a digital signal and gives the signal to the CPU 3. The frequency temperature characteristic of a piezoelectric oscillator and a frequency change versus control voltage change of the oscillator 7 are stored in advance in the storage device, the CPU 3 generates a frequency control signal of the oscillator based on the storage data information, the signals are converted into analog quantities by a digital- analog converter 5 and the result is fed to the oscillator 7 via the synthesizer 6. On the other hand, the change in the lapse of time in the frequency is processed by the count of the operating time of the oscillator and the data of the frequency change time characteristic and a time count circuit 8 integrates the operating time by counting the oscillated wave of the oscillator 7. The synthesizer 6 synthesizes the control voltage signals to the temperature change and change in the lapse of time fed to the oscillator 7 so as to compensate the frequency change due to various causes to the oscillator. |
