| 摘要 |
PURPOSE:To improve the reproducibility of an oscillating state by inserting a buffer circuit comprising a resistor connected in series and a capacitor connected in parallel between a crystal oscillator and a tuning circuit so as to attain ease of adjusting operation as the entire crystal oscillator. CONSTITUTION:In adjusting the oscillating state, after a tuning frequency (f) of a tuning circuit 6 is set to a natural frequency F0 of the crystal oscillator 3 where an oscillating voltage characteristic Y (output level) shows a maximum value by changing an inductance L1 of a coil 5 and changing a capacitor C1 of a variable capacitor 2, the oscillating frequency almost decided by the natural frequency F0 of the crystal oscillator 3 has only to be adjusted minutely. Thus, it is not necessary to set the frequency to an intermediate frequency as a point C in the oscillating voltage characteristic X of a conventional crystal oscillator, then the adjusting operation as the entire crystal oscillator is simplified, allowing to decrease the time required for the adjustment. Further, the reproducibility of a setting value is improved by setting the tuning frequency to the frequency where the output level shows a maximum value in comparison with a conventional setting method where the tuning frequency is set to the intermediate value. |
