| 摘要 |
PURPOSE:To obtain a desired oscillation frequency based on a measurement, by cutting off a capacitor connected to a circuit base board previously when an adjustment is given to a piezoelectric oscillator which is used for production of a display clock of CRT and the like. CONSTITUTION:A quartz oscillator 1, inverting circuits 2 and 3, resistances 4 and 5 plus capacitors (C) 10-13 are attached to a circuit base board to form an oscillating circuit. Then the oscillation signal is delivered from an output terminal 9. In a circuit of such constitution, the load capacity of an oscillator 1 is defined as C0 and C1 with the oscillation frequencies f0 and f1 respectively. The capacity of C13 is set so that the load capacity of the oscillator 1 that varies by cutting off C13 only becomes equal to the difference of C1 and C0. Then the capacities of C12 and C11 are set at the values of a double and a triple as much as the above-mentioned difference. Then C10-13 with such set capacities are all connected together, and C13 is cut off in case when the measured oscillation frequency is between f1 and f2. When the oscillation frequency is between f2 and f3 as well as between f3 and f4, C12 and C11 are cut off respectively to obtain a desired oscillation frequency. |
