| 摘要 |
PURPOSE:To prevent the fluctuation of the oscillation frequency, by comparing the phase of the triangular wave output of a voltage control oscillator with that of the output of a reference oscillator and by supplying this phase difference as a control voltage to the voltage control oscillator. CONSTITUTION:The output of a voltage control oscillator consisting of resistances 1, 2, and 5, a capacitor 6, an operational amplifier 4, a voltage comparator 3, and a voltage polarity switching circuit 8 and the output of a reference frequency oscillator 10 are applied to a phase comparing circuit 9, and this comparison output is applied as a control voltage to the control terminal of the voltage control oscillator. Since the output voltage is changed in the direction for coincidence between these output signals when they have a phase difference, the output voltage is lowered to lower the triangular wave oscillation frequency when the triangular wave oscillation frequency is higher than the reference frequency. When the triangular wave oscillation frequency is lower, the output voltage rises to raise the oscillation frequency. |
