| 摘要 |
PURPOSE:To always cause the amplitude of a sawtooth wave to be constant by connecting a circuit to by-pass a current to be charged to a capacitor and applying a feedback so as to control the quantity of the current by-passed in proportion to the wave height value of the generated sawtooth wave. CONSTITUTION:When a frequency(f) to open and close a switch S1 is changed in a high direction, the amplitude of the sawtooth wave generated in a capacitor C1 intends to be small. A voltage, in which the sawtooth wave is integrated by a diode D1 and a capacitor C2, is made small, the output voltage of an error amplifier 2, in which the difference between the integrating voltage and a reference voltage VCC is amplified, is also made small, and the base voltage of a transistor TR1 is also made small. For such a reason, the collector current of the transistor TR1 is decreased, the charging current of the capacitor C1 is increased, and it intends to enlarge the amplitude of the sawtooth wave. The output voltage of the error amplifier 2 is continued to be increased until the integrating voltage of the capacitor C1 and the reference voltage VCC are made equal, and it is stabilized when they are made equal. |
