| 摘要 |
<p>PURPOSE:To vary the oscillation period of an oscillator, which oscillates by charging and discharging a capacitor repeatedly, linearly when a control voltage is adjusted, by composing a charging circuit of a constant current circuit. CONSTITUTION:A charging circuit 3 for a capacitor (C)2 connected to a differential amplifier 1 uses a constant current circuit composed of a transistor (TR) 3b, a diode 3c, and resistances 3d-3f, and the charging voltage of the C2 is raised linearly. When the charging voltage of the C2 rises above a control voltage from a terminal 6 to the base of the TR1b of th amplifier 1, a TR1a turns on and a TR1b turns off, which is detected by the TR7 of a switching circuit 7 to turn on the TR4b of a discharging circuit 4, thereby discharging the C2. Simultaneously, the TR5c of a bias power source circuit 5 is turned on to apply a low-level bias voltage to the TR1b. When the voltage of the C2 drops below the bias voltage of the TR1b, the TR1a turns off and the TR1b turns on, performing oscillation. In this case, the oscillation period varies linearly with the control voltage from the terminal 6.</p> |
