| 摘要 |
PURPOSE:To perform soft start smoothly at the start of an automatic control circuit, by providing a means gradually reducing a feedback amount from an output to an input terminal of an error amplifier. CONSTITUTION:Before the start of an automatic control circuit, a switch SW1 is closed and an SW2 is opened, and the output of an error amplifier 11 is amplified at an amplifier A, fed back to an input terminal I2 via a diode D1 and a resistor R2 and the amplifier 11 is fixed to a voltage at an active region for the waiting state. A capacitor C1 is charged to an output voltage e0 of the amplifier 11 via a resistor R3. At the start of the automatic control circuit, the SW1 is opened and the SW2 is closed, the charge in the capacitor C1 is gradually discharged via a resistor R4, the amount of feedback of the amplifier 11 to an input terminal I2 is gradually decreased, the output of the amplifier 11 is gradually increased, allowing to perform soft start smoothly. |
