| 摘要 |
A soft start circuit of a power supply device is provided to prevent malfunction in a dip-up test by controlling an electric potential into a zero potential in a power off. An input voltage is charged in a delay part(110). If a voltage charged in the delay part is higher than a set voltage, a control part(120) supplies a driving power to a power supply device. A voltage detection part(130) detects a level of an AC voltage. A potential control part(140) controls an electric potential of the voltage charged in the delay part according to the level of the AC voltage detected in the voltage detection part. The voltage detection part includes an AC power input terminal(Vin), a first resistor(R1), a second resistor(R2), a capacitor(C1), and a third resistor(R3). The AC power is inputted to the AC power input terminal. One end of the first resistor is connected to the AC power input terminal. One end of the second resistor is connected to the other end of the first resistor. The other end of the second resistor is connected to a ground terminal. One end of the capacitor is commonly connected to the other end of the first resistor and one end of the second resistor. The other end of the capacitor is connected to the ground terminal. One end of the third resistor is commonly connected to the other end of the first resistor, one end of the second resistor, and one end of the capacitor. The other end of the third resistor is connected to the control part. |
