| 摘要 |
A power supply circuit which includes a current limit circuit for limiting the inrush current when the power supply is switched on. The current limit circuit is coupled between a supply voltage at the input end of the power supply and a storage capacitor at the output end of the power supply. The current limit circuit includes a first semiconductor switch having a resistor in parallel with its switching path. In parallel with the control path of the first semiconductor switch is a parallel circuit that includes a first capacitor, a first resistor and the switching path of a second semiconductor switch. The control electrode of the second semiconductor switch is connected to a tap on a first voltage divider to which a second capacitor is connected in parallel. The switching path of a third semiconductor switch is connected parallel to the control path of the second semiconductor switch. The third semiconductor switch is cut off in response to a control current supplied by a threshold value circuit when the supply voltage is below a threshold value.
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