| 摘要 |
PURPOSE:To suppress a rush current, by flowing a charging current of a capacitor through a current limit element, through the opening of a switching element with the detection of power failure and the closing of the switching element after a prescribed set time at the restoration of the power failure. CONSTITUTION:A switching signal which goes to a low level at the detection of power failure and again goes to a high level with a delay after the restoration of the power supply, is outputted from a delay circuit 13 with a power supply detection signal. A switching device 14 is opened for a prescribed time through this switching signal, a trigger voltage applied to a gate of a thyristor 4 is lost and the thyristor 4 is opened for a prescribed time. Then, since a rush current flows through a current limit resistor 3, the rush current peak can be suppressed, allowing to prevent damages to circuit components and failure on the reception system. |
