| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an inrush current prevention circuit, in which circuit power consumption after preventing an inrush current is small and a control circuit of a load circuit is enabled to accurately control the inrush current prevention circuit even when and the load circuit and the inrush current prevention circuit are at different reference potential.SOLUTION: An inrush current prevention circuit 6 includes: a charge determination circuit 600 for determining the charge state of a smoothing capacitor 4, whose negative pole is a ground G1, to output a detection signal s0 when the charge state is a predetermined state; a low resistance element 610, inserted to a charge path of the smoothing capacitor 4, for specifying a ground G2 having lower potential than the ground G1; a field effect transistor 620 whose drain terminal is connected to the ground G1 and source terminal is connected to the ground G2; and a signal amplifier circuit 630, operated relative to the ground G1, for supplying a current signal S2 to the gate terminal of the field effect transistor 620 according to the input of the detection signal s0, to make the field effect transistor 620 conduct.</p> |
