| 摘要 |
PROBLEM TO BE SOLVED: To prevent a power supply circuit from ceasing to operate, caused by the drop in battery output voltage by inrush current, etc., by delaying the operation start of the power circuit constituted of the controller for controlling the output voltage to be constant from the start of power supply. SOLUTION: After the passage of a time sufficiently for charging an input capacitor 3, a break circuit 10 starts the operation of a control circuit 8, and a current for exciting an inductor 4 flowing in an inductor 4 and a transistor 5, flows. Since the input capacitor 3 has been already charged, a large current such as an inrush current does not flow, and the current for charging the input capacitor 3 and the current for exciting the inductor 4, flowing in the inductor 4 and the transistor 5, never flow at the same time from a power source. Thus, there never occurs troubles such as the input voltage dropping sharply due to the internal resistance of the battery or that the control circuit ceases to operate, and the power circuit can obtain normal output voltage. |
