| 摘要 |
PURPOSE:To reduce the mean value of an overcurrent and to reduce the heating value of a parts by switching the charge/discharge of a capacitor in response to the presence or absence of the output of an overcurrent detecting circuit, and turning on and off a switching circuit in accordance with the charge/discharge state. CONSTITUTION:An output 8a is given to a load which always needs electric power from an accumulator 4 via an overcurrent detecting circuit 1, stabilizing circuit 6 and a switching circuit 3. While an output 8b is fed to an intermittent load via a switching circuit 7 by turning on and off a switch SW5. When the overcurrent flows, a transistor TR12 is turned on to start charging a capacitor 21a. Then a TR23 is turned on when the capacitor 21a reaches a fixed level of voltage Vc, and therefore TR32a and TR32b are turned off. Thus an overcurrent state is released. The capacitor 21a discharges through the resistances 22a and 22b. Then the TR23 is turned off with the TR32a and TR32b turned on, respectively when the level of the Vc is lowered. However said break and restoration are repeated again in case the factor of the overcurrent is not eliminated. Therefore, the mean value of the overcurrent is lowered and the heating value of each part is reduced. Thus a power supply circuit can be protected. |
