| 摘要 |
PURPOSE:To perform the display of the residual capacity of a battery with good accuracy, by resetting the integration quantity of an integrator circuit for integrating the charge quantity to a battery when the voltage of the battery falles below set voltage. CONSTITUTION:When the voltage of a battery B falls below set voltage, it is necessary to charge the battery B. Because switches SW1-SW3 are respectively closed to the side of a C-terminal at the time of charging, the battery B is charged and a current is flowed to a potential memory element M through a resistor R1 to raise potential. With the rising of this potential, LED1-LED5 are successively lighted by the outputs from comparators CP1-CP5. Subsequently, when the switches SW1-SW3 are closed to the side of a D-terminal and load L is driven by the battery B, a part of the discharge current from the battery B flows to the element M which is, in turn, discharged to lower potential. LED1-LED5 are also turned OFF and the element M is shortcircuited to reset an integration amount. Because the element M performs integration from the beginning at the charging time of the battery B even if the charging and discharging of the battery B is repeatedly performed, the residual capacity of the battery can be displayed with good accuracy.
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