| 摘要 |
PURPOSE:To detect a charging condition by the time elapsed indicating below battery voltage, comparing a R, C integration circuit applied higher voltage than the maximum charging voltage of a battery to be charged and battery voltage while this circuit is discharged temporarily and is charged. CONSTITUTION:A battery to be charged 4 is connected between terminals 1a, 1c of a charging electric power source 1 through a current reduction resistance 2, 3. Further, a quick charging line is formed by a transistor 5 and a trickle charging line is formed by the resistance 3. An integration circuit 13 of a resistance 11 and a capacitor 12 is provided between a high voltage terminal 1b and a earth terminal 1c and a discharge circuit of the resistance 14 and a transistor 15 is provided between both ends of the capacitor 12. The voltage of the capacitor 12 and that of the battery 4, are compared in a comparison circuit 7 and its output is supplied to a detection controlling circuit 18. The charging condition of the battery is detected by measuring the time elapsed in the case where the voltage of the capacitor 12 is lower than that of the battery 4 regardless of the magnitude of an inclination gradient of a charging voltage characteristic of the battery. |
