| 摘要 |
PURPOSE:To avoid that the life of a primary battery is shortened by a method wherein the voltage of a capacitor is compared with the voltage of the primary battery and, when both voltages are approximately the same, the primary battery is connected to a parallel circuit which is composed of a load and the capacitor. CONSTITUTION:In a comparator CO, its power supply is supplied from a DC power supply PS when the voltage of the DC power supply PS exists, and its power supply is supplied from a capacitor C when the DC power supply PS does not exist. The comparator compares the voltage of the capacitor C with the voltage of a primary battery; it is operated according to the result of the comparison. When the voltage of the capacitor C and the voltage of the primary battery B are approximately the same, the primary battery B is connected to a parallel circuit which is composed of a load L and the capacitor C. Thereby, there exists no possibility that the primary battery B is charged undesirably, and it is possible to avoid that the life of the primary battery B is shortened. |
