| 摘要 |
PURPOSE: To increase the operation time of an apparatus by applying a reserve power source to the residual voltage of the initial power source to extend the time in which a battery pack can supply voltage higher than the lower limit set value when the voltage of main pour source is reduced to the lower limit value of preset voltage. CONSTITUTION: An apparatus shown by a load 25 is operated when the voltage supplied from a battery pack is between predetermined upper and lower limit values. When a switch 13 is on the first position, the voltage of the initial power source is applied to the terminals 17, 18 of the battery pack 10. When the switch 13 is shifted to the second position, a reserve power source 12 is connected in series to a main power source 11 so that the voltage of the voltage of the pour source 11 plus the voltage of the power source 12 is applied to the terminals 17, 18 of the battery pack. The switch 13 is adapted to come surely to the first position when a battery is loaded. When the voltage of the initial power source 11 reaches the lower limit of the preset voltage, the switch 13 is shifted to the second position. Thus, even if the number of batteries is increased, the voltage of the apparatus does not exceed the upper limit and the operation time of the apparatus can be extended. |
