| 摘要 |
<p>PURPOSE:To more accurately monitor the residual capacity of a battery, by a method wherein detected voltage changes in conjunction with the switch of a power source circuit and the detected voltage at the time of load is made lower than that at the time of non-load. CONSTITUTION:The output voltage of a reference voltage generator 6 is obtained in conjunction with a switch 4 and the voltage at the open time of the switch 4 is set to VRH and the voltage at the close time of the switch 4 is set to VRL. Then, VRH is set to non-load voltage when the capacity of a battery 3 is almost lost and VRL is set to the voltage when a current is supplied to a load 2 when the capacity is almost lost. When the switch 4 is closed, the battery 3 is reduced in its capacity by self-discharge and voltage B is dropped. At the time of VB<VRH, a comparator 5 outputs LOW. When the switch 4 is closed, the battery 3 is discharged at the load 2 and, at the time of VB<VRL, the comparator 5 outputs LOW to issue an alarm. As mentioned above, by differentiating the detected voltage at the time of load from that at the time of non-load, the residual capacity of the battery is more accurately monitored.</p> |
