492
2006
不显示,程序处于等待电池放人的状态.
当充足电的电池放人,P1.0 口的电压高于 P1.1
口的电压. P3.6 口为 1,定时器 T0 开始计时,数码
管也开始显示,且每隔 3 min 计一次数,与此同时
每 3 s 检测一次电池电压,即检测 P3.6 的状态. 随
着电池不断放电,其电压逐惭下降,当放电达到其
终止电压 2 V 时,P1.0 口的电压开始低于 P1.1 口
的电压,P3.6 口由 l 变为 0,定时器 T0 停止计时. 同
时 P3.7 口输出 0 使 VTl 截止停止电池放电,这时
数码管显示的数值不再变化,显示值就是电池的容
量.
放人电池后,用万用表测量 R15 两端的电压,
可通过调整 R13 或 R14 的阻值,使电压为 0.94 V,
此时对应的放电电流为 200 mA.
在使用过程中,如果在测试电路没有断电的情
况下取下电池再重新放人电池时,要先按一下复位
键 K 电路才能重新开始工作,不然电路无法工作,
因取下电池和电池放电终了的结果是一样的,测试
电路都会作出测试结束的判断.
参考文献:
[1] 沈红卫. 单片机应用系统设计实例与分析[M]. 北京:
北京航空航天大学出版社, 2003.
[2] 王鸿麟, 钱建立, 周晓军. 智能快速充电器设计与制作
[M]. 北京: 科学出版社, 2001.
[3] 万福君. 单片微机原理系统—设计与开发应用[M]. 合
肥: 中国科学技术出版社, 1995.
Rechargeable Battery Capacity Test Circuit Design
Abstract: Along with the electronic technology development, rechargeable batteries such as nickel cadmium
and nickel hydrogen are more and more used, and the battery capacity (Ah) becomes a common concern when
the clients purchase them. This article introduces a battery capacity test circuit which is manufactured based on
the AT89C2051 monolithic integrated circuit. The circuit may automatically measure the capacity of the
rechargeable batteries such as nickel cadmium and nickel hydrogen ones. The measurement scope ranges
between 0.01—9.99Ah. The analysis is also conducted on the electronic circuit hardware and the software
design implementation, the parameter configuration and the debugging. The design is believed to have certain
applicable value.
Key words: battery capacity; monolithic integrated circuit; hardware; software