Power Efficient Battery Charger by Using Constant Current/Constant Voltage Controller

The Battery Charger Specification presents solution for rechargeable batteries used in portable electronic equipment such as laptop computer systems, cellular telephones and video cameras and the demands for low cost battery chargers are rising these days without give attention for the performance. The goal of the paper was combining high efficiency and versatility with low-cost design and this paper includes the design of the snubber cell, and the components of the current/voltage control charge method. This charger applies a relatively constant current and constant voltage to the battery indefinitely regardless of the AC input rang voltage all the equations described in this paper. The design of prototype converter is verified through an experimental result.

一种新型接地电阻测试装置的设计

介绍一种基于 AD7705和 ATMega8的新型接地电阻测试装置，分析该接地电阻测 试装置的设计原理，详细地说明系统的软硬件设计方法，并创造性地提出利用恒流源来构成系统 的采样电路。

电磁流量计信号转换器的校验器设计方法研究

设计了一种电磁流量计转换器的校验器,能直接利用电磁流量计信号转换器输出的励磁电流来提供校验器的电源及同步信号而不需要外接电源,可用于各种电磁流量计信号转换器的校验。实践证明,该校验器的使用,将大大提高电磁流量计的测量精度。

一种高精度接地电阻测量变送器

介绍了一种以高精度恒流源、24位无误码AD转换器AD7714以及微处理单元ATMEGA8为核心的接地电阻测量变送器,并详细地说明了系统的硬件原理电路。通过理论与实验证明,该变送器具有很高的精度。