SCI-TECH INNOVATION shared documents; information safety; network safety Design of System of Wireless Communications Based on nRF24L01 Wang Feng，Xin Lei，Shi Xing-sheng，Wu Jie，Zhou Rui （North University of China, Taiyuan 030051 China） Abstract:In this paper,the authors introduced wireless communications of half-duplex which take nRF24L01 as wireless transceiver, and ATmega16 single chip as cybernetics core. Then, the authors tested speed and distance of transmission of sys- tem, and expounded main points of design of hardware and software. Key words: ATmega16; nRF24L01; half-duplex; wireless communications Discussion on Optimum Value of Power Factor of Mine Electric Power Substation Liang Ji-jun （SDIC Jincheng Energy Investment Co., Ltd, Jincheng 048016 China） Abstract:The suitable power factor value not only improves voltage quality of power system and users,but also reduces power consumption of power supply circuit, and improves capacity of electric power supply. Both low power factor and high compensation will bring harm to industries. In this paper, combining actual situation of 35 kV converting station,the author has chosen optimum value of power factor through comparing technologies. Key words: power factor; compensation; best 4）cos 0.95时， 需要的补偿容量多， 电容 器投资大， 设备折旧维护费大， 虽电能损失少， 但 年运行费用上升， 为避免低谷负荷时无功倒送， 所 以该变电所设计cos 0.95。 5） 采用计算机优化确定变电所最佳cos值的 方法是科学的， 它避免了凭经验提出补偿值， 此方 法应用基本理论公式编成电算程序， 使用方便， 计 算精确， 在变电所设计中值得推广使用。 （实习编辑高 腾） （上接第93 页） （上接第90 页） 应用 技 术应 用 技术Applied TechnologyApplied Technology -097-