绕线式异步电动机起动控制电路改进分析

本文提出电流继电器控制绕线式异步电动机起动电路改进方法，并对改进电路优劣进行了分析。     

N600-16．7／538／538型汽轮发电机组的启动方式探讨

上海汽轮机有限公司生产的N600-16．7／538／538汽轮机，为一次中间再热、四缸、四排汽、凝汽式汽轮机。其特点是采用数字电液调节系统，操作简便，运行可靠。文章根据西屋公司的经验，结合采纳了大型汽轮机运行经验和对本体结构的棱算和热力计算，推出了低参数，高中压联合启动方式，以及热态时的中压缸启动方式，并且考虑到旁路系统故障(Bypass off)情况下简易的高压缸启动这三种启动方式。     

接触器自锁控制线路教学改进及推广应用

针对接触器自锁控制线路在教学演示时出现的难点,提出了在实验演示台上加装时间继电器的改进方法,详细说明了改进线路的动作原理、应用流程以及该方法在其他基本控制线路上的推广应用。     

Particle contamination, the disruption of electronic connectors in the signal transmission system

Particle pollution in air, also sometimes known as fine dust contamination, may cause electric contact failure. Recent research further proved that the fine particle is becoming a major disruption of the electronic connectors in signal transmission system. This paper specifies the connector contact in mobile phone application. To study the contact failure of mobile phone, a series of inspections and analytical research methods are introduced. Special features that cause the contact failure are summarized. Particle accumulation is the main problem; organic material such as lactates from sweat of the human body may act as adhesives to stick the separate particles together and make them adhere on the contact surface; chemical properties of dust cause serious local corrosion. The corrosion products may trap the particles and firmly attach on the contact surface; micro motion frequently occurs at the contact interface. Hard particle can be embedded into the surface, and soft particle could be squeezed and inserted into the contact; silicon compounds in dust play the most important role in forming high resistance regions that lead to failure; deposition of particles depends on the amount of materials, static electricity attracting force and gravity force applied on the particles. Current dust test can hardly reflect the serious contact failure. It is difficult to simulate the complexity of contact failure caused by particle contamination. Thus alternative ways of simulation experiment and improvement of contact reliability are proposed.     

C650型卧式车床电气控制线路改进设计

分析了C650型卧式车床的常用线路,设计了只用三个接触器的控制线路,从而使线路得到了简化,减少了故障环节.     

三相鼠笼式异步电动机的星—三角起动

三相鼠笼式异步电动机星-三角起动的控制线路用时间继电器完成，既可达到减小起动电流，又可防止电流短路事故，且延长了接触器的寿命。     

电解电容老化对电子电路的影响

测量了RC耦合二级放大器在新旧发射极旁路电容作用下的电压增益．指出了电解电容老化问题对电路产生的影响．     

n选1开关电路设计

针对学生在实习中电度表校验装置负荷电流的选通线路故障而使互感器烧毁问题,现设计一运用交流接触器控制n个开关组合、只允许一个开关工作(导通)的线路,在实际应用中取得了理想的效果.     

浅谈PLC中定时器的应用

传统继电接触器控制由于其系统运行通用性和灵活新较差,其使用、调试困难;而现代的PLC控制,由于控制精度高,灵活方便,而得到广泛的应用.而PLC中定时器的应用对初学者来说,往往难以理解透彻.笔者就PLC中定时器应用的方面作一个说明,供大家参考.     

浅谈PLC“串行”工作方式与梯形图的编制

详细介绍了由继电接触器控制电路图设计梯形图时,PLC“串行”工作方式对梯形图控制结果的影响以及解决方法。