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为学原文及翻译资料

为学原文及翻译资料
为学原文及翻译资料

为学原文及翻译

为学

文言文《为学》选自初中文言文大全其诗文如下:

【前言】

《为学》本文选自《白鹤堂集》,原题为《为学一首示子侄》。《历代文选清文卷》(人民教育出版社出版),有删节。

【原文】

天下事有难易乎?为之,则难者亦易矣;不为,则易者亦难矣。人之为学有难易乎?学之,则难者亦易矣;不学,则易者亦难矣。

吾资之昏,不逮人也,吾材之庸,不逮人也;旦旦而学之,久而不怠焉,迄乎成,而亦不知其昏与庸也。吾资之聪,倍人也,吾材之敏,倍人也;屏弃而不用,其与昏与庸无以异也。圣人之道,卒于鲁也传之。然则昏庸聪敏之用,岂有常哉?

蜀之鄙有二僧:其一贫,其一富。贫者语于富者曰:“吾欲之南海,何如?”富者曰:“子何恃而往?”曰:“吾一瓶一钵足矣。”富者曰:“吾数年来欲买舟而下,犹未能也,子何恃而往?”越明年,贫者自南海还,以告富者,富者有惭色。

西蜀之去南海,不知几千里也。僧富者不能至而贫者至焉。人之立志,顾不如蜀鄙之僧哉?是故聪与敏,可恃而不可恃也;自恃其聪与敏而不学者,自败者也。昏与庸,可限而不可限也;不自限其昏与庸,而力学不倦者,自力者也。

【注释】

为学:做学问

南海:指佛教圣地普陀山

为:做

之:往,到,代词,的

则:那么

者:代词

亦:也

鄙:边远的地方

其:其中的

语:告诉

欲:想要

何如:怎样

子:对令方的尊称

恃:凭借,倚仗

往:去往

买舟:雇船

下:顺流而下

犹:尚且,还

未:不,没有

越明年:到了第二年。越,及、到自:从

还:返回,归来

以:相当于“把”,“拿”,“将”

综合英语(一)课文及翻译

Lesson One: The Time Message Elwood N, Chapman 新的学习任务开始之际,千头万绪,最重要的是安排好时间,做时间的主人。本文作者提出了7点具体建议,或许对你有所启迪。 1 Time is tricky. It is difficult to control and easy to waste. When you look a head, you think you have more time than you need. For Example,at the beginning of a semester, you may feel that you have plenty of time on your hands, but toward the end of the term you may suddenly find that time is running out. You don't have enough time to cover all your duties (duty), so you get worried. What is the answer? Control! 译:时间真是不好对付,既难以控制好,又很容易浪费掉,当你向前看时,你觉得你的时间用不完。例如,在一个学期的开始,你或许觉得你有许多时间,但到学期快要结束时,你会突然发现时间快用光了,你甚至找不出时间把所有你必须干的事情干完,这样你就紧张了。答案是什么呢?控制。 2 Time is dangerous. If you don't control it, it will control you. I f you don't make it work fo r you, it will work against you. So you must become the master of time, not its servant. As a first-year college student, time management will be your number one Problem. 译:时间是危险的,如果你控制不了时间,时间就会控制你,如果你不能让时间为你服务,它就会起反作用。所以,你必须成为时间的主人,而不是它的奴仆,作为刚入学的大学生,妥善安排时间是你的头等大事。 3 Time is valuable. Wasting time is a bad habit. It is like a drug. The more time you waste,the easier it is to go on wasting time. If seriously wish to get the most out of college, you must put the time message into practice. 译:时间是珍贵的,浪费时间是个坏习惯,这就像毒品一样,你越浪费时间,就越容易继续浪费下去,如果你真的想充分利用上大学的机会,你就应该把利用时间的要旨付诸实践。 Message1. Control time from the beginning. 4 Time is today, not tomorrow or next week. Start your plan at the Beginning of the term. 译:抓紧时间就是抓紧当前的时间,不要把事情推到明天或是下周,在学期开始就开始计划。 Message2. Get the notebook habit. 5 Go and buy a notebook today, Use it to plan your study time each day. Once a weekly study plan is prepared, follow the same pattern every week with small changes. Sunday is a good day to make the Plan for the following week.

翻译资料英语

FINANCIAL INNOV ATION Like other industries, the financial industry is in business to earn profits by selling its products. If a soap company perceives that there is a need in the marketplace for a laundry detergent with fabric softener, it develops a product to fit the need .Similarly, in order to maximize their profits, financial institutions develop new products to satisfy their own needs as well as those of their customers; in other words, innovation-which can be extremely beneficial to the economy-is driven by the desire to get (or stay) rich. This view of the innovation process leads to the following simple analysis: A chance in the financial institutions for innovations that are likely to be profitable. Starting in the 1960s, individuals and financial institutions operating in financial markets were confronted with drastic changes in the economic environment: Inflation and interest rates climbed sharply and became hard to predict, a situation that changed demand conditions in financial markets. Computer technology advanced rapidly, which changed supply conditions. In addition, financial regulations became especially inconvenient. Banking institution discovers many old ways of doing business being able to not have earned money again; they provide the masses finance with service and financial products sale neither well. Many financial intermediary is discovered they have no way to raise having arrived at a fund, but these self that will not a suspense of business right away with original tradition finance implement. For existing under new economy environment, research and development puts up banking institution be obliged to being able to satisfy customer need moreover the new product being able to gain a profit of and serving, this process is called financial engineering. In their case, necessity was the mother of innovation. Our discussion of why financial innovation occurs suggests that there are three basic types of financial innovations: Escapism to responding to needing condition change, to the small advantages supplying with condition change and to controlling. We have had one now understandable that banking institution is innovative for instance the cause institutions, let’s look at examples of how financial institutions in their search for profits have produced financial innovations of the three basic types. 1

1外文文献翻译原文及译文汇总

华北电力大学科技学院 毕业设计(论文)附件 外文文献翻译 学号:121912020115姓名:彭钰钊 所在系别:动力工程系专业班级:测控技术与仪器12K1指导教师:李冰 原文标题:Infrared Remote Control System Abstract 2016 年 4 月 19 日

红外遥控系统 摘要 红外数据通信技术是目前在世界范围内被广泛使用的一种无线连接技术,被众多的硬件和软件平台所支持。红外收发器产品具有成本低,小型化,传输速率快,点对点安全传输,不受电磁干扰等特点,可以实现信息在不同产品之间快速、方便、安全地交换与传送,在短距离无线传输方面拥有十分明显的优势。红外遥控收发系统的设计在具有很高的实用价值,目前红外收发器产品在可携式产品中的应用潜力很大。全世界约有1亿5千万台设备采用红外技术,在电子产品和工业设备、医疗设备等领域广泛使用。绝大多数笔记本电脑和手机都配置红外收发器接口。随着红外数据传输技术更加成熟、成本下降,红外收发器在短距离通讯领域必将得到更广泛的应用。 本系统的设计目的是用红外线作为传输媒质来传输用户的操作信息并由接收电路解调出原始信号,主要用到编码芯片和解码芯片对信号进行调制与解调,其中编码芯片用的是台湾生产的PT2262,解码芯片是PT2272。主要工作原理是:利用编码键盘可以为PT2262提供的输入信息,PT2262对输入的信息进行编码并加载到38KHZ的载波上并调制红外发射二极管并辐射到空间,然后再由接收系统接收到发射的信号并解调出原始信息,由PT2272对原信号进行解码以驱动相应的电路完成用户的操作要求。 关键字:红外线;编码;解码;LM386;红外收发器。 1 绪论

英语原文及其翻译

Exploring Filipino School Counselors’ Beliefs about Learning Allan B. I. Bernardo [Abstract] School reform efforts that focus on student learning require school counselors to take on important new roles as advocates of student learning and achievement.But how do school counselors understand the process of learning? In this study, we explore the learning beliefs of 115 Filipino school counselors who indicated their degree of agreementwith 42 statements about the process of learning and the factors thatinfluence this process.A principal components analysis of the responses to the 42 statements suggested three factors:(F1)social-cognitive constructivist beliefs, (F2) teacher-curriculum-centered behaviorist beliefs,and (F3) individual difference factors.The preliminary results are briefly discussed in terms of issues related to how Filipino school counselors’ conceptions of learning may guide their strategies for promoting student learning and achievement. [Key words]beliefs about learning, conceptions of learning, school counselors, student learning, Philippines School reform efforts in different parts of the world have focusedon students’learning. In particular,most school improvement programsnow aim to ensure that students acquire the high-level knowledge and skills that help them to thrive in today’s highly competitive globaleconomy (e.g., Lee & Williams, 2006). I n this regard, school reform programs draw from various contemporary theories and research on learning (e.g.,Bransford,Brown, & Cocking, 1999; Lambert & McCombs, 1998).The basic idea is that all school improvement efforts should be directed at ensuring students achieve high levels of learning or attainment of well-defined curricular objectives and standards.For example, textbooks (Chien & Young, 2007), computers and educational technology (Gravoso, 2002; Haertnel & Means, 2003;Technology in Schools Task Force, 2003), and educational assessment systems (Black & Wiliam2004; Cheung & Ng, 2007; Clark, 2001; Stiggins, 2005) are being reconsidered as regards how they can effectively provide scaffolds and resources for advancing student learning. Likewise,the allocation and management of a school’s financial resources are assessed in terms ofwhether these are effectively mobilized and utilized towards improving student learning (Bolam, 2006; Chung & Hung, 2006; Retna, 2007). In this regard, some advocates have also called for an examination of the role of school counselors in these reform efforts (Herr, 2002). Inthe United States, House and Hayes (2002) challenged school counselors to take proactive leadership roles in advocating for the success of all

文献翻译英文原文

https://www.doczj.com/doc/5818492017.html,/finance/company/consumer.html Consumer finance company The consumer finance division of the SG group of France has become highly active within India. They plan to offer finance for vehicles and two-wheelers to consumers, aiming to provide close to Rs. 400 billion in India in the next few years of its operations. The SG group is also dealing in stock broking, asset management, investment banking, private banking, information technology and business processing. SG group has ventured into the rapidly growing consumer credit market in India, and have plans to construct a headquarters at Kolkata. The AIG Group has been approved by the RBI to set up a non-banking finance company (NBFC). AIG seeks to introduce its consumer finance and asset management businesses in India. AIG Capital India plans to emphasize credit cards, mortgage financing, consumer durable financing and personal loans. Leading Indian and international concerns like the HSBC, Deutsche Bank, Goldman Sachs, Barclays and HDFC Bank are also waiting to be approved by the Reserve Bank of India to initiate similar operations. AIG is presently involved in insurance and financial services in more than one hundred countries. The affiliates of the AIG Group also provide retirement and asset management services all over the world. Many international companies have been looking at NBFC business because of the growing consumer finance market. Unlike foreign banks, there are no strictures on branch openings for the NBFCs. GE Consumer Finance is a section of General Electric. It is responsible for looking after the retail finance operations. GE Consumer Finance also governs the GE Capital Asia. Outside the United States, GE Consumer Finance performs its operations under the GE Money brand. GE Consumer Finance currently offers financial services in more than fifty countries. The company deals in credit cards, personal finance, mortgages and automobile solutions. It has a client base of more than 118 million customers throughout the world

英语原文及翻译

高速视频处理系统中的信号完整性分析 摘要:结合高速DSP图像处理系统讨论了高速数字电路中的信号完整性问题,分析了系统中信号反射、串扰、地弹等现象破坏信号完整性的原因,通过先进IS工具的辅助设计,找出了确保系统信号完整性的具体方法。 关键词:高速电路设计信号完整性 DSP系统 深亚微米工艺在IC设计中的使用使得芯片的集成规模更大、体积越来越小、引脚数越来越多;由于近年来IC工艺的发展,使得其速度越来越高。从而,使得信号完整性问题引起电子设计者广泛关注。 在视频处理系统中,多维并行输入输出信号的频率一般都在百兆赫兹以上,而且对时序的要求也非常严格。本文以DSP图像处理系统为背景,对信号完整性进行准确的理论分析,对信号完整性涉及的典型问题[1]——不确定状态、传输线效应、反射、串扰、地弹等进行深入研究,并且从实际系统入手,利用IS仿真软件寻找有效的途径,解决系统的信号完整性问题。 1 系统简介 为了提高算法效率,实时处理图像信息,本图像处理系统是基于DSP+FPGA结构设计的。系统由SAA7111A视频解码器、TI公司的TMS320C6701 DSP、Altera公司的EPlK50QC208 FPGA、PCI9054 PCI接口控制器以及SBRAM、SDRAM、FIFO、FLASH等构成。FPGA是整个系统的时序控制中心和数据交换的桥梁,而且能够对图像数据实现快速底层处理。DSP是整个系统实时处理高级算法的核心器件。系统结构框图如图1所示。 在整个系统中,PCB电路板的面积仅为15cm×l5cm,系统时钟频率高达167MHz,时钟沿时间为0.6ns。由于系统具有快斜率瞬变和极高的工作频率以及很大的电路密度,使得如何处理高速信号问题成为一个制约设计成功的关键因素。 2 系统中信号完整性问题及解决方案 2.1 信号完整性问题产生机理 信号的完整性是指信号通过物理电路传输后,信号接收端看到的波形与信号发送端发送的波形在容许的误差范围内保持一致,并且空间邻近的传输信号间的相互影响也在容许的范围之内。因此,信号完整性分析的主要目标是保证高速数字信号可靠的传输。实际信号总是存在电压的波动,如图2所示。在A、B两点由于过冲和振铃[2]的存在使信号振幅落入阴影部分的不确定区,可能会导致错误的逻辑电平发生。总线信号传输的情况更加复杂,任何一个信号发生相位上的超前或滞后都可能使总线上数据出错,如图3所示。图中,CLK为时钟信号,D0、D1、D2、D3是数据总线上的信号,系统允许信号最大的建立时间[1]为△t。在正常情况下,D0、D1、D2、D3信号建立时间△t1<△t,在△t时刻之后数据总线的数据已稳定,系统可以从总线上采样到正确的数据,如图3(a)所示。相反,当信号D1、D2、D3受过冲和振铃等信号完整问题干扰时,总线信号就发生

英文翻译与英文原文.陈--

翻译文献:INVESTIGATION ON DYNAMIC PERFORMANCE OF SLIDE UNIT IN MODULAR MACHINE TOOL (对组合机床滑台动态性能的调查报告) 文献作者:Peter Dransfield, 出处:Peter Dransfield, Hydraulic Control System-Design and Analysis of TheirDynamics, Springer-Verlag, 1981 翻译页数:p139—144 英文译文: 对组合机床滑台动态性能的调查报告 【摘要】这一张纸处理调查利用有束缚力的曲线图和状态空间分析法对组合机床滑台的滑动影响和运动平稳性问题进行分析与研究,从而建立了滑台的液压驱动系统一自调背压调速系统的动态数学模型。通过计算机数字仿真系统,分析了滑台产生滑动影响和运动不平稳的原因及主要影响因素。从那些中可以得出那样的结论,如果能合理地设计液压缸和自调背压调压阀的结构尺寸. 本文中所使用的符号如下: s1-流源,即调速阀出口流量; S el—滑台滑动摩擦力 R一滑台等效粘性摩擦系数: I1—滑台与油缸的质量 12—自调背压阀阀心质量 C1、c2—油缸无杆腔及有杆腔的液容; C2—自调背压阀弹簧柔度; R1, R2自调背压阀阻尼孔液阻, R9—自调背压阀阀口液阻 S e2—自调背压阀弹簧的初始预紧力; I4, I5—管路的等效液感 C5、C6—管路的等效液容: R5, R7-管路的等效液阻; V3, V4—油缸无杆腔及有杆腔内容积; P3, P4—油缸无杆腔及有杆腔的压力 F—滑台承受负载, V—滑台运动速度。本文采用功率键合图和状态空间分折法建立系统的运动数学模型,滑台的动态特性可以能得到显著改善。

为学原文及翻译

为学 文言文《为学》选自初中文言文大全其诗文如下: 【前言】 《为学》本文选自《白鹤堂集》,原题为《为学一首示子侄》。《历代文选清文卷》(人民教育出版社出版),有删节。 【原文】 天下事有难易乎?为之,则难者亦易矣;不为,则易者亦难矣。人之为学有难易乎?学之,则难者亦易矣;不学,则易者亦难矣。 吾资之昏,不逮人也,吾材之庸,不逮人也;旦旦而学之,久而不怠焉,迄乎成,而亦不知其昏与庸也。吾资之聪,倍人也,吾材之敏,倍人也;屏弃而不用,其与昏与庸无以异也。圣人之道,卒于鲁也传之。然则昏庸聪敏之用,岂有常哉? 蜀之鄙有二僧:其一贫,其一富。贫者语于富者曰:“吾欲之南海,何如?”富者曰:“子何恃而往?”曰:“吾一瓶一钵足矣。”富者曰:“吾数年来欲买舟而下,犹未能也,子何恃而往?”越明年,贫者自南海还,以告富者,富者有惭色。 西蜀之去南海,不知几千里也。僧富者不能至而贫者至焉。人之立志,顾不如蜀鄙之僧哉?是故聪与敏,可恃而不可恃也;自恃其聪与敏而不学者,自败者也。昏与庸,可限而不可限也;不自限其昏与庸,而力学不倦者,自力者也。 【注释】 为学:做学问 南海:指佛教圣地普陀山 为:做 之:往,到,代词,的 则:那么 者:代词 亦:也 鄙:边远的地方 其:其中的 语:告诉 欲:想要 何如:怎样 子:对令方的尊称 恃:凭借,倚仗 往:去往 买舟:雇船 下:顺流而下 犹:尚且,还 未:不,没有 越明年:到了第二年。越,及、到 自:从 还:返回,归来 以:相当于“把”,“拿”,“将” 至:到达 志:志向

顾:难道 屏:通“摒”,摒弃 去:距离 色:神态,神色 矣:语气助词 曰:说,道 【翻译】 天下的事情有困难和容易之分吗?做了,那么困难也变得容易。不做,那么容易也变得困难。人们做学问有困难与容易的之分吗?去学,那么困难也变得容易;不学,那么容易也变得困难。 我天资愚笨,赶不上别人;我才能平庸,赶不上别人。我每天持之以恒地提高自己,(也可翻译为:每天不停地学习,)等到学成了,也就不知道自己愚笨与平庸了。我天资聪明,超过别人;能力也超过别人,却不努力去发挥,即与普通人无异。孔子的学问最终是靠不怎么聪明的曾参传下来的。如此看来聪明愚笨,难道是一成不变的吗? 四川边远的地方有两个和尚,其中一个贫穷,另一个富有。穷和尚对富和尚说:“我想要去南海,怎么样?”富和尚说:“你凭借什么去?”穷和尚说:“我一个水瓶和一个饭碗就足够了。”富和尚说:“我多年来想要雇船顺流而下,还没能够去成呢,你凭借什么去!”到了第二年,穷和尚从南海返回,把(达到过南海)这件事告诉了富和尚。富和尚面有惭愧之色。 四川的西部距离南海不知道有几千里的路,富和尚不能到而穷和尚到了。一个人立志求学,难道还不如四川边远的地方的和尚吗?因此,聪明与敏捷,可以依靠但也不可以依靠;自己依靠着聪明与敏捷而不努力学习的人,是自己毁了自己。愚笨和平庸,可以限制又不可以限制;不被自己的愚笨平庸所局限而努力不倦地学习的人,是靠自己努力学成的。 【鉴赏】 这个故事告诉我们,我们只有立下了目标,努力去实现,才会获得成功。主观努力是成败的关键。人贵立志,事在人为。人要立长志,不要常立志。人之为学,贵在立志,无论客观条件的好坏,天资的高低,关键在于主观努力。 文中“吾一瓶一钵足矣”的两个“一”字表现贫者对物质要求极低,一个“足”字体现了他战胜困难的坚定信心,表现了贫者面对困难知难而进的勇气和实现远大理想的坚定信念,以及无所畏惧的坚强意志和敢于大胆实践的精神成功到行动,坚持到立志文中以四川两个和尚去南海的故事为例,生动形象地说明了难与易的辩证关系,告诉我们事在人为的道理。所以我们要奋发学习。 (注:文档可能无法思考全面,请浏览后下载,供参考。可复制、编制,期待你的好评与关注)

英文简历必备-个人资料中英翻译

个人资料 name 姓名 alias 别名 pen name 笔名 date of birth 出生日期 birth date 出生日期 born 出生于 birth place 出生地点 age 年龄 native place 籍贯 province 省 city 市 autonomous region 自治区prefecture 专区 county 县 nationality 民族,国籍citizenship 国籍 duel citizenship 双重国籍address 地址 current address 目前地址present address 目前地址permanent address 永久地址postal code 邮政编码 home phone 住宅电话 office phone 办公电话business phone 办公电话Tel.电话 sex 性别 male 男

female 女 height 身高 weight 体重 marital status 婚姻状况family status 家庭状况married 已婚 single/unmarried 未婚divorced 离异 separated 分居 number of children 子女人数none 无 street 街 lane 胡同,巷 road 路 district 区 house number 门牌 health 健康状况 health condition 健康状况blood type 血型 short-sighted 近视 far-sighted 远视 color-blind 色盲 ID card No.身份证号码 date of availability 可到职时间available 可到职membership 会员,资格president 会长 vice-president 副会长director 理事 standing director 常务理事

为学阅读附答案

阅读《为学》,完成后的小题。 天下事有难易乎为之,则难者亦易矣;不为,则易者亦难矣。人之为学有难易乎学之,则难者亦易矣;不学,则易者亦难矣。 吾资之昏,不逮人也,吾材之庸,不逮人也;旦旦而学之,久而不怠焉,迄乎成,而亦不知其昏与庸也。吾资之聪,倍人也,吾材之敏,倍人也;屏弃而不用,其与昏与庸无以异也。圣人之道,卒于鲁也传之。然则昏庸聪敏之用,岂有常哉! 蜀之鄙,有二僧:其一贫,其一富。贫者语于富者曰:“吾欲之南海,何如”富者曰:“子何恃而往”曰:“吾一瓶一钵足矣。”富者曰:“吾数年来欲买舟而下,犹未能也。子何恃而往!”越明年,贫者自南海还,以告富者,富者有惭色。 西蜀之去南海,不知几千里也,僧富者不能至而贫者至焉。人之立志,顾不如蜀鄙之僧哉是故聪与敏,可恃而不可恃也;自恃其聪于敏而不学者,自败者也。昏与庸可限而不可限也;不自限其昏与庸,而力学不倦者,自力者也。 小题1:解释下面句子中划线词的意思(2分) ①吾资之昏,不逮人也。逮:②西蜀之去南海去: ③蜀之鄙有二僧鄙:④子何恃而往!恃: 小题2:翻译下列句子(2分) ①吾欲之南海,何如翻译: ②人之立志,顾不如蜀鄙之僧哉翻译: 小题3:本文的中心论点是什么(用原文回答)(2分) 小题4:蜀鄙二僧的故事告诉我们什么道理(2分) 小题5:学习本文后,你悟出了什么道理(2分) 参考答案: 小题1:逮:及,赶得上;去:距离;鄙:边境恃:凭借、依仗。 小题1:(1)我打算到南海去,怎么样(2)人们立志,难道还不如四川边境的那个穷和尚吗 小题1:人之为学有难易乎学之,则难者亦易矣,不学,则易者亦难矣。 小题1:事在人为,有志者事竟成。 小题1:人贵有志,事在人为。 小题1:此题考查学生对文言实词的理解能力,结合具体语境理解词义即可,有时还要注意词语的特殊用法。 小题1:本题考查学生翻译文言文的能力。要求具有落实重点词语的能力,不能遗漏,同时要与上下文连贯,有时还要补出省略的主语,同时要抓住其中的关键字。 小题1:本题考查文章的中心论点。议论文的中心论点从标题、开头、结尾来分析即可,有时也可以根据文章的内容用自己的语言来概括。 小题1:本题考查理解文章内容的能力。结合对文章大意的理解来谈道理即可。 小题1:本题考查理解文章内容的能力。结合对文章大意的理解来谈道理即可。

专业英语原文和翻译

Basic Control Actions and Industrial Automatic Control An automatic controller compares the actual value of the plant output with the desired value, determines the deviation, and produces a control signal which will reduce the deviation to zero or to a small value.The manner in which the automatic conroller produces the control signal is called the control action. Classifications of industrial automatic controllers Induetrial automatic controllers may be classified according to their control action as: ·two-position or on-off controllers; ·proportional controllers; ·integral controllers; ·proportional-plus-integral controllers; ·proportional-plus-derivative controllers; ·proportional-plus-derivative-plus-integral controllers. Most industrial automatic controllers use eletricity or pressurized fluid such as oil or air as power sources. Automatic controllers may also be classified according to the kind of power employed in the operation, such as pneumatic controllers, hydraulic controllers, or electronic controllers.What kind of controller to use must be decided by the nature of the plant and the operating conditions,including such considerations as safety, availability, reliability, accuracy, weight, and size? Elements of industrial automatic controllers An automatic controller must detect the actuating error signal, which is usually at a very low power level, and amplify it to a sufficiently high level. Thus, an amplifier is necessary. The output of an automatic controller is fed to a power device, such as a pneumatic motor or valve, a hydraulic motor, or an electric motor. The controller usually consists of an error detector and amplifier. The measuring element is a device that converts the output variable into another suitable variable, such as a displacement, pressure, or electric signal, which can be used for comparing the output to the reference input signal. This element is in the feedback path of the closed-loop system. The set point of the controller must be converted to a reference input of the same units as the feedback signal from the measuring element. The amplifier amplifies the power of the actuating error signal, which in turn operates the actuator. The actuator is an element which alters the input to the plant according to the control signal so that the feedback signal may be brought into correspondence with the reference input signal. Self-operated controllers In most industrial automatic controllers, separate units are used for the measuring element and for the actuator. In a very simple one, however, such as a self-operated controller, these elements are assembled in one unit. Self-operated controllers utilize power developed by the measuring element and are very simple and inexpensive. The set point is determined by the adjustment of the spring force. The controlled pressure is measured by the diaphragm. The actuating error signal is the net force acting on the diaphragm. Its position determines the valve opening. The operation of self-operated controller is as follows: Suppose that the output pressure is lower than the reference pressure, as determined by the set point. Then the downward spring force is greater than the upward pressure force, resulting in a downward movement of the diaphragm. This increases the flow rate and raises the output pressure.

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