《《数电课程设计—医院病人紧急呼叫系统》.doc》由会员分享，可在线阅读，更多相关《《数电课程设计—医院病人紧急呼叫系统》.doc（15页珍藏版）》请在三一文库上搜索。
1、电子技术课程设计医院病人紧急呼叫系统学生姓名： 高志强指导老师：李红芳学号 ：201308120203专业：电子信息科学与技术院系：物理与电子工程学院日期：2015 06 14目录一、设计总体思路2二、单元电路设计5三、安装与调试11四、故障分析与电路改进12五、总结与体会13六、附录15七、参考文献13一、设计总体思路 1.设计内容及要求根据要求设计一个医院病人紧急呼叫系统。具体要求如下：1、 当病人紧急呼叫时，能显示病人的编号；x2、 根据病人病情设置优先级别。当有多人呼叫时，病情严重着优先；3、 医务人员处理当前最高级别病人的呼叫后，系统按优先级别显示其它呼叫病人的编号。 2.基本原理与
2、框图系统可由信号呼叫锁存、优先编码、显示电路及逻辑控制清除电路等几部分组成。系统首先通过不同的按钮开关接受不同的呼叫信号，并将其对应信号锁存在与之相对应的D触发器中，然后将这些呼叫信号传到8路优先编码器，编码器再根据触发器中信号优先级的高低依次对这些信号进行编码，然后将当前最高优先级别的信号显示出来。医务人员根据当前显示病人编号进行处理，处理一个按一下控制开关，则可清除当前处理的病人并显示下个次要优先级别的病人，清除的原理就是：每当按一下复位按钮就会产生一个上升沿脉冲，使计数器置数，并将当前显示的数通过计数器输入到译码器中，与之对应输出一个低电平信号最为触发器清零信号。此时，显示器中显示的是次
3、级编码信号。同理将依次处理完毕，最后全部处理完后将显示零。 系统工作的原理图框图 3. 总电路图 根据系统需要及电路的框图可用EWB仿真软件做出总电路图： 医院病人紧急呼叫系统总电路图 二、单元电路设计1.信号锁存电路此系统所用D触发器为74LS74，当预置端及清除端均为高电平且当CLK上升沿时将输入信号D锁存在Q中的功能，Q=D。这里我们所使用的为端，首先使为高电平，当输入一个上升沿脉冲时变为低电平。74LS74功能表如下：输 入输 出预 置清 除时 钟 CP01xx1010xx0100xx111111011001110x保持 74LS74锁存部分电路图如下：此电路使用2个74LS74双D触
4、发器4个输入端分别代表4个病人，是先把D端置高电平，当给了时钟CP后，Q端出高电平1，端出低电平0，此时的低电平可直接作用于优先编码器的编码输入端，使之输出对应的二进制数据。而当译码器给了清除端CLR信号0后，端出1，利用这点可以对信号进行清除，显示其它病人的信号。2. 优先编码电路此系统所用编码器为74LS148优先编码器，根据D触发器传来的信号进行编码产生一个地址码再经过反相器就可以在显示电路中显示是哪个病人需要护理了。74LS148编码器的真值表如下：输入输出EII0I1I2I3I4I5I6I7A2A1A0GSEO1111110111111111111000000010010011000
5、110101000111011100011111001000111111011000111111110100011111111111074LS148编码部分电路图如下：此电路使用了一个74LS148优先编码器，在E10电路正常工作状态下，允许1-4当中同时有几个输入端为低电平，即有编码输入信号。其中4至1的优先权依次降低，对应的A2、A1、A0三个输出对应的二进制代码。利用这一点，可以将触发器中传来的信号来控制74LS48七段显示器译码器的消隐端，当无病人给信号时，则显示零。3显示电路根据优先编码器74LS148的地址码可以选取接入译码器74LS48，输出a、b、c、d、e、f、g和七段共阴极
6、显示器的相应端口相连。一般显示器元件同时具有译码器74LS48功能，只需将优先编码器74LS148的地址码输出的信号经过反相器后直接与显示器给出的四个端口相连即可。 4. 逻辑控制及复位电路此系统是利用医务人员控制的复位开关产生一个上升沿启动74LS160使优先编码器输出的地址码保持输出，将这些地址码输入到74LS138译码，从而去控制对应D触发器的清零端 ，达到复位的目的。74LS160计数器的真值表如下： ET EP CPD3 D2 D1 D0 Q3Q2Q1Q00 0 0001 0 D CBAD CBA1 10 保持1 1 0 保持1 1 1 1计数74LS138译码器的真值表如下：逻辑控
7、制及复位清零部分电路图如下：74LS160为异步清零计数器，即端输入低电平，不受CP控制，输出端立即全部为低电平。74LS160还具有同步预置功能，在 端无效时，端输入低电平，在时钟共同作用下，CP上跳后计数器状态等于预置输入DCBA，即所谓“同步”预置功能。此系统利用的是74LS160置数功能。74LS138 为3 线8 线译码器，当一个选通端G1为高电平，另两个选通端G2A和G2B为低电平时，可将地址端（A、B、C）的二进制编码在一个对应的输出端以低电平译出。如上图，74LS148优先编码器的地址码通过74LS160的ABCD输入端输入，当按下清除开关产生一个上升沿CP送到CLK，利用74
8、LS160的同步预置功能，把74LS160的输出端置成与输入端一样的编码，送至74LS138译码器译码译出与地址码相对应的低电平接至74LS74D触发器的清除端，从而实现信号的逻辑控制与清除。三、安装与调试通过EWB仿真软件进行运行无误后，可以根据仿真图进行安装工作，安装之前一定要检测工具箱、导线和芯片的好坏，这是最重要的；然后就是接线了，整体结构布局应从全局出发，决定电子装置各部分的空间位置。将整个功能电路分成几个单元电路，我这里就将它分成信号锁存电路、优先编码电路、显示电路和逻辑及控制电路，接好一个单元电路之后就得对此单元电路进行检测，看看是否与理论值相同，不相同就得查查是否线路松动还是接
9、错了；将各个单元电路接好检测好后级联起来调试至成功。四、故障分析与电路改进1、假如显示功能有时对有时错，这时应该看看线是否有松动。当优先编码单元电路和显示器检测功能完好的情况下，按下信号呼叫按钮，但显示器无变化，这时可能是按钮接触不良，无法给锁存器提供信号锁存所需的上升沿，也可能是74LS74没有工作在锁存功能，像清零端不是高电平、没接有效电平都有可能导致锁存器不能锁存D中的信息。2、显示器有显示，但是是乱码，不能和呼叫信号相匹配，并且检测到了显示器能正常工作，这就可能是优先编码的问题，我们这里需要的是4、3、2、1这四个优先级，这就必须把5、6、7端接高电平及无效段，还有无呼叫信号时要不显示
10、，这意味着我们不需要的0端也要接电源。3、如果呼叫信号还是能正确显示，但就是不能复位清零，使得低优先级的无法得到及时处理，这个就得先从复位开关开始检测，是否产生上升沿至又74LS160，然后看看要复位清零的地址码是否准确传入74LS160对应端，确定74LS160工作在保持功能，如果还不能清零，就继续检测74LS138译码器是否正常译码，最后就是检查译码信号是否传给了D触发器的。电路改进： 电路进行清除当前显示时，倘若将某个触发器清零，但二进制译码器还将保持原有的输出，这时此触发器的清零端将维持清零状态将不能立刻收到信号。要解决这种弊端得连个装置就是每当译码器工作一次就得将其进行复位，使得各D
11、触发器的清零端口全为高电平无效。此方案可以利用74LS138的使能端来实现。五、总结与体会数字电子技术的课程设计，今天终于能告一段落，这次的课程设计又一次加强了我们动手、思考和解决问题的能力，在这之前我们也做过训练我这方面能力的课程设计和实习，像电工电子实习。但这次是第一次完全由自己设计电路，遇到的困难可想而知，但最终还是很好的完成了任务，而且使我受益匪浅。 这次的数电课程设计，我做的是个比较简单的医院病人紧急呼叫系统，任务拿到手上之后觉得确实很简单再加上以前数电也还学的不错，直到真真自己动手设计时才发现理想与实际之间的差距很大，以前学的那些芯片管脚及功能都很模糊，比如呼叫信号怎样锁存，处理完
12、高优先级的呼叫后怎么清除等等一连串的问题。通过这个课程设计，我的最大收获就是对一些芯片的功能有了更好的理解和运用，以及对以前学的知识存在的一些问题也迎刃而解，同时也对学的知识有了一个实践性的证明。通过这次课程设计使我懂的了理论与实际相结合的重要性，只是一味的学那些死的理论知识是远远不够的，只有把所学的理论和实践相结合，才能真正掌握一门科学，一味的纸上谈兵是行不通的，实践还可以提高自己的实际动手能力和独立思考的能力，这也是为在当代急需的实践型人才的社会的一种准备。其次就是接实物电路的时候觉得最主要的就是要沉着冷静加细心。付出就会有收获，两周的课程设计，虽然过程曲折难尽，但也收获良多，在老师、组员
13、和其他同学的帮助下很好的完成了老师布置的任务，这种经历不管是泪水曲折还是所获得的成果，都将成为我人生旅途的一段美好的回忆。6、 附录 元器件清单：元器件功能名称数量74LS74 双D触发器 两片74LS1488/3优先编码器一片74LS1383/8译码器一片74LS04六非门一片按钮开关五个导线若干七、参考文献数字电子技术基础 周良权编电子技术课程设计指导 彭介华编电子技术基础实验 陈大钦编 Dfbgsjkfskfjnffggwejkgjewkfgjwefjeifjiofjsiugsheluihgeuigherliuawprhggggggweihgiwedfipwjfweipfh98gfweu
14、igthweuigfhwugiqhw9u8fhqjweuj98fqjw98fjqwuigweugiuogheuoghueosiugeghwe87fyhuhwe87fhwuieghweuifhwe8ugeguhewgiuwehgu8qwhg98uqwHGUQW8GHQU89WEHFUIFHQWIYDQW8RYFQWP8FYHWPIghewguiuiuiuiuiuiuihhhghggggggggggggggggggggggggggggggggggdddddddddddddddddddddddddddddddddddddddddddddddddddddddddOpinions and suggest
15、ions on the partys mass line educational practiceAccording to the central and provincial, municipal unified deployment, according to municipal Party committee about carrying out the partys mass line educational practice activity in the citys implementation opinions, the spirit of the partys mass lin
16、e educational practice activities from 20* in January to 99 months, carried out at all levels of departments and directly affiliated institutions and grass-roots party organizations. According to my actual County, the county to carry out the education practice put forward the following implementatio
17、n opinions.First, the overall requirementsCounty county education practice to the eighteen Party of eight, the spirit of the the third Plenary Session of the 18th CPC Central Committee as the guidance, conscientiously implement the spirit of general secretary Xi Jinping book series of important spee
18、ch, earnestly implement the Central Committee really, opinions and advice , party implementing the guiding ideology of opinions to determine the objectives and requirements, step method, in accordance with the look in the mirror, dress up, wash bath, cure treatment, the general requirements of for t
19、he people pragmatic honest people as the theme, in carrying forward the spirit of Zhuanglang Zhuang, improve their work style, service to the masses of the people, the foundation of consolidating grassroots, promote transformation across efforts, to further implement the central eight regulations an
20、d The opposition party and government austerity waste regulations , double section provincial regulations, municipal provisions of the twelve plan and the implementation measures for on improving the work style of close ties with the masses law, highlight style building, carry out the whole wind spi
21、rit, resolutely oppose formalism, bureaucracy, hedonism and wasteful extravagance to solve the problems, Party members and cadres of the style and the masses of people strong, the Ministry of Party members and cadres to further improve their thinking and understanding, to further change the style of
22、 the wind, the masses to close, honest and pragmatic people honest image to further establish the foundation to further reinforce the basic level. Style of the building of the new results to promote the construction of a powerful force of the county and the ecological culture of the county and count
23、y construction.In educational practice activities of the unit is mainly: the county and below county departments under the organs, enterprises and institutions directly under the township, street, and community, village, non-public economic organizations, social organizations and other grass-roots o
24、rganizations. Agencies and branches, each single unit, follow the rules on internal institutions. Educational practice with step by step.To adhere to the county leadership, leadership and leading cadres to focus on outstanding catch to directly contact the service of the masses of law supervision de
25、partments and window units, service industry, educational practice, pay attention to grasp the heavy towns, streets and villages, community education activities and the masses of grassroots groups in close contact to strengthen, and the majority of Party members, cadres and the mass line line Marx d
26、octrine view of the masses and the partys education.Always speak seriously as a basic attitude, adhere to positive education, to carry out criticism and self criticism group, adhere to the pragmatic, more emphasis on leadership, pay more attention to the layers of the demonstration, more focus on th
27、e four winds, solve the problem, pay more attention to open the door, the participation of the masses, pay more attention to the classification guidance. Orderly, pay more attention to the cooperation and cohesion driven, more strict requirements on injection, really supervision practice, ensure edu
28、cation practice is not empty is not empty is not partial, not as a mere formality.Two, the key point of the taskThe main task of the countys education practice is to seize against four wind this focus on centralized solve outstanding problems asked County, township leadership and leading cadres of t
29、he four winds, the disadvantages of the style, scale behavior to a large scale investigation, overhaul, cleaning greatly. At the same time, respond to the concerns of the masses, safeguard the interests of the masses, pay attention to solve practical problems, solve the people around the unwholesome
30、 tendencies especially on eat, take the card, Yong lazy luxury, extravagance and waste fees, privileges and other issues, timely and effective, without any discount to solve, to improve the style of real implementation of the requirements of real to the grassroots, real let group Benefit the public.
31、(a) focus on solving the four winds outstanding issuesThe central and provincial requirements, the county leadership and leading cadres of key performance concept is not correct, do not dare to play, to engage in image project, political project, a leadership guide, a set of ideas, orders and prohib
32、itions, and a policy, there are countermeasures county. The units directly under the heavy focus on solving Yung lazy drag, buck passing skin, work is not implemented, the service is not active. The dynamic problem of law enforcement and supervision departments and window units, service industry mai
33、nly solve the door hard, ugly face, something difficult, and arbitrary charges, fines, levies, and breach of privilege, chinakayao, not the problem of law. The township, street The collar of leading bodies and leading cadres to solve key does nottheir own conditions to develop the correct road, the
34、maximum to avoid investment risk, gain profit.(three) vigorously promote the brand. To establish brand awareness, awareness of the use of brand, brand value, brand acquisition performance, enhance the competitive strength. Concentrated manpower, careful planning, packaging and publicity of a number
35、of unique, market influence and coverage of the brand, the implementation of key breakthroughs, to enhance the competitive strength, walking business road the competition of alienation and characteristics, the pursuit of stability and development of the market.(four) to promote the integration of re
36、sources. To further broaden their horizons, effective integration of resources within the group, the city resources, other industries and regional resources, mutual trust, mutual benefit, seeking win-win principle, in the framework of national policies and regulations, strict inspection and argument
37、ation, legal consultation, examination and approval procedures, strict regulation of economic activities, attract injection the social investment to the industry group, to achieve leveraging the development, ensure that the value of state-owned assets.(five) to strengthen the construction management
38、 personnel. Strengthen the management of education and training of cadres and workers of the existing business, firmly establish the concept of the market, enhance the sense of crisis to adapt to market competition, the sense of urgency, improve the ability to respond to market competition, improve
39、management and operation of the market. At the same time, according to the need of industrial development, vigorously the introduction of high-quality management management personnel, and strive to build a high-quality professional management team, hard work, and promote the entire workforce knowled
40、ge structure, age structure, structure optimization and upgrading ability, enhance core competitiveness, adapt to the need of market competition.(six) seriously study the policy for policy. Serious research about social support the development of cultural undertakings in the country and the XX policy, especially the policy of industrial development, financial investment policy, financial policy and tax policy, and actively seek policy, projects and funds, enterprise and industry group mission to promote leapfrog development.15