电子课程设计-公用电话计时器.doc

Delegates, staff: Hello! in the run-up to the Spring Festival, we held one session of four staff representatives Conference 2013-workshop, full back in 2012, careful analysis of the current situation, discuss 2013 development plans. 　　Here, on behalf of my company 2013 work reports to the General Assembly, for consideration. 　　Pillar I, 2012 back in 2012, XX power companies adhere to the party's 17 great spirit for guidance, comprehensively implement the scientific concept of development, promoting cost-leadership strategy, standards, focus on implementation, lean management, continuously improve, smooth present safety situation of enterprise management, business management and control scientific and standardized, and the dedication of staff, manage a harmonious and democratic atmosphere of the good situation. Main indicators are as follows:-the battery indicator: power generation totaled 7.815 billion kWh, beyond the annual budget implementation capacity of 315 million kWh, an increase of 757 million kWh. 　　Sales totaled 7.425 billion kWh, exceeding sales of 330 million kWh the annual Executive budget, an increase of 729 million kWh. --Security measures: unplanned outages 2.5 times. 　　No personal injury accident occurred, no major accident and above, no major fire accidents without environmental pollution accidents, safety for three consecutive years to maintain stability to good posture. 　　– Business financial indicators: total profits of 255 million Yuan, beyond the annual budget of 207 million Yuan, beyond the Datang company index 41.89 million Yuan, an increase of 1.76 million Yuan, FCM assessment at grade four. 　　--Energy: power supply standard coal completing 312.25 g/kWh, down 0.1 g/kWh; integrated auxiliary power consumption ratio in 5.12%, down 0.26%; pollutant emissions performance greatly reduced compared to last year, carbon 0.09 g/kWh, sulfur dioxide 0.104 g/kWh NOx 0.512 g/kWh; dust removal efficiency of more than 99.8%. --Reliability index: equivalent availability factor in 93.47%, increased 7.95% from a year earlier. 　　Equivalent forced outage rate 0.08%, 0.16% reduction over the same period a year earlier. 　　Major achievements: first, we should adhere to the two "management system" basis, strengthening technological research, strengthen hidden hazards control and intrinsic safety Enterprise construction took new steps. -The two "management system" for improvement. Focus on promoting the power of the company management system and the application and implementation of the safety loop five-star management system, improve the safety management system, realize the system of safety control. Further regulate security routines, safety supervision and management network role to play to achieve closed-loop. Strengthening the supervision and management of habitual violation of, strengthening the safety supervision of outsourcing contractors. Carried out in spring and autumn of security inspections, flood control and inspection, safety production month, day supervision of production safety and the Olympic Games and other
模拟电子技术课程设计报告
--简易公用电话计时器
1.设计任务和基本要求
1.1设计任务
用中小规模集成电路设计一个公用电话计时系统。
1.2基本要求
1) 每3分钟计时一次。
2) 显示通话次数，最多为99次。
3) 每次定时误差小于1秒。
4) 具有手动复位功能。
5) 具有声响提醒功能。
本设计主要有标准信号源，分频器，3分钟定时器，计数器译码显示，声响提醒等电路组成，其工作原理为：当按下复位按键时，复位电路保证3分钟电路及二位十进制计数器同时清零，此时电话通话次数为零。当松开复位按键时，计时开始， 3分钟定时器的功能时每三分钟输出一个脉冲，该脉冲被送到计数译码器显示电路，便显示出通话次数；同时该脉冲被送到声响提醒电路，可控制声响时间及声调，实现声响提醒功能。该设计分频器，3分钟定时器主要由12位异步二进制计数器/分频器CD4040来实现，通话次数计数器显示电路由二位十进制计数器完成，采用中规模集成计数器CD4029，74LS47组成。
2.设计方案
2.1工作原理
下图为该计时器的工作框图，主要有标准信号源、分频器、3分钟定时器、计数译码显示、声响
提醒等电路组成。其工作原理为：当按下复位键时，复位电路保证3分钟电路及二位十进制计数器同时清零，此时显示通话次数为零。当松开复位按键时，计时开始，此时由标准信号发生器产生的f0

图1. 计时器的工作框图
3.单位电路模块设计

3.1标准信号源
产生脉冲信号的电路很多，例如由集成门电路构成的多谐振荡器，由555定时器组成的方波发生器等。由于该标准信号源要求频率稳定性及输出信号精度比较高，故采用由CD4011与非门（CMOS）电路及晶体原件组成的多谐振频率的信号如图2所示，晶振的标称频率为32768Hz。
由于石英晶体的选频特性非常好，只有其串联谐振频率的信号才最容易通过，而其他频率会被晶体大大衰减，所以电路在满足震荡的条件下，其输出频率仅取决于晶体的标称频率，与其他原件参数无关。电路中的电阻R是保证G1门工作在线性状态而加入的，电容C抑制告辞谐波，以保证输出频率稳定。G3门是为了改善输出波形质量，增加带负载能力而加入的缓冲级。
3.2 分频器
由于f=32768Hz频率比较高，为了得到低频信号且又能满足定时要求的脉冲，可采用CD4040二进制计数器/分频器进行分频。CD4040是由12个T型触发器组成的串行二进制计数器/分频器。复位端高电平有效，2个输入端，一个是时钟CP，一个是复位清零端，有12个分频输出端Q1-Q12,最大分频系数为212=4096。n位二进制计数器的最高位输出信号的频率fn 与计数器脉冲频率fcp的关系为fn=fcp/2n 。现选择12位异步二进制计数器CD4040，则CD4040计数器最高位输出频率为 f12=f0=fcp/212=8Hz 电路如图2，CR为清零端。

图2 标准信号源电路及分频器 图4 三分钟定时电路
3.3 3分钟定时器
该电路是本系统的关键。n位二进制计数器的输出状态与计数脉冲的个数关系为： (N)D=2n-1Qn-1+2n-2Qn-2+……+20Q0
因为输入脉冲的周期T0=1/f0定时为3分钟=180秒所需要的输入脉冲的个数N为：N=180/T0=180f0=1440个
又因为(N)D=(1440)D=()B即要求计数器的模等于1440，利用反馈清零法，可设计出该电路 。如图4所示，当CD4040累计到1440个脉冲时，G1输出为1， G2输出为0， G3被置为1。一旦4040的CR端为高电平，其输出立即被清零，由于CR组成的触发器具有记忆功能，故G3输出不变，当f0上升沿到来时，G3输出为0，CD4040的清零信号解除。可见G3输出的信号fT是周期为3分钟，输出高电平为 1/16秒 的窄脉冲。二极管D1的作用见 图6.复位电路。
3.4 通话次数计数器显示电路
该电路由二位十进制计数器完成，可采用中规模集成计数器CD4029组成。
译码器选用OC门输出的七段显示译码器74LS47，显示器采用共阳极七段LED数码管。其中R是限流电阻，即当74LS47输出为低电平时，流入其输出端电流要小于74LS47的最大允许灌电流。若R过小，流入74LS47的灌电流增大；若R过大，则LED数码管太暗。一般R选择200W～500W（在5V电源下）。
CD4029通过控制输入端可构成二进制或者BCD计数器，它有3个控制端，即二进制/十进制转换B/D，加/减转换U/D和预置数LD，另外它还有4个置数端D0-D3,4个输出端Q0-Q3,脉冲输入端CP，进位输入端,进位输出端。CD4029具有优先进位功能的四位二/十进制加/减计数器，进位功能可以根据加法和减法或者二进制和十进制来确定CP上升沿进行计数。
电路如图4所示。由于CD4029无清零端，实现复位功能需要置数清零。译码器选用OC门输出的七段显示译码器74LS47，显示器采用共阳极七段LED数码管。其中R是限流电阻，即当74LS47输出为低电平时，流入74LS47的灌电流增大；如果R过大，则LED数码管太暗。一般R选择200Ω-500Ω （在5V电源下）。
3.5复位电路
根据设计要求，在每次通话之前一定要清零。当复位按键按下时，3分钟定时电力和通话次数计数电路均被清零。如图6所示。当S（复位开关）按下时，+5V电源同时加到2分钟定时器的清零端和通话次数的指数段，使其强迫清零。但由于二极管D1的存在，+5V电源加不到门电路CD4001的输出端，避免了CD4001的损坏。另外。由于D2的作用，使得3分钟定时脉冲仅能加到3分钟定时器的清零端和通话次数计数器的计数脉冲输入端，而传送不到通话次数计数器的置数端上来，从而实现了正常的计数。

图5 通话次数计数显示电路 图6 复位电路
4.调试要点
4.1．标准信号源调试
利用示波器观察振荡器输出波形是否正确。若用万用表直流量程测量其输出，应为2.5V左右输出。然后用示波器观察分频器CD4040的Q11端输出，检验是否有8Hz信号输出。
4.2．3分钟信号测量
3分钟定时信号脉冲输出高电平时间极短，故利用示波器测量时，把示波器扫描速度开关打在“扫描停止”档，观察光点的变化。
4.3．计数显示电路调试
首先外加入1Hz左右的脉冲信号，观察计数器、译码、显示电路是否正常工作。
附录（各元件引脚功能）：
一：4040
输入
输出

L
不变

L
进入下一状态
X
H
全部输出为L

表1 CD4040功能表
功能：十二进制计数器，在此试验中是十二进制分频器
二：CD4011 三：CD4082 四：CD4001

功能：由四个二输入端 功能：由两个四输入端 功能：由四个二输入端
的与非门组成 的与非门组成。 的或非门组成。

五：CD4029

L
L
L
H

L
H

L
H
H
L

H
H

保持

H

保持

表2 4029功能表
六：74LS47 七：共阳极的七段LED显示器

主要介绍的是永磁直流电动机；首先简述了永磁电机、永磁直流电动机从产生到到逐步改善的发展过程，以及以此为基础的未来发展的趋势；activities, comprehensive and tamping Safety Foundation ... Troubleshooting, management mechanism, give full play to role of technical supervision and realization of troubleshooting, management, improved process management. This year completed the boiler lower header leakage, boiler pressure, a major risk management, completed 29 of great risks and 3 General problems of governance. Complete chemistry lab construction, thermal control, and complete the boiler scale integrated management, host shafting vibration of 10 scientific and technological projects, such as. 　　Complete supercritical 630MW on-line simulation system development and application of circulating water MCC standby power transformation, the transformation of desulfurization waste water, the unit water supply system of comprehensive treatment and discharge valve modification of coal mill 5 key technological transformation projects, group health is improved. --Science and technology innovation is further increased. Strengthen the characteristics of supercritical unit major issues, gradually clearing the particularity of supercritical unit and regularity. Developed motor oil time management, switch action times, statistics, coal-aided measurement software, improves the production level of lean management. Increased investment in science and technology, reporting science and technology projects and 14 technical project total cost percentage of the total annual production output of 0.25%. "Large-scale coal-fired power plant flue gas desulfurization, denitrification complete development and application of key technologies" project, won the national science and technology progress second prize. 630MW supercritical units optimized control strategies and the 630MW development and application of on-line simulation system for supercritical units, supercritical 600MW units of turbine driven boiler feed pump set of comprehensive treatment of defects Datang technology respectively one or two and third. 　　Meanwhile, information technology achievements, the company was named "China power information technology benchmarking enterprises." --Repair and maintenance has improved further. Modify the inspection standards and standards on a regular basis, standardizing work procedures, checking and inspection project. Deepening the BFS++ system, and implements maintenance information shared. Reorganizing RB logic again, and ensure the success of the RB. Innovating the mechanism of maintenance management, implemented a project manager system Successful completion of two autonomous maintenance, reliability improved steadily. Implementing two c-level maintenance, project themselves 48.7% and 42.3%, respectively. Accomplish two circulating pumps repair and overhaul of four Mills, maintenance teams to get exercise. 　　Promote the work of energy saving and consumption reducing, complete the unit energy consumption diagnosis, plant water balance test, 10 energy-saving projects. 　　Second, we should adhere to "three" on the economic benefits of improving, outreach