三极管放大倍数

三极管放大倍数 ——简易数字三极管β值显示仪 班级:光电?光通信071 姓名:张华容,2007031039, 张磊,2007031051, 指导老师:赵建 杨笔锋 使用仪器及编号:直流稳压电源,20051851, 万用表,100202502, 课程时间:2010年6月9日 supplies and get to use, the registration of company assets, record maintenance, maintenance of effective management; 2.6 cost management: preparation of the annual administrative budget, control administrative costs, determine the scope of cost-sharing, sharing the office expenses by month; 2.7 information management: responsible for documents, materials, information and publicity, communication links, and ensure promptly, ranking officers reporting; responsible for the collation and analysis of information, provide the basis for corporate decisions; corporate culture construction, planning, editing, internal publications; 2.8 vehicle management: responsible for the management, repairs and maintenance of vehicles; 2.9 legal disputes: the company responsible for the handling of disputes; 2.10 other: maintaining normal working order, and security. General Manager General Manager job description 1, 1.1 develop strategies and plans: according to company strategic planning, establish the annual management plan, reported to the Board of Directors for approval; 1.2 decomposition measures: according to the Board of Directors issued the annual management plan, annual index of decomposition, through the Organization of coordination mandate in charge of the Department Organization and implementation, ensuring comprehensive implementation of annual indicators; 1.3 inspection: convenes the General Manager Office, through 目录 一、系统设计要求..................................................................................................... 2 1.1 设计任务 ................................................................................................. 2 1.2 基本要求 ................................................................................................. 2 二、的比较论证和选择....................................................................................... 3 2.1 电源部分 ................................................................................................... 3 2.2 主体控制、数据处理部分 .......................................................................... 3 2.3 前端采集部分 .......................................................................................... 4 2.4 显示部分 ................................................................................................. 4 2.5 总体设计框图 .......................................................................................... 4 三、单元模块的设计 ................................................................................................. 5 3.1 各单元模块功能介绍及电路设计 .............................................................. 5 3.1.1 电源模块 .......................................................................................... 5 3.1.2 三极管β参数测试模块 .................................................................. 5 3.1.3 选择电路 ........................................................................................ 6 3.1.4 信号处理模块 ................................................................................. 6 ........................................................ 7 3.1.5 显示模块 ................................ 3.2 电路参数计算及特殊元器件介绍 ................................................................ 8 3.2.1 电路参数计算 ................................................................................... 8 3.2.2 特殊元器件介绍................................................................................ 8 四、系统电路图和PCB图 .......................................................................................... 9 4.1 系统电路图及工作原理................................................................................ 9 4.2 PCB图 ..................................................................................................... 10 五、系统调试及测试结果 ........................................................................................ 10 5.1 系统调试 ................................................................................................. 10 5.1.1 调试所用仪器 ................................................................................. 10 5.1.2 调试过程 ........................................................................................ 10 5.2 系统测试及结果 .........................................................................................11 5.3 系统测试中的问..................................................................................... 12 六、设计总结.......................................................................................................... 12 七、参考资料.......................................................................................................... 12 supplies and get to use, the registration of company assets, record maintenance, maintenance of effective management; 2.6 cost 1 management: preparation of the annual administrative budget, control administrative costs, determine the scope of cost-sharing, sharing the office expenses by month; 2.7 information management: responsible for documents, materials, information and publicity, communication links, and ensure promptly, ranking officers reporting; responsible for the collation and analysis of information, provide the basis for corporate decisions; corporate culture construction, planning, editing, internal publications; 2.8 vehicle management: responsible for the management, repairs and maintenance of vehicles; 2.9 legal disputes: the company responsible for the handling of disputes; 2.10 other: maintaining normal working order, and security. General Manager General Manager job description 1, 1.1 develop strategies and plans: according to company strategic planning, establish the annual management plan, reported to the Board of Directors for approval; 1.2 decomposition measures: according to the Board of Directors issued the annual management plan, annual index of decomposition, through the Organization of coordination mandate in charge of the Department Organization and implementation, ensuring comprehensive implementation of annual indicators; 1.3 inspection: convenes the General Manager Office, through 摘要: 该系统以三位半LED显示A/D转换芯片ICL7107作为数据处理芯片，将前端 采集到的电压进行处理，利用数码管来实时显示被测三极管放大倍数β～实现了 三级管放大倍数的测量及其显示。能够对NPN和PNP三极管进行β值测量;被 测三极管β值在50~300之间;测试误差控制在10%以内。 关键词:ICL7107 三极管 测试 放大倍数 Abstract This system with three and a half LED display A/D conversion chip ICL7107 as data processing chip, will be collected in front of voltage, using digital tube to real-time display measured by triode magnification, triple tubes beta and magnification of the measurement. NPN transistor and beta PNP be measurement, Beta tested is between 50 and 300, Test control error in less than 10%. Key words:ICL7107 transistor measurement magnification 一、 系统设计要求: 1.1 设计任务:设计并制作一台三级管放大倍数测试、显示仪，能够对 三极管放大倍数进行测量。示意图如下所示: 被测三β参数测数据处 显示部分 极管 试电路 理电路 1.2 基本要求: (1)能够对NPN和PNP三极管进行β值测量; supplies and get to use, the registration of company assets, record maintenance, maintenance of effective management; 2.6 cost management: preparation of the annual administrative budget, control administrative costs, determine the scope of cost-sharing, sharing the office expenses by month; 2.7 information management: responsible for documents, materials, information and publicity, communication links, and ensure promptly, ranking officers reporting; responsible for the collation and analysis of information, provide the basis for corporate decisions; corporate culture construction, planning, editing, internal publications; 2.8 vehicle management: responsible for the management, repairs and maintenance of vehicles; 2.9 legal disputes: the company responsible for the handling of disputes; 2.10 other: maintaining normal working order, and security. General Manager General Manager job description 1, 1.1 develop strategies and plans: according to company strategic planning, establish the annual management plan, reported to the Board of Directors for approval; 1.2 decomposition measures: according to the Board of Directors issued the annual management plan, annual index of decomposition, through the Organization of coordination mandate in charge of the Department Organization and implementation, ensuring comprehensive implementation of annual indicators; 1.3 inspection: convenes the General Manager Office, through (2)被测三极管β值范围:50~300; (3)测试误差<10%; (4)β值至少用三位数码管显示。 二、方案的比较论证和选择: 2.1 电源部分: 方案一:使用220V市电，经过降压整流、滤波、稳压得到5V电压。框图如下所示: 方案二:直接使用实验室提供的多路直流稳压电源提供6V左右的电压，由于每一次测试时加的电压会有所差异，因此再用一个5.1V的稳压二极管得到稳定的电压输出。框图如下: 直流稳压电源 稳压二极管 5.1V电压输出 方案比较与选择:方案一需要一个变压器，变压器体积较大，并且使作品体积大大增加，影响成品美观，而且成本较高。方案二成本低又能很好的满足系统要求，电路也比方案一简单。因此选择方案二，简单经济，稳定性好。 2.2 主体控制、数据处理部分: 方案一:使用一个STC89C51单片机作为控制和数据处理芯片，前端采集到的电压经运放放大后，经过模数转换芯片ADC0804转换为数字信号输送给单片机，单片机处理后进行显示。 方案二:使用一个三位半LED显示A/D转换芯片ICL7107来进行数据处理，然后再进行显示。 方案比较与选择:方案一需要两片芯片及运放若干，而且还需要编程，电路较为复杂，成本较高，而方案二只需一片ICL7107和少量的外围电路就可实现系统设计的要求。因此选择方案二，简单经济。 supplies and get to use, the registration of company assets, record maintenance, maintenance of effective management; 2.6 cost 3 management: preparation of the annual administrative budget, control administrative costs, determine the scope of cost-sharing, sharing the office expenses by month; 2.7 information management: responsible for documents, materials, information and publicity, communication links, and ensure promptly, ranking officers reporting; responsible for the collation and analysis of information, provide the basis for corporate decisions; corporate culture construction, planning, editing, internal publications; 2.8 vehicle management: responsible for the management, repairs and maintenance of vehicles; 2.9 legal disputes: the company responsible for the handling of disputes; 2.10 other: maintaining normal working order, and security. General Manager General Manager job description 1, 1.1 develop strategies and plans: according to company strategic planning, establish the annual management plan, reported to the Board of Directors for approval; 1.2 decomposition measures: according to the Board of Directors issued the annual management plan, annual index of decomposition, through the Organization of coordination mandate in charge of the Department Organization and implementation, ensuring comprehensive implementation of annual indicators; 1.3 inspection: convenes the General Manager Office, through 2.3 前端采集部分: 方案一:使用专用的恒流源给三极管的基极提供稳定的电流，通过检测与三极管发射极(集电极)相连的电阻上的电压来采集前端信号。 方案二:NPN测试电路使用一对性能完全相同的PNP型三极管和两个电阻组成一个恒流源， PNP测试电路使用一对性能完全相同的NPN型三极管和两个电阻组成一个恒流源，产生几十微安恒定的电流作为PNP三极管的基极电流。用一个开关来进行选择其中的一个通路。 方案比较与选择:方案一使用现成的恒流源，不需要自己搭建，精度比较高，而且输出电流稳定，但是花费太高;方案二使用较少的分立元件搭建恒流源电路，电路比较简单，花费很少，精度不够高。因为题目要求三极管测试的允许误差较大(小于10%)，因此选择方案二，能够很好的达到题目的要求。 2.4 显示部分: 方案一:使用LCD来进行显示。 方案二:使用数码管进行显示。 方案比较与选择:因为该系统需要显示的只是一些简单的数字，而且ICL7107外接的数码管是共阳的，所以选择三个共阳数码管来进行显示完全满足系统的要求。而且操作简单，经济。 2.5 总体设计框图: 根据题目要求和设计方案本系统主要由PNP/NPN电压采集电路(恒流源电路，三级管放大电路)，衰减电路，ICL7107数据处理、显示电路组成，系统框图如下所示: PNP电压采集 ICL7107电路 三位数码二 选管显示 一 处理电路 NPN电压采集 电路 supplies and get to use, the registration of company assets, record maintenance, maintenance of effective management; 2.6 cost management: preparation of the annual administrative budget, control administrative costs, determine the scope of cost-sharing, sharing the office expenses by month; 2.7 information management: responsible for documents, materials, information and publicity, communication links, and ensure promptly, ranking officers reporting; responsible for the collation and analysis of information, provide the basis for corporate decisions; corporate culture construction, planning, editing, internal publications; 2.8 vehicle management: responsible for the management, repairs and maintenance of vehicles; 2.9 legal disputes: the company responsible for the handling of disputes; 2.10 other: maintaining normal working order, and security. General Manager General Manager job description 1, 1.1 develop strategies and plans: according to company strategic planning, establish the annual management plan, reported to the Board of Directors for approval; 1.2 decomposition measures: according to the Board of Directors issued the annual management plan, annual index of decomposition, through the Organization of coordination mandate in charge of the Department Organization and implementation, ensuring comprehensive implementation of annual indicators; 1.3 inspection: convenes the General Manager Office, through 三、 单元模块的设计: 3.1 各单元模块功能介绍及电路设计: 3.1.1 电源模块:电源模块为系统各模块供电，根据各模块电压需求，电源模块只需提供+5V电压即可。电源电路设计中，有直流稳压电源为系统提供6V左右的电压，再通过稳压二极管，便可得到+5V稳定的电压输出。如下图所示，电阻R7和稳压二极管D2构成了一个基本稳压电路，电阻R7在这里起到一个分压和限流的作用，发光二极管D1为电源指示灯，R20为分压电阻，电容C6,C7为系统电源滤波电容，J1为正、负电源和GND的输入接口，VCC即为输入的6V左右的电源。 3.1.2 三极管β参数测试模块: NPN测试部分:用一对性能完全相同的PNP三极管Q2、Q3和电阻R8、R12构成一个微电流源，调节R8的值三极管Q1的基极可以得到几十微安比较稳定的电流。Q1发射极的电流值随着β参数的不同而作线性变换，电位器R10上的电压值也唯一的随着β参数二进行变化。电路图如下所示。 PNP测试部分:和NPN测试部分原理完全相同，只不过恒流源用两只完全相同的NPN三极管和电阻R16、R17构成，最终检测三极管Q4集电极的电压值的变化。与NPN检测电路不同的地方是:NPN电路检测的是三极管发射极的电压值，即电位器R10上的电压;而PNP检测电路上检测的是三极管集电极上的电压值，即电位器R14上的电压，调试时将它们调到一个比较合适的值，可以最大程 supplies and get to use, the registration of company assets, record maintenance, maintenance of effective management; 2.6 cost 5 management: preparation of the annual administrative budget, control administrative costs, determine the scope of cost-sharing, sharing the office expenses by month; 2.7 information management: responsible for documents, materials, information and publicity, communication links, and ensure promptly, ranking officers reporting; responsible for the collation and analysis of information, provide the basis for corporate decisions; corporate culture construction, planning, editing, internal publications; 2.8 vehicle management: responsible for the management, repairs and maintenance of vehicles; 2.9 legal disputes: the company responsible for the handling of disputes; 2.10 other: maintaining normal working order, and security. General Manager General Manager job description 1, 1.1 develop strategies and plans: according to company strategic planning, establish the annual management plan, reported to the Board of Directors for approval; 1.2 decomposition measures: according to the Board of Directors issued the annual management plan, annual index of decomposition, through the Organization of coordination mandate in charge of the Department Organization and implementation, ensuring comprehensive implementation of annual indicators; 1.3 inspection: convenes the General Manager Office, through 度的减小系统误差，电路如下图所示: 恒流源工作原理:以PNP测试电路为例:将三极管Q6的集电极和基极连在一起，把它当做一个二极管来使用，此时Q6的基极和发射极构成一个PN结，由于Q6发射极接地，则Q6基极电压保持为恒定的0.7V左右，相应的Q5基极电压也为0.7V。当三极管Q5工作时，由于基极和发射极的压降在0.5V左右，则发射极电压为0.7-0.5=0.2V左右，电阻R17一端接地，因此R17上的压降为0.2V左右，电流为I=0.2/R17，即Q5发射极电流Ie为0.2/R17。又由于Q5的Ie?Ic，因此Ic=0.2/R17。在实际应用中，由于三极管Q5和Q6性能完全相同，因此可保证Q5发射极电压基本保持为一个稳定的电压，则集电极电流也相应的保持为一个稳定的电流输出，实现了横流输出的功能。 3.1.3 选择电路:该部分使用 一个二选一开关作为NPN检测电路和 PNP检测电路的电压选择。如下图所 示:当开关拨到上面时，采集NPN电 路上的电压;拨到下面时，采集PNP 电路上的电压，采集到的电压通过电 阻R5耦合到芯片的信号输入端(31 脚)。 3.1.4 信号处理模块:该模块使用三位半LED显示A/D转换芯片ICL7107及其supplies and get to use, the registration of company assets, record maintenance, maintenance of effective management; 2.6 cost management: preparation of the annual administrative budget, control administrative costs, determine the scope of cost-sharing, sharing the office expenses by month; 2.7 information management: responsible for documents, materials, information and publicity, communication links, and ensure promptly, ranking officers reporting; responsible for the collation and analysis of information, provide the basis for corporate decisions; corporate culture construction, planning, editing, internal publications; 2.8 vehicle management: responsible for the management, repairs and maintenance of vehicles; 2.9 legal disputes: the company responsible for the handling of disputes; 2.10 other: maintaining normal working order, and security. General Manager General Manager job description 1, 1.1 develop strategies and plans: according to company strategic planning, establish the annual management plan, reported to the Board of Directors for approval; 1.2 decomposition measures: according to the Board of Directors issued the annual management plan, annual index of decomposition, through the Organization of coordination mandate in charge of the Department Organization and implementation, ensuring comprehensive implementation of annual indicators; 1.3 inspection: convenes the General Manager Office, through 若干外围电路构成主处理电路，电路如下:电位器R19滑动端和电阻R18采集到的电压值分别输入到ICL7107的IN+端和IN-端，ICL7107对其进行处理。其中:R1和C1接到7107的38、39、40管脚，构成了一个多谐振荡器，为芯片提供定时脉冲;电位器R3和R4接到芯片的36管脚，为芯片提供一个基准电压;电容C2接到芯片的33、34管脚，不能使用瓷片电容;C4、C5、R6接到芯片的27、28、29管脚，是芯片工作的积分网络，不能使用磁片电容;26管脚接-5V的电压;30、32、35管脚接地;31脚为信号输入端IN+，30脚为信号接地端IN-，中间接一个电容C3退偶;1脚接+5V电压，加电容C8退偶。电阻R2和按钮开关S1构成测试电路连接到7107的37号管脚(TEST)。正常情况下，当键按下，数码管全亮。若有数码管没亮，则说明电路连接有问题或是数码管有坏的。其他管脚接数码管。 3.1.5 显示模块:该模块使用三个共阳数码管来显示三极管的放大倍数，如下图所示:三位数码管分别显示放大倍数β参数的个位、十位、和百位，这里的电阻R21为保护电阻，起到降压的作用，减小加在数码管上的电压。数码管的驱动由ICL7107完成。 supplies and get to use, the registration of company assets, record maintenance, maintenance of effective management; 2.6 cost 7 management: preparation of the annual administrative budget, control administrative costs, determine the scope of cost-sharing, sharing the office expenses by month; 2.7 information management: responsible for documents, materials, information and publicity, communication links, and ensure promptly, ranking officers reporting; responsible for the collation and analysis of information, provide the basis for corporate decisions; corporate culture construction, planning, editing, internal publications; 2.8 vehicle management: responsible for the management, repairs and maintenance of vehicles; 2.9 legal disputes: the company responsible for the handling of disputes; 2.10 other: maintaining normal working order, and security. General Manager General Manager job description 1, 1.1 develop strategies and plans: according to company strategic planning, establish the annual management plan, reported to the Board of Directors for approval; 1.2 decomposition measures: according to the Board of Directors issued the annual management plan, annual index of decomposition, through the Organization of coordination mandate in charge of the Department Organization and implementation, ensuring comprehensive implementation of annual indicators; 1.3 inspection: convenes the General Manager Office, through 3.2 电路参数计算及特殊元器件介绍: 3.2.1 电路参数计算: 电源部分:电阻R17起到分压的作用，取10k;R12为LED保护电阻，取1k; 、C8退偶，取100nF(104)的瓷片电容。 电容C6滤波，取100uF;电容C7 恒流源部分:在测量NPN三极管放大倍数时，由于我们需要一个非常小的基极电流值，大概20uA，因此电阻R8的值取10k;R12的值取1k，R11取220Ω，R9取220，由于需要测试50~300之间的β值，因此R10取100Ω的电位器 ;测PNP放大倍数时，R16取1k，R17取10k，R15取220Ω，R13取220Ω，电位器R14取100Ω。三极管Q2、Q3 、Q5、Q6取的放大倍数应该尽量大，因此我们选用放大倍数为400的三极管。 信号处理部分:根据系统要求，经查阅相关芯片资料，得知R1须大于50k，因此选择100k，C1须大于50pF，因此选择100pF(101)的瓷片电容。电阻R2选择10k;因为36脚需要100mV的基准电压，则电位器R3选择1k，R4选择27k;C2的值要求比较准确，因此选择0.1uF(104)的钽电容;R5选择1MΩ的电阻;C3选择一个较小的瓷片电容，值为22nF(224);C4选择0.47uF(474)的钽电容，C5选择0.22uF(224)的钽电容，R6选择47k的电阻。 显示部分:电阻R21为数码管保护电阻，取220Ω的普通电阻即可。 3.2.2 特殊元器件介绍: 本系统采用的核心控制/信号处理元器件为三位半LCD/LED显示A/D转换芯片ICL7107。该芯片是高性能、低功耗的三位半A/D转换器电路。它包含有七段译supplies and get to use, the registration of company assets, record maintenance, maintenance of effective management; 2.6 cost management: preparation of the annual administrative budget, control administrative costs, determine the scope of cost-sharing, sharing the office expenses by month; 2.7 information management: responsible for documents, materials, information and publicity, communication links, and ensure promptly, ranking officers reporting; responsible for the collation and analysis of information, provide the basis for corporate decisions; corporate culture construction, planning, editing, internal publications; 2.8 vehicle management: responsible for the management, repairs and maintenance of vehicles; 2.9 legal disputes: the company responsible for the handling of disputes; 2.10 other: maintaining normal working order, and security. General Manager General Manager job description 1, 1.1 develop strategies and plans: according to company strategic planning, establish the annual management plan, reported to the Board of Directors for approval; 1.2 decomposition measures: according to the Board of Directors issued the annual management plan, annual index of decomposition, through the Organization of coordination mandate in charge of the Department Organization and implementation, ensuring comprehensive implementation of annual indicators; 1.3 inspection: convenes the General Manager Office, through 码器、参考源、时钟系统和显示驱动器，可直接驱动数码管。 ICL7107将高精度、通用性和真正的低成本很好的结合在一起，它具有低于 o10uV的自动校零功能，零漂小于1uV/C，低于10pA的输入电流，极性转换误差小于一个字。在用于测量负载单元、压力规管和其他桥式传感器时会有更突出的优点。可很好的用于制作数显电流表、数显电压表、数显温度计等实用性产品。它有两种封装:DIP-40(双列直插式封装)，PQFP-44(塑料方块平面封装)。我们采用的是DIP-40(40管脚)这种封装形式的7107。 其所具有的主要特点为: , 保证零电平输入时，个量程的读值均为零。 , 1pA典型输入电流。 , 很低的噪声(小于15uVpp)。 , 片上时钟。 , 低功耗(典型值小于10mW)。 , 不需外接有源电路。 , 真正的差动输入和差动参考源，直接驱动LED显示驱动 四、系统电路图和PCB图: 4.1 系统电路图及工作原理: supplies and get to use, the registration of company assets, record maintenance, maintenance of effective management; 2.6 cost 9 management: preparation of the annual administrative budget, control administrative costs, determine the scope of cost-sharing, sharing the office expenses by month; 2.7 information management: responsible for documents, materials, information and publicity, communication links, and ensure promptly, ranking officers reporting; responsible for the collation and analysis of information, provide the basis for corporate decisions; corporate culture construction, planning, editing, internal publications; 2.8 vehicle management: responsible for the management, repairs and maintenance of vehicles; 2.9 legal disputes: the company responsible for the handling of disputes; 2.10 other: maintaining normal working order, and security. General Manager General Manager job description 1, 1.1 develop strategies and plans: according to company strategic planning, establish the annual management plan, reported to the Board of Directors for approval; 1.2 decomposition measures: according to the Board of Directors issued the annual management plan, annual index of decomposition, through the Organization of coordination mandate in charge of the Department Organization and implementation, ensuring comprehensive implementation of annual indicators; 1.3 inspection: convenes the General Manager Office, through 工作原理简述:给被测三极管基极加一个由恒流源产生的恒定的电流，检测此时三极管发射极/集电极上的电压信号，这个信号只随着三极管放大倍数β变化，调整好这个电压信号的强度后将其加到ICL7107的信号输入端，经7107进行数据处理之后利用三位半数码管进行显示。 4.2 PCB图: 该PCB为手动布局 ，线宽设置为40mil，焊 盘为80mil，过孔40mil。 最终成品PCB板的尺寸大 小为8cm×9cm。 五、系统调试及测试结果: 5.1 系统调试: 5.1.1 调试所用仪器: 1、直流稳压电源(资产编号:20051851) 2、万用表(资产编号:100202502) 5.1.2 调试过程: 先根据原理计算出各参数值后，搭建一个恒流源电路，调节参数值，使输出电流的值约为20uA。此时再连上放大倍数已知的被测三极管，将电位器的值调到最小，然后再连接到搭建好了的ICL7107电路上，调节电位器R13的值，使supplies and get to use, the registration of company assets, record maintenance, maintenance of effective management; 2.6 cost management: preparation of the annual administrative budget, control administrative costs, determine the scope of cost-sharing, sharing the office expenses by month; 2.7 information management: responsible for documents, materials, information and publicity, communication links, and ensure promptly, ranking officers reporting; responsible for the collation and analysis of information, provide the basis for corporate decisions; corporate culture construction, planning, editing, internal publications; 2.8 vehicle management: responsible for the management, repairs and maintenance of vehicles; 2.9 legal disputes: the company responsible for the handling of disputes; 2.10 other: maintaining normal working order, and security. General Manager General Manager job description 1, 1.1 develop strategies and plans: according to company strategic planning, establish the annual management plan, reported to the Board of Directors for approval; 1.2 decomposition measures: according to the Board of Directors issued the annual management plan, annual index of decomposition, through the Organization of coordination mandate in charge of the Department Organization and implementation, ensuring comprehensive implementation of annual indicators; 1.3 inspection: convenes the General Manager Office, through 7107基准参考电压保持为100mV大小，调好之后就固定不再动。此时调节连接被测三极管的电位器R10(R14)，当数码管显示的值和被测三极管的实际值基本相等时，该电位器就固定不再动。然后再多用几个放大倍数已知的三极管进行调试，将R10(R14)微调到一个比较合适的水平后就固定不再动。做好板子、焊好元件后先检查电路焊接有没有虚焊或是短线，一切都没问题时加电源进行调试。 5.2 系统测试及结果: 各选择十几个放大倍数在50~300之间的NPN和PNP型三极管进行测试。取一个三极管用万用表测出它们的实际放大倍数并记录后，再将它们接入测试电路测量三极管的放大值并记录，测完后再换其它的三极管测试，每种型号的测10组数据。如下表:表中，实际值为万用表测的值，测量值为该设计测的值。 NPN管测试数据: 实际值 111 198 207 219 252 256 257 258 262 265 测量值 101 199 203 223 258 260 266 268 273 273 由上表中的数据可以看出，各三极管放大倍数的测试误差都是小于10%的。实际 111+198+207+219+252+256+257+258+262+265值总的平均值为:; x=228.5,110 101+199+203+223+258+260+266+268+273+273测量值的平均值为:x=232.4,; 210 ||xx,12因此系统总的误差为:。因此NPN检测电路可以很好的满足,,,×100%1.71%x1 题目的要求。 PNP管测试数据: 实际值 207 217 218 219 221 225 228 230 266 277 测量值 211 219 227 221 220 230 226 237 274 281 由上表中的数据可以看出，各三极管放大倍数的测试误差都是小于10%的。实际 207+217+218+219+221+225+228+230+266+277x=230.8,值总的平均值为:; 110 211+219+227+221+220+230+226+237+274+281x=234.6,测量值的平均值为:; 210 supplies and get to use, the registration of company assets, record maintenance, maintenance of effective management; 2.6 cost 11 management: preparation of the annual administrative budget, control administrative costs, determine the scope of cost-sharing, sharing the office expenses by month; 2.7 information management: responsible for documents, materials, information and publicity, communication links, and ensure promptly, ranking officers reporting; responsible for the collation and analysis of information, provide the basis for corporate decisions; corporate culture construction, planning, editing, internal publications; 2.8 vehicle management: responsible for the management, repairs and maintenance of vehicles; 2.9 legal disputes: the company responsible for the handling of disputes; 2.10 other: maintaining normal working order, and security. General Manager General Manager job description 1, 1.1 develop strategies and plans: according to company strategic planning, establish the annual management plan, reported to the Board of Directors for approval; 1.2 decomposition measures: according to the Board of Directors issued the annual management plan, annual index of decomposition, through the Organization of coordination mandate in charge of the Department Organization and implementation, ensuring comprehensive implementation of annual indicators; 1.3 inspection: convenes the General Manager Office, through ||xx,12因此系统总的误差为:。因此PNP检测电路可以很好的满足,,,×100%1.65%x1 题目的要求。综上:该系统可很好的完成系统设计的要求。 5.3 系统测试中的问题: 刚开始测试时数码管显示不稳定，考虑到可能是前端采集部分受到了电磁干扰，因此在30脚和31脚接一个22nF的电容，问题解决。 六、设计总结: 该电路的特点是原理简单，成本低，可较好的实现三极管放大倍数的测量。优点是电路简单，实现起来相对容易，成本低廉。但是存在精度不高的缺点，因此在许多需要精确测量的场合不能直接使用该系统，需对该系统加以改进。但是可以在一些精度要求不高的场合使用。在实际测量时，会发现三极管实际放大倍数和数码管显示的值不是成线性的变化，因此，可考虑在信号采集端设计一个补偿电路，实现三极管放大倍数与显示之间的精确匹配。还有，该系统的抗干扰能力不强，要进一步改进可以从这里下手。 通过这一次电子设计课程的学习，让我对整个电子设计的流程有了一个清晰的认识与感知，同时对理论知识也进行了巩固和加深。在实际的制作过程中，我们经历了数码管不显示、乱显示的困惑，也体会到了制作成功后的那种深深的喜悦之情。明白了做产品的不易与艰辛，理解到每一个环节都很重要，都需要我们去耐心的，反复的检查与调试，这样才能取得成功。 七、参考资料: 1 胡宴如、耿苏燕 主编:《模拟电子技术基础》，高等教育出版社2004年。 2 杨志忠 主编:《数字电子技术基础》，高等教育出版社2004年。 3 《电子技术基础实验》 四川大学出版社2005年 supplies and get to use, the registration of company assets, record maintenance, maintenance of effective management; 2.6 cost management: preparation of the annual administrative budget, control administrative costs, determine the scope of cost-sharing, sharing the office expenses by month; 2.7 information management: responsible for documents, materials, information and publicity, communication links, and ensure promptly, ranking officers reporting; responsible for the collation and analysis of information, provide the basis for corporate decisions; corporate culture construction, planning, editing, internal publications; 2.8 vehicle management: responsible for the management, repairs and maintenance of vehicles; 2.9 legal disputes: the company responsible for the handling of disputes; 2.10 other: maintaining normal working order, and security. General Manager General Manager job description 1, 1.1 develop strategies and plans: according to company strategic planning, establish the annual management plan, reported to the Board of Directors for approval; 1.2 decomposition measures: according to the Board of Directors issued the annual management plan, annual index of decomposition, through the Organization of coordination mandate in charge of the Department Organization and implementation, ensuring comprehensive implementation of annual indicators; 1.3 inspection: convenes the General Manager Office, through