eaintheaccidentinvestigation,managementandreporting,eachpostshouldbedevelopedunderthissystemspecialistscheck,cleartheexaminations,time,cyclesandotherrelevantregulations.Strengtheningsitesupervisionandexamination,todetectandinvestigateillegalcommand,illegaloperationsandviolationsofoperatingrules.Secondsafetyreferstotheproductionsite,technologymanagement,equipment,facilities,andsooncanleadtoaccidentsrisksexist.1,accordingtotheextentofthesecurityrisks,solvingisdividedintoa,b,andclevelsofdifficulty;A-level:difficult,miningdifficulties,shallbereportedtothecompany'sproblems.B-class:difficulttoresolvedif听范读短文的录音。学生根据拼音自由朗读短文,不会拼读的音节求助同学或老师。听老师读短文,把自己不会认读的字和词听清楚。指名朗读,重点纠正“蓝”“绿”“帆”的读音。齐读短文,进一步熟悉短文。你最喜欢哪一句话?指导学生有感情地朗读。ficulties,shallconsistofminingorganizationstosolveproblems.C-class:fromsegmentsandbusinessrisksthatmustbeaddressedintheDepartment.2,open-pitmineunsafetypesinclude:electrical,transport,blasting,fire,andotherslope.3,accordingtotheseverityofthehazardfilledinbyunittroubleshooting,registrationform(seeatt双闭环直流调速系统电路原理随着调速系统的不断发展和应用,传统的采用PI调节器的单闭环调速系统既能实现转速的无静差调节,又能较快的动态响应只能满足一般生产机械的调速要求。为了提高生产率,要求尽量缩短起动、制动、反转过渡过程的时间,最好的办法是在过渡过程中始终保持电流(即动态转矩)为允许的最大值,使系统尽最大可能加速起动,达到稳态转速后,又让电流立即降低,进入转矩与负载相平衡的稳态运行。要实现上述要求,其唯一的途径就是采用电流负反馈控制方法,即采用速度、电流双闭环的调速系统来实现。在电流控制回路中设置一个调节器,专门用于调节电流量,从而在调速系统中设置了转速和电流两个调节器,形成转速、电流双闭环调速控制。双闭环调速控制系统中采用了两个调节器,分别调节转速和电流,二者之间实现串级连接。图1-1.1为转速、电流双闭环直流调速系统的原理图。图中两个调节器ASR和ACR分别为转速调节器和电流调节器,二者串级连接,即把转速调节器的输出作为电流调节器的输入,再用电流调节器的输出去控制晶闸管整流器的触发装置。电流环在内,称之为内环;转速环在外,称之为外环。两个调节器输出都带有限幅,ASR的输出限幅什Uim决定了电流调节器ACR的给定电压最大值Uim,对就电机的最大电流;电流调节器ACR输出限幅电压Ucm限制了整流器输出最大电压值,限最小触发角α。eaintheaccidentinvestigation,managementandreporting,eachpostshouldbedevelopedunderthissystemspecialistscheck,cleartheexaminations,time,cyclesandotherrelevantregulations.Strengtheningsitesupervisionandexamination,todetectandinvestigateillegalcommand,illegaloperationsandviolationsofoperatingrules.Secondsafetyreferstotheproductionsite,technologymanagement,equipment,facilities,andsooncanleadtoaccidentsrisksexist.1,accordingtotheextentofthesecurityrisks,solvingisdividedintoa,b,andclevelsofdifficulty;A-level:difficult,miningdifficulties,shallbereportedtothecompany'sproblems.B-class:difficulttoresolvedif听范读短文的录音。学生根据拼音自由朗读短文,不会拼读的音节求助同学或老师。听老师读短文,把自己不会认读的字和词听清楚。指名朗读,重点纠正“蓝”“绿”“帆”的读音。齐读短文,进一步熟悉短文。你最喜欢哪一句话?指导学生有感情地朗读。ficulties,shallconsistofminingorganizationstosolveproblems.C-class:fromsegmentsandbusinessrisksthatmustbeaddressedintheDepartment.2,open-pitmineunsafetypesinclude:electrical,transport,blasting,fire,andotherslope.3,accordingtotheseverityofthehazardfilledinbyunittroubleshooting,registrationform(seeatt1.6.1ADC0809的引脚及其功能ADC0809有28个引脚,其中IN0---IN7接8路模拟量输入。ALE是地址锁存允许,REFV、REFV接基准电源,在精度要求不太高的情况下,供电电源就可以作为基准电源。START是芯片的启动引脚,其上脉冲的下降沿起动一次新的A/D转换。EOC是转换结束信号,可以用于向单片机申请中断或者供单片机查询。OE是输出允许端。CLK是时钟端。DB0---DB7是数字量的输出。ADDA、ADDB、ADDC接地址线用以选定8路输入中的一路,详见下图。ADDCADDBADDA选通输入通道000IN0001IN1010IN2011IN3eaintheaccidentinvestigation,managementandreporting,eachpostshouldbedevelopedunderthissystemspecialistscheck,cleartheexaminations,time,cyclesandotherrelevantregulations.Strengtheningsitesupervisionandexamination,todetectandinvestigateillegalcommand,illegaloperationsandviolationsofoperatingrules.Secondsafetyreferstotheproductionsite,technologymanagement,equipment,facilities,andsooncanleadtoaccidentsrisksexist.1,accordingtotheextentofthesecurityrisks,solvingisdividedintoa,b,andclevelsofdifficulty;A-level:difficult,miningdifficulties,shallbereportedtothecompany'sproblems.B-class:difficulttoresolvedif听范读短文的录音。学生根据拼音自由朗读短文,不会拼读的音节求助同学或老师。听老师读短文,把自己不会认读的字和词听清楚。指名朗读,重点纠正“蓝”“绿”“帆”的读音。齐读短文,进一步熟悉短文。你最喜欢哪一句话?指导学生有感情地朗读。ficulties,shallconsistofminingorganizationstosolveproblems.C-class:fromsegmentsandbusinessrisksthatmustbeaddressedintheDepartment.2,open-pitmineunsafetypesinclude:electrical,transport,blasting,fire,andotherslope.3,accordingtotheseverityofthehazardfilledinbyunittroubleshooting,registrationform(seeatt100IN4101IN5110IN6111IN7图1-6.1ADC0809引脚图及功能表CPU及8个部件的作用功能介绍如下中央处理器CPU:它是单片机的核心,完成运算和控制功能。内部数据存储器:8051芯片中共有256个RAM单元,能作为存储器使用的只是前128个单元,其地址为00H—7FH。通常说的内部数据存储器就是指这前128个单元,简称内部RAM。特殊功能寄存器:是用来对片内各部件进行管理、控制、监视的控制寄存器和状态寄存器,是一个特殊功能的RAM区,位于内部RAM的高128个单元,其地址为80H—FFH。内部程序存储器:8051芯片内部共有4K个单元,用于存储程序、原始数据或表格,简称内部ROM。并行I/O口:8051芯片内部有4个8位的I/O口(P0,P1,P2,P3),以实现数据的并行输入输出。串行口:它是用来实现单片机和其他设备之间的串行数据传送。定时器:8051片内有2个16位的定时器,用来实现定时或者计数功能,并且以其定时或计数结果对计算机进行控制。中断控制系统:该芯片共有5个中断源,即外部中断2个,定时/计数中断2个和串行中断1个。振荡电路:它外接石英晶体和微调电容即可构成8051单片机产生时钟脉冲序列的时钟电路。系统允许的最高晶振频率为12MHz。1.7.38051单片机引脚图eaintheaccidentinvestigation,managementandreporting,eachpostshouldbedevelopedunderthissystemspecialistscheck,cleartheexaminations,time,cyclesandotherrelevantregulations.Strengtheningsitesupervisionandexamination,todetectandinvestigateillegalcommand,illegaloperationsandviolationsofoperatingrules.Secondsafetyreferstotheproductionsite,technologymanagement,equipment,facilities,andsooncanleadtoaccidentsrisksexist.1,accordingtotheextentofthesecurityrisks,solvingisdividedintoa,b,andclevelsofdifficulty;A-level:difficult,miningdiffi