电阻(zu)符(fu)号是(shi)什么|电阻(zu)器(qi)的作用|电阻(zu)器(qi)的电路符(fu)号及图片识(shi)别(bie)-KIA MOS管
信(xin)息来源:本(ben)站 日期:2019-07-10
电(dian)(dian)(dian)阻(zu)(zu)(zu)符号是(shi)(shi)什么(me)?电(dian)(dian)(dian)阻(zu)(zu)(zu)是(shi)(shi)什么(me)?我们一步(bu)一步(bu)的(de)去了(le)解电(dian)(dian)(dian)阻(zu)(zu)(zu)、电(dian)(dian)(dian)阻(zu)(zu)(zu)符号及(ji)电(dian)(dian)(dian)阻(zu)(zu)(zu)的(de)其他知识(shi)。电(dian)(dian)(dian)阻(zu)(zu)(zu)(Resistance,通(tong)常(chang)用(yong)“R”表(biao)示(shi)(shi)),是(shi)(shi)一个物理(li)量,在物理(li)学中表(biao)示(shi)(shi)导体(ti)(ti)对电(dian)(dian)(dian)流(liu)(liu)阻(zu)(zu)(zu)碍(ai)作(zuo)用(yong)的(de)大(da)小。导体(ti)(ti)的(de)电(dian)(dian)(dian)阻(zu)(zu)(zu)越(yue)大(da),表(biao)示(shi)(shi)导体(ti)(ti)对电(dian)(dian)(dian)流(liu)(liu)的(de)阻(zu)(zu)(zu)碍(ai)作(zuo)用(yong)越(yue)大(da)。不(bu)同(tong)的(de)导体(ti)(ti),电(dian)(dian)(dian)阻(zu)(zu)(zu)一般不(bu)同(tong),电(dian)(dian)(dian)阻(zu)(zu)(zu)是(shi)(shi)导体(ti)(ti)本身的(de)一种特性。电(dian)(dian)(dian)阻(zu)(zu)(zu)将会导致电(dian)(dian)(dian)子流(liu)(liu)通(tong)量的(de)变化(hua),电(dian)(dian)(dian)阻(zu)(zu)(zu)越(yue)小,电(dian)(dian)(dian)子流(liu)(liu)通(tong)量越(yue)大(da),反之亦然。而超导体(ti)(ti)则(ze)没有电(dian)(dian)(dian)阻(zu)(zu)(zu)。
简(jian)单的介绍(shao)一下我在各种电(dian)路图中看过(guo)的电(dian)阻(zu)符号:
1、普通电阻:符号是一很扁的长方形
2、滑动(dong)变阻(zu)器(qi):符(fu)号楼主是知道(dao)的
3、微调(diao)电阻(zu):符号是在普通电阻(zu)的(de)符号上画一条斜线(xian)(xian),在斜线(xian)(xian)的(de)上端有一短线(xian)(xian),像(xiang)丁字形
4、可调电(dian)阻:符(fu)号(hao)是(shi)在普(pu)通(tong)电(dian)阻的符(fu)号(hao)上(shang)画(hua)一条倾斜的箭头
下面介绍电(dian)(dian)(dian)(dian)阻器的电(dian)(dian)(dian)(dian)路符号及图片识别 ,电(dian)(dian)(dian)(dian)阻器主要用(yong)来(lai)控制(zhi)电(dian)(dian)(dian)(dian)路中的电(dian)(dian)(dian)(dian)压(ya)和电(dian)(dian)(dian)(dian)流,起(qi)降压(ya),分压(ya),限流,分流,隔离,匹配和信号幅度等调节作用(yong)。
黑(hei)0,棕(zong)1,红(hong)2,橙3,黄4,绿(lv)5,蓝(lan)6,紫7,灰8,白9
1)第一色环,第二色环相应(ying)地代表电阻值的第一位、第二位有效数字(zi)。
2)第三色(se)环(huan)表示第一位,第二位之后加的‘0’的个数。
3)第(di)四色(se)环代(dai)(dai)表(biao)电阻值的(de)允许误差。棕色(se)代(dai)(dai)表(biao)±1%,红色(se)代(dai)(dai)表(biao)±2%,金(jin)色(se)代(dai)(dai)表(biao)±5%,银色(se)代(dai)(dai)表(biao)±10.
例(li)如: 如上(shang)图中的15k电阻(zu),色(se)环(huan)为:棕绿(lv)黑红棕 ,第(di)一(yi)第(di)二色(se)环(huan)为有效(xiao)数(shu)字(zi),棕1,绿(lv)5,代表前两(liang)个(ge)(ge)有效(xiao)数(shu)字(zi)为15,第(di)三个(ge)(ge)色(se)环(huan)黑色(se)代表0,第(di)四(si)个(ge)(ge)色(se)环(huan)为‘红2’。代表0的个(ge)(ge)数(shu)。即 15 0 00 =15k ,最(zui)后(hou)一(yi)个(ge)(ge)棕色(se)为误差系(xi)数(shu)±1%。
当电流(liu)流(liu)过(guo)(guo)电阻(zu)(zu)的时候,电阻(zu)(zu)就(jiu)会发热。功(gong)率(lv)越大,发热越厉害,过(guo)(guo)大就(jiu)会烧(shao)毁电阻(zu)(zu)。电阻(zu)(zu)长时间正常工作所允许的最(zui)大功(gong)率(lv)叫做额(e)定(ding)功(gong)率(lv)。
电(dian)阻器的(de)功率有1/8W(瓦),1/4、1/2、1w、2w、3w、4w、5w、10w、100w等(deng)。
电流(liu)流(liu)过电阻器时,对电流(liu)有阻碍(ai)作用,其(qi)阻碍(ai)的大(da)小,即为电阻值。其(qi)基本单位是欧(ou)(ou)姆(简称(cheng)欧(ou)(ou)),符号用希(xi)腊(la)文'Ω'表示,大(da)小有千(qian) 欧(ou)(ou),兆(zhao)欧(ou)(ou),其(qi)关系如(ru)下:1 kΩ =1000Ω,1MΩ=1000kΩ
电(dian)路(lu)中常用‘R’表(biao)(biao)示电(dian)阻,‘C’表(biao)(biao)示电(dian)容,“L‘表(biao)(biao)示电(dian)感。
电阻(zu)器(qi)的串联(lian)(lian)(lian):电阻(zu)串联(lian)(lian)(lian)后(hou),其总阻(zu)值等于各(ge)个(ge)串联(lian)(lian)(lian)电阻(zu)阻(zu)值之和。因(yin)此,可用小电阻(zu)串联(lian)(lian)(lian)后(hou)替代(dai)大(da)电阻(zu)。
电(dian)阻(zu)(zu)器的(de)并联(lian)(lian):电(dian)阻(zu)(zu)并联(lian)(lian)后(hou),其总阻(zu)(zu)值(zhi)会变小(xiao),总阻(zu)(zu)值(zhi)的(de)倒数(shu)等(deng)于各个并联(lian)(lian)电(dian)阻(zu)(zu)的(de)倒数(shu)之(zhi)和(he)。
可变电阻(zu)(zu)(zu)器(qi)(电位器(qi))是(shi)一种(zhong)阻(zu)(zu)(zu)值(zhi)可以连续变化的(de)电阻(zu)(zu)(zu)器(qi)
电阻器的主(zhu)要(yao)作用是限流与降压。
1、限流(liu)
电(dian)(dian)阻器在电(dian)(dian)路中(zhong)限制电(dian)(dian)流(liu)的经过,电(dian)(dian)阻值越大电(dian)(dian)流(liu)越小。
如图2-9所示发光二(er)极管(guan)电(dian)路中,R为限流(liu)(liu)电(dian)阻(zu)(zu)。从欧(ou)姆定律I=U/R可知,当电(dian)压U一(yi)定时,流(liu)(liu)过电(dian)阻(zu)(zu)器(qi)的电(dian)流(liu)(liu)J与其阻(zu)(zu)值R成反比。由(you)于限流(liu)(liu)电(dian)阻(zu)(zu)R的存(cun)在(zai),将发光二(er)极管(guan)VD的电(dian)流(liu)(liu)限制在(zai)10mA,保(bao)证(zheng)VD正常工作。
调整晶(jing)体(ti)管(guan)(guan)的工(gong)(gong)作点(dian)(dian)是电阻(zu)器用(yong)作限流(liu)(liu)(liu)的一个例子。如图(tu)2-10所(suo)示为晶(jing)体(ti)管(guan)(guan)放大电路,晶(jing)体(ti)管(guan)(guan)集电极电流(liu)(liu)(liu)Ic(工(gong)(gong)作点(dian)(dian))由(you)其基极电流(liu)(liu)(liu)Ib决议。改(gai)动晶(jing)体(ti)管(guan)(guan)基极电阻(zu)Rb的阻(zu)值,即(ji)可改(gai)动Ib,也就是改(gai)动了(le)Ic,即(ji)改(gai)动了(le)晶(jing)体(ti)管(guan)(guan)的工(gong)(gong)作点(dian)(dian)。
2、降压(ya)
电(dian)流经过电(dian)阻(zu)器时必然(ran)会产生电(dian)压(ya)降,电(dian)阻(zu)值越(yue)大,电(dian)压(ya)降越(yue)大。
如图(tu)2-11所示继电(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)电(dian)(dian)(dian)(dian)(dian)(dian)路中,R为降(jiang)压电(dian)(dian)(dian)(dian)(dian)(dian)阻。电(dian)(dian)(dian)(dian)(dian)(dian)压降(jiang)U的(de)(de)大(da)小与(yu)电(dian)(dian)(dian)(dian)(dian)(dian)阻值R与(yu)电(dian)(dian)(dian)(dian)(dian)(dian)流I的(de)(de)乘积(ji)成正(zheng)比,即U=IR。应用电(dian)(dian)(dian)(dian)(dian)(dian)阻器(qi)(qi)R的(de)(de)降(jiang)压作用,能够使较高的(de)(de)电(dian)(dian)(dian)(dian)(dian)(dian)源电(dian)(dian)(dian)(dian)(dian)(dian)压顺应元器(qi)(qi)件工(gong)作电(dian)(dian)(dian)(dian)(dian)(dian)压的(de)(de)请求。如图(tu)2-11电(dian)(dian)(dian)(dian)(dian)(dian)路中,继电(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)工(gong)作电(dian)(dian)(dian)(dian)(dian)(dian)压6V、工(gong)作电(dian)(dian)(dian)(dian)(dian)(dian)流60mA,而电(dian)(dian)(dian)(dian)(dian)(dian)源电(dian)(dian)(dian)(dian)(dian)(dian)压为12V,必需串接一个(ge)100Ω的(de)(de)降(jiang)压电(dian)(dian)(dian)(dian)(dian)(dian)阻R后,方可正(zheng)常工(gong)作。
放(fang)大(da)(da)器(qi)的负(fu)载电(dian)(dian)阻也是(shi)应用(yong)(yong)电(dian)(dian)阻器(qi)的降压(ya)作用(yong)(yong)的例子(zi)。如(ru)图(tu)2-12所示晶体管放(fang)大(da)(da)电(dian)(dian)路中,集(ji)电(dian)(dian)极(ji)(ji)电(dian)(dian)阻R,即是(shi)负(fu)载电(dian)(dian)阻。输(shu)人(ren)信号Ui使晶体管集(ji)电(dian)(dian)极(ji)(ji)电(dian)(dian)流Ic相应变化,由于(yu)Rc的降压(ya)作用(yong)(yong),从(cong)VT集(ji)电(dian)(dian)极(ji)(ji)即可得到放(fang)大(da)(da)后的输(shu)出电(dian)(dian)压(ya)Uo(与Ui反相)。
3、分压
基于电阻(zu)的降压作用,电阻(zu)器还能够用作分压器。
如图(tu)2-13所(suo)示,电(dian)阻(zu)器R1和(he)R2构成(cheng)一个分(fen)压(ya)器,由于两(liang)个电(dian)阻(zu)串联,经过这(zhei)两(liang)个电(dian)阻(zu)的电(dian)流J相等(deng),而电(dian)阻(zu)上的压(ya)降U=IR,R1上压(ya)降为(wei)1/3U,R2上压(ya)降为(wei)2/3U,完(wan)成(cheng)了分(fen)压(ya)(负载电(dian)阻(zu)必需远(yuan)大于R1、R2),分(fen)压(ya)比为(wei)R1/R2。
RC滤(lv)波网络是一种特(te)殊(shu)的(de)(de)分(fen)压(ya)器(qi)。如(ru)图2-14所示整流(liu)(liu)滤(lv)波电路中,R与C2可了(le)解为(wei)分(fen)压(ya)器(qi),输出(chu)电压(ya)Uo取自C2上的(de)(de)压(ya)降。关于(yu)直(zhi)(zhi)流(liu)(liu)C2的(de)(de)容(rong)抗无限大(da),而关于(yu)交(jiao)流(liu)(liu)C2的(de)(de)容(rong)抗远小于(yu)R,因(yin)而C2上直(zhi)(zhi)流(liu)(liu)压(ya)降很(hen)大(da),而交(jiao)流(liu)(liu)压(ya)降很(hen)小,到达扩滤(lv)波的(de)(de)目的(de)(de)。
联系方(fang)式:邹先生(sheng)
联(lian)系电话:0755-83888366-8022
手机:18123972950
QQ:2880195519
联系(xi)地址:深圳市福田区(qu)车公(gong)庙天安数码城天吉(ji)大厦CD座5C1
请搜微信(xin)公众号:“KIA半(ban)导体”或扫(sao)一扫(sao)下图“关注”官(guan)方微信(xin)公众号
请“关注”官方微(wei)信公众号:提供 MOS管(guan) 技术(shu)帮助