电(dian)子元器(qi)件-常用(yong)电(dian)子元器(qi)件基础知识大(da)全-KIA 电(dian)子元器(qi)件
信息(xi)来源:本(ben)站 日期:2018-01-04
简称电(dian)(dian)阻,是指具有一定技术(shu)性能的(de)(de)在电(dian)(dian)路(lu)中(zhong)专起电(dian)(dian)阻作用的(de)(de)元件,可用来调节电(dian)(dian)路(lu)中(zhong)的(de)(de)电(dian)(dian)流和电(dian)(dian)压,或者作为电(dian)(dian)路(lu)中(zhong)的(de)(de)负载。
a、 阻(zu)值:指电阻(zu)的数值大(da)小。0Ω—几百MΩ
b、 耗散功(gong)率(lv):指电(dian)阻长(zhang)期工作时所能(neng)承受(消耗)的最(zui)大功(gong)率(lv)。
电阻常用的材料有碳膜、金属(shu)膜、金属(shu)氧化膜、线(xian)绕、水泥(陶瓷)线(xian)绕半导体等(deng)材料。
①固定电阻:指电阻值固定不变(bian)的电阻
②微(wei)调电阻:指电阻(zu)值可以微(wei)调的电阻(zu)
③可调电阻(zu):俗称电(dian)位器(qi),指电(dian)阻(zu)值(zhi)连续可调的电(dian)阻(zu)
④热敏电(dian)阻:指电阻值随着温(wen)度变化(hua)(hua)而变化(hua)(hua)的电阻
a、 正温(wen)度系(xi)数热敏电(dian)(dian)阻(zu):指(zhi)电(dian)(dian)阻(zu)值随温(wen)度升(sheng)高而增大的电(dian)(dian)阻(zu)(PTC)
b、 负(fu)温(wen)度(du)系(xi)数热敏电阻:指(zhi)电阻值(zhi)随温(wen)度(du)升高而减小的(de)电阻
⑤压敏(min)电(dian)阻:指电阻值随(sui)着(zhe)电压(ya)的(de)变化而变化的(de)电阻。
⑥湿敏电阻(zu):指电(dian)阻值随着温(wen)度变化(hua)而变化(hua)的电(dian)阻
⑦光敏(min)电(dian)阻:指电阻(zu)值随着温度变化而变化的电阻(zu)
⑧电阻的(de)功率表示法:一般大功(gong)(gong)(gong)率(lv)(lv)(lv)(lv)(lv)(lv)(3W以(yi)上(shang))电(dian)(dian)(dian)阻(zu)均在电(dian)(dian)(dian)阻(zu)外壳上(shang)标明(ming)其功(gong)(gong)(gong)率(lv)(lv)(lv)(lv)(lv)(lv)值,如:3W、5W、7W、10W、20W、30W等,而小功(gong)(gong)(gong)率(lv)(lv)(lv)(lv)(lv)(lv)(3W以(yi)下)则(ze)(ze)部分标明(ming)功(gong)(gong)(gong)率(lv)(lv)(lv)(lv)(lv)(lv),(如:3W、2W、1W、等),不标明(ming)功(gong)(gong)(gong)率(lv)(lv)(lv)(lv)(lv)(lv)的则(ze)(ze)多(duo)为功(gong)(gong)(gong)率(lv)(lv)(lv)(lv)(lv)(lv)1W以(yi)下的小功(gong)(gong)(gong)率(lv)(lv)(lv)(lv)(lv)(lv)电(dian)(dian)(dian)阻(zu),对于实际使用(yong)中,可(ke)用(yong)功(gong)(gong)(gong)率(lv)(lv)(lv)(lv)(lv)(lv)大的电(dian)(dian)(dian)阻(zu)代替(ti)功(gong)(gong)(gong)率(lv)(lv)(lv)(lv)(lv)(lv)小的电(dian)(dian)(dian)阻(zu),反之则(ze)(ze)不能代替(ti),若没有(you)知(zhi)道电(dian)(dian)(dian)阻(zu)功(gong)(gong)(gong)率(lv)(lv)(lv)(lv)(lv)(lv)大小时,在实际应用(yong)中可(ke)用(yong)电(dian)(dian)(dian)阻(zu)体积相同或稍大的来代替(ti)。
①直接标明电阻的数值和单位,如:1.5 Ω 、160Ω 、1Ω 等。
②直接(jie)标明电阻的数值而把单位(wei)“Ω ”省去,如:100即100Ω 、1 即1Ω 、22M即22MΩ。
③用几(ji)X几(ji)表示几(ji)点几(ji)Ω ,如:4Ω7、9Ω1即(ji)(ji)为9.1Ω 、8M2即(ji)(ji)8.2MΩ 等。
有些用几R几 代表几点几Ω ,如:1R5即(ji)1.5Ω 、3R9即(ji)3.9Ω 等。
④电(dian)阻值后面有其(qi)它英(ying)文字母(如:J、K、M等(deng))或罗马数(shu)字(Ⅰ、Ⅱ、Ⅲ)或正负百分之几(如:±5%,±10%,±20%)的(de)则表示该电(dian)阻的(de)误差等(deng)级。
⑤数码表示方(fang)法(片状电(dian)阻(zu)及部分微调电(dian)阻(zu)和电(dian)位器用此法)
用三位数字(zi)表(biao)示,第(di)一、二位表(biao)示有效(xiao)数,第(di)三位数表(biao)示倍乘数(1为(wei)(wei)101 ,2为(wei)(wei) 102 ,3为(wei)(wei) 103 ,4为(wei)(wei)104 ,……8为(wei)(wei) 108 ,但9为(wei)(wei) 100 )把有效(xiao)数乘以倍乘数即电阻值。(单位:Ω)
⑥色环(huan)表示法:
用色环(huan)表示电(dian)阻(zu)和误(wu)差的电(dian)阻(zu)叫色环(huan)电(dian)阻(zu)
①四(si)色环电阻(为普通(tong)电(dian)阻,应用最多(duo) )
第一、二色(se)环(huan)表(biao)(biao)示有效数,第三色(se)环(huan)表(biao)(biao)示倍乘(cheng)(cheng)数,第四(si)色(se)环(huan)表(biao)(biao)示误差(cha),(注:此色(se)环(huan)多为金,银色(se)或其他(ta)色(se)环(huan)远些)把(ba)有效数乘(cheng)(cheng)以(yi)倍乘(cheng)(cheng)数,即(ji)为该电阻的电阻值(单(dan)位为Ω )
▲由于电阻值有制造误(wu)(wu)差(cha),万用表(biao)有测量(liang)误(wu)(wu)差(cha),人的(de)眼(yan)力(li)也有误(wu)(wu)差(cha),故用万用表(biao)测量(liang)电阻值时有一定的(de)误(wu)(wu)差(cha)是允许的(de),误(wu)(wu)差(cha)在(zai) 以内均视为正常。
▲用高阻档(dang)(RX10K档(dang)或(huo)1K档(dang))测(ce)试大阻值(几十KΩ以上)的电阻时,而导致读数(shu)明显变小测(ce)量误(wu)差增大。
▲对于四色(se)(se)环(huan)电(dian)阻:前面再(zai)个色(se)(se)环(huan)表示有效(xiao)数,即(ji)为该电(dian)阻数值的(de)前两(liang)位(wei),而倍乘数即(ji)为阻值的(de)倍数,故把前两(liang)位(wei)色(se)(se)环(huan)的(de)有效(xiao)数照读(写)下来,再(zai)乘以倍乘数即(ji)其电(dian)阻值。
▲练习时可把色(se)(se)(se)环电阻的阻值根据色(se)(se)(se)环读(du)数出(chu)来(lai),再(zai)用万用表(biao)电阻档测(ce)试(shi),若测(ce)试(shi)值与(yu)自己读(du)出(chu)值基本相同(误差(cha) ),则你看(kan)色(se)(se)(se)环基本准(zhun)确,若测(ce)量值与(yu)读(du)出(chu)值相差(cha)太大(da),则可能某些(xie)色(se)(se)(se)环的颜色(se)(se)(se)看(kan)错,应(ying)该(gai)重(zhong)新(xin)再(zai)测(ce)试(shi)再(zai)看(kan),直至准(zhun)确为止。
▲阻(zu)值小要用低(di)阻(zu)档(X10或X1)测(ce)试(shi)(shi)而阻(zu)值大要用高阻(zu)档(X10K或X1K)测(ce)试(shi)(shi),阻(zu)值不(bu)(bu)大不(bu)(bu)小(中等(deng))可用中阻(zu)档位(wei)(如:X1K、X100、X10等(deng))测(ce)试(shi)(shi),但表针指(zhi)在接近(jin)刻度中向左(zuo)右位(wei)置,此时(shi),不(bu)(bu)但容易看(kan)清读数(shu)而且读数(shu)最准(zhun)确。
▲快速读出四色环电(dian)阻
第三色环 |
电阻值(zhi) |
例 |
第三(san)色(se)环 |
电阻值(zhi) |
例 |
银(yin) |
零(ling)点几(ji) |
棕灰银(yin)金 |
红 |
几点几K |
绿(lv)棕红金 |
金 |
几点(dian)几 |
红红金(jin)金(jin) | 橙 |
几十几 K |
橙橙橙金 |
黑 |
几十几 |
棕黑(hei)黑(hei)金 |
黄 |
几百几 K |
黄(huang)紫黄(huang)金 |
棕 |
几(ji)百几(ji) |
红紫棕金 |
绿 |
几点几M |
棕(zong)绿(lv)绿(lv)金 |
蓝(lan) |
几(ji)十几(ji) |
橙(cheng)白蓝(lan)银 |
|
|
|
②五色环电阻(为精密电(dian)阻,多用在仪器仪表或要求高的电(dian)路中使用)
第一、二、三色环为(wei)(wei)有(you)效(xiao)数(shu),第四色环表(biao)示倍乘(cheng)数(shu),第五色环表(biao)示误差(cha)(注:此色环多为(wei)(wei)金(jin)、银色或离其它色环远些)把有(you)效(xiao)数(shu)乘(cheng)以倍乘(cheng)数(shu)即为(wei)(wei)该电阻阻值(单位:Ω )
①对于普通(tong)固定电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)(zu)用万用表(biao)电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)(zu)档测试(shi)其电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)(zu)值(zhi)时应与电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)(zu)的(de)标称(cheng)值(zhi)(即电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)(zu)上(shang)标明的(de)阻(zu)(zu)(zu)(zu)(zu)(zu)值(zhi))基本相(xiang)(xiang)同(误差<±20%)为(wei)正常。若(ruo)(ruo)阻(zu)(zu)(zu)(zu)(zu)(zu)值(zhi)相(xiang)(xiang)差过(guo)大(即误差为(wei)>±20%)则该电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)(zu)已变(bian)值(zhi)(即变(bian)大或变(bian)小,以阻(zu)(zu)(zu)(zu)(zu)(zu)值(zhi)变(bian)大居多,而阻(zu)(zu)(zu)(zu)(zu)(zu)值(zhi)变(bian)小则少(shao)见)而不能使用,若(ruo)(ruo)阻(zu)(zu)(zu)(zu)(zu)(zu)值(zhi)变(bian)为(wei)无穷(qiong)大(∞)则该电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)(zu)已开路(lu)损坏(huai),若(ruo)(ruo)阻(zu)(zu)(zu)(zu)(zu)(zu)值(zhi)变(bian)为(wei)零(极少(shao)见),则该电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)(zu)已短路(lu)损坏(huai)。
②对于微调(diao)电(dian)阻(zu)(又叫微调(diao)电(dian)位(wei)(wei)(wei)器(qi)(qi))和可调(diao)电(dian)阻(zu)(又叫电(dian)位(wei)(wei)(wei)器(qi)(qi))用万用表电(dian)阻(zu)档(dang)测试(shi)其两端电(dian)阻(zu)值(zhi)应与其标称值(zhi)基本相同(误差<±20%)为正常,否则该电(dian)位(wei)(wei)(wei)器(qi)(qi)不良(liang)或(huo)损坏。同时(shi)测试(shi)电(dian)位(wei)(wei)(wei)器(qi)(qi)中(zhong)心(xin)头(中(zhong)间引脚)与任(ren)一端之间的电(dian)阻(zu)值(zhi)应在零至标称值(zhi)之间连续(xu)可微调(diao)为正常,否则该电(dian)位(wei)(wei)(wei)器(qi)(qi)不良(liang)或(huo)损坏。
③对(dui)于正(zheng)温度系热敏电(dian)(dian)阻(zu)(PTC),常(chang)温下(xia)其(qi)电(dian)(dian)阻(zu)值(zhi)(zhi)应(ying)为(wei)几十左右为(wei)正(zheng)常(chang),若(ruo)电(dian)(dian)阻(zu)值(zhi)(zhi)过大则内部接触不良,若(ruo)电(dian)(dian)阻(zu)为(wei)无穷大,则已开路(lu)损(sun)坏,若(ruo)电(dian)(dian)阻(zu)值(zhi)(zhi)基本(ben)为(wei)零,则已短路(lu)损(sun)坏,同时(shi)该电(dian)(dian)阻(zu)通电(dian)(dian)加(jia)热时(shi)其(qi)阻(zu)值(zhi)(zhi)会变(bian)得如大(几百(bai)KΩ 以上(shang))为(wei)正(zheng)常(chang)。
④对于负(fu)温度(du)(du)系(xi)(xi)数热敏(min)电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu),常温下(xia)测试其电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)值(zhi)应与其标称值(zhi)基本相(xiang)同(tong)(误差(cha))为正常。若电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)值(zhi)相(xiang)差(cha)过大(da)(da),则(ze)该(gai)电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)不(bu)良或损(sun)坏,若电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)值(zhi)变为无穷(qiong)大(da)(da),则(ze)该(gai)电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)已开路损(sun)坏。同(tong)时该(gai)电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)温度(du)(du)越高阻(zu)(zu)(zu)(zu)(zu)值(zhi)越小,而温度(du)(du)越低阻(zu)(zu)(zu)(zu)(zu)值(zhi)变得越大(da)(da)为正常。否则(ze)该(gai)负(fu)温度(du)(du)系(xi)(xi)数热敏(min)电(dian)(dian)阻(zu)(zu)(zu)(zu)(zu)不(bu)良或损(sun)坏。
⑤对(dui)于压(ya)敏(min)(min)电(dian)(dian)(dian)阻(zu)(zu)器,由于其(qi)工作(zuo)电(dian)(dian)(dian)压(ya)较高(几十V以上)故用万用表(biao)电(dian)(dian)(dian)阻(zu)(zu)档测试时其(qi)电(dian)(dian)(dian)阻(zu)(zu)值(zhi)应为(wei)无穷大(da)(da)(da)为(wei)正常(因表(biao)内电(dian)(dian)(dian)池电(dian)(dian)(dian)压(ya)较低)否则该压(ya)敏(min)(min)电(dian)(dian)(dian)阻(zu)(zu)不良或损坏,压(ya)敏(min)(min)电(dian)(dian)(dian)阻(zu)(zu)在某(mou)额(e)(e)定电(dian)(dian)(dian)压(ya)以下时,阻(zu)(zu)值(zhi)均很大(da)(da)(da)(一般为(wei)无穷大(da)(da)(da),只有大(da)(da)(da)到或超过其(qi)额(e)(e)定电(dian)(dian)(dian)压(ya)时其(qi)阻(zu)(zu)值(zhi)才稳剧减少。
⑥对湿敏电(dian)阻,在空气干燥条件(jian)下测试(shi)其电(dian)阻值应减少(几十KΩ左右);而当没较强光线(xian)照射时其阻值则(ze)变得较小(几十Ω以下)为正常。否则(ze)该光敏电(dian)阻不良(liang)或损坏(huai)。
①对于薄膜(如(ru)碳膜(mo)、金属膜(mo)等)材料的固定电阻,若损坏时则不能进行(xing)维修,只能要更(geng)换解决。
②对于线绕电阻,多发(fa)生开(kai)路(lu)性(xing)故障,此时(shi)为(wei)电阻丝在某一位置烧(shao)断(duan)引起,可能断(duan)处焊接好(hao)后还(hai)可以继续使用,若为(wei)水泥(ni)(线绕)电阻,则打开(kai)外壳查找烧(shao)断(duan)处并修补好(hao)后,再用水泥(ni)封装凉干即可使用,当然最好(hao)还(hai)是换新解决为(wei)好(hao)。
③对于微调电阻,容易因(yin)为使(shi)用(yong)中间滑动触片与碳膜因(yin)氧(yang)化而接触不良的(de)故障,此时(shi)用(yong)电位器清(qing)洗(xi)剂清(qing)洗(xi)解(jie)决,清(qing)洗(xi)无效只能(neng)更(geng)换(huan)解(jie)决。
④对于(yu)电位器,容易(yi)发生碳(tan)膜磨损而(er)使中间滑动片(pian)(中心(xin)抽头)接触不良的故障,此时可调整中心(xin)滑动片(pian)与碳(tan)膜之间位(wei)置或用电(dian)位(wei)器清(qing)洗(xi)剂清(qing)洗(xi)解(jie)决。
⑤对于正温度系数热敏电阻(PTC),最易发生(sheng)电阻与压片之间的接触不良的故障,此时可调整压片及清洗修(xiu)(xiu)复,若电阻体已经(jing)碎(sui),则不能(neng)修(xiu)(xiu)复,只(zhi)能(neng)更换。
⑥对于负温度系数(shu)热敏电阻,若损坏则(ze)不能修复只能换新。
⑦对于压敏电阻(zu)(zu)及光(guang)敏电阻(zu)(zu),若损坏(huai)则不(bu)能(neng)修复(fu)只能(neng)换新。
⑧对(dui)于(yu)湿敏电阻,若(ruo)损坏(huai)时(shi)(shi)一(yi)般只(zhi)有(you)(you)更(geng)换解决,而(er)难(nan)以(yi)修复,但对于录(lu)象机(ji)、摄象机(ji)(DV)等的湿(shi)敏电阻损坏(huai)而(er)没有(you)(you)器件更(geng)换时(shi)(shi),在应急情况下可用一(yi)个(ge)2千(qian)欧左右的固定电阻代(dai)换解决,此时(shi)(shi)将失(shi)去(qu)潮(chao)湿(shi)检测(ce)功(gong)能(neng)。
简称电容,由两(liang)片或两(liang)组(zu)平(ping)衡金(jin)属板中间一(yi)层电介质(绝缘层)构成,是一(yi)种可(ke)以储存电荷的(de)器件,具有充(chong)放电的(de)特性。
常见的(de)有空气、陶瓷、云母(mu)、涤纶(lun)、聚(ju)丙烯、铝、银等,电解(jie)质等电介质材料。
①容量:指储(chu)存电(dian)荷(he)能力大小(xiao)的(de)量(liang)。
容(rong)量的(de)基本单(dan)位是法(fa)(fa)(fa)拉,简(jian)称(cheng)法(fa)(fa)(fa)(F),常用单(dan)位的(de)毫法(fa)(fa)(fa)(mF)、微法(fa)(fa)(fa)(uF)、毫微法(fa)(fa)(fa)即纳(na)法(fa)(fa)(fa)(nF)、微微法(fa)(fa)(fa)即皮法(fa)(fa)(fa)(pF)等。
②耐压:指电容长期工作(zuo)时所(suo)能承受的电压(ya)(ya) 耐压(ya)(ya):几V——几KV
①固(gu)定无极性电容(rong)
指电(dian)(dian)容(rong)(rong)量固定不变(bian)无(wu)极性电(dian)(dian)容(rong)(rong),如:陶瓷(ci)(瓷(ci)介)电(dian)(dian)容(rong)(rong)、云(yun)母电(dian)(dian)容(rong)(rong)、薄膜电(dian)(dian)容(rong)(rong)(如:涤纶(lun)、聚丙烯等电(dian)(dian)容(rong)(rong))
②微调(diao)(无极(ji)性)电(dian)容
指电(dian)(dian)容(rong)量可微(wei)调(diao)的(de)无(wu)极(ji)性(xing)电(dian)(dian)容(rong)。(注:微(wei)调(diao)电(dian)(dian)容(rong)均为无(wu)极(ji)性(xing)电(dian)(dian)容(rong) )。如:空气陶瓷、薄膜等微(wei)调(diao)电(dian)(dian)容(rong)。
③可调电(dian)容
指(zhi)电容(rong)量连(lian)续可调(可变(bian))的无极性(xing)电容(rong)(注:可调电容(rong)均为(wei)无极性(xing)电容(rong))。如:空气、薄膜等可调电容(rong)。常见的有单(dan)连(lian)、双连(lian)、四(si)连(lian)可调(可变(bian))电容(rong)。
④电解电容
指采用铝(lv)、钽、铌等电解(jie)(jie)(jie)质(zhi)作(zuo)电介(jie)质(zhi)的电容(rong)(rong)称为电解(jie)(jie)(jie)电容(rong)(rong),电解(jie)(jie)(jie)电容(rong)(rong)大多数为有极性(xing)电容(rong)(rong)。
注(zhu):电解(jie)电容(rong)没有微(wei)调与可调结构,全部为容(rong)量(liang)固定的(de)电容(rong)。
①直(zhi)接标明耐压数(shu)值和单(dan)位(wei)。如:(6V、25V、50V、100V等)
(注:电(dian)解电(dian)容(rong)一般(ban)采用此法(fa),其它电(dian)容(rong)一般(ban)较少用)
②直接(jie)标明耐压数值而将(jiang)单(dan)位(V)省去。如(ru):25即(ji)25V、63即(ji)63V、100即(ji)100V等(deng)
③用(yong)数字与字母表示耐压(ya)值,由一位数(shu)字(zi)和一个字(zi)母组成,数(shu)字(zi)表(biao)示(shi)耐压(ya)10的倍(bei)(bei)乘数(shu),字(zi)母表(biao)示(shi)耐压(ya)的有(you)(you)效数(shu),将有(you)(you)效数(shu)乘以倍(bei)(bei)乘数(shu)即(ji)为此电容的耐压(ya)值。
(注:涤(di)纶电容(rong)(rong)采用(yong)此法较常见,其它电容(rong)(rong)应用(yong)此法少些)
例: 1A=10V 2A=100V 2B=125V
2C=160V 3D=2KV 3G=4KV
1E=25V 2F=315V 4W=45KV
④用颜色来(lai)表示耐(nai)压(ya)
部分瓷介电容有颜(yan)色来表(biao)示其耐(nai)压值,即外表(biao)不同颜(yan)色来表(biao)示不同的耐(nai)压
⑤部分进口瓷(ci)(ci)介(陶瓷(ci)(ci))电容,在(zai)容量下面画有一横线(xian)的则为耐(nai)压(ya)50V,不画横线(xian)的则为耐(nai)压(ya)500V。
⑥有些(xie)电容的耐压单位有WV表示V,如:50WV即50V、350WV即350V等(deng)。
⑦凡是没有用(yong)上述方法标明(ming)耐压(ya)值的(de),则该电容(rong)可认(ren)为(wei)是耐压(ya)25V(或以(yi)下)的(de)低压(ya)电容(rong)。
①直接标明容量的(de)数值和单位,如(ru):5PF、33PF、100PF、22nf、0.01uF、47uF、22F等。
(注:电解电容大(da)多数(shu)采用此法(fa))
②直接标明(ming)容(rong)量的数值,而单位用u、n、p表示uF、nF、pF,如:47u即47Uf。
③用(yong)几(ji)(ji)(ji)X几(ji)(ji)(ji)代表(biao)几(ji)(ji)(ji)点几(ji)(ji)(ji)X,如:8P2即(ji)8.2Pf、6n8即(ji)6.8Nf、4u7即(ji)4.7uF等。
④凡是电容量的数(shu)值用零点几或点几乖(guai)来(lai)表示而没有(you)标明单(dan)位(wei)的。其容量数值单(dan)位(wei)为零点几uF,如(ru):0.01即0.01uF等。
⑤电容量的(de)数值为整数而不标(biao)明单位的。其单位(wei)为(wei)PF(注:三位(wei)数最后一位(wei)不为(wei)零的除(chu)外(wai))。如:3即(ji)将(jiang)3PF、15即(ji)15PF、120即(ji)120PF等(deng)。
⑥数码表示法:用三(san)位(wei)(wei)(wei)数(shu)(shu)字表示(注:最后一(yi)位(wei)(wei)(wei)为(wei)零的除外(wai)),第一(yi)、二位(wei)(wei)(wei)数(shu)(shu)字表示有(you)效数(shu)(shu),第三(san)位(wei)(wei)(wei)数(shu)(shu)字表示倍乘数(shu)(shu)(1为(wei) 101 、2为(wei)102 、3为(wei) 103 ……8为(wei) 108 ,但(dan)9却为(wei) 100 )把有(you)效数(shu)(shu)乘以倍乘数(shu)(shu),即为(wei)电(dian)容量,其单位(wei)(wei)(wei)为(wei)PF。
⑦色环(色条)表(biao)示法
与色(se)环电阻表示法(fa)相(xiang)同(tong),但单(dan)位为PF
⑧有厂家电容(rong)容(rong)量单(dan)位用大写英文MDF或(huo)MF代(dai)表uF。如(ru):25MDF即25uF、100MF即100uF。
⑨有(you)(you)些(xie)电(dian)(dian)容(rong)在电(dian)(dian)容(rong)量(liang)的数(shu)值后面标有(you)(you)字(zi)母或正(zheng)负百(bai)分之几(ji)的则为表示(shi)该(gai)电(dian)(dian)容(rong)的误(wu)差等级。
注:大多数厂家(jia)的电容(rong)量(liang)误(wu)差等(deng)级用上(shang)述字母来表示,但也有(you)个(ge)别厂家(jia)用其它字母或(huo)字符(fu)来表示,误(wu)差等(deng)级在这不(bu)一(yi)一(yi)举出。
①对于未剪脚(jiao)的铝电解电容,则长脚(jiao)端为正而短脚(jiao)端为负。
②有极(ji)性电容在出厂前均要求标(biao)明正负(fu)极(ji)(可(ke)以(yi)正负(fu)极(ji)标(biao)明,也可(ke)以(yi)只标(biao)明正极(ji)或负(fu)极(ji)端)可(ke)以(yi)从电容的外壳直接看出。
③用(yong)万(wan)用(yong)表(biao)(biao)电(dian)(dian)(dian)(dian)阻(zu)(zu)档测(ce)试正(zheng)负(fu)极(ji)(ji)(仅(jin)供(gong)参考(kao)) 用(yong)万(wan)用(yong)表(biao)(biao)电(dian)(dian)(dian)(dian)阻(zu)(zu)档的(de)最高量程(cheng)档(RX1K或10K档)测(ce)试有极(ji)(ji)性电(dian)(dian)(dian)(dian)解电(dian)(dian)(dian)(dian)容的(de)正(zheng)反(fan)(fan)(fan)向(xiang)漏(lou)电(dian)(dian)(dian)(dian)电(dian)(dian)(dian)(dian)阻(zu)(zu)(即绝(jue)缘(yuan)电(dian)(dian)(dian)(dian)阻(zu)(zu)大(da)(da)(da))时(shi),而反(fan)(fan)(fan)向(xiang)漏(lou)电(dian)(dian)(dian)(dian)大(da)(da)(da)(即绝(jue)缘(yuan)电(dian)(dian)(dian)(dian)阻(zu)(zu)小)的(de)特点。当测(ce)试时(shi)表(biao)(biao)针(zhen)先向(xiang)右边摆动(dong)(容量越(yue)大(da)(da)(da)表(biao)(biao)针(zhen)摆动(dong)也越(yue)大(da)(da)(da)),然后(hou)慢(man)(man)慢(man)(man)向(xiang)左边退回来。若表(biao)(biao)针(zhen)能退回到(dao)无穷(qiong)大(da)(da)(da)(刻(ke)度(du)左边起始(shi)位(wei)置),则该电(dian)(dian)(dian)(dian)容量基本没有漏(lou)电(dian)(dian)(dian)(dian),若表(biao)(biao)针(zhen)不能退回到(dao)无穷(qiong)大(da)(da)(da)位(wei)置而在某(mou)一刻(ke)度(du)停下来,则此时(shi)的(de)电(dian)(dian)(dian)(dian)阻(zu)(zu)阻(zu)(zu)值为(wei)(wei)漏(lou)电(dian)(dian)(dian)(dian)电(dian)(dian)(dian)(dian)阻(zu)(zu)(即绝(jue)缘(yuan)电(dian)(dian)(dian)(dian)阻(zu)(zu))反(fan)(fan)(fan)复测(ce)试多(duo)次(ci)(应调换表(biao)(biao)笔)测(ce)试出其正(zheng)反(fan)(fan)(fan)向(xiang)漏(lou)电(dian)(dian)(dian)(dian)(绝(jue)缘(yuan)电(dian)(dian)(dian)(dian)阻(zu)(zu))。凡是漏(lou)电(dian)(dian)(dian)(dian)小(即绝(jue)缘(yuan)电(dian)(dian)(dian)(dian)阻(zu)(zu)大(da)(da)(da))的(de)一次(ci)则黑(hei)表(biao)(biao)笔接的(de)电(dian)(dian)(dian)(dian)极(ji)(ji)为(wei)(wei)电(dian)(dian)(dian)(dian)解电(dian)(dian)(dian)(dian)容正(zheng)极(ji)(ji)而红(hong)表(biao)(biao)笔接的(de)为(wei)(wei)负(fu)极(ji)(ji),反(fan)(fan)(fan)之则表(biao)(biao)笔极(ji)(ji)性刚好相反(fan)(fan)(fan)。
注:黑表笔接(jie)电解电容正极(ji)而红表笔接(jie)负极(ji)测试正向漏(lou)电电阻(zu)。
红表(biao)笔接电(dian)解电(dian)容负极而(er)黑表(biao)笔接正极测试(shi)负向漏电(dian)电(dian)阻(zu)。
电(dian)容(rong)的耐压可以从电(dian)容(rong)的外表(biao)直接看出而不用(yong)测试,但若有耐压表(biao)的情况下也(ye)可以用(yong)耐压表(biao)直接测试出来。
①对于合格的电(dian)容,其容量为电(dian)容外壳上(shang)标志(zhi)值,一般可(ke)直接看(kan)出来而(er)不用(yong)测试(shi)。
②若有电(dian)(dian)容表(biao)(biao)(部(bu)分数字(zi)万用(yong)表(biao)(biao)也可(ke)测试电(dian)(dian)容容量(liang),但只能(neng)(neng)测试小(xiao)电(dian)(dian)容容量(liang)而不能(neng)(neng)测大(da)电(dian)(dian)容容量(liang))。则可(ke)利用(yong)电(dian)(dian)容表(biao)(biao)直接(jie)测试出(chu)电(dian)(dian)容的容量(liang)。
③部分指针万(wan)用表在串入一定(ding)电压值(zhi)的交流电的情(qing)况下也可以测量(liang)出其(qi)电容容量(liang),但误差较(jiao)大,不提倡采用。
④用普(pu)通(tong)机械式指针(zhen)万用表(biao)(biao)也可粗略(lve)测(ce)试出电容(rong)(rong)(rong)的(de)容(rong)(rong)(rong)量(liang)(liang)大(da)(da)(da)(da)小(xiao)(xiao),方法是(shi)用万用表(biao)(biao)的(de)电阻(zu)(zu)档(容(rong)(rong)(rong)量(liang)(liang)小(xiao)(xiao)要(yao)用高阻(zu)(zu)档,而(er)容(rong)(rong)(rong)量(liang)(liang)大(da)(da)(da)(da)要(yao)用低阻(zu)(zu)档)。调(diao)换表(biao)(biao)笔(bi)测(ce)试多次,则电容(rong)(rong)(rong)量(liang)(liang)越(yue)大(da)(da)(da)(da)表(biao)(biao)针(zhen)摆(bai)(bai)动(dong)幅(fu)度(du)也越(yue)大(da)(da)(da)(da),而(er)容(rong)(rong)(rong)量(liang)(liang)越(yue)小(xiao)(xiao)表(biao)(biao)针(zhen)摆(bai)(bai)动(dong)幅(fu)度(du)也越(yue)小(xiao)(xiao),根据表(biao)(biao)针(zhen)摆(bai)(bai)动(dong)幅(fu)度(du)的(de)大(da)(da)(da)(da)小(xiao)(xiao)与其标准容(rong)(rong)(rong)量(liang)(liang)电容(rong)(rong)(rong)比较,即可估(gu)算该(gai)电容(rong)(rong)(rong)的(de)容(rong)(rong)(rong)量(liang)(liang)大(da)(da)(da)(da)小(xiao)(xiao)(注:一般情(qing)况下(xia)使用电容(rong)(rong)(rong)的(de)容(rong)(rong)(rong)量(liang)(liang)无(wu)须(xu)(xu)要(yao)求特别(bie)精确(que),其电容(rong)(rong)(rong)只须(xu)(xu)在一定范围内即可正常使用。一般情(qing)况下(xia)只用普(pu)通(tong)指针(zhen)式万用表(biao)(biao)进行时电容(rong)(rong)(rong)容(rong)(rong)(rong)量(liang)(liang)粗略(lve)测(ce)试即可)。
注(zhu):当容量(liang)大(da)用高阻档测试时,表针(zhen)(zhen)会打(da)超刻(ke)(ke)度(du)线而难以比较(jiao)容量(liang)大(da)小(xiao),此(ci)时就降低(di)量(liang)程(cheng)测试以表针(zhen)(zhen)不(bu)打(da)超刻(ke)(ke)度(du)为(wei)限,方能(neng)比较(jiao)容量(liang)大(da)小(xiao)。
▲容量太小(xiao)(小(xiao)于0.01uF)则有最高阻档测试均准以看(kan)到表(biao)针摆动是正常的,对这些电(dian)容则难以用(yong)电(dian)阻档比较其容量大小(xiao),只采(cai)用(yong)电(dian)容表(biao)测试.
▲若测试时(shi)表针(zhen)指到零欧处停下来不(bu)能(neng)退回来,则此时(shi)电容(rong)已短路(lu)损坏(huai),而不(bu)能(neng)测试其容(rong)量.
指电(dian)容对交流(liu)电(dian)的等效(xiao)电(dian)阻称为容抗(kang)。
具有通高频阻低频,通交(jiao)流(liu)阻直流(liu)的特性。
a)电容的用途
可用来滤波、耦合、退耦、旁路、调谐、谐振等(deng)用途(tu)。
b)电容的好(hao)坏判断
用(yong)万(wan)用(yong)表(biao)(biao)(biao)(biao)判断电(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)档(dang)(容(rong)(rong)(rong)(rong)(rong)量(liang)(liang)小(xiao)一定要(yao)用(yong)高(gao)阻(zu)(zu)(zu)档(dang)而容(rong)(rong)(rong)(rong)(rong)量(liang)(liang)大可(ke)用(yong)低阻(zu)(zu)(zu)档(dang))测(ce)试电(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)时(shi)(应(ying)调换表(biao)(biao)(biao)(biao)笔测(ce)试多次或(huo)把电(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)短路放电(dian)(dian)(dian)(dian)(dian)(dian)(dian)后(hou)再测(ce)试)容(rong)(rong)(rong)(rong)(rong)量(liang)(liang)大表(biao)(biao)(biao)(biao)针(zhen)(zhen)(zhen)摆动(dong)(dong)(dong)幅度(du)(du)也越(yue)大,且表(biao)(biao)(biao)(biao)针(zhen)(zhen)(zhen)摆动(dong)(dong)(dong)后(hou)应(ying)慢慢退(tui)回(hui)(hui)来(lai)为(wei)(wei)正(zheng)常(chang)(即只有这样该(gai)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)才是(shi)好的(de)(de))。若(ruo)(ruo)与同容(rong)(rong)(rong)(rong)(rong)量(liang)(liang)好的(de)(de)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)比较(jiao)在(zai)测(ce)试表(biao)(biao)(biao)(biao)针(zhen)(zhen)(zhen)摆动(dong)(dong)(dong)幅度(du)(du)过(guo)(guo)小(xiao)功根本(ben)不摆动(dong)(dong)(dong)则(ze)该(gai)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)容(rong)(rong)(rong)(rong)(rong)量(liang)(liang)已变(bian)小(xiao)或(huo)失效损(sun)坏(huai),同时(shi)表(biao)(biao)(biao)(biao)针(zhen)(zhen)(zhen)摆动(dong)(dong)(dong)应(ying)慢慢退(tui)回(hui)(hui)来(lai)(容(rong)(rong)(rong)(rong)(rong)量(liang)(liang)小(xiao)退(tui)回(hui)(hui)速(su)(su)度(du)(du)快而容(rong)(rong)(rong)(rong)(rong)量(liang)(liang)大退(tui)回(hui)(hui)速(su)(su)度(du)(du)慢)。若(ruo)(ruo)退(tui)回(hui)(hui)到某(mou)一位置表(biao)(biao)(biao)(biao)针(zhen)(zhen)(zhen)停(ting)(ting)下(xia)来(lai)则(ze)此(ci)时(shi)的(de)(de)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)为(wei)(wei)该(gai)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)的(de)(de)漏(lou)(lou)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)。此(ci)漏(lou)(lou)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)越(yue)大越(yue)好(最好为(wei)(wei)无(wu)穷大),此(ci)漏(lou)(lou)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)过(guo)(guo)小(xiao)则(ze)该(gai)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)漏(lou)(lou)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)过(guo)(guo)大而性能(neng)不良(liang),此(ci)漏(lou)(lou)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)基本(ben)为(wei)(wei)零(ling)(即表(biao)(biao)(biao)(biao)针(zhen)(zhen)(zhen)在(zai)刻度(du)(du)零(ling)欧(ou)停(ting)(ting)下(xia)来(lai)),则(ze)该(gai)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)已短路(击(ji)穿(chuan)(chuan))损(sun)坏(huai)。对于容(rong)(rong)(rong)(rong)(rong)量(liang)(liang)较(jiao)小(xiao)的(de)(de)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)用(yong)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)档(dang)的(de)(de)最高(gao)档(dang)均(jun)难以看到表(biao)(biao)(biao)(biao)针(zhen)(zhen)(zhen)摆动(dong)(dong)(dong)是(shi)正(zheng)常(chang)的(de)(de)。但若(ruo)(ruo)该(gai)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)有漏(lou)(lou)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)或(huo)击(ji)穿(chuan)(chuan)短路现象则(ze)可(ke)能(neng)测(ce)试出来(lai)(注:对于此(ci)类电(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)有漏(lou)(lou)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)或(huo)击(ji)穿(chuan)(chuan)睦均(jun)可(ke)认为(wei)(wei)该(gai)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)已性能(neng)不良(liang)或(huo)损(sun)坏(huai)而不要(yao)使用(yong))
①对于容大于1uF的无(wu)极性电容,用(yong)(yong)万用(yong)(yong)表电阻档(dang)的RX1K档(dang)或10K档(dang)测试时应能明(ming)显看出(chu)表针向右(you)摆动后较快退回到(dao)无(wu)穷(qiong)大位(wei)置为(wei)正常。若(ruo)不(bu)能退回到(dao)无(wu)穷(qiong)大位(wei)置则(ze)该电容有漏(lou)(lou)电现象而最(zui)好不(bu)要(yao)使用(yong)(yong)它,若(ruo)漏(lou)(lou)电电阻基本(ben)为(wei)零则(ze)该电容已经击穿短路损坏。
②对于容量大(da)于0.01uF(10uF)而(er)小于1uF的(de)无极性电(dian)容,用电(dian)阻(zu)档(dang)的(de)最高量程(最好用RX10K档(dang),用X1K档(dang)有(you)些电(dian)容难以观察)档(dang),测试时应(ying)能(neng)看(kan)到(dao)表针较微摆动(即表针摆动很小)后很快退回(hui)到(dao)无穷大(da)位置为正常,并且不能(neng)有(you)漏电(dian)或短路(lu)现象,否则该电(dian)容不良或损坏(huai)。
③对(dui)(dui)于容(rong)量(liang)(liang)小于0.01uF(10nF即10000pF)的无极性电(dian)(dian)(dian)容(rong),用万(wan)用表(biao)电(dian)(dian)(dian)阻(zu)档的最高量(liang)(liang)程(cheng)(如:测(ce)试(shi)时均难以(yi)看到表(biao)针摆动(dong)(因容(rong)量(liang)(liang)太小,表(biao)笔刚接(jie)触电(dian)(dian)(dian)容(rong)时已对(dui)(dui)该电(dian)(dian)(dian)容(rong)充电(dian)(dian)(dian)完(wan)毕(bi)而表(biao)针还来不(bu)(bu)及摆动(dong))是(shi)正常(chang)的。若怀(huai)疑这(zhei)些电(dian)(dian)(dian)容(rong)容(rong)量(liang)(liang)变小或失效损坏(huai)(huai)则(ze)只能(neng)用电(dian)(dian)(dian)容(rong)表(biao)测(ce)试(shi)或在(zai)实(shi)际应(ying)用中代(dai)(dai)换法(fa)(替(ti)代(dai)(dai)法(fa))即用一个好的代(dai)(dai)替(ti)怀(huai)疑已损坏(huai)(huai)的)进行判断,对(dui)(dui)这(zhei)些电(dian)(dian)(dian)容(rong)绝对(dui)(dui)在(zai)测(ce)试(shi)时不(bu)(bu)能(neng)有漏电(dian)(dian)(dian)功短路现象(xiang),否则(ze)均可认为该电(dian)(dian)(dian)容(rong)已损坏(huai)(huai)而不(bu)(bu)能(neng)继(ji)续使用。
④对于(yu)有(you)(you)极性电(dian)(dian)(dian)(dian)(dian)(dian)解(jie)电(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong),由(you)(you)于(yu)容(rong)(rong)(rong)量(liang)较大(da)(da)(da),故(gu)测(ce)(ce)试(shi)(shi)时可(ke)根(gen)据容(rong)(rong)(rong)量(liang)大(da)(da)(da)小(xiao)(xiao)(xiao)选(xuan)择适合(he)的(de)档(dang)位量(liang)程来(lai)(lai)进行测(ce)(ce)试(shi)(shi)(即(ji)(ji)(ji)容(rong)(rong)(rong)量(liang)小(xiao)(xiao)(xiao)用(yong)(yong)高档(dang)而(er)容(rong)(rong)(rong)量(liang)大(da)(da)(da)用(yong)(yong)低档(dang),如(ru):10uF以(yi)(yi)下可(ke)用(yong)(yong)X10K或(huo)X1K档(dang),100uF左(zuo)右可(ke)用(yong)(yong)X1K或(huo)X100 档(dang),1000uF以(yi)(yi)下可(ke)用(yong)(yong)X100或(huo) ,1000uF以(yi)(yi)上(shang)可(ke)用(yong)(yong)RX10或(huo) ,以(yi)(yi)上(shang)档(dang)位选(xuan)择供参考)测(ce)(ce)试(shi)(shi)时应该(gai)(gai)容(rong)(rong)(rong)量(liang)越(yue)大(da)(da)(da)表(biao)针(zhen)摆(bai)动越(yue)大(da)(da)(da)。(同档(dang)位置(zhi)量(liang)程比较)并且(qie)表(biao)针(zhen)摆(bai)动后(hou)应该(gai)(gai)会(hui)慢(man)慢(man)退(tui)回来(lai)(lai)正(zheng)(zheng)常。表(biao)针(zhen)退(tui)回到(dao)某一刻度(du)位置(zhi)停下来(lai)(lai)而(er)不能退(tui)回到(dao)无穷(qiong)大(da)(da)(da)(即(ji)(ji)(ji)表(biao)针(zhen)刻度(du)起始(shi)位置(zhi)),则(ze)表(biao)明(ming)该(gai)(gai)电(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)有(you)(you)漏(lou)电(dian)(dian)(dian)(dian)(dian)(dian)现象,漏(lou)电(dian)(dian)(dian)(dian)(dian)(dian)越(yue)小(xiao)(xiao)(xiao)(即(ji)(ji)(ji)漏(lou)电(dian)(dian)(dian)(dian)(dian)(dian)电(dian)(dian)(dian)(dian)(dian)(dian)阻越(yue)大(da)(da)(da))越(yue)好,若(ruo)漏(lou)电(dian)(dian)(dian)(dian)(dian)(dian)过(guo)大(da)(da)(da)(即(ji)(ji)(ji)漏(lou)电(dian)(dian)(dian)(dian)(dian)(dian)电(dian)(dian)(dian)(dian)(dian)(dian)阻越(yue)小(xiao)(xiao)(xiao))则(ze)该(gai)(gai)电(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)性能不良,若(ruo)漏(lou)电(dian)(dian)(dian)(dian)(dian)(dian)电(dian)(dian)(dian)(dian)(dian)(dian)阻基本为零,则(ze)该(gai)(gai)电(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)已击穿损坏。同时由(you)(you)于(yu)电(dian)(dian)(dian)(dian)(dian)(dian)解(jie)电(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)具(ju)有(you)(you)正(zheng)(zheng)向漏(lou)电(dian)(dian)(dian)(dian)(dian)(dian)小(xiao)(xiao)(xiao)(即(ji)(ji)(ji)漏(lou)电(dian)(dian)(dian)(dian)(dian)(dian)电(dian)(dian)(dian)(dian)(dian)(dian)阻大(da)(da)(da))而(er)反(fan)向漏(lou)电(dian)(dian)(dian)(dian)(dian)(dian)大(da)(da)(da)(即(ji)(ji)(ji)漏(lou)电(dian)(dian)(dian)(dian)(dian)(dian)电(dian)(dian)(dian)(dian)(dian)(dian)阻小(xiao)(xiao)(xiao))的(de)特点。故(gu)测(ce)(ce)试(shi)(shi)的(de)一般(ban)正(zheng)(zheng)向漏(lou)电(dian)(dian)(dian)(dian)(dian)(dian)较小(xiao)(xiao)(xiao)即(ji)(ji)(ji)可(ke),而(er)反(fan)向漏(lou)电(dian)(dian)(dian)(dian)(dian)(dian)大(da)(da)(da)小(xiao)(xiao)(xiao)可(ke)不考虑,还有(you)(you)对于(yu)有(you)(you)极性电(dian)(dian)(dian)(dian)(dian)(dian)解(jie)电(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong),若(ruo)存放时间过(guo)长其漏(lou)电(dian)(dian)(dian)(dian)(dian)(dian)也会(hui)变(bian)大(da)(da)(da),只要(yao)使用(yong)(yong)一段时间甚至测(ce)(ce)试(shi)(shi)多次其漏(lou)电(dian)(dian)(dian)(dian)(dian)(dian)也会(hui)变(bian)小(xiao)(xiao)(xiao)。
简称(cheng)电(dian)感,俗称(cheng)线圈,是由线圈绕(rao)制而成的具(ju)有电(dian)感作(zuo)用的元件。
①空芯电感:指线圈绕(rao)在(zai)空心支架上(shang)或(huo)直接绕(rao)制而成(cheng)的电感。
②磁芯电感:指线圈绕(rao)在磁芯上(即(ji)线圈里面(mian)有(you)磁芯)形成的(de)。
③铜芯(xin)电(dian)感:指(zhi)线(xian)圈绕在(zai)铜芯(xin)上的电(dian)感。
④铁芯电(dian)(dian)感:指线圈绕在(zai)铁芯上的电(dian)(dian)感。
⑤带抽头电感:指线(xian)圈上抽出一(yi)个或多(duo)个抽头的电感。
指电感(gan)能力大小的(de)量,称(cheng)为(wei)电感(gan)量。电感(gan)量的(de)基本单位为(wei)亨利,简称(cheng)亨(H),常用单位还(hai)有毫亨(mH),微(wei)亨(μH)等。
1H=103 mH=106μH
指电(dian)感对交流电(dian)的阻(zu)碍作(zuo)用(即等效电(dian)阻(zu))。XL=2лfL
具有(you)通直流阻交流,通低频(pin)阻高频(pin)的特(te)性(xing)。
当(dang)通过电(dian)感(gan)(gan)线圈的电(dian)流发(fa)生(sheng)变化(hua)时,线圈将产(chan)生(sheng)一个自(zi)感(gan)(gan)电(dian)动(dong)势来(lai)阻碍电(dian)流的变化(hua),这种作(zuo)用叫电(dian)感(gan)(gan)的自(zi)感(gan)(gan)作(zuo)用。
两(liang)个相互(hu)靠近的线圈,当一(yi)个有(you)变化的电(dian)(dian)流通过(guo)时另一(yi)个也会感应出感生电(dian)(dian)动(dong)势(shi),这种作用(yong)叫电(dian)(dian)感的互(hu)感作用(yong)。变压器就是根据互(hu)感作用(yong)原理制成的。
可(ke)用(yong)于滤波,阻波,限流,变(bian)换,调谐,消振等(deng)作(zuo)用(yong)。
①直接(jie)标明(ming)电感量的数值和(he)单位(wei)。如(ru):10mH ,150μH。
②用几(ji)X几(ji)代表几(ji)点(dian)几(ji)X。如:1H2即(ji)(ji)1.2H,3m3即(ji)(ji)3.3mH,8μ2即(ji)(ji)8.2μH。
③用色环或色点表示法(fa):用四(si)(si)色(se)(se)环(色(se)(se)点)来表(biao)(biao)(biao)示(shi),第(di)一二色(se)(se)环(色(se)(se)点)表(biao)(biao)(biao)示(shi)有效数,第(di)三色(se)(se)环(色(se)(se)点)表(biao)(biao)(biao)示(shi)倍(bei)乘(cheng)数,第(di)四(si)(si)色(se)(se)环表(biao)(biao)(biao)示(shi)误差。(与四(si)(si)色(se)(se)环电阻表(biao)(biao)(biao)示(shi)方法相同)
灰红棕金 即是82X101±5%
④用圈数(匝数)表示
有(you)些电感线圈不标明其(qi)电感量而直接(jie)标明该电感线圈应该绕制的圈数(匝数),如:3T即(ji)3圈(匝),19T即(ji)19匝等。
⑤有很多电感线圈(quan)是由厂家制(zhi)定(ding),其(qi)上(shang)面既无电感量(liang)也没有标(biao)明绕制(zhi)的圈(quan)数,在实际应用中,只能用相同的线圈(quan)更换或按原来(lai)规格重(zhong)绕。
用万用表电(dian)阻(zu)(zu)档可粗略测试电(dian)感线(xian)(xian)(xian)圈的(de)好坏,方法(fa)是测试线(xian)(xian)(xian)圈两端的(de)直流电(dian)阻(zu)(zu)与正常值(zhi)比(bi)较(jiao)或(huo)相(xiang)(xiang)同(tong)的(de)线(xian)(xian)(xian)圈比(bi)较(jiao),若(ruo)电(dian)阻(zu)(zu)值(zhi)基本相(xiang)(xiang)同(tong)(误差≤±10%)则(ze)可以(yi)认为(wei)(wei)该(gai)(gai)线(xian)(xian)(xian)圈是好的(de),若(ruo)电(dian)阻(zu)(zu)值(zhi)相(xiang)(xiang)差过大(da)则(ze)该(gai)(gai)线(xian)(xian)(xian)圈不良(liang),若(ruo)电(dian)阻(zu)(zu)值(zhi)变为(wei)(wei)无穷大(da)则(ze)该(gai)(gai)线(xian)(xian)(xian)圈已(yi)(yi)开路损坏,若(ruo)电(dian)阻(zu)(zu)值(zhi)变为(wei)(wei)零则(ze)该(gai)(gai)线(xian)(xian)(xian)圈已(yi)(yi)短路损坏。
①电感线圈若(ruo)发(fa)生短路或(huo)者局部短路的故障(zhang)时(shi)应把线圈拆(chai)开按原(yuan)来规格(ge)重绕即可(ke)修复。
②电感线(xian)(xian)圈(quan)(quan)若发生内(nei)部接触不良或开路(lu)故(gu)障时(shi)可小(xiao)心拆开线(xian)(xian)圈(quan)(quan)检查,接触不良处(chu)(多为线(xian)(xian)圈(quan)(quan)接头处(chu))或断路(lu)处(chu)重(zhong)新焊(han)接牢(lao)固即可修(xiu)(xiu)复(fu),也(ye)可按(an)原来规格(ge)用新线(xian)(xian)重(zhong)绕来修(xiu)(xiu)复(fu)。
③在大多数情(qing)(qing)况下(xia)若(ruo)电感线圈(quan)有故障时若(ruo)有新(xin)备件的情(qing)(qing)况下(xia)建议更(geng)换解决,若(ruo)无(wu)新(xin)备件的情(qing)(qing)况下(xia)才对其进(jin)行修复。
变压器是一种(zhong)能变换交(jiao)流电(dian)压、电(dian)流及阻抗(kang)的多线圈器件。
1.变压(ya)(ya)器变换交(jiao)流(liu)电压(ya)(ya)电流(liu)及阻抗的关系(xi):
N1,N2分别(bie)(bie)为初(chu)(chu)次级(ji)的圈数;U1,U2分别(bie)(bie)为初(chu)(chu)次级(ji)的电(dian)压(ya);I1,I2分别(bie)(bie)为初(chu)(chu)次的电(dian)流;Z1,Z2分别(bie)(bie)为初(chu)(chu)次级(ji)的阻抗(kang)。初(chu)(chu)级(ji)线(xian)圈(N1)又(you)叫(jiao)原线(xian)圈;次级(ji)线(xian)圈(N2)又(you)叫(jiao)副线(xian)圈。
变压器初次(ci)级圈数比与初次(ci)级电压成正比,与初次(ci)级电流成反比,与初次(ci)级阻抗(kang)的(de)开方(fang)成正比。用公(gong)式表示为:
①高(gao)频变压器:指用于变(bian)换(huan)高(gao)频(pin)电(dian)信(xin)号的变(bian)压器(qi)。如(ru)天(tian)线(xian)线(xian)圈,振荡变(bian)压器(qi)等。
②中频变压(ya)器:(俗称(cheng)中(zhong)周):指超外(wai)差无线电接收机(ji)中(zhong)用于变(bian)换中(zhong)颇电信号的变(bian)压器。
③低(di)频变压器(qi):指用(yong)于变(bian)(bian)换低频电(dian)信号的变(bian)(bian)压器(qi),如音(yin)频变(bian)(bian)压器(qi)。
④电源变压器:指(zhi)用于变(bian)换交流市电的(de)变(bian)压(ya)器。
⑤自耦变压器:指初次级线圈可共用的变压器。
用(yong)(yong)万用(yong)(yong)表(biao)电阻档可(ke)粗略判断变(bian)压(ya)器(qi)的(de)好坏,方(fang)法是测量变(bian)压(ya)器(qi)各线(xian)圈(quan)的(de)直(zhi)流电阻与正常值或(huo)好的(de)变(bian)压(ya)器(qi)比较,若所有(you)线(xian)圈(quan)的(de)阻值正常,则可(ke)以认为该变(bian)压(ya)器(qi)是好的(de);若有(you)一个(ge)或(huo)多个(ge)线(xian)圈(quan)不良或(huo)损(sun)坏。同(tong)时测试不同(tong)线(xian)圈(quan)之间或(huo)各线(xian)圈(quan)与外壳(铁芯)之间的(de)绝缘电阻应为无穷大为正常,否则该变(bian)压(ya)器(qi)也是不良或(huo)损(sun)坏。
①变(bian)压器(qi)初(chu)级(ji)线圈串联有温(wen)(wen)度保险(xian)丝的(de)变(bian)压器(qi),若发(fa)生初(chu)级(ji)开(kai)路时,则多为此(ci)温(wen)(wen)度保险(xian)丝熔断引起(qi),可更换一个温(wen)(wen)度保险(xian)丝解决,若无此(ci)保险(xian)丝更换的(de)情(qing)况下(xia)也可以短路此(ci)保险(xian)来解决。
②对于一般变压(ya)器,若线圈(quan)损坏时,则可按原线圈(quan)的参数重绕(rao)即可修复。
③在(zai)大多数情况下变压器损(sun)坏(huai)难修复或修复工程太大时(shi)则(ze)建议换解决。
①铁芯截面积(S):S=舌宽×叠厚
②铁芯(xin)截面(mian)积(S)与变压(ya)器功率(P)的关系:S=1.25
③每伏(fu)圈数(shu)(N):指(zhi)每伏(fu)电压应绕制的线(xian)圈(quan)圈(quan)数(shu)(匝数(shu))
f为交流(liu)电频(pin)率,S为铁芯截面积,Bmax为磁感应强度(du)
④初(chu)级圈(quan)数(N1)与次级圈(quan)数(N2)
N1=U1N(U1为初级电压);N2=U2N(U2为次(ci)级电压)
⑤线径(d):指绕制线圈的导(dao)线直径(mm)。
I为导线(xian)的电流(I=P/U)
初(chu)级线径(jing)d1=;次级线径(jing)
简称二极管(guan),是一种双层结构的半导(dao)体器件,由(you)一个PN结组成,具有单向导(dao)电的特性。
1. PN结
① P型半导体:指空穴多(duo)数(shu)为载流子的杂(za)质半导体(ti)。
② N型半导(dao)体:指电(dian)子为多数载(zai)流子的(de)杂(za)质半导(dao)体(ti)。
③ PN结:把(ba)P型(xing)半导体(ti)与N型(xing)半导体(ti)复合,在(zai)其交界(jie)面处形成的(de)空(kong)间,电荷区(即阻(zu)挡层)叫PN结。
④ PN结的特性:具有单向(xiang)导电(dian)的特性。
①正向(xiang)电流:指正向(xiang)导通(tong)时允许通(tong)过(guo)的电(dian)大电(dian)流(liu)。
②反向击(ji)穿电压:指PN结反(fan)向击穿(chuan)时的(de)电高电压,即是二极(ji)管的(de)耐(nai)压。
③正向导通电压:指正向导通时所需(xu)的(de)电压。锗材(cai)料(PN结):0.2V(0.2—0.3V);硅材(cai)料(PN结):0.6V(0.5—0.7V);化合物材(cai)料2V左右(1—3V)。
④ 结电容:指PN结(jie)形成的(de)电(dian)容(rong)(rong)称为(wei)结(jie)电(dian)容(rong)(rong)。
可用(yong)于整(zheng)流、稳(wen)压、开关、阻尼、调谐等用(yong)途。
①对(dui)于一般(ban)二(er)极(ji)管,有(you)标志(如色圈)的一端为(wei)负(fu)极(ji)而另一端为(wei)正极(ji)。
②对于发光二极(ji)管,若未剪脚(jiao)的情况下则长(zhang)脚(jiao)为正极(ji),短脚(jiao)为负(fu)极(ji)。
③对于二极(ji)管,大多数可以(yi)从其内部构造(zao)直接(jie)看出其正负(fu)极(ji)。
④用(yong)万用(yong)表电(dian)阻(zu)档(dang)判(pan)断(duan):用(yong)万用(yong)表电(dian)阻(zu)档(dang)测试二(er)极(ji)管(guan)的(de)正(zheng)反向(xiang)电(dian)阻(zu)时,根据二(er)极(ji)管(guan)的(de)PN结具(ju)有正(zheng)向(xiang)电(dian)阻(zu)小(xiao)反向(xiang)电(dian)阻(zu)大的(de)特点来判(pan)断(duan)。测试时电(dian)阻(zu)小(xiao)的(de)一次黑表笔接的(de)为正(zheng)极(ji),而红(hong)表笔接的(de)是负(fu)极(ji)。
用万用表电(dian)阻(zu)(zu)(zu)档测试二(er)极管(guan)的正反(fan)向(xiang)电(dian)阻(zu)(zu)(zu)时,二(er)极管(guan)(PN结)正向(xiang)电(dian)阻(zu)(zu)(zu)越小越好,反(fan)向(xiang)电(dian)阻(zu)(zu)(zu)越大(da)越好。若二(er)极管(guan)的正反(fan)向(xiang)电(dian)阻(zu)(zu)(zu)都很(hen)小或(huo)(huo)很(hen)大(da)则此管(guan)已击穿短路或(huo)(huo)开路损坏(huai)。
三(san)极管是一种对(dui)信号(hao)具有放(fang)大和开关(guan)作(zuo)用的(de)三(san)层结(jie)构的(de)半(ban)导体器件(jian),由两个(ge)PN结(jie)组成(cheng)。
三(san)极管分(fen)为PNP型和NPN型两种类型的结构(gou)。
E或(huo)e代表(biao)发(fa)射极,B或(huo)b代表(biao)基极,C或(huo)c代表(biao)集(ji)电(dian)极,BC结(jie)(bc结(jie)):集(ji)电(dian)结(jie)
BE结(jie)(be 结(jie)):发(fa)射结(jie)
①PCM:指集电极最大(da)(da)耗(hao)散功率(lv),即是三极管(guan)(guan)的(de)最大(da)(da)功率(lv)。PCM<1W为小功率(lv)管(guan)(guan);PCM>1W为大(da)(da)功率(lv)管(guan)(guan);PCM=1W左右的(de)为中功率(lv)管(guan)(guan)。
②ICM:指集电(dian)极(ji)最大(da)电(dian)流,即是三极(ji)管的最大(da)电(dian)流。
③Bvceo:指基极(ji)开路时集电(dian)极(ji)与发(fa)射极(ji)的(de)最大反向击穿电(dian)压(ya),即是三(san)极(ji)管的(de)耐压(ya)。
④Iceo :指基(ji)极(ji)(ji)开路时集电(dian)极(ji)(ji)与发射(she)极(ji)(ji)的最大反向漏电(dian)电(dian)流(liu),即是(shi)三极(ji)(ji)管的穿透电(dian)流(liu)。
⑤fT:指(zhi)特征频(pin)率(lv)(lv),即是指(zhi)在其发射极放大(da)电(dian)路(lu)中(zhong)放大(da)倍数下降到(dao)1时的频(pin)率(lv)(lv)。
fT≤3MHz为低频管;fT>3MHz为高(gao)频管;fT>几百MHz称(cheng)为超高(gao)频管
⑥hFE:指三极管(guan)的直流放大(da)系数(直流放大(da)倍数)
hFE=(Ic为集电(dian)极(ji)电(dian)流,IB为基(ji)极(ji)电(dian)流)
⑦β值:指三极(ji)管的(de)交流放大倍数
(ΔIC为(wei)集电(dian)极电(dian)流变化(hua)量(liang),ΔIB为(wei)基极电(dian)流变化(hua)量(liang))
用万(wan)用表(biao)电(dian)(dian)阻(zu)档测(ce)试(shi)三极(ji)(ji)管(guan)(guan)各脚之(zhi)间的正反(fan)向电(dian)(dian)阻(zu)时,凡(fan)是(shi)有一次红(hong)表(biao)笔(bi)(bi)接(jie)(jie)固定(ding)(ding)一个电(dian)(dian)极(ji)(ji)是(shi),黑(hei)(hei)表(biao)笔(bi)(bi)分别(bie)接(jie)(jie)其余(yu)两个电(dian)(dian)极(ji)(ji)电(dian)(dian)阻(zu)都比较(jiao)小,则此(ci)管(guan)(guan)为(wei)PNP管(guan)(guan)(简(jian)(jian)称P管(guan)(guan)),且(qie)红(hong)表(biao)笔(bi)(bi)接(jie)(jie)的电(dian)(dian)极(ji)(ji)为(wei)基(ji)极(ji)(ji);若凡(fan)是(shi)有一次黑(hei)(hei)表(biao)笔(bi)(bi)接(jie)(jie)固定(ding)(ding)一个电(dian)(dian)极(ji)(ji),红(hong)表(biao)笔(bi)(bi)分别(bie)接(jie)(jie)其余(yu)两个电(dian)(dian)极(ji)(ji)电(dian)(dian)阻(zu)都比较(jiao)小,则此(ci)管(guan)(guan)为(wei)NPN管(guan)(guan)(简(jian)(jian)称N管(guan)(guan))且(qie)黑(hei)(hei)表(biao)笔(bi)(bi)接(jie)(jie)的为(wei)基(ji)极(ji)(ji)。
根据(ju)上述方法(fa)判断(duan)出PNP与(yu)NPN管(guan)且找出了基(ji)极(ji)后,余下的(de)两个电(dian)(dian)(dian)极(ji)可(ke)用下述方法(fa)判断(duan),方法(fa)是:万用表(biao)(biao)置电(dian)(dian)(dian)阻档的(de)RX1K档,红(hong)黑(hei)表(biao)(biao)笔(bi)分别(bie)接(jie)余下的(de)两个电(dian)(dian)(dian)极(ji),若为(wei)PNP型(xing)管(guan)则在红(hong)表(biao)(biao)笔(bi)接(jie)的(de)电(dian)(dian)(dian)极(ji)与(yu)基(ji)极(ji)之(zhi)间并接(jie)一个100K左右(you)的(de)电(dian)(dian)(dian)阻(此(ci)电(dian)(dian)(dian)阻可(ke)用手指(zhi)代替)此(ci)时(shi)(shi)表(biao)(biao)针(zhen)若有明显变(bian)化,则红(hong)表(biao)(biao)笔(bi)接(jie)的(de)电(dian)(dian)(dian)极(ji)为(wei)集电(dian)(dian)(dian)极(ji),而黑(hei)表(biao)(biao)笔(bi)接(jie)的(de)电(dian)(dian)(dian)极(ji)为(wei)发射极(ji);若此(ci)管(guan)为(wei)NPN型(xing)管(guan)测试时(shi)(shi)表(biao)(biao)笔(bi)极(ji)性刚好相反,其测试方法(fa)与(yu)PNP型(xing)管(guan)完全相同。
基极电(dian)流(liu)有微小的变化,集电(dian)极电(dian)流(liu)就有较大(da)(da)的变化,即用小电(dian)流(liu)去控制(zhi)大(da)(da)电(dian)流(liu)从而实现电(dian)流(liu)的放大(da)(da),这(zhei)就是三极管的放大(da)(da)作用原理。
用(yong)万(wan)能表电(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)档(dang)(dang)测(ce)试(shi)三(san)极(ji)(ji)管(guan)(guan)(guan)两(liang)个(ge)PN结(jie)(jie)(jie)(发射(she)结(jie)(jie)(jie)和集(ji)电(dian)(dian)(dian)(dian)(dian)结(jie)(jie)(jie),即(ji)be结(jie)(jie)(jie)和bc结(jie)(jie)(jie))的(de)正向(xiang)电(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)越(yue)(yue)(yue)小(用(yong)Rx1K档(dang)(dang)测(ce)试(shi)量时为(wei)(wei)(wei)几(ji)K欧(ou)(ou)左右)越(yue)(yue)(yue)好,而反(fan)(fan)向(xiang)电(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)越(yue)(yue)(yue)大(da)(da)(用(yong)Rx1K档(dang)(dang)测(ce)试(shi)时为(wei)(wei)(wei)几(ji)十K欧(ou)(ou)以(yi)(yi)上(shang)(shang),且大(da)(da)多数(shu)管(guan)(guan)(guan)子为(wei)(wei)(wei)无(wu)穷大(da)(da))越(yue)(yue)(yue)好,若两(liang)个(ge)或其中(zhong)一(yi)(yi)个(ge)PN结(jie)(jie)(jie)的(de)正向(xiang)电(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)过(guo)大(da)(da)(如Rx1K档(dang)(dang)测(ce)试(shi)有(you)(you)(you)几(ji)十欧(ou)(ou)以(yi)(yi)上(shang)(shang))或反(fan)(fan)向(xiang)电(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)过(guo)小(如Rx1K档(dang)(dang)测(ce)试(shi)小于几(ji)十K欧(ou)(ou))则(ze)此(ci)管(guan)(guan)(guan)性能不(bu)良(liang),若两(liang)个(ge)或其中(zhong)一(yi)(yi)个(ge)PN结(jie)(jie)(jie)的(de)正反(fan)(fan)向(xiang)电(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)都很小(如基(ji)本为(wei)(wei)(wei)零)或都很大(da)(da)(如基(ji)本为(wei)(wei)(wei)无(wu)穷大(da)(da))则(ze)此(ci)管(guan)(guan)(guan)由(you)于两(liang)个(ge)或一(yi)(yi)个(ge)PN结(jie)(jie)(jie)击穿(chuan)或开路损(sun)坏(huai)。同时集(ji)电(dian)(dian)(dian)(dian)(dian)极(ji)(ji)与(yu)发射(she)析之(zhi)间的(de)正反(fan)(fan)电(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)越(yue)(yue)(yue)大(da)(da)(最好为(wei)(wei)(wei)无(wu)穷大(da)(da),但(dan)有(you)(you)(you)些管(guan)(guan)(guan)子在几(ji)十K欧(ou)(ou)以(yi)(yi)上(shang)(shang))越(yue)(yue)(yue)陷越(yue)(yue)(yue)好。若此(ci)管(guan)(guan)(guan)电(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)过(guo)小则(ze)该(gai)管(guan)(guan)(guan)穿(chuan)透电(dian)(dian)(dian)(dian)(dian)流过(guo)大(da)(da)而性能不(bu)良(liang),若此(ci)电(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)基(ji)本为(wei)(wei)(wei)零则(ze)该(gai)管(guan)(guan)(guan)集(ji)发之(zhi)间已(yi)击穿(chuan)损(sun)坏(huai),还(hai)有(you)(you)(you)用(yong)HFE档(dang)(dang)测(ce)量或用(yong)电(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)档(dang)(dang)估(gu)测(ce)三(san)极(ji)(ji)管(guan)(guan)(guan)的(de)放大(da)(da)能力(li)(HFE值),管(guan)(guan)(guan)子类型用(yong)途不(bu)同其放大(da)(da)能力(li)也不(bu)同,但(dan)应(ying)(ying)有(you)(you)(you)放大(da)(da)能力(li)(HFE值应(ying)(ying)有(you)(you)(you)几(ji)倍以(yi)(yi)上(shang)(shang),而没有(you)(you)(you)放大(da)(da)能力(li)的(de)管(guan)(guan)(guan)子则(ze)不(bu)能用(yong)。)
①.三(san)极管(guan)(guan)性能不良(liang)或损(sun)坏(huai)时,则不能对三(san)极管(guan)(guan)进行修整而只(zhi)能换新或好的三(san)极管(guan)(guan)解决。
②.三极(ji)管损坏时,应尽可(ke)能选择用同(tong)型号的管子(zi)(zi)更换。若没有(you)同(tong)型号管子(zi)(zi)时,则应选用性能参数相同(tong)或(huo)相近的管子(zi)(zi)。
③选(xuan)用代用管子(zi)时(shi),其参数Icm,Pcm,Bvceo等(deng)参数应(ying)等(deng)于或大于原(yuan)型号管子(zi)方(fang)可代替。
④低频管只(zhi)能在低频电(dian)(dian)路中应用,而高(gao)频管不(bu)但可以在高(gao)频电(dian)(dian)路中应用而且可以在低频电(dian)(dian)路中应用。故在实际应用中高(gao)频管可代替低频管,反之则不(bu)能。
1.中(zhong)国
由数字(zi)---字(zi)母---字(zi)母---数字(zi)---(字(zi)母)组(zu)成
① 第一项数字表(biao)示电极数目,如:2——二极管,3—-三极管
② 第二项字母表示材料(liao)和极性,如(ru):A——锗材料(liao)PNP型 B——锗材料(liao)NPN型
C——硅(gui)(gui)材料(liao)(liao)PNP型(xing) D——硅(gui)(gui)材料(liao)(liao)NPN型(xing) E——化(hua)合物材料(liao)(liao)
③ 第三项(xiang)字母表示器件(jian)的类型,如:
G——高频小功率管 A——高频大功率管
X——低频小功率(lv)管 D——低频大功率(lv)管
K——开(kai)关管(guan)(guan) W——稳(wen)压管(guan)(guan) P——普通管(guan)(guan) E——整流(liu)管(guan)(guan) N——阻尼(ni)管(guan)(guan) B——变容(rong)管(guan)(guan)
④ 第(di)四项数(shu)字(zi),表(biao)示(shi)登(deng)记(ji)序号
⑤ 第五项(xiang)字(zi)母(mu),用字(zi)母(mu)A,B,C,D等表示原型的改进型
例:2AP9——锗普通(tong)二极(ji)管(guan)(guan)(guan) 2CW56——硅稳压二极(ji)管(guan)(guan)(guan) 3DG6B——硅NPN型(xing)高(gao)频(pin)(pin)(pin)小(xiao)功(gong)率管(guan)(guan)(guan)为3DG6的改进型(xing) 3AX31——锗PNP型(xing)低(di)频(pin)(pin)(pin)小(xiao)功(gong)率三极(ji)管(guan)(guan)(guan) 3BX31——锗NPN型(xing)低(di)频(pin)(pin)(pin)小(xiao)功(gong)率三极(ji)管(guan)(guan)(guan) 3CD511——硅PNP型(xing)低(di)频(pin)(pin)(pin)大功(gong)率三极(ji)管(guan)(guan)(guan) 3DD15——硅NPN型(xing)低(di)频(pin)(pin)(pin)大功(gong)率三极(ji)管(guan)(guan)(guan)
2.日本
由数字(zi)(zi)——字(zi)(zi)母-——字(zi)(zi)母——数字(zi)(zi)——(字(zi)(zi)母)组成
① 第(di)一项数字表示为:0——光电(dian)晶(jing)体(ti)管;1——二极管及(ji)整(zheng)流(liu)器; 2——三(san)极管及(ji)可控整(zheng)流(liu)器。
② 第二项字(zi)母“S”表示(shi)为半导体器件。
③ 第三项(xiang)字母(mu)表示(shi)器件的类(lei)型,第一项(xiang)为0,1的无此第三项(xiang)。
A——pnp型(xing)(xing)高频(pin)(pin)用(yong) B——PNP型(xing)(xing)低频(pin)(pin)用(yong) C——NPN型(xing)(xing)高频(pin)(pin)用(yong) D——NPN型(xing)(xing)低频(pin)(pin)用(yong)
J——P沟道(dao)场效(xiao)应管(guan) K——N沟道(dao)场效(xiao)应管(guan)
④第四项数字(zi)表示(shi)登记序号。
⑤第五项字(zi)母在区(qu)分原型(xing)与(yu)变型(xing)时(shi)候使用,用字(zi)母A,B,C,D等(deng)表示原型(xing)的改进型(xing)。
例:2SC1815,2SA1015,2SC1942,2SD3298A,2SD1555,2SK134等。注:日本型号(hao)三极管为了标记方便常省去型号(hao)前面的“2S”,如:A1015,C1815,C3298A,D1555等。
3. 欧(ou)洲(zhou)
由字母——字母——数字——(字母)组成。
① 第一项(xiang)字母表(biao)示器(qi)件(jian)所用的(de)类型。
A——锗材(cai)料 B——硅材(cai)料
②第二项字(zi)母表示器(qi)件(jian)的类型。
A——检波,开关(guan),混频(pin)(pin)(pin)三极管(guan)(guan)(guan);B——变容(rong)二(er)极管(guan)(guan)(guan);C——低频(pin)(pin)(pin)小(xiao)功率(lv)管(guan)(guan)(guan);F——高(gao)(gao)频(pin)(pin)(pin)小(xiao)功率(lv)管(guan)(guan)(guan);D——低频(pin)(pin)(pin)小(xiao)功率(lv)管(guan)(guan)(guan);L——高(gao)(gao)频(pin)(pin)(pin)大(da)功率(lv)管(guan)(guan)(guan);S——小(xiao)功率(lv)开关(guan)管(guan)(guan)(guan);U——大(da)功率(lv)开关(guan)管(guan)(guan)(guan):E——稳压管(guan)(guan)(guan);Y——整流管(guan)(guan)(guan)。
③第三项数字表示登记序号。
专(zhuan)用(yong)器(qi)件用(yong)一个字(zi)母二位(wei)(wei)数字(zi)表示登(deng)记序(xu)号;通(tong)用(yong)器(qi)件三(san)位(wei)(wei)数字(zi)表示登(deng)记序(xu)号。
④第四(si)项字母,经字母A,B,C,D等表示原型的改(gai)进型或(huo)按某数分档的标记。
例:BF198——为(wei)通用器件,硅NPN型(xing)高频小功率(lv)三极(ji)管(guan);BUY71——为(wei)专用器件,硅NPN型(xing)大功率(lv)开关三极(ji)管(guan)。
4. 美国
由数字——字母——数字——(字母)组成。
① 第一项(xiang)数字(zi)及(ji)第二(er)项(xiang)字(zi)母(mu)“N”表(biao)示为(wei):1N——二(er)极(ji)管(guan)及(ji)整流器;2N——三极(ji)管(guan)及(ji)可控整流器;3N——四极(ji)管(guan)。
② 第三(san)项数字表示登记(ji)序号。
③ 第四项字母,用A,B,C,D等(deng)表示原型的(de)改(gai)进型。例:1N4007,2N3055等(deng)。
5. 韩(han)国三星公司的数字三极管(guan),如:9011,9012,9013,9014,9015,9016,9018等(deng)。
集成电(dian)(dian)路(lu)(lu)(integratedcircuit,港(gang)台称之(zhi)为(wei)积(ji)体电(dian)(dian)路(lu)(lu))是一(yi)(yi)种微型电(dian)(dian)子器件(jian)(jian)或部件(jian)(jian)。采用一(yi)(yi)定(ding)的(de)工艺(yi),把一(yi)(yi)个(ge)(ge)电(dian)(dian)路(lu)(lu)中所需的(de)晶体管(guan)、二(er)极(ji)管(guan)、电(dian)(dian)阻、电(dian)(dian)容(rong)和(he)电(dian)(dian)感等元件(jian)(jian)及(ji)布线互连一(yi)(yi)起,制作在(zai)一(yi)(yi)小(xiao)块或几小(xiao)块半(ban)导体晶片或介质(zhi)基片上,然后封装(zhuang)在(zai)一(yi)(yi)个(ge)(ge)管(guan)壳(qiao)内,成为(wei)具(ju)有所需电(dian)(dian)路(lu)(lu)功能的(de)微型结(jie)构;其(qi)中所有元件(jian)(jian)在(zai)结(jie)构上已组成一(yi)(yi)个(ge)(ge)整体,这样,整个(ge)(ge)电(dian)(dian)路(lu)(lu)的(de)体积(ji)大大缩小(xiao),且(qie)引出(chu)线和(he)焊接点的(de)数目也大为(wei)减少,从而使(shi)电(dian)(dian)子元件(jian)(jian)向(xiang)着微小(xiao)型化、低功耗和(he)高可(ke)靠性方面迈进了一(yi)(yi)大步(bu)。
集成(cheng)电(dian)(dian)路具有体积小(xiao),重量轻(qing),引出线和焊(han)接点(dian)少,寿命长(zhang),可(ke)靠性(xing)高,性(xing)能好等(deng)优点(dian),同(tong)时成(cheng)本低,便于大规(gui)模生产。它不仅在工(gong)、民用(yong)电(dian)(dian)子(zi)设备如收录(lu)机、电(dian)(dian)视机、计算机等(deng)方面得到(dao)广泛的应用(yong),同(tong)时在军(jun)事、通(tong)讯、遥控等(deng)方面也得到(dao)广泛的应用(yong)。用(yong)集成(cheng)电(dian)(dian)路来(lai)装配(pei)电(dian)(dian)子(zi)设备,其装配(pei)密度比晶体管可(ke)提高几十倍(bei)至(zhi)几千(qian)倍(bei),设备的稳定工(gong)作(zuo)时间也可(ke)大大提高。
它(ta)在(zai)电路中用(yong)字(zi)母“IC”(也有(you)用(yong)文字(zi)符号“N”等)表(biao)示。
(一)按(an)功能结(jie)构分类
集(ji)成(cheng)电(dian)路(lu)按其功能、结构的不同,可以分为模拟集(ji)成(cheng)电(dian)路(lu)、数字集(ji)成(cheng)电(dian)路(lu)和数/模混合集(ji)成(cheng)电(dian)路(lu)三(san)大类。
模(mo)拟集(ji)成(cheng)(cheng)电路(lu)又称线(xian)性电路(lu),用来产生(sheng)、放大和(he)处(chu)(chu)理各种模(mo)拟信(xin)号(hao)(hao)(指(zhi)幅度随时(shi)间边(bian)疆变化的(de)信(xin)号(hao)(hao)。例如(ru)半导体收音(yin)(yin)机的(de)音(yin)(yin)频(pin)信(xin)号(hao)(hao)、录放机的(de)磁带信(xin)号(hao)(hao)等),其输入(ru)信(xin)号(hao)(hao)和(he)输出信(xin)号(hao)(hao)成(cheng)(cheng)比例关系。而数字集(ji)成(cheng)(cheng)电路(lu)用来产生(sheng)、放大和(he)处(chu)(chu)理各种数字信(xin)号(hao)(hao)(指(zhi)在时(shi)间上(shang)和(he)幅度上(shang)离散(san)取值的(de)信(xin)号(hao)(hao)。例如(ru)VCD、DVD重放的(de)音(yin)(yin)频(pin)信(xin)号(hao)(hao)和(he)视频(pin)信(xin)号(hao)(hao))。
(二)按(an)制作工艺分类(lei)
集成(cheng)电(dian)路按制作工艺(yi)可分(fen)为半导体集成(cheng)电(dian)路和(he)薄膜集成(cheng)电(dian)路。
膜集成电路又分类(lei)厚膜集成电路和薄膜集成电路。
(三(san))按集成度(du)高低分类(lei)
集(ji)成(cheng)(cheng)(cheng)(cheng)电(dian)路按(an)集(ji)成(cheng)(cheng)(cheng)(cheng)度高低的(de)不同可(ke)分为小规(gui)模(mo)(mo)集(ji)成(cheng)(cheng)(cheng)(cheng)电(dian)路、中(zhong)规(gui)模(mo)(mo)集(ji)成(cheng)(cheng)(cheng)(cheng)电(dian)路、大(da)规(gui)模(mo)(mo)集(ji)成(cheng)(cheng)(cheng)(cheng)电(dian)路、超大(da)规(gui)模(mo)(mo)集(ji)成(cheng)(cheng)(cheng)(cheng)电(dian)路、特大(da)规(gui)模(mo)(mo)集(ji)成(cheng)(cheng)(cheng)(cheng)电(dian)路和巨(ju)大(da)规(gui)模(mo)(mo)集(ji)成(cheng)(cheng)(cheng)(cheng)电(dian)路。
(四)按导电类型(xing)不(bu)同分类
集成(cheng)电路按导电类型可(ke)分为双极(ji)型集成(cheng)电路和单极(ji)型集成(cheng)电路,他们都是数字集成(cheng)电路.
双极型(xing)(xing)(xing)集成(cheng)(cheng)电(dian)(dian)路的制作工艺复杂,功(gong)(gong)耗较大,代(dai)表集成(cheng)(cheng)电(dian)(dian)路有TTL、ECL、HTL、LST-TL、STTL等类型(xing)(xing)(xing)。单极型(xing)(xing)(xing)集成(cheng)(cheng)电(dian)(dian)路的制作工艺简单,功(gong)(gong)耗也较低(di),易于(yu)制成(cheng)(cheng)大规(gui)模集成(cheng)(cheng)电(dian)(dian)路,代(dai)表集成(cheng)(cheng)电(dian)(dian)路有CMOS、NMOS、PMOS等类型(xing)(xing)(xing)。
(五)按用途分类
集(ji)(ji)(ji)成(cheng)(cheng)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路按用(yong)途(tu)可分为(wei)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)视机(ji)(ji)用(yong)集(ji)(ji)(ji)成(cheng)(cheng)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路、音(yin)响用(yong)集(ji)(ji)(ji)成(cheng)(cheng)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路、影碟机(ji)(ji)用(yong)集(ji)(ji)(ji)成(cheng)(cheng)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路、录像(xiang)机(ji)(ji)用(yong)集(ji)(ji)(ji)成(cheng)(cheng)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路、电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)脑(nao)(微机(ji)(ji))用(yong)集(ji)(ji)(ji)成(cheng)(cheng)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路、电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)子琴(qin)用(yong)集(ji)(ji)(ji)成(cheng)(cheng)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路、通信用(yong)集(ji)(ji)(ji)成(cheng)(cheng)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路、照相机(ji)(ji)用(yong)集(ji)(ji)(ji)成(cheng)(cheng)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路、遥控集(ji)(ji)(ji)成(cheng)(cheng)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路、语言(yan)集(ji)(ji)(ji)成(cheng)(cheng)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路、报警器用(yong)集(ji)(ji)(ji)成(cheng)(cheng)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路及(ji)各种专用(yong)集(ji)(ji)(ji)成(cheng)(cheng)电(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路。
(六)按应用领域分
集成电路按应用领域可分为(wei)标准通用集成电路和专用集成电路。
(七)按外形分
集(ji)成电(dian)路按外形可分(fen)为圆形(金属(shu)外壳晶(jing)体(ti)管封装(zhuang)型(xing),一(yi)般适(shi)合用于(yu)大功(gong)率(lv))、扁(bian)平型(xing)(稳(wen)定性好,体(ti)积小)和双列(lie)直插(cha)型(xing).
①直插式封装
直(zhi)插(cha)(cha)式(shi)(shi)(shi)(shi)封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)集成(cheng)(cheng)电(dian)路是(shi)引(yin)(yin)脚插(cha)(cha)入印制(zhi)板(ban)中(zhong),然后(hou)再焊(han)接的一(yi)种集成(cheng)(cheng)电(dian)路封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)形式(shi)(shi)(shi)(shi),主(zhu)要(yao)有单(dan)列(lie)(lie)(lie)式(shi)(shi)(shi)(shi)封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)和(he)双(shuang)列(lie)(lie)(lie)直(zhi)插(cha)(cha)式(shi)(shi)(shi)(shi)封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)。其中(zhong)单(dan)列(lie)(lie)(lie)式(shi)(shi)(shi)(shi)封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)有单(dan)列(lie)(lie)(lie)直(zhi)插(cha)(cha)式(shi)(shi)(shi)(shi)封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)(SingleInlinePackage,缩(suo)(suo)写为SIP和(he)单(dan)列(lie)(lie)(lie)直(zhi)插(cha)(cha)式(shi)(shi)(shi)(shi)封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)(Zig-ZagInlinePackage,缩(suo)(suo)写为ZIP),单(dan)列(lie)(lie)(lie)直(zhi)插(cha)(cha)式(shi)(shi)(shi)(shi)封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)的集成(cheng)(cheng)电(dian)路只有一(yi)排(pai)(pai)引(yin)(yin)脚,单(dan)列(lie)(lie)(lie)曲(qu)插(cha)(cha)式(shi)(shi)(shi)(shi)封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)的集成(cheng)(cheng)电(dian)路一(yi)排(pai)(pai)引(yin)(yin)脚又分成(cheng)(cheng)两排(pai)(pai)进行(xing)安(an)装(zhuang)(zhuang)。双(shuang)列(lie)(lie)(lie)直(zhi)插(cha)(cha)式(shi)(shi)(shi)(shi)封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)又称DIP封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)(DualInlinePackage),这种封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)的集成(cheng)(cheng)电(dian)路具有两排(pai)(pai)引(yin)(yin)脚。适合PCB的穿孔(kong)安(an)装(zhuang)(zhuang);易于对PCB布线;安(an)装(zhuang)(zhuang)方便。双(shuang)列(lie)(lie)(lie)直(zhi)插(cha)(cha)式(shi)(shi)(shi)(shi)封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)的结构形式(shi)(shi)(shi)(shi)主(zhu)要(yao)有多层陶瓷双(shuang)列(lie)(lie)(lie)直(zhi)插(cha)(cha)式(shi)(shi)(shi)(shi)封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)、单(dan)层陶瓷双(shuang)列(lie)(lie)(lie)直(zhi)插(cha)(cha)式(shi)(shi)(shi)(shi)封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)、引(yin)(yin)线框架(jia)式(shi)(shi)(shi)(shi)封(feng)(feng)(feng)(feng)(feng)装(zhuang)(zhuang)等。
②.贴(tie)片封装
随着生产(chan)技术(shu)的(de)(de)提高,电(dian)子产(chan)品的(de)(de)体积越来越小(xiao),体积较大的(de)(de)直(zhi)插式封(feng)装集成(cheng)电(dian)路已经不能满(man)足需要。故设计者又研(yan)制出一(yi)种(zhong)贴(tie)片封(feng)装的(de)(de)集成(cheng)电(dian)路,这种(zhong)封(feng)装的(de)(de)集成(cheng)电(dian)路引脚(jiao)很小(xiao),可以直(zhi)接焊(han)接在印制电(dian)路板(ban)的(de)(de)印制导线(xian)上。贴(tie)片封(feng)装的(de)(de)集成(cheng)电(dian)路主要有薄(bo)型(xing)(xing)QFP(TQFP)、细(xi)引脚(jiao)间距QFP(VQFP)、缩(suo)小(xiao)型(xing)(xing)QFP(SQFP)、塑(su)料QFP(PQFP)、金属QFP(MetalQFP)、载(zai)带QFP(TapeQFP)、J型(xing)(xing)引脚(jiao)小(xiao)外形(xing)封(feng)装(SOJ)、薄(bo)小(xiao)外形(xing)封(feng)装(TSOP)、甚小(xiao)外形(xing)封(feng)装(V S O P)、缩(suo)小(xiao)型(xing)(xing)S OP(SSOP)、薄(bo)的(de)(de)缩(suo)小(xiao)型(xing)(xing)SOP(TSSOP)及小(xiao)外形(xing)集成(cheng)电(dian)路(SOIC)等派生封(feng)装。
③.BGA封(feng)装 (Ball Grid ArrayPackage)
又名球栅阵列(lie)封装(zhuang),BGA封装(zhuang)的引脚以(yi)圆形或柱状焊点按阵列(lie)形式分(fen)布在封装(zhuang)下(xia)面。采用该封装(zhuang)形式的集成(cheng)电路主要有CPU以(yi)及南北桥等的高密度、高性能、多功能集成(cheng)电路。
BGA封(feng)装集成电路的优(you)点是虽然增(zeng)加(jia)了引(yin)(yin)脚(jiao)数,但引(yin)(yin)脚(jiao)间距并没有减(jian)小反而增(zeng)加(jia)了,从而提高(gao)了组装成品率(lv);厚度(du)和重量(liang)都较以前的封(feng)装技术有所减(jian)少;寄(ji)生参数减(jian)小,信号传输延迟小,使(shi)用频率(lv)大大提高(gao);组装可用共面(mian)焊接(jie),可靠性高(gao)。
④.厚膜封装厚膜
集(ji)成(cheng)电路(lu)(lu)就是把专用的集(ji)成(cheng)电路(lu)(lu)芯片与相关的电容、电阻元件都(dou)集(ji)成(cheng)在一个基(ji)板上,然后在其外部采(cai)用标准的封装(zhuang)形式,并(bing)引(yin)出引(yin)脚的一种模块化的集(ji)成(cheng)电路(lu)(lu)。
①测量内部电阻法(fa)
用万(wan)用表电阻(zu)(zu)档(dang)的(de)R×1K档(dang)在(zai)IC非在(zai)路(lu)的(de)情况下(xia)测量(liang)其各脚对地或各脚之间的(de)正反向电阻(zu)(zu)与正常值或好的(de)IC比较,在(zai)若(ruo)电阻(zu)(zu)值基本相同(误差(cha)≤±10%)则(ze)可认为该(gai)IC是好的(de);若(ruo)部(bu)分(fen)或全部(bu)脚电阻(zu)(zu)值相差(cha)过大则(ze)该(gai)IC不良或损坏。
② 测(ce)量(liang)在路(lu)电阻法
用万用表电(dian)(dian)(dian)阻档的(de)R×1K档在电(dian)(dian)(dian)路板(ban)上测量IC各(ge)脚对(dui)地(di)(指电(dian)(dian)(dian)路板(ban)的(de)地(di)线)的(de)正反(fan)向电(dian)(dian)(dian)阻值(zhi)与正常值(zhi)或好(hao)的(de)电(dian)(dian)(dian)路板(ban)比较,若电(dian)(dian)(dian)阻值(zhi)基本相同(误差≤±10%)则可认为该IC是好(hao)的(de);若部(bu)(bu)分(fen)或全部(bu)(bu)脚电(dian)(dian)(dian)阻值(zhi)相差过(guo)大,则在检查部(bu)(bu)分(fen)或全部(bu)(bu)引脚外围电(dian)(dian)(dian)路元件正常的(de)情况(kuang)下(xia),则该IC不良或损坏。
③ 测量直流(liu)工作(zuo)电压(ya)法
用万(wan)用表(biao)直流电(dian)(dian)压档(dang)测量IC各脚(jiao)对地的(de)(de)直流工(gong)作电(dian)(dian)压与正常值(zhi)或好的(de)(de)电(dian)(dian)路比较(jiao),若(ruo)电(dian)(dian)压值(zhi)基(ji)本相(xiang)同(tong)(误(wu)差≤±10%)则可以(yi)认为(wei)该IC是(shi)好的(de)(de);若(ruo)电(dian)(dian)压值(zhi)误(wu)差过大则在检查相(xiang)应引脚(jiao)的(de)(de)外围电(dian)(dian)路元(yuan)件(jian)正常的(de)(de)情况(kuang)下为(wei)该IC不(bu)良或损坏。
④ 代(dai)换(huan)法
在检查(cha)集(ji)成(cheng)电(dian)(dian)路外围(wei)元件(jian)正(zheng)常情(qing)况下IC却不能(neng)(neng)正(zheng)常工作,则可用(yong)一块(kuai)好的(de)IC代(dai)(dai)换(huan)(huan)怀(huai)疑已损(sun)坏(huai)的(de)IC,若(ruo)(ruo)代(dai)(dai)换(huan)(huan)后(hou)电(dian)(dian)路能(neng)(neng)正(zheng)常工作则说明原IC是不良或损(sun)坏(huai);若(ruo)(ruo)代(dai)(dai)换(huan)(huan)后(hou)电(dian)(dian)路还是不能(neng)(neng)正(zheng)常工作则原IC有可能(neng)(neng)没有损(sun)坏(huai),应继续检查(cha)外围(wei)电(dian)(dian)路元件(jian)。
俗称喇叭,是一种电声(sheng)转换器件,能把音频(pin)电信号(hao)转换为声(sheng)音。
①压(ya)电陶(tao)瓷(ci)喇叭:由(you)压(ya)电陶瓷片组成,是(shi)根据压(ya)电效应原理发声的。
②电动式喇(la)叭:由(you)永久(jiu)磁(ci)铁,音圈,纸盘,振(zhen)膜(mo)等构成。其发声原理是:根据同性磁(ci)极相互排斥,异性磁(ci)极相互吸引的原理,当音圈通入音频电(dian)信号时将(jiang)产生音频电(dian)磁(ci)场与永久(jiu)磁(ci)铁上产生的磁(ci)场产生相互作用力,于(yu)是音圈带动纸盘运(yun)动,从而使纸盘振(zhen)动空气发出声音。
①功率:分为(wei)最(zui)小功率和最(zui)大功率两种
最小功率(PMIN):又叫(jiao)不失(shi)真功率,指失(shi)真度在额定范围的功率。
最大功率(lv)(lv)(PMAX):又叫(jiao)峰(feng)值功率(lv)(lv),指喇叭所能承(cheng)受的最大功率(lv)(lv)。
②阻抗(kang):指喇叭对音频电信号的等效电阻(zu)。阻(zu)抗(kang)=音圈的直流电阻(zu)+音圈感抗(kang)。
③频率特性(xing):指喇叭重放声(sheng)(sheng)音(yin)(yin)的(de)频(pin)率(lv)范围,全(quan)音(yin)(yin)域高(gao)音(yin)(yin),中(zhong)音(yin)(yin),低(di)音(yin)(yin)等。声(sheng)(sheng)音(yin)(yin)的(de)频(pin)率(lv)范围为20Hz——20KHz。
④口径:指喇叭(ba)纸盘(pan)的直径。
用(yong)万用(yong)表电(dian)阻档(dang)的(de)1Ω档(dang)可粗略(lve)判断喇叭(ba)(ba)的(de)好坏(huai)。方(fang)法是:测试音(yin)圈(quan)的(de)直(zhi)流电(dian)阻应(ying)(ying)略(lve)小(xiao)(xiao)于喇叭(ba)(ba)的(de)阻抗值且测试时喇叭(ba)(ba)应(ying)(ying)能发出“喀嚓”声为(wei)正(zheng)常,若(ruo)有直(zhi)流电(dian)阻过小(xiao)(xiao)则(ze)(ze)音(yin)圈(quan)短路(lu)损坏(huai),若(ruo)电(dian)阻值为(wei)无穷大则(ze)(ze)音(yin)圈(quan)已开(kai)路(lu)损坏(huai),同时用(yong)手(shou)轻按纸盘应(ying)(ying)弹性良好,不能有杂(za)音(yin),否则(ze)(ze)该(gai)喇叭(ba)(ba)也不良。
① 从喇叭接线柱可直接看出,有加(jia)号(hao)(+)的为(wei)正相(xiang)位,减号(hao)(-)为(wei)负相(xiang)位。
③用万用表(biao)直流电压(电流)档(dang)的(de)最低量程档(dang)(如:0.5V档(dang))红黑表(biao)笔(bi)分别接喇叭接线柱(zhu)两端,再用手轻轻按(an)下纸盘,若表(biao)针会轻微向右摆(bai)动则(ze)表(biao)笔(bi)极性刚好相(xiang)反。
①扬声(sheng)器有(you)故(gu)障时建议更换(huan)(huan)一个同型号的(de)新(xin)扬声(sheng)器解(jie)决(jue),但(dan)在没有(you)新(xin)的(de)扬声(sheng)器更换(huan)(huan)或想降低(di)修复成本时也可(ke)对(dui)其进行修理。
②音圈引(yin)出线(xian)(xian)折断的修(xiu)(xiu)理(li):扬声器使用日久或引(yin)线(xian)(xian)质(zhi)量太差时,由于(yu)纸盘的振(zhen)动(dong)而(er)极易引(yin)起音圈引(yin)出线(xian)(xian)折断,此时可用相同或相近的喇叭(ba)专用的编织软线(xian)(xian)更换即可修(xiu)(xiu)复。注:请不要(yao)用其它硬线(xian)(xian)或花线(xian)(xian)来更换,否则不但(dan)音质(zhi)受(shou)影(ying)响而(er)且引(yin)出线(xian)(xian)也很易再次折断。
③若为音(yin)(yin)圈(quan)(quan)(quan)损坏时,则应用ΩΩ天(tian)那(nei)水(香蕉水)浸开防尘罩及旧(jiu)音(yin)(yin)圈(quan)(quan)(quan)再(zai)用同型号音(yin)(yin)圈(quan)(quan)(quan)(也可以(yi)自(zi)行绕制)更(geng)换来修(xiu)复,更(geng)换音(yin)(yin)圈(quan)(quan)(quan)等应按原来音(yin)(yin)圈(quan)(quan)(quan)的(de)位置(zhi)(zhi)来用粘合(he)剂粘固新(xin)音(yin)(yin)圈(quan)(quan)(quan),若难以(yi)分别原位置(zhi)(zhi)时,也可以(yi)先装入音(yin)(yin)圈(quan)(quan)(quan)连线再(zai)通入声(sheng)音(yin)(yin)信号调(diao)整(zheng)音(yin)(yin)圈(quan)(quan)(quan)的(de)位置(zhi)(zhi)使(shi)声(sheng)音(yin)(yin)最大(da)音(yin)(yin)质最好然后用粘合(he)剂粘固凉干后即可修(xiu)复。
④若(ruo)纸盘(pan)(pan)损(sun)破时可(ke)用相(xiang)同纸盘(pan)(pan)材料修补破损(sun)处即可(ke)修复,若(ruo)纸盘(pan)(pan)损(sun)破严重(zhong)时则只能换一个(ge)新纸盘(pan)(pan)解决。
⑤若铁芯与永久磁铁松动移(yi)位(wei)导致与音圈(quan)相碰时,在业余条件下一般(ban)难以(yi)修(xiu)复(fu)而建(jian)议更换一个新扬声器(qi)解决。
⑥对于(yu)球顶(ding)高音(yin)喇叭,由于(yu)音(yin)圈(quan)与(yu)纸盘(振膜)为(wei)一个(ge)整(zheng)体,若音(yin)圈(quan)损坏(huai)时,则拆(chai)开旧音(yin)圈(quan)总(zong)成来更(geng)换一个(ge)新(xin)的(de)音(yin)圈(quan)吝(lin)惜成即可(其修理最简单(dan))。
1.晶体:又叫晶振(zhen),晶体振(zhen)荡器,谐振(zhen)器等。由石英(ying)晶片或压(ya)电陶瓷片组(zu)成,常用于振(zhen)荡电路中。
2.滤波器(qi):常见有晶体滤(lv)波(bo)器(qi)和陶瓷(ci)滤(lv)波(bo)器(qi),用于(yu)对某一(yi)频(pin)率的信号进行选频(pin)或滤(lv)除(chu)。
3.声表面(mian)滤波器:由叉指(zhi)换能器组(zu)成的
指由多(duo)个相同或不(bu)同器(qi)件制造或组合在一起的(de)器(qi)件,称(cheng)为(wei)复合器(qi)件。
采用(yong)多个阻(zu)值完(wan)全相同的(de)电阻(zu)把(ba)一端并接在一起作为公共端构成的(de)电阻(zu)排。
采用多个(ge)容量完全相同的单体电容把(ba)其一端(duan)并接起来作(zuo)为公(gong)共端(duan)构(gou)成的电容排或者在同一制造中封装在一起构(gou)成。
指把多个电(dian)(dian)感线(xian)圈与电(dian)(dian)容按一(yi)定连接(jie)方(fang)式连接(jie)在一(yi)起构成,多用于滤波器(qi)。
由两(liang)个整流二极管(guan)封装在一起构成,多用于整流电路等(deng)。
简称桥堆,由四个(ge)整(zheng)流二极管(guan)按一定方式连接在一起构成(cheng),常(chang)用于(yu)整(zheng)流电路中(zhong)。
指基极与发射极之间(jian)接有分压电阻的三极管。
由两个三(san)极管复合而成,复合(he)管的极性与前(qian)管极性相同,复(fu)合(he)管的放大倍数(shu)为两管放大倍数(shu)乘积。
把一(yi)个(ge)发(fa)光二极管和一(yi)个(ge)光敏三(san)极管封(feng)装在一(yi)起构成光电耦合器。
常见有四脚(jiao)光电耦(ou)合器和六脚(jiao)光电耦(ou)合器
联系(xi)方(fang)式:邹先(xian)生(KIA MOS管(guan))
手机:18123972950
QQ:2880195519
联系地址:深圳市福田区车(che)公庙天安(an)数码城天吉大(da)厦CD座5C1
关注KIA半(ban)导体工(gong)程专辑请(qing)搜微信号:“KIA半(ban)导体”或点击本文下方图片(pian)扫一扫进入官方微信“关注”
长按(an)二维(wei)码识别关注