genzheshehuidekaizhanhekexuejishudeqianjin,gezhongdianziqichehengdedaoleguangfandeyunyong。youyudianziqichehengdaduozhuangzhizaiyewaiyunyong,yinerdiancijiaoraochangchangyingxiangtixidezuoyebingzaodaoleidiandejinfan。changjiandexianxiangshiwaibiaotiaoshu、漂移等。接地是按捺電磁攪擾、避免雷擊的重要辦法。它也是攪擾屏蔽和進步體係安全性的重要內容。它在電子汽車衡器中起著至關重要的作用。
1、“地”的概念
一般說來,“地”指zhi的de是shi參can閱yue電dian位wei點dian,紛fen歧qi定ding是shi地di球qiu的de電dian位wei點dian。由you於yu地di球qiu自zi身shen是shi導dao體ti,它ta的de電dian容rong很hen大da,所suo以yi地di球qiu的de電dian位wei是shi穩wen定ding的de,所suo以yi地di球qiu的de電dian位wei能neng夠gou用yong作zuo參can閱yue電dian位wei-零電位。
2、電子汽車衡的接地辦法。
(1)懸架接地:指電子汽車衡作業地上與地上體係的絕緣,使地上體係上的攪擾不會進入設備,進步設備的牢靠性。這種辦法最常用於電子衡器。
(2)單點接地:在整個電路中,用一點作為接地址,其他單元與該接地址相連。
(3)多點接地:設備或體係中每個方位的方位直接銜接到最近的接地平麵。
3、電子汽車衡接地的運用
全quan電dian子zi汽qi車che衡heng的de規gui劃hua裝zhuang置zhi中zhong,從cong工gong程cheng實shi踐jian的de結jie構gou布bu局ju和he抗kang攪jiao擾rao及ji安an全quan的de視shi點dian,常chang常chang選xuan用yong混hun合he接jie地di,即ji依yi據ju衡heng器qi中zhong各ge設she備bei的de功gong率lv和he電dian平ping以yi及ji設she備bei的de靈ling敏min度du選xuan用yong懸xuan浮fu接jie地di、單點接地以及多點接地的辦法混合運用,發揮各接地辦法的長處。以到達更好的作用。下麵以一台全電子汽車衡為例來加以闡明。
假定一台由秤台、多個稱重傳感器、銜接的外部設備如打印機、核算機、大屏幕等構成的電子汽車衡。依照選用一種或多種接地辦法,下麵咱們逐個剖析和闡明。
3.1秤台接地
由(you)於(yu)汽(qi)車(che)衡(heng)的(de)秤(cheng)台(tai)一(yi)般(ban)均(jun)處(chu)於(yu)野(ye)外(wai),易(yi)感(gan)應(ying)帶(dai)電(dian)以(yi)及(ji)遭(zao)受(shou)雷(lei)擊(ji)等(deng),在(zai)車(che)輛(liang)上(shang)下(xia)秤(cheng)台(tai)時(shi)又(you)極(ji)易(yi)引(yin)進(jin)靜(jing)電(dian),在(zai)傳(chuan)感(gan)器(qi)等(deng)連(lian)線(xian)絕(jue)緣(yuan)損(sun)壞(huai)時(shi)也(ye)極(ji)易(yi)帶(dai)電(dian);別的,秤台也是傳感器、接線盒以及傳感器傳輸線免受直接攪擾的門戶,秤台的傑出接地,關於傳感器和接線盒的安全和作業牢靠性起著很大的作用;suoyixuanyongduodianjiediguiyubijiaobaofudejiedibanfa。biede,youyuchuanganqihechengtaizhijianzhijiechumo,youjingguochuanganqidejinshubufenyudadixianjie,wanchengduodianjiedi。zheyang,jiyouyongdexiaochuchengtijingdiandeleiji,youkebimianleidianganyinggouchengdeshebeisunhuai。
3.2傳感器接地
傳感器歸於高靈敏單元,極易受靜電和電磁輻射影響;且傳感器同秤台相同,相同也處於野外,遭受雷擊的可能性較高,所以,歸納上述原因,傳感器的接地一般也選用多點接地;彈dan性xing體ti及ji裝zhuang置zhi結jie構gou部bu件jian就jiu近jin接jie地di,信xin號hao傳chuan輸shu線xian的de屏ping蔽bi線xian一yi端duan經jing過guo彈dan性xing體ti接jie地di,另ling一yi端duan在zai接jie線xian盒he裏li與yu接jie線xian盒he外wai殼ke銜xian接jie,經jing過guo接jie線xian盒he外wai殼ke與yu秤cheng台tai銜xian接jie或huo搭da接jie接jie地di。由you於yu接jie線xian盒he與yu傳chuan感gan器qi連lian線xian相xiang對dui較jiao短duan,接jie地di址zhi近jin,所suo以yi,根gen本ben不bu會hui在zai傳chuan感gan器qi的de接jie地di址zhi構gou成cheng較jiao大da的de地di回hui路lu,所suo以yi在zai確que保bao設she備bei安an全quan的de前qian提ti下xia有you用yong的de按an捺na了le攪jiao擾rao。
3.3接線盒接地
jiexianheshixianjiechengtihechengzhongwaibiaodezhongjianhuanjie,jiedidelaokaoyufou,zhijieyingxiangdaochengtihewaibiaozhijiandexinhaochuandi。suoyijiexianhejiediyeshishidangzhongyaodehuanjie。jiexianheyibannenggoujingguowaikeyuchengtixianjie,youshiyehuikaolvjiangjiexianhezaiyuchengtidajie,yijinbujiedilaokaoxing,tianjiashebeianquanxinghejiexianheketidepingbizuoyong。
3.4屏蔽線的接地
chuanganqichuanshuxian,hesuanjitongxunxianhedapingmudexianjiexian。youyuzhexiechuanshuxiandelianxianjiaochang,pingbixiandepingbizuoyongguanyubimiandianciganyingfashengdejiaoraozuoyonghenda。pingbixiandepingbizuoyongshiwanquanlaijiedilaifahuide,bujiedihuojiedibulaokao,pingbixianbuzhihaowuyongchu,fanerhuichengweijiaoraoyuan。pingbixianyibanchangbeixuanyongdandianjiedibanfajiedadi;zheyangnenggoubimianliangtaishebeijingguopingbixiangouchengdixianhuilu,duichuanshuxianfashengjiaorao。danpingbixianzuoliangdianxianjieyeshikexingde,shouyaotianjialepingbixianshangjiaoraoxinhaodexiefangtonglu;別(bie)的(de),在(zai)兩(liang)頭(tou)接(jie)地(di)作(zuo)用(yong)傑(jie)出(chu)的(de)情(qing)況(kuang)下(xia),由(you)於(yu)開(kai)釋(shi)回(hui)路(lu)的(de)添(tian)加(jia),降(jiang)低(di)了(le)靜(jing)電(dian)積(ji)累(lei)等(deng)攪(jiao)擾(rao)源(yuan)的(de)發(fa)生(sheng),即(ji)便(bian)構(gou)成(cheng)地(di)線(xian)回(hui)路(lu),地(di)線(xian)回(hui)路(lu)上(shang)的(de)電(dian)流(liu)也(ye)極(ji)弱(ruo)小(xiao),很(hen)難(nan)構(gou)成(cheng)對(dui)傳(chuan)輸(shu)線(xian)的(de)攪(jiao)擾(rao)。兩(liang)點(dian)接(jie)地(di)實(shi)踐(jian)上(shang)添(tian)加(jia)了(le)屏(ping)蔽(bi)線(xian)的(de)接(jie)地(di)牢(lao)靠(kao)性(xing),增(zeng)強(qiang)了(le)屏(ping)蔽(bi)作(zuo)用(yong)。
3.5外表接地
外表接地實踐上分為兩部分:首shou要yao是shi外wai表biao殼ke體ti和he金jin屬shu結jie構gou件jian以yi及ji各ge接jie插cha口kou的de金jin屬shu外wai殼ke接jie地di。一yi般ban選xuan用yong單dan點dian接jie地di將jiang地di線xian接jie到dao供gong電dian電dian源yuan的de地di線xian,然ran後hou經jing過guo電dian源yuan地di線xian接jie大da地di。其qi次ci,在zai外wai表biao內nei部bu包bao含han電dian路lu板ban、元器件等一般會選用懸浮辦法。這種接法確保了外部的攪擾不會進入外表內部,一同又避免了外表殼體帶電構成安全隱患。
前qian麵mian講jiang到dao,外wai表biao殼ke體ti等deng的de接jie地di是shi靠kao電dian源yuan線xian接jie地di的de,這zhe就jiu要yao求qiu稱cheng重zhong外wai表biao在zai鋪pu設she電dian源yuan線xian時shi必bi定ding要yao注zhu意yi地di線xian的de銜xian接jie,那na種zhong電dian源yuan不bu接jie地di或huo不bu牢lao靠kao接jie地di的de做zuo法fa是shi極ji端duan過guo錯cuo的de,不bu隻zhi存cun在zai安an全quan問wen題ti,關guan於yu外wai表biao的de攪jiao擾rao防fang護hu也ye會hui帶dai來lai很hen大da的de問wen題ti。
3.6外部設備接地
電子汽車衡銜接大屏幕、核算機、打(da)印(yin)機(ji)等(deng)外(wai)部(bu)設(she)備(bei)是(shi)很(hen)常(chang)見(jian)的(de)。這(zhe)些(xie)外(wai)部(bu)設(she)備(bei)在(zai)組(zu)成(cheng)稱(cheng)重(zhong)體(ti)係(xi)時(shi),要(yao)求(qiu)有(you)必(bi)要(yao)很(hen)好(hao)的(de)電(dian)源(yuan)接(jie)地(di)。在(zai)銜(xian)接(jie)這(zhe)些(xie)外(wai)部(bu)設(she)備(bei)時(shi),尤(you)其(qi)是(shi)銜(xian)接(jie)打(da)印(yin)機(ji)和(he)核(he)算(suan)機(ji)時(shi),不(bu)良(liang)的(de)接(jie)地(di)將(jiang)直(zhi)接(jie)導(dao)致(zhi)稱(cheng)重(zhong)外(wai)表(biao)呈(cheng)現(xian)數(shu)字(zi)跳(tiao)動(dong)、漂移和過錯信息提示等問題。這是由於打印機和核算機等設備,它們內部的信號地和大地(電源地)都dou是shi銜xian接jie到dao一yi同tong的de,假jia如ru不bu做zuo好hao電dian源yuan接jie地di,電dian源yuan線xian地di線xian上shang耦ou合he的de攪jiao擾rao信xin號hao就jiu會hui經jing過guo打da印yin機ji或huo核he算suan機ji的de信xin號hao地di導dao入ru外wai表biao內nei部bu的de信xin號hao地di,損sun壞huai了le外wai表biao本ben來lai的de懸xuan浮fu地di狀zhuang況kuang,構gou成cheng外wai表biao地di線xian攪jiao擾rao,影ying響xiang外wai表biao正zheng常chang作zuo業ye。所suo以yi,銜xian接jie外wai部bu設she備bei時shi,外wai部bu設she備bei電dian源yuan必bi定ding要yao做zuo到dao電dian源yuan傑jie出chu接jie地di。