白色(se)發光二極管屬(shu)于電(dian)壓感測裝置(zhi)，在(zai)實際(ji)操作中以(yi)(yi)20mA的電(dian)流為最大電(dian)流，但在(zai)使(shi)用過程中經(jing)常引(yin)起電(dian)流增大，如果不采取防護措施(shi)，則(ze)該(gai)增大電(dian)流在(zai)一定時(shi)間和寬度以(yi)(yi)上會損壞。led燈珠破損的主要(yao)原因是：

①電(dian)(dian)(dian)(dian)源電(dian)(dian)(dian)(dian)壓突然上(shang)升(sheng)。②線(xian)路(lu)(lu)上(shang)的元件(jian)、印刷線(xian)或其(qi)(qi)他(ta)導線(xian)短路(lu)(lu)led燈(deng)(deng)珠(zhu)(zhu)(zhu)導致(zhi)供(gong)電(dian)(dian)(dian)(dian)線(xian)路(lu)(lu)的局(ju)部短路(lu)(lu)，該區域的電(dian)(dian)(dian)(dian)壓上(shang)升(sheng)。③某led燈(deng)(deng)珠(zhu)(zhu)(zhu)因自(zi)身質(zhi)量的原因破損而形成短路(lu)(lu)，其(qi)(qi)原電(dian)(dian)(dian)(dian)壓下降到(dao)其(qi)(qi)他(ta)led燈(deng)(deng)珠(zhu)(zhu)(zhu)。④燈(deng)(deng)內(nei)溫度過高led燈(deng)(deng)珠(zhu)(zhu)(zhu)性能降低。⑤燈(deng)(deng)內(nei)進(jin)水，水通電(dian)(dian)(dian)(dian)。③組(zu)裝時由(you)于無法(fa)進(jin)行(xing)防靜(jing)電(dian)(dian)(dian)(dian)作業(ye)led燈(deng)(deng)珠(zhu)(zhu)(zhu)內(nei)部發生了(le)靜(jing)電(dian)(dian)(dian)(dian)損壞(huai)。施加(jia)電(dian)(dian)(dian)(dian)壓和電(dian)(dian)(dian)(dian)流(liu)值正常(chang)，但容易導致(zhi)led燈(deng)(deng)珠(zhu)(zhu)(zhu)損壞(huai)。因此(ci)，led燈(deng)(deng)珠(zhu)(zhu)(zhu)如何保護電(dian)(dian)(dian)(dian)路(lu)(lu)。

保護電路中保險絲的使(shi)用

保(bao)(bao)險絲是一次性的(de)(de)，反(fan)應(ying)速度慢，效(xiao)果差，使用麻煩(fan)，所以(yi)保(bao)(bao)險絲不適(shi)合應(ying)用于(yu)LED燈泡產品(pin)。因為LED燈現(xian)在主要(yao)用于(yu)城市的(de)(de)光輝工程。led燈珠對保(bao)(bao)護(hu)電(dian)(dian)(dian)路(lu)的(de)(de)要(yao)求高：超過正常使用電(dian)(dian)(dian)流，可(ke)以(yi)立即開(kai)始保(bao)(bao)護(hu)，保(bao)(bao)護(hu)LED的(de)(de)供電(dian)(dian)(dian)通道，同時保(bao)(bao)護(hu)LED和電(dian)(dian)(dian)源，在整個燈正常后(hou)，可(ke)以(yi)自動恢復供電(dian)(dian)(dian)，不影響LED的(de)(de)工作。線路(lu)不要(yao)太(tai)復雜。體積不能太(tai)大。成本更低。因此，熔斷法的(de)(de)實(shi)現(xian)比較困(kun)難。2.采(cai)用二極管瞬態(tai)電(dian)(dian)(dian)壓抑制(zhi)（簡稱TVS）

暫定(ding)(ding)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)抑制二(er)極管(guan)是(shi)二(er)極管(guan)型高效率保護(hu)元(yuan)件(jian)之(zhi)一。當該兩極受到瞬(shun)(shun)態逆高能(neng)沖擊時(shi)，以10的(de)(de)負(fu)12次方秒極短的(de)(de)速(su)度，立即(ji)將兩極之(zhi)間(jian)的(de)(de)高電(dian)(dian)(dian)(dian)阻降低到低電(dian)(dian)(dian)(dian)阻，吸收到數(shu)千瓦的(de)(de)浪(lang)涌功率，將兩極間(jian)的(de)(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)鉗(qian)制到規定(ding)(ding)的(de)(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)值，可以有效保護(hu)電(dian)(dian)(dian)(dian)子線路中的(de)(de)精(jing)密元(yuan)件(jian)。暫定(ding)(ding)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)抑制二(er)極管(guan)具有響應(ying)時(shi)間(jian)快、瞬(shun)(shun)態功率大、漏電(dian)(dian)(dian)(dian)流(liu)小、破壞(huai)(huai)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)的(de)(de)偏差一致、鉗(qian)位電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)容易控制、不破壞(huai)(huai)界限、體積小等優點。然而，在實際(ji)應(ying)用中，很難找到符合請求電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)值的(de)(de)TVS設備。led燈珠損(sun)壞(huai)(huai)的(de)(de)主要原因是(shi)電(dian)(dian)(dian)(dian)流(liu)過(guo)大使芯片內部過(guo)熱。TVS只能(neng)檢測過(guo)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，不能(neng)檢測過(guo)電(dian)(dian)(dian)(dian)流(liu)。選(xuan)擇適當的(de)(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)保護(hu)點是(shi)困難的(de)(de)，實際(ji)生產(chan)，不應(ying)用。選(xuan)擇自動(dong)修(xiu)復保險絲。

自(zi)復(fu)(fu)(fu)式保險(xian)絲也稱為高分子(zi)聚(ju)(ju)合(he)(he)物(wu)(wu)的(de)(de)正(zheng)溫熱(re)(re)敏(min)電(dian)(dian)(dian)阻(zu)pTC，由聚(ju)(ju)合(he)(he)物(wu)(wu)和導(dao)電(dian)(dian)(dian)性微(wei)粒(li)子(zi)等構成。導(dao)電(dian)(dian)(dian)粒(li)子(zi)經(jing)過(guo)(guo)特(te)殊(shu)處(chu)理(li)在(zai)聚(ju)(ju)合(he)(he)物(wu)(wu)中形成鎖(suo)狀傳(chuan)導(dao)路徑。pTC自(zi)恢(hui)復(fu)(fu)(fu)保險(xian)絲在(zai)正(zheng)常工作電(dian)(dian)(dian)流(liu)通過(guo)(guo)（或環(huan)(huan)境(jing)溫度正(zheng)常溫度）時，pTC自(zi)恢(hui)復(fu)(fu)(fu)保險(xian)絲處(chu)于低電(dian)(dian)(dian)阻(zu)狀態(tai)(tai)(tai)。當電(dian)(dian)(dian)路通過(guo)(guo)異(yi)常的(de)(de)過(guo)(guo)電(dian)(dian)(dian)流(liu)（或環(huan)(huan)境(jing)溫度上升）時，高電(dian)(dian)(dian)流(liu)（或提高環(huan)(huan)境(jing)溫度）產(chan)生的(de)(de)熱(re)(re)使聚(ju)(ju)合(he)(he)物(wu)(wu)迅速膨(peng)脹。如(ru)果(guo)pTC自(zi)恢(hui)復(fu)(fu)(fu)熔斷(duan)器形成的(de)(de)導(dao)電(dian)(dian)(dian)路被切斷(duan)，電(dian)(dian)(dian)路中的(de)(de)過(guo)(guo)電(dian)(dian)(dian)流(liu)（超(chao)溫狀態(tai)(tai)(tai)）消(xiao)失(shi)，則聚(ju)(ju)合(he)(he)物(wu)(wu)被冷卻，pTC自(zi)恢(hui)復(fu)(fu)(fu)熔斷(duan)器成為高電(dian)(dian)(dian)阻(zu)狀態(tai)(tai)(tai)。電(dian)(dian)(dian)路過(guo)(guo)電(dian)(dian)(dian)流(liu)（超(chao)溫狀態(tai)(tai)(tai)）消(xiao)失(shi)后，聚(ju)(ju)合(he)(he)物(wu)(wu)冷卻，pTC自(zi)恢(hui)復(fu)(fu)(fu)保險(xian)絲處(chu)于高電(dian)(dian)(dian)阻(zu)狀態(tai)(tai)(tai)。自(zi)復(fu)(fu)(fu)式保險(xian)管在(zai)正(zheng)常工作狀態(tai)(tai)(tai)下的(de)(de)發熱(re)(re)較小，在(zai)異(yi)常工作狀態(tai)(tai)(tai)下發熱(re)(re)的(de)(de)極高電(dian)(dian)(dian)阻(zu)值較大(da)，限制其電(dian)(dian)(dian)流(liu)流(liu)動，起到保護作用。對(dui)于特(te)定(ding)的(de)(de)電(dian)(dian)(dian)路，可以(yi)如(ru)下選擇。

①分(fen)割保護(hu)。通常的LED燈(deng)分(fen)為很多串聯的分(fen)支。每(mei)個(ge)(ge)分(fen)支的前(qian)(qian)部(bu)可以(yi)分(fen)別添加一個(ge)(ge)pTC元件來保護(hu)。這種方法的優點是(shi)精度高，保護(hu)可靠。②全面(mian)保護(hu)。一個(ge)(ge)pTC組件安(an)裝在所有珠(zhu)子之前(qian)(qian)以(yi)保護(hu)整個(ge)(ge)燈(deng)泡。這種方法的優點是(shi)簡單而(er)不占空(kong)間。對于民用(yong)(yong)產(chan)品，實際使用(yong)(yong)效果(guo)依然滿(man)意(yi)。