消防應急燈廣泛用于公共場所的走廊、消防通道內。現在各廠礦企業、大型超市、醫院學校等都安裝了這種應急燈。市場上眾多的消防應急燈具是由消防公安及安監部門監制的產品．品種繁多，但功能基本一致。當市電停電時，消防應急燈自動點亮，來電時自動熄滅。消防應急燈作為一種備用照明設備，在燈具內裝有停電時提供電源的蓄電池G(或稱電瓶)。由于應急燈長時間與市電并聯在一起工作，所以容易出現故障。

消防應急燈電路原理

應急燈(deng)當有市電(dian)時(shi)(shi)．通過(guo)變壓器(qi)B降壓、整(zheng)流(liu)、濾波．此時(shi)(shi)6V的直(zhi)流(liu)繼(ji)電(dian)吸合，常開(kai)觸(chu)點閉合，使整(zheng)流(liu)后(hou)的直(zhi)流(liu)電(dian)通過(guo)R1降壓向電(dian)瓶充(chong)電(dian)，LED作電(dian)源指示(shi)燈(deng)。當市電(dian)停電(dian)時(shi)(shi)，6V的繼(ji)電(dian)器(qi)失電(dian)．常開(kai)點斷開(kai)，接(jie)通常閉點，應急燈(deng)泡ZD接(jie)到電(dian)瓶端．得(de)電(dian)發(fa)光起到應急照(zhao)明作用。市電(dian)恢復時(shi)(shi)．回復到上述過(guo)程。

該圖片由注冊用戶"洋洋盈耳"提供，版權聲明反饋

消防應急燈常見故障原因

(1)電瓶長期充電，電液干枯，過早損壞。(2)變壓器長期通電過熱燒壞。(3)最常見的是繼電器線圈長期通電燒壞或其接點燒蝕。這種燈較簡易(yi)價格低．然(ran)而故障也出現(xian)得(de)多。

消防應急燈常見故障及維修

由于電瓶(ping)長期充電。又無充滿保護(hu)電路．故最容(rong)易(yi)壞，其次是(shi)(shi)變壓(ya)器，再(zai)就是(shi)(shi)驅動三極管Q2(或Q3)，如果燈泡長期被(bei)點亮(liang)。管于發(fa)熱，也容(rong)易(yi)損(sun)壞。一(yi)般更換這幾個(ge)元件便(bian)能正常(chang)工作。

當市電(dian)(dian)(dian)(dian)(dian)正常供電(dian)(dian)(dian)(dian)(dian)時。通過(guo)變壓(ya)器降壓(ya)、整(zheng)流、濾波(bo)，在(zai)C1上(shang)得到(dao)大(da)約(yue)13V的(de)(de)直流電(dian)(dian)(dian)(dian)(dian)壓(ya)。該電(dian)(dian)(dian)(dian)(dian)壓(ya)經R3、Q1、D6給電(dian)(dian)(dian)(dian)(dian)瓶充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)。Q1的(de)(de)基(ji)極(ji)(ji)接有穩壓(ya)二極(ji)(ji)管DZ1，電(dian)(dian)(dian)(dian)(dian)阻R4既是(shi)(shi)Q1基(ji)極(ji)(ji)的(de)(de)偏(pian)流電(dian)(dian)(dian)(dian)(dian)阻，又是(shi)(shi)穩壓(ya)管的(de)(de)限流電(dian)(dian)(dian)(dian)(dian)阻，使Q1基(ji)極(ji)(ji)約(yue)為8.9V，這樣充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)受到(dao)限制，最(zui)高為7.6V．可保護電(dian)(dian)(dian)(dian)(dian)池(chi)。其充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流隨(sui)著電(dian)(dian)(dian)(dian)(dian)瓶的(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)而變化，電(dian)(dian)(dian)(dian)(dian)壓(ya)越低充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流越大(da)，反之越小。在(zai)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)狀態(tai)，Q2飽和導通，Q3由(you)于D7、R10的(de)(de)作用而截(jie)(jie)止(zhi)，Q4也截(jie)(jie)止(zhi)，所以照明燈ZD1、ZD2不亮。

當220v交流(liu)電(dian)(dian)因故停電(dian)(dian)時(shi)(shi)，變壓(ya)器B1次(ci)級無輸出電(dian)(dian)．電(dian)(dian)路中直(zhi)流(liu)13V電(dian)(dian)壓(ya)消失，D7正(zheng)極(ji)無電(dian)(dian)壓(ya)，由于(yu)Q2在(zai)停電(dian)(dian)前處于(yu)飽和導(dao)(dao)通狀(zhuang)態，所(suo)以(yi)Q3立即導(dao)(dao)通，Q4基極(ji)電(dian)(dian)位升高，Q4也隨之導(dao)(dao)通，照明(ming)燈(deng)DZ1、DZ2被(bei)點(dian)亮。Q4導(dao)(dao)通后(hou)其集電(dian)(dian)極(ji)為(wei)低(di)電(dian)(dian)位，由于(yu)R1跨(kua)接在(zai)Q4集電(dian)(dian)極(ji)與Q3基極(ji)之間，Q3基極(ji)電(dian)(dian)位下(xia)降(jiang)，維持Q3的導(dao)(dao)通狀(zhuang)態，照明(ming)燈(deng)一直(zhi)被(bei)點(dian)亮。紅色(se)LED作為(wei)充電(dian)(dian)指示燈(deng)，綠色(se)LED作為(wei)主電(dian)(dian)源指示燈(deng)。紅燈(deng)亮表示電(dian)(dian)瓶正(zheng)在(zai)充電(dian)(dian)，綠燈(deng)亮表示有交流(liu)220V電(dian)(dian)壓(ya)。0N／OFF為(wei)照明(ming)燈(deng)的開關按(an)鈕，220V交流(liu)電(dian)(dian)源停電(dian)(dian)時(shi)(shi)．可以(yi)通過此按(an)鈕打開或關閉照明(ming)燈(deng)。

當應急燈出故(gu)障時．可先(xian)觀察兩(liang)指示(shi)(shi)燈(deng)的(de)工作狀態。交流(liu)(liu)220V供電(dian)(dian)正常時．綠色指示(shi)(shi)燈(deng)應(ying)(ying)(ying)亮(liang)，電(dian)(dian)瓶(ping)充(chong)(chong)電(dian)(dian)紅色指示(shi)(shi)燈(deng)也應(ying)(ying)(ying)亮(liang)。如(ru)(ru)果(guo)(guo)綠燈(deng)不亮(liang)，則應(ying)(ying)(ying)檢查變(bian)壓(ya)器(qi)次級是否有(you)9V交流(liu)(liu)電(dian)(dian)壓(ya)，電(dian)(dian)容C1兩(liang)端應(ying)(ying)(ying)有(you)13V左(zuo)(zuo)右的(de)直流(liu)(liu)電(dian)(dian)。如(ru)(ru)果(guo)(guo)兩(liang)處都沒有(you)電(dian)(dian)壓(ya)。一般(ban)是變(bian)壓(ya)器(qi)B1損壞。電(dian)(dian)源(綠色)指示(shi)(shi)燈(deng)亮(liang)，充(chong)(chong)電(dian)(dian)(紅色)指示(shi)(shi)燈(deng)不亮(liang)，可測Q1發射極有(you)無(wu)7V左(zuo)(zuo)右電(dian)(dian)壓(ya)，如(ru)(ru)無(wu)電(dian)(dian)壓(ya)，則應(ying)(ying)(ying)檢查Q1之前的(de)相應(ying)(ying)(ying)元件。檢修中(zhong)，可斷開(kai)電(dian)(dian)瓶(ping)正極，測量應(ying)(ying)(ying)急燈(deng)的(de)開(kai)路充(chong)(chong)電(dian)(dian)電(dian)(dian)壓(ya)與通(tong)路充(chong)(chong)電(dian)(dian)電(dian)(dian)壓(ya)，正常時應(ying)(ying)(ying)為7V左(zuo)(zuo)右，充(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)(liu)約為450mA。如(ru)(ru)果(guo)(guo)電(dian)(dian)壓(ya)過高(gao)，則應(ying)(ying)(ying)查Q1是否擊(ji)穿短路，DZ1、R14是否開(kai)路，過高(gao)的(de)充(chong)(chong)電(dian)(dian)電(dian)(dian)壓(ya)，將(jiang)造成電(dian)(dian)瓶(ping)過充(chong)(chong)損壞。

交流(liu)220V停電時．照明燈ZD1、ZD2不亮(liang)．首先查(cha)燈泡是否(fou)(fou)損(sun)壞(huai)．再檢(jian)查(cha)三(san)極管(guan)Q2、Q3、Q4及相(xiang)關(guan)元件是否(fou)(fou)損(sun)壞(huai)；電瓶老(lao)化等。