應急燈的工作原理詳解

應急燈的工作原理分(fen)為在(zai)供電正常時(shi)情(qing)況(kuang)下，停電情(qing)況(kuang)下，制作情(qing)況(kuang)下。

應急(ji)燈(deng)又稱(cheng)方便燈(deng),它不(bu)但可以(yi)在停(ting)電時作照明用,也(ye)可以(yi)在無文(wen)流供電電潭的情況下實(shi)現照明等作用。

在供電(dian)(dian)(dian)(dian)(dian)(dian)正(zheng)常時(shi)，J2得電(dian)(dian)(dian)(dian)(dian)(dian)吸(xi)合，其動觸點與(yu)“N/O（常開(kai)點）”接通(tong)，后備蓄電(dian)(dian)(dian)(dian)(dian)(dian)池正(zheng)端(duan)與(yu)IC1的反相(xiang)端(duan)相(xiang)聯。IC1（LM308）和(he)D5、D6組成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)比較 器，參考(kao)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)由D5、D6決定。這里用一個(ge)(ge)硅二極(ji)管(guan)（D5）和(he)一個(ge)(ge)6.2V的穩壓(ya)(ya)(ya)(ya)二極(ji)管(guan)（D6）組成(cheng)6.9V的參考(kao)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，對充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)進行(xing)監(jian)控。當(dang)IC1 的2腳輸入(ru)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)（既(ji)蓄電(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)）低于(yu)6.9V時(shi)，IC1的6腳輸出高電(dian)(dian)(dian)(dian)(dian)(dian)平，T1導(dao)通(tong)，J1得電(dian)(dian)(dian)(dian)(dian)(dian)，其動觸點與(yu)“N/O（常開(kai)點）”接通(tong)，電(dian)(dian)(dian)(dian)(dian)(dian)源電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)通(tong)過(guo)R2對 蓄電(dian)(dian)(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)，同(tong)時(shi)LED2點亮為充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)指示。改變R2阻值可調整充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流。隨著充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間增加，IC1的2腳電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)逐(zhu)漸增加，當(dang)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)大(da)于(yu)參考(kao)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)6.9V 時(shi)，IC1的6腳輸出低電(dian)(dian)(dian)(dian)(dian)(dian)平，T1截止，J1失電(dian)(dian)(dian)(dian)(dian)(dian)，斷開(kai)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)回路，實現自動充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)保護功能。

當停電(dian)(dian)時，J2失去電(dian)(dian)源，其(qi)動觸點(dian)與“N/C（常閉點(dian)）”接通，蓄電(dian)(dian)池通過(guo)S1對應急燈電(dian)(dian)路供電(dian)(dian)，實現(xian)停電(dian)(dian)時自動切換功能。S1在(zai)這里用來手動切斷(duan)應急燈電(dian)(dian)路部分(fen)。

制作時，X1選用次級為6V/200mA的電源變壓器。J1、J2選用線圈電壓為6V的繼電器。其他器件選擇可參考圖示，無特殊要求。電路調試很簡單，接 通主電源電時，J2應該動作，LED1為電源指示。然后測量IC1的3腳電壓是否為6.9V左右，之后可用一個外接電源接入IC2腳來調整充電保護電路。 當輸入電壓大于6.9V時，J1應該動作斷開。短開S1，用外接電源接入應急燈電路，測量IC2的輸出是否50Hz，然后可測量X2輸出部分電壓是否為 220V左右既可。LED3為停電/應急燈工作。