應急燈的工作原理詳解

應急燈的工作(zuo)原理分為在供電(dian)正常時情(qing)(qing)況下，停電(dian)情(qing)(qing)況下，制作(zuo)情(qing)(qing)況下。

應(ying)急(ji)燈(deng)又稱方便燈(deng),它不但可以在(zai)停(ting)電(dian)時(shi)作(zuo)照(zhao)明用(yong),也可以在(zai)無文流供電(dian)電(dian)潭的(de)情況下實現照(zhao)明等作(zuo)用(yong)。

在供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)正常時(shi)，J2得(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)吸(xi)合，其(qi)動(dong)觸(chu)點與“N/O（常開(kai)(kai)點）”接(jie)通(tong)，后備蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)正端與IC1的(de)(de)反相端相聯。IC1（LM308）和(he)D5、D6組成(cheng)(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)比較 器，參考電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)由D5、D6決定。這里(li)用一(yi)個硅(gui)二極管（D5）和(he)一(yi)個6.2V的(de)(de)穩壓(ya)(ya)(ya)(ya)二極管（D6）組成(cheng)(cheng)6.9V的(de)(de)參考電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，對充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)進行(xing)監(jian)控。當IC1 的(de)(de)2腳(jiao)輸入電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)（既蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)）低(di)于6.9V時(shi)，IC1的(de)(de)6腳(jiao)輸出(chu)高電(dian)(dian)(dian)(dian)(dian)(dian)(dian)平，T1導(dao)通(tong)，J1得(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，其(qi)動(dong)觸(chu)點與“N/O（常開(kai)(kai)點）”接(jie)通(tong)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)通(tong)過(guo)R2對 蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，同(tong)時(shi)LED2點亮為充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)指示。改變R2阻值可調整充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流。隨著充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間增(zeng)加，IC1的(de)(de)2腳(jiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)逐(zhu)漸(jian)增(zeng)加，當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)大于參考電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)6.9V 時(shi)，IC1的(de)(de)6腳(jiao)輸出(chu)低(di)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)平，T1截止，J1失電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，斷開(kai)(kai)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)回路，實(shi)現自動(dong)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)保(bao)護(hu)功能。

當停電(dian)(dian)時(shi)，J2失去(qu)電(dian)(dian)源(yuan)，其(qi)動(dong)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)，實現停電(dian)(dian)時(shi)自動(dong)切換(huan)功能(neng)。S1在這里(li)用來手(shou)動(dong)切斷應急燈電(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。