移動DVD液晶屏驅動電路供電原理分析 移動DVD是如何供電的

原理分析

移動(dong)(dong)(dong)DVD機(ji)，受其體積限制，外接電池電壓(ya)大多為9V左右，但其液(ye)晶(jing)屏(ping)驅動(dong)(dong)(dong)部(bu)分(fen)，需要多組不同的電壓(ya)，因此移動(dong)(dong)(dong)DVD機(ji)液(ye)晶(jing)屏(ping)驅動(dong)(dong)(dong)部(bu)分(fen)的供(gong)電電路相對較為復(fu)雜，故障率也較高。附圖為新(xin)科SDP1710型(xing)移動(dong)(dong)(dong)DVD機(ji)液(ye)晶(jing)屏(ping)驅動(dong)(dong)(dong)部(bu)分(fen)電路圖。

此電(dian)(dian)路(lu)(lu)為液晶(jing)屏驅動供(gong)電(dian)(dian)電(dian)(dian)路(lu)(lu)（又稱二次(ci)升壓電(dian)(dian)路(lu)(lu)）。因彩(cai)色TFT顯示屏播放視頻圖像時，要(yao)求有快速響應(ying)時間，對于控(kong)制(zhi)電(dian)(dian)路(lu)(lu)，意味(wei)著要(yao)加上更(geng)高(gao)(gao)的(de)驅動電(dian)(dian)壓；TFT屏的(de)非晶(jing)薄(bo)膜(mo)晶(jing)體(ti)管的(de)閾值電(dian)(dian)壓較高(gao)(gao)，輸入的(de)信號有的(de)高(gao)(gao)達20V。而此電(dian)(dian)壓作為便捷式產品(pin)，一般難(nan)以(yi)達到(dao)要(yao)求，故需(xu)要(yao)通過(guo)升壓電(dian)(dian)路(lu)(lu)來變(bian)換。

由N106五端(duan)5V穩壓(ya)集成(cheng)電(dian)(dian)路(lu)(lu)③腳(jiao)輸出5V電(dian)(dian)壓(ya)，此電(dian)(dian)壓(ya)作(zuo)為整(zheng)個液晶屏驅動的輸入電(dian)(dian)壓(ya)（不包括CCFL共電(dian)(dian)）。一路(lu)(lu)供升壓(ya)電(dian)(dian)路(lu)(lu)；一路(lu)(lu)供N112（PU5100）脈(mo)寬調制集成(cheng)電(dian)(dian)路(lu)(lu)。

N112的(de)③腳(jiao)加(jia)上5V電(dian)(dian)(dian)壓(ya)，經內部穩(wen)壓(ya)，恒流(liu)得(de)到1.25V的(de)基準電(dian)(dian)(dian)壓(ya)，由⑨腳(jiao)輸(shu)出。12腳(jiao)外掛C174為定時(shi)電(dian)(dian)(dian)容(rong)。R151為定時(shi)電(dian)(dian)(dian)阻(zu)，其值(zhi)決定N112的(de)工作頻率，①、11腳(jiao)輸(shu)入的(de)正(zheng)負反(fan)饋電(dian)(dian)(dian)壓(ya)，經N112內部誤差(cha)放大、PWM比較等(deng)，由④腳(jiao)輸(shu)出受控脈(mo)沖信號，經R143控制VD122（BR）開關管(guan)。

當(dang)VD122導通(tong)時(shi)(shi)，對(dui)(dui)L137蓄積電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)。而(er)(er)VD122截止(zhi)時(shi)(shi)，L137電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)(gan)中(zhong)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)經V123二極(ji)(ji)(ji)管(guan)（MI）對(dui)(dui)C182充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，并供負載(zai)能(neng)量(liang)(liang)，周(zhou)而(er)(er)復始(shi)。V1電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)(zhi)(zhi)為-14V，調節(jie)N112①腳外接(jie)反饋(kui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)R140阻(zu)(zu)值(zhi)(zhi)(zhi)可改變其(qi)(qi)輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)(zhi)(zhi)；⑩腳基(ji)準電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，與(yu)來自15腳的(de)(de)(de)反饋(kui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)經N112內部(bu)誤差(cha)放(fang)大，PWM比較(jiao)等，經⑤腳輸出(chu)一個受控(kong)的(de)(de)(de)脈(mo)沖(chong)信號，經R146控(kong)制VD127（IR）開關(guan)管(guan)，當(dang)VD127導通(tong)時(shi)(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)從L131電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)(gan)經集電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)到發射極(ji)(ji)(ji)形成回路(lu)(lu)，從而(er)(er)在L13l中(zhong)蓄積能(neng)量(liang)(liang)。而(er)(er)VD127截止(zhi)時(shi)(shi)，L131電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)(gan)中(zhong)的(de)(de)(de)能(neng)量(liang)(liang)經VD128（MI）對(dui)(dui)C181電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，并供負載(zai)能(neng)量(liang)(liang)周(zhou)而(er)(er)復始(shi)工作。V2電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)(zhi)(zhi)為13.6V，調節(jie)R144阻(zu)(zu)值(zhi)(zhi)(zhi)可改變其(qi)(qi)輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)(zhi)(zhi)；由(you)⑩腳輸入的(de)(de)(de)基(ji)準電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，與(yu)來自14腳的(de)(de)(de)反饋(kui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)經N112內部(bu)誤差(cha)放(fang)大，PWM比較(jiao)等。經⑥腳輸出(chu)一個受控(kong)的(de)(de)(de)脈(mo)沖(chong)信號，經R145控(kong)制VD125（IR）開關(guan)管(guan)，當(dang)VD125導通(tong)時(shi)(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)從L132電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)(gan)經集電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)到發射極(ji)(ji)(ji)形成回路(lu)(lu)，從而(er)(er)在L132電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)(gan)中(zhong)蓄積能(neng)量(liang)(liang)，VD125截止(zhi)時(shi)(shi)L132電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)(gan)中(zhong)的(de)(de)(de)能(neng)量(liang)(liang)經VD126二極(ji)(ji)(ji)管(guan)（MI）對(dui)(dui)C124電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，并供負載(zai)能(neng)量(liang)(liang)周(zhou)而(er)(er)復始(shi)工作。V3電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)(zhi)(zhi)為7.5V，調節(jie)14腳外接(jie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)R152阻(zu)(zu)值(zhi)(zhi)(zhi)，可改變其(qi)(qi)輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)(zhi)(zhi)。V1、V2、V3電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)主要(yao)作為方波(bo)放(fang)大電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源。