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(yi)動(dong)DVD機，受其體積限制，外接電(dian)(dian)池電(dian)(dian)壓(ya)大多為(wei)9V左(zuo)右，但其液(ye)晶屏(ping)(ping)驅(qu)動(dong)部分，需要(yao)多組不同的電(dian)(dian)壓(ya)，因此(ci)移(yi)動(dong)DVD機液(ye)晶屏(ping)(ping)驅(qu)動(dong)部分的供(gong)電(dian)(dian)電(dian)(dian)路(lu)相對較(jiao)(jiao)為(wei)復雜，故障率也較(jiao)(jiao)高。附(fu)圖為(wei)新(xin)科SDP1710型(xing)移(yi)動(dong)DVD機液(ye)晶屏(ping)(ping)驅(qu)動(dong)部分電(dian)(dian)路(lu)圖。

此電(dian)(dian)(dian)路(lu)(lu)為(wei)液晶(jing)屏(ping)驅動供(gong)電(dian)(dian)(dian)電(dian)(dian)(dian)路(lu)(lu)（又(you)稱二(er)次升壓電(dian)(dian)(dian)路(lu)(lu)）。因彩色TFT顯示屏(ping)播放視(shi)頻圖像時，要求有快速響(xiang)應時間，對于(yu)控制電(dian)(dian)(dian)路(lu)(lu)，意味(wei)著要加上更高的(de)(de)驅動電(dian)(dian)(dian)壓；TFT屏(ping)的(de)(de)非晶(jing)薄(bo)膜(mo)晶(jing)體(ti)管的(de)(de)閾(yu)值電(dian)(dian)(dian)壓較高，輸入的(de)(de)信(xin)號有的(de)(de)高達20V。而此電(dian)(dian)(dian)壓作為(wei)便(bian)捷式產品，一般難以達到(dao)要求，故(gu)需要通過升壓電(dian)(dian)(dian)路(lu)(lu)來變換。

由(you)N106五端(duan)5V穩壓(ya)(ya)集成(cheng)電路(lu)(lu)③腳(jiao)輸出5V電壓(ya)(ya)，此電壓(ya)(ya)作為整個液晶(jing)屏驅動的輸入(ru)電壓(ya)(ya)（不包(bao)括(kuo)CCFL共電）。一路(lu)(lu)供升壓(ya)(ya)電路(lu)(lu)；一路(lu)(lu)供N112（PU5100）脈(mo)寬調制集成(cheng)電路(lu)(lu)。

N112的(de)③腳(jiao)加(jia)上5V電(dian)壓(ya)，經(jing)內部穩壓(ya)，恒流得到1.25V的(de)基(ji)準電(dian)壓(ya)，由(you)⑨腳(jiao)輸出。12腳(jiao)外掛C174為(wei)定(ding)時電(dian)容。R151為(wei)定(ding)時電(dian)阻，其(qi)值(zhi)決定(ding)N112的(de)工(gong)作頻率，①、11腳(jiao)輸入的(de)正負反饋電(dian)壓(ya)，經(jing)N112內部誤差(cha)放大、PWM比較等(deng)，由(you)④腳(jiao)輸出受控(kong)(kong)脈沖信號，經(jing)R143控(kong)(kong)制VD122（BR）開關管。

當VD122導(dao)通時(shi)，對(dui)(dui)(dui)L137蓄積電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)(liang)。而(er)VD122截(jie)止(zhi)時(shi)，L137電(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)中(zhong)(zhong)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)(liang)經(jing)(jing)(jing)V123二(er)極(ji)(ji)(ji)(ji)管（MI）對(dui)(dui)(dui)C182充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，并(bing)供(gong)負載能量(liang)(liang)(liang)，周而(er)復(fu)始(shi)。V1電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)值為-14V，調節(jie)N112①腳(jiao)外接反(fan)饋(kui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)R140阻(zu)(zu)值可改(gai)變其(qi)輸(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)值；⑩腳(jiao)基準電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，與(yu)(yu)來(lai)自15腳(jiao)的(de)反(fan)饋(kui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)經(jing)(jing)(jing)N112內部(bu)誤差放大，PWM比較等，經(jing)(jing)(jing)⑤腳(jiao)輸(shu)出一個(ge)受控的(de)脈沖(chong)信(xin)號，經(jing)(jing)(jing)R146控制VD127（IR）開關管，當VD127導(dao)通時(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流從L131電(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)經(jing)(jing)(jing)集電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)到發(fa)射極(ji)(ji)(ji)(ji)形成回(hui)路，從而(er)在(zai)L13l中(zhong)(zhong)蓄積能量(liang)(liang)(liang)。而(er)VD127截(jie)止(zhi)時(shi)，L131電(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)中(zhong)(zhong)的(de)能量(liang)(liang)(liang)經(jing)(jing)(jing)VD128（MI）對(dui)(dui)(dui)C181電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，并(bing)供(gong)負載能量(liang)(liang)(liang)周而(er)復(fu)始(shi)工作(zuo)。V2電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)值為13.6V，調節(jie)R144阻(zu)(zu)值可改(gai)變其(qi)輸(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)值；由⑩腳(jiao)輸(shu)入的(de)基準電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，與(yu)(yu)來(lai)自14腳(jiao)的(de)反(fan)饋(kui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)經(jing)(jing)(jing)N112內部(bu)誤差放大，PWM比較等。經(jing)(jing)(jing)⑥腳(jiao)輸(shu)出一個(ge)受控的(de)脈沖(chong)信(xin)號，經(jing)(jing)(jing)R145控制VD125（IR）開關管，當VD125導(dao)通時(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流從L132電(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)經(jing)(jing)(jing)集電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)到發(fa)射極(ji)(ji)(ji)(ji)形成回(hui)路，從而(er)在(zai)L132電(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)中(zhong)(zhong)蓄積能量(liang)(liang)(liang)，VD125截(jie)止(zhi)時(shi)L132電(dian)(dian)(dian)(dian)(dian)(dian)(dian)感(gan)中(zhong)(zhong)的(de)能量(liang)(liang)(liang)經(jing)(jing)(jing)VD126二(er)極(ji)(ji)(ji)(ji)管（MI）對(dui)(dui)(dui)C124電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，并(bing)供(gong)負載能量(liang)(liang)(liang)周而(er)復(fu)始(shi)工作(zuo)。V3電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)值為7.5V，調節(jie)14腳(jiao)外接電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)R152阻(zu)(zu)值，可改(gai)變其(qi)輸(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)值。V1、V2、V3電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)主要(yao)作(zuo)為方(fang)波放大電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路供(gong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)。