【可視對講(jiang)系統(tong)(tong)】可視對講(jiang)門禁系統(tong)(tong)原理說明 可視對講(jiang)門禁系統(tong)(tong)接(jie)線(xian)圖
可視對講門禁系統原理說明
下圖是該對講門鈴的主電路(lu),二圖是室內(nei)話機部分。
變壓(ya)器次級輸出的交流低壓(ya)經(jing)(jing)橋(qiao)式整流、電(dian)(dian)(dian)(dian)容濾波、7812穩壓(ya),得到+12V直流電(dian)(dian)(dian)(dian)壓(ya),經(jing)(jing)插座Vl輸入,一路直接給(gei)繼電(dian)(dian)(dian)(dian)器K供電(dian)(dian)(dian)(dian),另一路經(jing)(jing)D3隔離(li),產生VCC給(gei)其他(ta)電(dian)(dian)(dian)(dian)路供電(dian)(dian)(dian)(dian)。
當(dang)戶外(wai)有人(ren)(ren)(ren)按(an)下(xia)按(an)鍵(jian)S1~S10之一時,如按(an)下(xia)的(de)(de)(de)是Sl,此(ci)時Q5基(ji)極通過R17、插(cha)座(zuo)V6①腳(jiao)(jiao)(jiao)(jiao)經Sl、話(hua)(hua)(hua)機(ji)開(kai)關(guan)SA②、③腳(jiao)(jiao)(jiao)(jiao),喇叭LB到地(di),形成電流通路(lu),相當(dang)于(yu)把R17下(xia)端接地(di),故Q5基(ji)極為低電平(ping),Q5飽和(he)導通,音(yin)樂lC②腳(jiao)(jiao)(jiao)(jiao)有觸(chu)發(fa)高(gao)電平(ping),其③腳(jiao)(jiao)(jiao)(jiao)輸出音(yin)樂信(xin)號,經Ul(LM386)放(fang)大(da)后(hou),由(you)Ul⑤腳(jiao)(jiao)(jiao)(jiao)輸出,經V6①腳(jiao)(jiao)(jiao)(jiao)、Sl,話(hua)(hua)(hua)機(ji)又(you)簧開(kai)關(guan)SA②、③腳(jiao)(jiao)(jiao)(jiao)送到喇叭LB,使之發(fa)出聲(sheng)(sheng)音(yin)。由(you)于(yu)話(hua)(hua)(hua)機(ji)開(kai)關(guan)SA的(de)(de)(de)特殊結(jie)構(gou),該音(yin)頻信(xin)號還可耦合至話(hua)(hua)(hua)機(ji)開(kai)關(guan)SA④腳(jiao)(jiao)(jiao)(jiao),再(zai)經插(cha)座(zuo)V3②腳(jiao)(jiao)(jiao)(jiao)耦合至U2(TDA2822M)⑦腳(jiao)(jiao)(jiao)(jiao),放(fang)大(da)后(hou)由(you)①腳(jiao)(jiao)(jiao)(jiao)輸出,使按(an)門鈴者(zhe)也可以聽(ting)到LB1發(fa)出的(de)(de)(de)聲(sheng)(sheng)音(yin)。主人(ren)(ren)(ren)聽(ting)到LB發(fa)出的(de)(de)(de)聲(sheng)(sheng)音(yin)后(hou),摘(zhai)下(xia)話(hua)(hua)(hua)機(ji),屋內與戶外(wai)的(de)(de)(de)二人(ren)(ren)(ren)可以通話(hua)(hua)(hua)。MIC1拾(shi)取(qu)的(de)(de)(de)聲(sheng)(sheng)音(yin)信(xin)號送入U2⑥腳(jiao)(jiao)(jiao)(jiao),放(fang)大(da)后(hou)由(you)③腳(jiao)(jiao)(jiao)(jiao)輸出,經插(cha)座(zuo)V3①腳(jiao)(jiao)(jiao)(jiao)、話(hua)(hua)(hua)機(ji)上的(de)(de)(de)C3,話(hua)(hua)(hua)機(ji)開(kai)關(guan)SA①、③腳(jiao)(jiao)(jiao)(jiao)耦合到喇叭LB,主人(ren)(ren)(ren)可聽(ting)到對方的(de)(de)(de)說話(hua)(hua)(hua)聲(sheng)(sheng)。VCC經主電路(lu)的(de)(de)(de)R5降壓后(hou),再(zai)經插(cha)座(zuo)V3②腳(jiao)(jiao)(jiao)(jiao)給室內話(hua)(hua)(hua)機(ji)的(de)(de)(de)MIC2和(he)Ql供電。主人(ren)(ren)(ren)的(de)(de)(de)說話(hua)(hua)(hua)聲(sheng)(sheng)經MIC2拾(shi)取(qu)、Ql放(fang)大(da)后(hou),又(you)經話(hua)(hua)(hua)機(ji)開(kai)關(guan)SA④、⑥腳(jiao)(jiao)(jiao)(jiao),插(cha)座(zuo)V3②腳(jiao)(jiao)(jiao)(jiao)送至U2⑦腳(jiao)(jiao)(jiao)(jiao),放(fang)大(da)后(hou)由(you)①腳(jiao)(jiao)(jiao)(jiao)輸出,推動喇叭LB1發(fa)聲(sheng)(sheng),從而(er)實現(xian)二人(ren)(ren)(ren)間的(de)(de)(de)通話(hua)(hua)(hua)。
主人摘下話機后,插座V6①腳(jiao)(jiao)到(dao)地(di)的(de)(de)通路就(jiu)切斷了,R17下端恢復了高(gao)電(dian)(dian)平,Q5截(jie)止(zhi)(zhi)(zhi),音(yin)樂lC和(he)Ul都停止(zhi)(zhi)(zhi)工作。插座V3①腳(jiao)(jiao)由于開(kai)鎖開(kai)關SB的(de)(de)斷開(kai),通常是高(gao)電(dian)(dian)平,穩壓管(guan)ZD1處于擊穿狀態,Ql飽和(he),Q2截(jie)止(zhi)(zhi)(zhi),繼(ji)電(dian)(dian)器K不吸(xi)合門無法打開(kai)。當主人(ren)按下開(kai)鎖開(kai)關SB后,V3①腳(jiao)(jiao)接地(di),ZD1截(jie)止(zhi)(zhi)(zhi),Ql截(jie)止(zhi)(zhi)(zhi),Ql集電(dian)(dian)極的(de)(de)高(gao)電(dian)(dian)平經Cll耦合到(dao)Q2基極,Q2飽和(he),繼(ji)電(dian)(dian)器K得電(dian)(dian),觸點閉(bi)合,電(dian)(dian)磁鎖LOCK得電(dian)(dian)動作,樓(lou)宇門打開(kai)。
二、可視對講系統門鈴故障維修
按下Sl~Sl0中的任意一鍵(jian),若能聽到門鈴聲(sheng),說(shuo)明(ming)Q5、音(yin)樂IC和Ul工作基本正常。
雙方能通話(hua),說明U2和室內話(hua)機工作基本正(zheng)常。
插座V3①腳(jiao)正常是(shi)高(gao)電(dian)位(wei),①腳(jiao)對地(di)短(duan)接時(shi),若能聽(ting)到繼電(dian)器K的吸合聲,說(shuo)明開鎖電(dian)路是(shi)正常的。
樓宇門(men)對(dui)講系(xi)統,分立元件多、電路(lu)復雜,但有了原理圖,維修就容易(yi)了。
由于(yu)供(gong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓低(di),故障率并不高。電(dian)(dian)(dian)(dian)磁(ci)(ci)鎖(suo)使用頻繁,故易損壞(huai)(huai)。維修時,若(ruo)能(neng)聽(ting)到繼電(dian)(dian)(dian)(dian)器K的吸合聲,但電(dian)(dian)(dian)(dian)磁(ci)(ci)鎖(suo)不動(dong)(dong)作,可(ke)認定電(dian)(dian)(dian)(dian)磁(ci)(ci)鎖(suo)損壞(huai)(huai)。另外(wai),由于(yu)震動(dong)(dong)的原(yuan)因(yin),主(zhu)電(dian)(dian)(dian)(dian)路易發生開焊故障。
若哪(na)一部分(fen)電(dian)路不正常,首先應(ying)查(cha)供(gong)電(dian)部分(fen)。由于各部分(fen)接口(kou)標注清晰,把主板、按鍵板、話(hua)機(ji)摘下(xia)維修,一般(ban)容易(yi)排(pai)除故障。
例1:ZD2擊(ji)穿,無門鈴聲(sheng),但不(bu)知何故,按(an)下開(kai)鎖開(kai)關SB,卻聽不(bu)到K的(de)吸合(he)聲(sheng),換新K后故障排(pai)除。
例2:不(bu)能對講。經查(cha)U2(TDA2822M)損壞(huai)(huai),換新(xin)后不(bu)久又損壞(huai)(huai),經查(cha)VCC電壓為(wei)16V,高于(yu)TDA2822M的(de)(de)最大供電電壓15V。最后查(cha)出是(shi)電源板的(de)(de)7812擊穿,估(gu)計是(shi)過熱損壞(huai)(huai)。將其換新(xin)并加(jia)大散熱片,故障排除。
例(li)3:按(an)(an)下個別按(an)(an)鍵門(men)鈴不響,一般是按(an)(an)鍵的故障,換新后可排除故障。