【可視對講系(xi)統】可視對講門(men)禁系(xi)統原理說(shuo)明 可視對講門(men)禁系(xi)統接(jie)線圖
可視對講門禁系統原理說明
下圖是該對講門鈴的主(zhu)電路,二圖(tu)是室內話機部分(fen)。
變(bian)壓器次級輸出的交流(liu)(liu)低壓經(jing)橋式整流(liu)(liu)、電(dian)(dian)容濾波、7812穩壓,得(de)到+12V直(zhi)流(liu)(liu)電(dian)(dian)壓,經(jing)插座Vl輸入,一(yi)路直(zhi)接(jie)給繼(ji)電(dian)(dian)器K供(gong)電(dian)(dian),另一(yi)路經(jing)D3隔離,產生VCC給其他電(dian)(dian)路供(gong)電(dian)(dian)。
當(dang)戶外(wai)有人(ren)按(an)下(xia)按(an)鍵S1~S10之一時(shi),如按(an)下(xia)的(de)(de)(de)(de)是(shi)Sl,此時(shi)Q5基(ji)極通(tong)過R17、插座(zuo)(zuo)(zuo)V6①腳(jiao)(jiao)(jiao)經(jing)(jing)Sl、話(hua)機(ji)(ji)開(kai)(kai)關SA②、③腳(jiao)(jiao)(jiao),喇叭LB到地(di),形成電(dian)流通(tong)路,相當(dang)于把R17下(xia)端接(jie)地(di),故(gu)Q5基(ji)極為低電(dian)平(ping),Q5飽和導通(tong),音(yin)樂lC②腳(jiao)(jiao)(jiao)有觸發(fa)高電(dian)平(ping),其③腳(jiao)(jiao)(jiao)輸(shu)出(chu)音(yin)樂信號,經(jing)(jing)Ul(LM386)放(fang)大(da)后(hou),由(you)Ul⑤腳(jiao)(jiao)(jiao)輸(shu)出(chu),經(jing)(jing)V6①腳(jiao)(jiao)(jiao)、Sl,話(hua)機(ji)(ji)又簧(huang)開(kai)(kai)關SA②、③腳(jiao)(jiao)(jiao)送(song)到喇叭LB,使(shi)之發(fa)出(chu)聲(sheng)(sheng)(sheng)音(yin)。由(you)于話(hua)機(ji)(ji)開(kai)(kai)關SA的(de)(de)(de)(de)特殊(shu)結構,該音(yin)頻信號還(huan)可(ke)(ke)耦合(he)(he)(he)至話(hua)機(ji)(ji)開(kai)(kai)關SA④腳(jiao)(jiao)(jiao),再經(jing)(jing)插座(zuo)(zuo)(zuo)V3②腳(jiao)(jiao)(jiao)耦合(he)(he)(he)至U2(TDA2822M)⑦腳(jiao)(jiao)(jiao),放(fang)大(da)后(hou)由(you)①腳(jiao)(jiao)(jiao)輸(shu)出(chu),使(shi)按(an)門鈴者也(ye)可(ke)(ke)以聽(ting)(ting)到LB1發(fa)出(chu)的(de)(de)(de)(de)聲(sheng)(sheng)(sheng)音(yin)。主(zhu)人(ren)聽(ting)(ting)到LB發(fa)出(chu)的(de)(de)(de)(de)聲(sheng)(sheng)(sheng)音(yin)后(hou),摘下(xia)話(hua)機(ji)(ji),屋內(nei)與(yu)戶外(wai)的(de)(de)(de)(de)二人(ren)可(ke)(ke)以通(tong)話(hua)。MIC1拾(shi)取的(de)(de)(de)(de)聲(sheng)(sheng)(sheng)音(yin)信號送(song)入U2⑥腳(jiao)(jiao)(jiao),放(fang)大(da)后(hou)由(you)③腳(jiao)(jiao)(jiao)輸(shu)出(chu),經(jing)(jing)插座(zuo)(zuo)(zuo)V3①腳(jiao)(jiao)(jiao)、話(hua)機(ji)(ji)上的(de)(de)(de)(de)C3,話(hua)機(ji)(ji)開(kai)(kai)關SA①、③腳(jiao)(jiao)(jiao)耦合(he)(he)(he)到喇叭LB,主(zhu)人(ren)可(ke)(ke)聽(ting)(ting)到對方的(de)(de)(de)(de)說話(hua)聲(sheng)(sheng)(sheng)。VCC經(jing)(jing)主(zhu)電(dian)路的(de)(de)(de)(de)R5降壓后(hou),再經(jing)(jing)插座(zuo)(zuo)(zuo)V3②腳(jiao)(jiao)(jiao)給室(shi)內(nei)話(hua)機(ji)(ji)的(de)(de)(de)(de)MIC2和Ql供電(dian)。主(zhu)人(ren)的(de)(de)(de)(de)說話(hua)聲(sheng)(sheng)(sheng)經(jing)(jing)MIC2拾(shi)取、Ql放(fang)大(da)后(hou),又經(jing)(jing)話(hua)機(ji)(ji)開(kai)(kai)關SA④、⑥腳(jiao)(jiao)(jiao),插座(zuo)(zuo)(zuo)V3②腳(jiao)(jiao)(jiao)送(song)至U2⑦腳(jiao)(jiao)(jiao),放(fang)大(da)后(hou)由(you)①腳(jiao)(jiao)(jiao)輸(shu)出(chu),推(tui)動(dong)喇叭LB1發(fa)聲(sheng)(sheng)(sheng),從而實(shi)現二人(ren)間(jian)的(de)(de)(de)(de)通(tong)話(hua)。
主人摘下話機后,插座V6①腳到(dao)地(di)的通(tong)(tong)路就切斷了(le),R17下端恢復了(le)高(gao)(gao)電(dian)(dian)(dian)(dian)平(ping),Q5截止(zhi)(zhi),音樂lC和Ul都停止(zhi)(zhi)工作。插座V3①腳由于開(kai)鎖(suo)開(kai)關SB的斷開(kai),通(tong)(tong)常是高(gao)(gao)電(dian)(dian)(dian)(dian)平(ping),穩壓管ZD1處于擊穿狀(zhuang)態,Ql飽(bao)和,Q2截止(zhi)(zhi),繼電(dian)(dian)(dian)(dian)器(qi)K不(bu)吸合(he)(he)門無(wu)法打開(kai)。當主人按(an)下開(kai)鎖(suo)開(kai)關SB后,V3①腳接地(di),ZD1截止(zhi)(zhi),Ql截止(zhi)(zhi),Ql集(ji)電(dian)(dian)(dian)(dian)極的高(gao)(gao)電(dian)(dian)(dian)(dian)平(ping)經Cll耦合(he)(he)到(dao)Q2基極,Q2飽(bao)和,繼電(dian)(dian)(dian)(dian)器(qi)K得(de)電(dian)(dian)(dian)(dian),觸(chu)點閉合(he)(he),電(dian)(dian)(dian)(dian)磁鎖(suo)LOCK得(de)電(dian)(dian)(dian)(dian)動作,樓宇門打開(kai)。
二、可視對講系統門鈴故障維修
按(an)下Sl~Sl0中的(de)任意一鍵(jian),若能聽到門鈴聲,說明Q5、音樂IC和Ul工(gong)作基(ji)本正常。
雙方能通話,說明U2和(he)室內話機(ji)工作基(ji)本(ben)正常。
插座V3①腳(jiao)正常是(shi)高電位,①腳(jiao)對地短接時,若(ruo)能聽到繼電器(qi)K的吸合聲,說明開鎖電路是(shi)正常的。
樓宇門對講系(xi)統(tong),分立元件多、電路復(fu)雜,但有了原理圖,維修就(jiu)容易了。
由于(yu)供電(dian)電(dian)壓低(di),故(gu)障率并不高。電(dian)磁鎖(suo)使用頻繁,故(gu)易損壞。維(wei)修(xiu)時(shi),若能聽(ting)到繼電(dian)器K的吸合聲,但(dan)電(dian)磁鎖(suo)不動作(zuo),可認定電(dian)磁鎖(suo)損壞。另外,由于(yu)震動的原因,主電(dian)路易發生開焊故(gu)障。
若哪一(yi)部(bu)分電路不正(zheng)常,首先應查供電部(bu)分。由(you)于各(ge)部(bu)分接口標注清晰,把主板、按鍵板、話機摘下維修,一(yi)般(ban)容(rong)易(yi)排除故障。
例(li)1:ZD2擊(ji)穿,無門鈴(ling)聲(sheng),但不知何故,按下(xia)開鎖(suo)開關(guan)SB,卻聽不到(dao)K的吸合聲(sheng),換新K后故障排除(chu)。
例2:不能對講。經(jing)(jing)查U2(TDA2822M)損壞(huai)(huai),換(huan)新(xin)后不久又損壞(huai)(huai),經(jing)(jing)查VCC電(dian)壓為(wei)16V,高(gao)于TDA2822M的最(zui)大供電(dian)電(dian)壓15V。最(zui)后查出是電(dian)源板的7812擊(ji)穿,估計(ji)是過熱損壞(huai)(huai)。將其換(huan)新(xin)并加大散熱片,故(gu)障排除。
例(li)3:按(an)下(xia)個別按(an)鍵(jian)門鈴不響,一般是按(an)鍵(jian)的(de)故障(zhang),換(huan)新后可(ke)排除故障(zhang)。