吸油煙機貼片輕(qing)觸開關控制電路工作原理介紹
目前，面板使用薄膜按鍵的吸油煙機多采用CMOS集成電路或專用單片機、可控硅、三端穩壓器等構成的控制電路，電路顯得復雜，成本也高。為此，首韓科技設計制作了一種貼片輕觸開關電(dian)路，其成本(ben)比相(xiang)同(tong)功能的(de)其它電(dian)路要低(di)10多元(yuan)。由于使用元(yuan)器件較(jiao)少，故障率相(xiang)應也低(di)；抗干擾性強、可靠性高、自身耗電(dian)小(xiao)〔實測工(gong)作時僅(jin)0.7W左右），關機后〔不包括電(dian)源(yuan)變壓器）無(wu)靜態耗電(dian)。
該吸(xi)油煙(yan)(yan)機(ji)貼片輕(qing)觸(chu)開(kai)關(guan)的控(kong)制(zhi)(zhi)(zhi)電(dian)(dian)路：為(wei)(wei)便于說明工(gong)作原理，被控(kong)制(zhi)(zhi)(zhi)對(dui)象簡(jian)稱如下——電(dian)(dian)機(ji)M、燈泡H和(he)保險絲F等(deng)(deng)；具有輔助觸(chu)點的繼電(dian)(dian)器K1及K2、轉換式輕(qing)觸(chu)開(kai)關(guan)SB1SB3等(deng)(deng)，構(gou)成(cheng)(cheng)了交(jiao)叉(cha)控(kong)制(zhi)(zhi)(zhi)的互鎖開(kai)關(guan)，用(yong)于控(kong)制(zhi)(zhi)(zhi)吸(xi)油煙(yan)(yan)機(ji)電(dian)(dian)機(ji)M的運行〔快速(su)、慢(man)速(su)）和(he)停止;晶體三極管VT、K3、SB4等(deng)(deng)構(gou)成(cheng)(cheng)了單(dan)鍵雙穩態(tai)開(kai)關(guan)，用(yong)于控(kong)制(zhi)(zhi)(zhi)吸(xi)油煙(yan)(yan)機(ji)照(zhao)明燈H的亮滅。電(dian)(dian)源電(dian)(dian)路由電(dian)(dian)源變(bian)(bian)壓(ya)器T、整流二(er)極管VD6~VD9和(he)電(dian)(dian)容器C2等(deng)(deng)組(zu)成(cheng)(cheng)，將220V交(jiao)流市電(dian)(dian)變(bian)(bian)換成(cheng)(cheng)為(wei)(wei)12V左右的直(zhi)流電(dian)(dian)，供控(kong)制(zhi)(zhi)(zhi)電(dian)(dian)路工(gong)作用(yong)電(dian)(dian)。
平時，繼電器K1～K3均處于釋放狀態，電機M因斷電不運轉．燈泡H亦不亮。當按下貼片輕觸開關SB1時，繼電器K1通電吸合，其常開觸點K1-1閉合接通電機M的供電回路，使M通電高速運轉；與此同時，K1的輔助觸點K1-2閉合、使K1線圈通過K1-2、SB2構成新的供電回路，在SB1復位后使K1仍保持吸合(he)(he)(he)狀(zhuang)態(tai)(tai)不(bu)變。當(dang)按(an)下(xia)貼片輕(qing)觸(chu)開關(guan)SB2時(shi)(shi)，一方面繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)K1供電(dian)(dian)(dian)(dian)(dian)(dian)回路(lu)被切斷，K1釋放，電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)M斷電(dian)(dian)(dian)(dian)(dian)(dian)停止高(gao)速(su)運(yun)轉(zhuan)，另一方面，繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)K2通(tong)過SB2得(de)電(dian)(dian)(dian)(dian)(dian)(dian)吸(xi)(xi)合(he)(he)(he)，使其常開觸(chu)點K2-1接(jie)通(tong)，M通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)處于慢速(su)運(yun)轉(zhuan)狀(zhuang)態(tai)(tai)。與(yu)此同時(shi)(shi)，K2的(de)(de)輔助(zhu)觸(chu)點K2-2閉(bi)合(he)(he)(he)，使K2線圈通(tong)過K2-2、SB1構(gou)成(cheng)新的(de)(de)供電(dian)(dian)(dian)(dian)(dian)(dian)回路(lu)，在SB2復(fu)位后(hou)使K2仍保持(chi)吸(xi)(xi)合(he)(he)(he)狀(zhuang)態(tai)(tai)不(bu)變。當(dang)按(an)下(xia)貼片輕(qing)觸(chu)開關(guan)SB3按(an)鈕時(shi)(shi)，正在吸(xi)(xi)合(he)(he)(he)的(de)(de)繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)K1或(huo)K2立即斷電(dian)(dian)(dian)(dian)(dian)(dian)釋放，電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)M亦斷電(dian)(dian)(dian)(dian)(dian)(dian)停止運(yun)轉(zhuan)，實現了吸(xi)(xi)油煙機(ji)的(de)(de)關(guan)機(ji)。
當(dang)按(an)(an)動(dong)貼片輕(qing)觸開關(guan)SB4時，已充足電(dian)(dian)(dian)(dian)(dian)（實剝≤14V）的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)容器C1兩端的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)接至三極管VT的(de)(de)(de)基極使(shi)TT導通(tong)(tong)，繼電(dian)(dian)(dian)(dian)(dian)器K3得電(dian)(dian)(dian)(dian)(dian)吸(xi)合(he)，由其(qi)常開觸點(dian)K3-1接通(tong)(tong)燈泡H的(de)(de)(de)供電(dian)(dian)(dian)(dian)(dian)回路(lu)，使(shi)之(zhi)通(tong)(tong)電(dian)(dian)(dian)(dian)(dian)發亮，與此(ci)同(tong)時，輔(fu)助觸點(dian)K3-2亦(yi)吸(xi)合(he)，通(tong)(tong)過限流(liu)電(dian)(dian)(dian)(dian)(dian)阻器為VT提供偏流(liu)，使(shi)K3在SBA4復位后仍保(bao)持吸(xi)合(he)狀態不(bu)變(bian)(bian)(bian)。再次按(an)(an)動(dong)貼片輕(qing)觸開關(guan)SB4時、由于(yu)C1兩端電(dian)(dian)(dian)(dian)(dian)壓(ya)不(bu)能突變(bian)(bian)(bian)，故VT瞬間失(shi)去(qu)合(he)適(shi)偏壓(ya)而截止，K3斷(duan)電(dian)(dian)(dian)(dian)(dian)釋放，因(yin)K3-1斷(duan)開切斷(duan)H供電(dian)(dian)(dian)(dian)(dian)回路(lu)，使(shi)H斷(duan)電(dian)(dian)(dian)(dian)(dian)熄滅(mie)；因(yin)K3-2斷(duan)開而切斷(duan)T的(de)(de)(de)偏置回路(lu)，使(shi)VT在SB4復位后仍保(bao)持截止狀態不(bu)變(bian)(bian)(bian)。由此(ci)實現了每按(an)(an)動(dong)一(yi)次貼片輕(qing)觸開關(guan)SB4，即改變(bian)(bian)(bian)一(yi)次H的(de)(de)(de)亮滅(mie)狀態。
在吸(xi)油煙(yan)機貼(tie)片(pian)輕(qing)觸開(kai)關(guan)電(dian)(dian)路中，發光二極管VD1～VD3與各自的(de)限流電(dian)(dian)阻器(qi)R1～R串(chuan)接后(hou)再(zai)同繼電(dian)(dian)器(qi)K1一K3兩端并聯(lian)，它(ta)們(men)跟(gen)隨對應繼電(dian)(dian)器(qi)的(de)吸(xi)合與釋放(fang)而亮(liang)滅，故能直觀(guan)顯(xian)示出電(dian)(dian)機M的(de)運轉情(qing)況和燈泡H的(de)亮(liang)滅狀態。VD4和分流電(dian)(dian)阻器(qi)R4并聯(lian)后(hou)再(zai)與電(dian)(dian)機M的(de)控制電(dian)(dian)路供電(dian)(dian)串(chuan)聯(lian)，可直觀(guan)顯(xian)示貼(tie)片(pian)輕(qing)觸開(kai)關(guan)電(dian)(dian)機M工作與否(fou)。
