一、光電式接近開關原理是什么
原理:在光(guang)(guang)(guang)電(dian)耦合器(qi)輸入(ru)端(duan)加電(dian)信(xin)號使發(fa)光(guang)(guang)(guang)源發(fa)光(guang)(guang)(guang),光(guang)(guang)(guang)的強度(du)取決于激(ji)勵電(dian)流(liu)的大小,此光(guang)(guang)(guang)照射到封裝在一起的受(shou)光(guang)(guang)(guang)器(qi)上后,因(yin)光(guang)(guang)(guang)電(dian)效應而(er)產生了(le)光(guang)(guang)(guang)電(dian)流(liu),由受(shou)光(guang)(guang)(guang)器(qi)輸出(chu)端(duan)引出(chu),這(zhe)樣就實現了(le)電(dian)一光(guang)(guang)(guang)一電(dian)的轉換。
由振蕩(dang)回路產生(sheng)的調制脈(mo)(mo)沖(chong)經反射(she)電(dian)(dian)路后,由發(fa)光(guang)(guang)管GL輻射(she)出(chu)光(guang)(guang)脈(mo)(mo)沖(chong)。當被(bei)測(ce)物體進(jin)入受(shou)光(guang)(guang)器作用(yong)范(fan)圍時(shi),被(bei)反射(she)回來的光(guang)(guang)脈(mo)(mo)沖(chong)進(jin)入光(guang)(guang)敏三極管DU。光(guang)(guang)電(dian)(dian)開關(guan)并(bing)在接收電(dian)(dian)路中(zhong)將光(guang)(guang)脈(mo)(mo)沖(chong)解調為電(dian)(dian)脈(mo)(mo)沖(chong)信(xin)號,再經放(fang)大(da)(da)器放(fang)大(da)(da)和同步選通整形,然后用(yong)數字積分或RC積分方式排除干擾(rao),最后經延(yan)時(shi)(或不延(yan)時(shi))觸發(fa)驅動器輸出(chu)光(guang)(guang)電(dian)(dian)開關(guan)控制信(xin)號。
光電開關(guan)一般都具有良(liang)好的(de)回差特性,因而即使被檢測物在(zai)小范(fan)圍內(nei)晃(huang)動(dong)也不會影響驅(qu)動(dong)器的(de)輸出狀態,從而可使其保持在(zai)穩(wen)定工(gong)(gong)(gong)作(zuo)區(qu)。同時,自診斷系統還可以顯示受(shou)光狀態和穩(wen)定工(gong)(gong)(gong)作(zuo)區(qu),以隨時監(jian)視(shi)光電開關(guan)的(de)工(gong)(gong)(gong)作(zuo)。
這種新穎(ying)的(de)光(guang)(guang)電(dian)開關(guan)是(shi)一種采用脈(mo)沖(chong)調制(zhi)的(de)主動式(shi)光(guang)(guang)電(dian)探測系(xi)統型電(dian)子開關(guan),它所(suo)使用的(de)冷光(guang)(guang)源有紅外光(guang)(guang)、紅色光(guang)(guang)、綠色光(guang)(guang)和藍色光(guang)(guang)等,可非(fei)接觸,無損傷地迅速和控制(zhi)各種固體、液體、透明體、黑體、柔(rou)軟體和煙霧等物質(zhi)的(de)狀態(tai)和動作。具(ju)有體積小(xiao)、功能多(duo)、壽(shou)命長、精度(du)(du)高、響應速度(du)(du)快(kuai)、檢測距離遠以及抗光(guang)(guang)、電(dian)、磁干擾能力(li)強的(de)優點。
二、光電式接近開關的應用場合有哪些
光電開關已被(bei)用(yong)作物位(wei)檢測、液位(wei)控制(zhi)、產品計(ji)數、寬度判別、速度檢測、定長(chang)剪切、孔洞(dong)識別、信號(hao)延時(shi)、自(zi)動門傳感、色標檢出、沖床(chuang)和剪切機以及安全(quan)防護(hu)等諸多領域。此外,利(li)用(yong)紅外線的(de)(de)隱蔽性,還可(ke)在銀行、倉庫、商(shang)店、辦(ban)公室以及其它需要的(de)(de)場合作為防盜警戒(jie)之(zhi)用(yong)。