播種機堵塞報警器的工作原理簡介
播種(zhong)機存在(zai)一(yi)點不足,就(jiu)是在(zai)播種(zhong)時(shi)(shi),播種(zhong)機中的小(xiao)麥下落管道很(hen)容易(yi)被小(xiao)麥堵(du)塞,而人們又一(yi)時(shi)(shi)很(hen)難發現,導致人機白走一(yi)趟,浪費世間的同時(shi)(shi)無形之中也降(jiang)低了工作效率。這款小(xiao)麥播種(zhong)顆粒(li)堵(du)塞報(bao)警(jing)器,它能夠實施(shi)監測管道中小(xiao)麥的下落情(qing)況,管道一(yi)旦被堵(du)塞,電(dian)路立即發出報(bao)警(jing),從而提醒人們及時(shi)(shi)采取(qu)措施(shi)進行處理。
一、電路原理
該報(bao)(bao)警電(dian)(dian)路(lu)(lu)如下(xia)圖所示,電(dian)(dian)路(lu)(lu)采取紅外(wai)線(xian)原理,將管(guan)道中(zhong)(zhong)小(xiao)麥的(de)(de)(de)(de)下(xia)落(luo)情況轉換成電(dian)(dian)信號來控制報(bao)(bao)警電(dian)(dian)路(lu)(lu)。安裝(zhuang)時(shi)(shi),注意要將紅外(wai)發(fa)光(guang)(guang)管(guan)VD1和接收管(guan)VD2正(zheng)對著裝(zhuang)于小(xiao)麥下(xia)落(luo)管(guan)道中(zhong)(zhong),使VD1管(guan)發(fa)出(chu)(chu)的(de)(de)(de)(de)紅外(wai)光(guang)(guang)正(zheng)好照射(she)在VD2管(guan)上(shang)(shang)(shang),這樣閉合(he)電(dian)(dian)源(yuan)開關,當小(xiao)麥顆粒在管(guan)子內正(zheng)常(chang)下(xia)落(luo)時(shi)(shi),紅外(wai)光(guang)(guang)便(bian)被小(xiao)麥顆粒時(shi)(shi)斷時(shi)(shi)續的(de)(de)(de)(de)遮擋(dang),使得(de)VD2管(guan)的(de)(de)(de)(de)負(fu)極(ji)(ji)(ji)產生一系列(lie)連續的(de)(de)(de)(de)負(fu)脈沖(chong),并通過電(dian)(dian)容(rong)C1耦(ou)合(he)到電(dian)(dian)容(rong)C2的(de)(de)(de)(de)正(zheng)極(ji)(ji)(ji),從而使電(dian)(dian)容(rong)C2沖(chong)不上(shang)(shang)(shang)電(dian)(dian),VT1三(san)(san)極(ji)(ji)(ji)管(guan)基極(ji)(ji)(ji)電(dian)(dian)壓(ya)近(jin)似(si)為零,使得(de)時(shi)(shi)基電(dian)(dian)路(lu)(lu)555的(de)(de)(de)(de)2腳為低(di)電(dian)(dian)平,同時(shi)(shi)由于三(san)(san)極(ji)(ji)(ji)管(guan)VT1的(de)(de)(de)(de)作(zuo)用,只(zhi)要電(dian)(dian)容(rong)C2上(shang)(shang)(shang)的(de)(de)(de)(de)電(dian)(dian)壓(ya)為零,那么(me)電(dian)(dian)容(rong)C3也就(jiu)不會(hui)充(chong)上(shang)(shang)(shang)電(dian)(dian),否則(ze)三(san)(san)極(ji)(ji)(ji)管(guan)VT1導(dao)通,也會(hui)將其放電(dian)(dian),這樣時(shi)(shi)基電(dian)(dian)路(lu)(lu)555的(de)(de)(de)(de)2腳和6腳都(dou)為低(di)電(dian)(dian)平,其3腳輸出(chu)(chu)高(gao)電(dian)(dian)平,三(san)(san)極(ji)(ji)(ji)管(guan)VT2飽和導(dao)通,振(zhen)蕩電(dian)(dian)路(lu)(lu)不起振(zhen),揚聲(sheng)器不報(bao)(bao)警。
當(dang)管(guan)道(dao)一旦被堵住后,小麥顆粒將(jiang)不再(zai)落下,從而(er)使得VD1管(guan)發(fa)出的(de)紅外現(xian)實中照射(she)(或不照射(she))在VD2管(guan)上,這樣,C1正極(ji)的(de)電(dian)(dian)平始終為(wei)高或低,成(cheng)為(wei)一直流(liu)信(xin)號,它將(jiang)不再(zai)通過電(dian)(dian)容C1到達(da)三極(ji)管(guan)VT1基(ji)極(ji),于是電(dian)(dian)容C2開(kai)始充電(dian)(dian),緊接(jie)著,C3也隨(sui)著C2的(de)充電(dian)(dian)而(er)充電(dian)(dian),很快,電(dian)(dian)容C2、C3上的(de)電(dian)(dian)壓便(bian)到達(da)555的(de)反轉電(dian)(dian)壓,555的(de)2腳和6腳變成(cheng)高電(dian)(dian)平,555復位,3腳輸出低電(dian)(dian)平,三極(ji)管(guan)VT2截止,啟動振蕩電(dian)(dian)路,從而(er)使揚聲器(qi)發(fa)聲報警(jing)。
二、實物調試與安裝
按原(yuan)理圖連接好電(dian)路(lu)后,閉合電(dian)源開關k,先(xian)用手模(mo)擬(ni)小(xiao)麥顆(ke)粒下(xia)(xia)落,即(ji)將手放于VD1管(guan)與VD2管(guan)之間,做上(shang)下(xia)(xia)揮動,使(shi)照射在VD2管(guan)上(shang)的紅外(wai)線(xian)時(shi)斷時(shi)通,這(zhe)時(shi),揚(yang)聲(sheng)器(qi)應該不會發聲(sheng),若(ruo)不然(ran)可適(shi)當調(diao)節電(dian)位器(qi)RP1使(shi)其靈(ling)敏度達到最佳狀態,然(ran)后將手停(ting)止揮動,模(mo)擬(ni)管(guan)道堵塞,此時(shi)揚(yang)聲(sheng)器(qi)便會發聲(sheng)報警。
安裝實物時,最關鍵的一點就是紅外線對管的安裝,務必將兩管正對安裝于小麥下落的管道中。在播種工作進行時,閉合開關k,然后就可以工作了。對于機動播種機,則可以在播種機的耬齒附近安裝一個壓控開關來代替開關k,這樣,只有當播種機從機動車的懸掛位置放到地面上時,報警器才開始工作,避免了手動控制的麻煩。