播種機堵塞報警器的工作原理簡介

播種機存在一點不足，就是在播種時(shi)，播種機中的小麥(mai)(mai)下(xia)落(luo)管道很容易被小麥(mai)(mai)堵(du)(du)塞(sai)，而(er)(er)人們又一時(shi)很難發(fa)現(xian)，導致(zhi)人機白(bai)走(zou)一趟，浪費世間的同時(shi)無(wu)形之中也(ye)降低了工作效率。這款小麥(mai)(mai)播種顆(ke)粒(li)堵(du)(du)塞(sai)報警(jing)器，它能(neng)夠實(shi)施(shi)監測管道中小麥(mai)(mai)的下(xia)落(luo)情況，管道一旦(dan)被堵(du)(du)塞(sai)，電路立即發(fa)出報警(jing)，從而(er)(er)提醒人們及時(shi)采(cai)取(qu)措施(shi)進(jin)行處理。

一、電路原理

該報(bao)(bao)警電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)如下圖所(suo)示，電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)采取紅外(wai)線原理(li)，將管(guan)(guan)(guan)道中小麥的(de)下落情況轉(zhuan)換成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)信號來控(kong)制報(bao)(bao)警電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)。安(an)裝(zhuang)(zhuang)時(shi)(shi)，注(zhu)意(yi)要將紅外(wai)發(fa)光管(guan)(guan)(guan)VD1和接收管(guan)(guan)(guan)VD2正(zheng)對著裝(zhuang)(zhuang)于(yu)小麥下落管(guan)(guan)(guan)道中，使(shi)VD1管(guan)(guan)(guan)發(fa)出(chu)的(de)紅外(wai)光正(zheng)好(hao)照射(she)在VD2管(guan)(guan)(guan)上，這樣閉合(he)(he)電(dian)(dian)(dian)(dian)(dian)(dian)源開關，當小麥顆(ke)粒在管(guan)(guan)(guan)子內正(zheng)常下落時(shi)(shi)，紅外(wai)光便被小麥顆(ke)粒時(shi)(shi)斷時(shi)(shi)續(xu)的(de)遮擋，使(shi)得VD2管(guan)(guan)(guan)的(de)負極(ji)(ji)(ji)(ji)產(chan)生一系列連續(xu)的(de)負脈(mo)沖，并通過電(dian)(dian)(dian)(dian)(dian)(dian)容C1耦合(he)(he)到電(dian)(dian)(dian)(dian)(dian)(dian)容C2的(de)正(zheng)極(ji)(ji)(ji)(ji)，從而(er)使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)容C2沖不(bu)(bu)上電(dian)(dian)(dian)(dian)(dian)(dian)，VT1三(san)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)基(ji)極(ji)(ji)(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)壓近(jin)似為(wei)(wei)零，使(shi)得時(shi)(shi)基(ji)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)555的(de)2腳(jiao)為(wei)(wei)低電(dian)(dian)(dian)(dian)(dian)(dian)平，同時(shi)(shi)由于(yu)三(san)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)VT1的(de)作用，只要電(dian)(dian)(dian)(dian)(dian)(dian)容C2上的(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓為(wei)(wei)零，那么電(dian)(dian)(dian)(dian)(dian)(dian)容C3也(ye)就(jiu)不(bu)(bu)會充(chong)上電(dian)(dian)(dian)(dian)(dian)(dian)，否則(ze)三(san)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)VT1導通，也(ye)會將其放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)，這樣時(shi)(shi)基(ji)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)555的(de)2腳(jiao)和6腳(jiao)都為(wei)(wei)低電(dian)(dian)(dian)(dian)(dian)(dian)平，其3腳(jiao)輸出(chu)高電(dian)(dian)(dian)(dian)(dian)(dian)平，三(san)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)VT2飽(bao)和導通，振蕩電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)不(bu)(bu)起振，揚聲器不(bu)(bu)報(bao)(bao)警。

當管(guan)(guan)道一旦被堵住后，小麥顆粒(li)將不再落下，從(cong)而(er)使得(de)VD1管(guan)(guan)發(fa)出的紅外現(xian)實中照(zhao)射（或(huo)不照(zhao)射）在VD2管(guan)(guan)上，這樣，C1正極(ji)(ji)的電(dian)(dian)平始(shi)終為(wei)高(gao)或(huo)低，成為(wei)一直流信號，它將不再通過電(dian)(dian)容C1到(dao)(dao)達三(san)極(ji)(ji)管(guan)(guan)VT1基極(ji)(ji)，于是(shi)電(dian)(dian)容C2開(kai)始(shi)充電(dian)(dian)，緊(jin)接著，C3也隨(sui)著C2的充電(dian)(dian)而(er)充電(dian)(dian)，很快，電(dian)(dian)容C2、C3上的電(dian)(dian)壓便到(dao)(dao)達555的反轉電(dian)(dian)壓，555的2腳(jiao)和6腳(jiao)變成高(gao)電(dian)(dian)平，555復(fu)位，3腳(jiao)輸出低電(dian)(dian)平，三(san)極(ji)(ji)管(guan)(guan)VT2截止，啟動(dong)振蕩電(dian)(dian)路(lu)，從(cong)而(er)使揚聲(sheng)器發(fa)聲(sheng)報警。

二、實物調試與安裝
按原理圖連接好電路后，閉合電源開關k，先用手模擬(ni)小麥顆粒下(xia)落，即將手放于VD1管(guan)與VD2管(guan)之間(jian)，做上下(xia)揮動，使照射在VD2管(guan)上的(de)紅外線時斷時通，這時，揚聲器(qi)應該不會(hui)發(fa)聲，若不然(ran)可適當(dang)調節電位器(qi)RP1使其靈敏度達到(dao)最(zui)佳狀態，然(ran)后將手停止揮動，模擬(ni)管(guan)道堵塞，此時揚聲器(qi)便會(hui)發(fa)聲報警。

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。