【繼電(dian)器控(kong)制電(dian)路(lu)】繼電(dian)器控(kong)制電(dian)路(lu)解析 繼電(dian)器的正確(que)使用方法

一、繼電器控制電路

能帶動繼電器工作的CMOS集成塊

在人們的習慣中，總認為CMOS集成塊不能直接帶動繼電器工作，但實驗證明，部分CMOS集成塊不僅能直接帶動繼電器工作，而且工作穩定可靠。實驗中所用繼電器的型號為JRC5M－DC12V微型密封繼電器（其線圈電阻為750Ω）。現將CD4066 CMOS集成塊帶動繼電器的工(gong)作原理(li)分析如下：

CD4066是(shi)四雙向模擬(ni)開(kai)關(guan)，集(ji)(ji)成(cheng)塊SCR1～SCR4為(wei)控制端(duan)，用于控制四雙向模擬(ni)開(kai)關(guan)的通斷。當(dang)SCR1接(jie)高電(dian)平(ping)(ping)時(shi)，集(ji)(ji)成(cheng)塊①、②腳(jiao)導通，＋12V→K1→集(ji)(ji)成(cheng)塊①、②腳(jiao)→電(dian)源負極使K1吸合；反之當(dang)SCR1輸(shu)入低電(dian)平(ping)(ping)時(shi)，集(ji)(ji)成(cheng)塊①、②腳(jiao)開(kai)路(lu)，K1失電(dian)釋放，SCR2～SCR4輸(shu)入高電(dian)平(ping)(ping)或(huo)低電(dian)平(ping)(ping)時(shi)狀態與SCR1相同。

該圖片由注冊用戶"沉靜時光"提供，版權聲明反饋

電(dian)(dian)路中，繼電(dian)(dian)器線圈兩(liang)端(duan)均反相并聯(lian)了一只二極管，它(ta)是(shi)用(yong)于保護集成(cheng)塊的，切不(bu)可(ke)省去，否則在(zai)繼電(dian)(dian)器由(you)吸合(he)狀態轉為釋(shi)放(fang)時，由(you)于電(dian)(dian)感(gan)的作用(yong)線圈上將(jiang)產(chan)生較高的反電(dian)(dian)動勢(shi)，極容易導致集成(cheng)塊擊穿。并聯(lian)了二極管后，在(zai)繼電(dian)(dian)器由(you)吸合(he)變為釋(shi)放(fang)的瞬(shun)間，線圈將(jiang)通過二極管形成(cheng)短時間的續(xu)流(liu)回路，使線圈中的電(dian)(dian)流(liu)不(bu)致突變，從而(er)避免了線圈中反電(dian)(dian)動勢(shi)的產(chan)生，確保了集成(cheng)塊的安(an)全(quan)。

低電壓下繼電器的吸合措施

常(chang)常(chang)因(yin)為電(dian)源電(dian)壓低于繼電(dian)器(qi)的(de)(de)吸合(he)電(dian)壓而使其(qi)(qi)不能正常(chang)工作(zuo)，事實上(shang)，繼電(dian)器(qi)一(yi)旦(dan)吸合(he)，便可(ke)在額定(ding)電(dian)壓的(de)(de)一(yi)半左右可(ke)靠(kao)地工作(zuo)。因(yin)此(ci)，可(ke)以在開(kai)始(shi)時給繼電(dian)器(qi)一(yi)個啟動電(dian)壓使其(qi)(qi)吸合(he)，然后再讓(rang)其(qi)(qi)在較(jiao)低的(de)(de)電(dian)源電(dian)壓下工作(zuo)，如圖(tu)所示的(de)(de)電(dian)路(lu)便可(ke)實現(xian)此(ci)目的(de)(de)。

工作(zuo)(zuo)原(yuan)理：如圖(tu)所示。V1為(wei)單結晶體管BT33C，它與R1、R2、R3和C1組成一個(ge)張弛式振蕩器，SCR為(wei)單向可控(kong)硅，按(an)下(xia)(xia)啟動按(an)鈕AN1后(hou)，電(dian)(dian)(dian)(dian)路(lu)(lu)通電(dian)(dian)(dian)(dian)，因為(wei)SCR無(wu)觸(chu)發電(dian)(dian)(dian)(dian)壓，所以不導通，繼電(dian)(dian)(dian)(dian)器J不動作(zuo)(zuo)，電(dian)(dian)(dian)(dian)源(yuan)通過(guo)R4和VD1給(gei)(gei)電(dian)(dian)(dian)(dian)容(rong)(rong)C2迅速充(chong)電(dian)(dian)(dian)(dian)至接(jie)近(jin)(jin)電(dian)(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)(dian)壓（Vcc-VD1壓降）。同(tong)時(shi)，電(dian)(dian)(dian)(dian)源(yuan)經(jing)R1給(gei)(gei)電(dian)(dian)(dian)(dian)容(rong)(rong)C1充(chong)電(dian)(dian)(dian)(dian)。數秒后(hou)，C1上(shang)(shang)電(dian)(dian)(dian)(dian)壓充(chong)到V1的觸(chu)發電(dian)(dian)(dian)(dian)壓，C1立即通過(guo)V1放電(dian)(dian)(dian)(dian)，在(zai)(zai)R3上(shang)(shang)形成一個(ge)正(zheng)(zheng)脈沖(chong)，該脈沖(chong)一路(lu)(lu)加到V2基極(ji)(ji)，使(shi)V2迅速飽和導通，V2集電(dian)(dian)(dian)(dian)極(ji)(ji)也(ye)即電(dian)(dian)(dian)(dian)容(rong)(rong)C2正(zheng)(zheng)極(ji)(ji)近(jin)(jin)于接(jie)地。由于此時(shi)C2上(shang)(shang)充(chong)有上(shang)(shang)正(zheng)(zheng)下(xia)(xia)負的正(zheng)(zheng)極(ji)(ji)性電(dian)(dian)(dian)(dian)壓，所以C2負極(ji)(ji)也(ye)即J線圈一端(duan)呈負電(dian)(dian)(dian)(dian)位。R3上(shang)(shang)的正(zheng)(zheng)脈沖(chong)另一路(lu)(lu)經(jing)VD2、C3去觸(chu)發可控(kong)硅導通，SCR陰(yin)極(ji)(ji)也(ye)即J線圈另一端(duan)接(jie)近(jin)(jin)電(dian)(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)(dian)壓。這時(shi)，J線圈實際上(shang)(shang)承受約兩(liang)倍的電(dian)(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)(dian)壓，所以J1－1閉合，松開AN1后(hou)，J1－1自保。J1－2將V1、V2供電(dian)(dian)(dian)(dian)切斷，繼電(dian)(dian)(dian)(dian)器在(zai)(zai)接(jie)近(jin)(jin)電(dian)(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)(dian)壓下(xia)(xia)工作(zuo)(zuo)。圖(tu)中，AN2為(wei)停止(zhi)按(an)鈕，按(an)下(xia)(xia)AN2，J失電(dian)(dian)(dian)(dian)釋放，J1－1斷開，整(zheng)個(ge)控(kong)制(zhi)電(dian)(dian)(dian)(dian)路(lu)(lu)失電(dian)(dian)(dian)(dian)。

制作(zuo)本電(dian)路時，一(yi)(yi)般可(ke)(ke)取繼(ji)電(dian)器(qi)的額定電(dian)壓為(wei)電(dian)源(yuan)電(dian)壓的1.5倍左(zuo)右，一(yi)(yi)般情況(kuang)下，任何(he)型(xing)號(hao)的單向可(ke)(ke)控(kong)硅(gui)（或雙向可(ke)(ke)控(kong)硅(gui)）皆可(ke)(ke)滿足本電(dian)路需要。V2、C1、C3的耐壓視電(dian)源(yuan)電(dian)壓的高低(di)選取。C2耐壓最好不(bu)低(di)于電(dian)源(yuan)電(dian)壓的兩倍。

繼電器的三種附加電路

繼電(dian)(dian)(dian)器(qi)(qi)是電(dian)(dian)(dian)子電(dian)(dian)(dian)路(lu)中常(chang)用(yong)的(de)(de)一(yi)種元件，一(yi)般由晶(jing)體管、繼電(dian)(dian)(dian)器(qi)(qi)等元器(qi)(qi)件組成(cheng)的(de)(de)電(dian)(dian)(dian)子開關驅動電(dian)(dian)(dian)路(lu)中，往(wang)往(wang)還要加上一(yi)些附加電(dian)(dian)(dian)路(lu)以改變(bian)繼電(dian)(dian)(dian)器(qi)(qi)的(de)(de)工作特(te)性或起保護作用(yong)。繼電(dian)(dian)(dian)器(qi)(qi)的(de)(de)附加電(dian)(dian)(dian)路(lu)主要有如下三(san)種形式：

1.繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)串(chuan)聯RC電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)：電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)形式(shi)如圖1，這(zhe)種形式(shi)主要應用(yong)于繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)的(de)額定(ding)工作電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)低于電(dian)(dian)(dian)(dian)(dian)(dian)源電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)中。當電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)閉合(he)時(shi)，繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)線(xian)圈(quan)由于自感現(xian)象會(hui)產生電(dian)(dian)(dian)(dian)(dian)(dian)動勢阻(zu)礙(ai)線(xian)圈(quan)中電(dian)(dian)(dian)(dian)(dian)(dian)流的(de)增(zeng)大(da)，從(cong)而(er)延長了吸(xi)合(he)時(shi)間(jian)，串(chuan)聯上RC電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)后則可以縮短(duan)吸(xi)合(he)時(shi)間(jian)。原理是電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)閉合(he)的(de)瞬(shun)間(jian)，電(dian)(dian)(dian)(dian)(dian)(dian)容C兩端電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)不能突變可視(shi)為短(duan)路(lu)，這(zhe)樣就將比(bi)繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)線(xian)圈(quan)額定(ding)工作電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)高(gao)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)源電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)加(jia)到線(xian)圈(quan)上，從(cong)而(er)加(jia)快了線(xian)圈(quan)中電(dian)(dian)(dian)(dian)(dian)(dian)流增(zeng)大(da)的(de)速度(du)，使繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)迅速吸(xi)合(he)。電(dian)(dian)(dian)(dian)(dian)(dian)源穩定(ding)之(zhi)后電(dian)(dian)(dian)(dian)(dian)(dian)容C不起(qi)作用(yong)，電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)R起(qi)限流作用(yong)。

2.繼(ji)電器(qi)并聯RC電路(lu)(lu)(lu)：電路(lu)(lu)(lu)形式見(jian)圖(tu)2，電路(lu)(lu)(lu)閉合(he)后(hou)，當(dang)電流穩定時(shi)(shi)(shi)RC電路(lu)(lu)(lu)不起作用(yong)，斷開電路(lu)(lu)(lu)時(shi)(shi)(shi)，繼(ji)電器(qi)線圈由(you)于自感(gan)而產(chan)生感(gan)應電動(dong)勢，經RC電路(lu)(lu)(lu)放電，使線圈中電流衰減放慢，從(cong)而延長了(le)繼(ji)電器(qi)銜鐵(tie)釋放時(shi)(shi)(shi)間(jian)，起到延時(shi)(shi)(shi)作用(yong)。

3.繼(ji)電(dian)(dian)(dian)器(qi)并(bing)(bing)聯(lian)二(er)極(ji)管(guan)(guan)(guan)電(dian)(dian)(dian)路：電(dian)(dian)(dian)路形(xing)式見圖3，主要是(shi)為(wei)了保護晶(jing)(jing)體(ti)管(guan)(guan)(guan)等驅動元器(qi)件。當(dang)圖中晶(jing)(jing)體(ti)管(guan)(guan)(guan)VT由導通(tong)變為(wei)截止時，流經繼(ji)電(dian)(dian)(dian)器(qi)線圈(quan)(quan)的電(dian)(dian)(dian)流將迅速減小(xiao)，這時線圈(quan)(quan)會產生很(hen)高的自(zi)(zi)感電(dian)(dian)(dian)動勢與電(dian)(dian)(dian)源電(dian)(dian)(dian)壓疊加后加在VT的c、e兩極(ji)間，會使(shi)晶(jing)(jing)體(ti)管(guan)(guan)(guan)擊穿，并(bing)(bing)聯(lian)上二(er)極(ji)管(guan)(guan)(guan)后，即可將線圈(quan)(quan)的自(zi)(zi)感電(dian)(dian)(dian)動勢鉗位于(yu)二(er)極(ji)管(guan)(guan)(guan)的正向導通(tong)電(dian)(dian)(dian)壓，此值硅管(guan)(guan)(guan)約(yue)0.7V，鍺管(guan)(guan)(guan)約(yue)0.2V，從(cong)而避免擊穿晶(jing)(jing)體(ti)管(guan)(guan)(guan)等驅動元器(qi)件。并(bing)(bing)聯(lian)二(er)極(ji)管(guan)(guan)(guan)時一定要注意二(er)極(ji)管(guan)(guan)(guan)的極(ji)性不(bu)可接反，否則容(rong)易損(sun)壞晶(jing)(jing)體(ti)管(guan)(guan)(guan)等驅動元器(qi)件。

無電感式模擬繼電器

圖中，220V電源(yuan)經負載RL、R1、D1～D4、ZD1，為(wei)Q4、Q3在(zai)正負半周輪流提(ti)供偏置；同(tong)時(shi)經R3、D5～D8為(wei)光電耦合器(qi)Q1提(ti)供電源(yuan)。當(dang)前級TTL電路輸(shu)出高(gao)電平信號時(shi)，光電耦合器(qi)在(zai)市(shi)電正半周內導通，于是(shi)在(zai)R5兩(liang)端產生壓降，觸發SCR導通，負載RL得電工(gong)作。整個電路的(de)功能如同(tong)一只繼電器(qi)，但(dan)不會(hui)產生反(fan)向感應(ying)電壓，也(ye)就避免了負載被高(gao)反(fan)壓擊穿損壞的(de)可(ke)能。C1、R6為(wei)脈沖(chong)吸收元件，R3起限流作用(yong)。

為避免(mian)RL為感性負載時(shi)，可控(kong)硅的(de)(de)電(dian)(dian)壓與(yu)光(guang)電(dian)(dian)耦合(he)器電(dian)(dian)源產生的(de)(de)90°相位，該電(dian)(dian)路中光(guang)電(dian)(dian)耦合(he)器的(de)(de)電(dian)(dian)源取自SCR的(de)(de)陽極而不(bu)直接(jie)取自市電(dian)(dian)電(dian)(dian)源。

繼電器電路小改進

繼電(dian)器(qi)常安裝在(zai)電(dian)器(qi)設備的內部，其(qi)工作狀(zhuang)態不直觀，筆者將(jiang)其(qi)作如(ru)下(xia)圖改進。在(zai)線(xian)圈(quan)兩端接(jie)發(fa)(fa)光(guang)(guang)二極管(guan)(guan)VD1，當控制電(dian)壓為(wei)正(zheng)時(shi)(shi)，三極管(guan)(guan)導通，繼電(dian)器(qi)J吸(xi)合，同時(shi)(shi)發(fa)(fa)光(guang)(guang)二極管(guan)(guan)被點(dian)亮，表(biao)明繼電(dian)器(qi)線(xian)圈(quan)已加上電(dian)源(yuan)。發(fa)(fa)光(guang)(guang)二極管(guan)(guan)可裝在(zai)外殼顯眼(yan)之處。

二、繼電器的正確使用方法

1、繼電器額定工作電壓的選擇

繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)額(e)定工(gong)(gong)作(zuo)(zuo)(zuo)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)是(shi)繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)最主(zhu)要(yao)的(de)(de)一項技術參(can)數。在(zai)使用繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)時，應(ying)該首(shou)先(xian)考慮所(suo)在(zai)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)(即(ji)繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)線(xian)圈所(suo)在(zai)的(de)(de)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu))的(de)(de)工(gong)(gong)作(zuo)(zuo)(zuo)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)的(de)(de)額(e)定工(gong)(gong)作(zuo)(zuo)(zuo)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)應(ying)等(deng)于所(suo)在(zai)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)的(de)(de)工(gong)(gong)作(zuo)(zuo)(zuo)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)。一般所(suo)在(zai)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)的(de)(de)工(gong)(gong)作(zuo)(zuo)(zuo)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)是(shi)繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)額(e)定工(gong)(gong)作(zuo)(zuo)(zuo)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)(de)0.86。注意所(suo)在(zai)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)的(de)(de)工(gong)(gong)件電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)千萬不能超(chao)過(guo)繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)額(e)定工(gong)(gong)作(zuo)(zuo)(zuo)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，否則繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)線(xian)圈容易燒(shao)毀。另外，有(you)(you)些集成(cheng)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)，例如NE555電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)是(shi)可以直接驅動繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)工(gong)(gong)作(zuo)(zuo)(zuo)的(de)(de)，而(er)有(you)(you)些集成(cheng)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)，例如COMS電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)輸出(chu)電(dian)(dian)(dian)(dian)(dian)流小(xiao)，需要(yao)加一級晶體管(guan)放(fang)大(da)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)方(fang)可驅動繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)，這就應(ying)考慮晶體管(guan)輸出(chu)電(dian)(dian)(dian)(dian)(dian)流應(ying)大(da)于繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)的(de)(de)額(e)定工(gong)(gong)作(zuo)(zuo)(zuo)電(dian)(dian)(dian)(dian)(dian)流。

2、觸點負載的選擇

觸點負載是指觸點的承受能力。繼電器的(de)觸點在(zai)轉換(huan)時(shi)(shi)可承(cheng)受一定(ding)的(de)電(dian)(dian)(dian)壓和(he)電(dian)(dian)(dian)流(liu)。所以(yi)在(zai)使(shi)用繼(ji)(ji)電(dian)(dian)(dian)器(qi)(qi)時(shi)(shi)，應考(kao)慮加在(zai)觸點上的(de)電(dian)(dian)(dian)壓和(he)通(tong)過觸點的(de)電(dian)(dian)(dian)流(liu)不能超過該繼(ji)(ji)電(dian)(dian)(dian)器(qi)(qi)的(de)觸點負載(zai)能力。例如，有一繼(ji)(ji)電(dian)(dian)(dian)器(qi)(qi)的(de)觸點負載(zai)為(wei)28V(DC)×10A，表明該繼(ji)(ji)電(dian)(dian)(dian)器(qi)(qi)觸點只能工作(zuo)在(zai)直流(liu)電(dian)(dian)(dian)壓為(wei)28V的(de)電(dian)(dian)(dian)路上，觸點電(dian)(dian)(dian)流(liu)為(wei)10A，超過28V或10A，會影響繼(ji)(ji)電(dian)(dian)(dian)器(qi)(qi)正(zheng)常使(shi)用，甚至燒毀觸點。

3、繼電器線圈電源的選擇

這是(shi)(shi)指(zhi)繼(ji)電(dian)(dian)器線圈(quan)使用(yong)(yong)(yong)的是(shi)(shi)直(zhi)流(liu)電(dian)(dian)(DC)還是(shi)(shi)交流(liu)電(dian)(dian)(AC)。通常，初學(xue)者在進行電(dian)(dian)子(zi)制作(zuo)活動中，都是(shi)(shi)采用(yong)(yong)(yong)電(dian)(dian)子(zi)線路，而電(dian)(dian)子(zi)線路往(wang)往(wang)采用(yong)(yong)(yong)直(zhi)流(liu)電(dian)(dian)源供電(dian)(dian)，所以(yi)必須是(shi)(shi)采用(yong)(yong)(yong)線圈(quan)是(shi)(shi)直(zhi)流(liu)電(dian)(dian)壓(ya)的繼(ji)電(dian)(dian)器。樂灌胃和腹腔注射實驗，結果發現可樂對(dui)小(xiao)鼠精(jing)子(zi)活性和形態有一(yi)定(ding)影響。但(dan)是(shi)(shi)截(jie)至目前，仍無法證(zheng)明飲用(yong)(yong)(yong)碳酸(suan)飲料對(dui)人(ren)體(ti)有“殺精(jing)”效果。