一、示波器的種類

（一）按照信號的不同分類

1、模擬示波器

采用的(de)是模擬電(dian)路（示波(bo)管，其基礎(chu)是電(dian)子(zi)槍）電(dian)子(zi)槍向(xiang)屏幕發射電(dian)子(zi)，發射的(de)電(dian)子(zi)經(jing)聚焦形成電(dian)子(zi)束(shu)，并打到屏幕上。屏幕的(de)內表面(mian)涂有熒光物質,，這樣電(dian)子(zi)束(shu)打中的(de)點就會發出光來。

2、數字示波器

則是(shi)數(shu)(shu)據采(cai)集，A/D轉換(huan)，軟件編(bian)程等一系(xi)列的(de)(de)技術制(zhi)造出(chu)來的(de)(de)高性能示(shi)(shi)波(bo)(bo)器(qi)。數(shu)(shu)字示(shi)(shi)波(bo)(bo)器(qi)的(de)(de)工(gong)作(zuo)方式是(shi)通(tong)過模擬(ni)轉換(huan)器(qi)（ADC）把被測(ce)電壓轉換(huan)為數(shu)(shu)字信息。數(shu)(shu)字示(shi)(shi)波(bo)(bo)器(qi)捕獲的(de)(de)是(shi)波(bo)(bo)形的(de)(de)一系(xi)列樣(yang)值，并對(dui)樣(yang)值進行(xing)存(cun)儲(chu)，存(cun)儲(chu)限(xian)度是(shi)判斷累計的(de)(de)樣(yang)值是(shi)否能描繪出(chu)波(bo)(bo)形為止(zhi)，隨后，數(shu)(shu)字示(shi)(shi)波(bo)(bo)器(qi)重構波(bo)(bo)形。數(shu)(shu)字示(shi)(shi)波(bo)(bo)器(qi)可以分為數(shu)(shu)字存(cun)儲(chu)示(shi)(shi)波(bo)(bo)器(qi)（DSO），數(shu)(shu)字熒光示(shi)(shi)波(bo)(bo)器(qi)（DPO）和采(cai)樣(yang)示(shi)(shi)波(bo)(bo)器(qi)。

模(mo)擬(ni)(ni)示(shi)(shi)(shi)(shi)(shi)波(bo)(bo)器(qi)(qi)要(yao)提高(gao)帶(dai)寬，需要(yao)示(shi)(shi)(shi)(shi)(shi)波(bo)(bo)管(guan)(guan)、垂(chui)直放大(da)和(he)水平掃(sao)描全面推進。數(shu)(shu)字示(shi)(shi)(shi)(shi)(shi)波(bo)(bo)器(qi)(qi)要(yao)改(gai)善帶(dai)寬只(zhi)需要(yao)提高(gao)前端的A/D轉換(huan)器(qi)(qi)的性能，對(dui)示(shi)(shi)(shi)(shi)(shi)波(bo)(bo)管(guan)(guan)和(he)掃(sao)描電路(lu)沒(mei)有特殊要(yao)求。加上數(shu)(shu)字示(shi)(shi)(shi)(shi)(shi)波(bo)(bo)管(guan)(guan)能充(chong)分利用記憶、存(cun)儲(chu)和(he)處理，以及多種觸(chu)發和(he)超前觸(chu)發能力(li)。廿世紀八(ba)十年(nian)代數(shu)(shu)字示(shi)(shi)(shi)(shi)(shi)波(bo)(bo)器(qi)(qi)異(yi)軍突起，成(cheng)果累累，大(da)有全面取(qu)代模(mo)擬(ni)(ni)示(shi)(shi)(shi)(shi)(shi)波(bo)(bo)器(qi)(qi)之(zhi)勢，模(mo)擬(ni)(ni)示(shi)(shi)(shi)(shi)(shi)波(bo)(bo)器(qi)(qi)的確(que)從前臺退到后臺。

（二）按照結構和性能不同分類

1、普通(tong)示波器。電路結構簡單，頻(pin)帶較窄(zhai)，掃描(miao)線性差，僅用于觀察(cha)波形。

2、多用示(shi)波(bo)器(qi)(qi)。頻(pin)帶較寬(kuan)，掃描(miao)線(xian)性好，能對直流、低頻(pin)、高(gao)(gao)頻(pin)、超高(gao)(gao)頻(pin)信(xin)號(hao)和脈沖信(xin)號(hao)進行(xing)定(ding)量(liang)測試。借(jie)助(zhu)幅度(du)校(xiao)(xiao)準器(qi)(qi)和時(shi)間校(xiao)(xiao)準器(qi)(qi)，測量(liang)的準確度(du)可達±5%。

3、多線示波(bo)器。采用多束示波(bo)管，能在熒光(guang)屏(ping)上(shang)同時(shi)(shi)顯示兩個以(yi)上(shang)同頻(pin)信(xin)號的波(bo)形，沒有時(shi)(shi)差，時(shi)(shi)序關系(xi)準確。

4、多蹤(zong)示(shi)波器(qi)。具(ju)有電(dian)子開關和門控電(dian)路的結構，可(ke)在單(dan)束示(shi)波管(guan)的熒光(guang)屏上同(tong)時(shi)顯示(shi)兩個以上同(tong)頻信號的波形。但存在時(shi)差，時(shi)序關系(xi)不準確。

5、取樣(yang)示波(bo)器(qi)。采用取樣(yang)技術將(jiang)高頻(pin)信號(hao)轉換成(cheng)模(mo)擬低頻(pin)信號(hao)進行顯示，有效頻(pin)帶可(ke)達GHz級。

6、記(ji)憶示(shi)波器。采用存(cun)儲示(shi)波管或數字存(cun)儲技術(shu)，將單次電(dian)信號瞬變過程(cheng)、非周期現象(xiang)和超(chao)低頻信號長(chang)時(shi)間保(bao)留在(zai)示(shi)波管的熒光屏(ping)上或存(cun)儲在(zai)電(dian)路(lu)中，以供重復測試(shi)。

7、數(shu)(shu)字示(shi)波(bo)器(qi)。內部帶有微處理器(qi)，外部裝有數(shu)(shu)字顯(xian)示(shi)器(qi)，有的產(chan)品在示(shi)波(bo)管(guan)熒光屏(ping)上(shang)既可(ke)(ke)顯(xian)示(shi)波(bo)形，又可(ke)(ke)顯(xian)示(shi)字符。被測信號經模一(yi)數(shu)(shu)變(bian)換器(qi)（A/D變(bian)換器(qi)）送入數(shu)(shu)據(ju)存(cun)儲器(qi)，通(tong)過鍵盤操作(zuo)，可(ke)(ke)對捕獲(huo)的波(bo)形參數(shu)(shu)的數(shu)(shu)據(ju)，進行加、減、乘、除、求平均值(zhi)、求平方根(gen)值(zhi)、求均方根(gen)值(zhi)等(deng)的運算(suan)，并(bing)顯(xian)示(shi)出答案數(shu)(shu)字。

該圖片由注冊用戶"天空之城"提供，版權聲明反饋

二、示波器的組成部分

（一）顯示電路

顯示電路包括示波(bo)管(guan)及其控制電路兩個部分(fen)(fen)。示波(bo)管(guan)是一(yi)(yi)種特殊的電子(zi)管(guan)，是示波(bo)器一(yi)(yi)個重(zhong)要組(zu)成部分(fen)(fen)。示波(bo)管(guan)由電子(zi)槍、偏(pian)轉(zhuan)系統和熒光屏3個部分(fen)(fen)組(zu)成。

1、電子槍

電(dian)(dian)(dian)子(zi)槍(qiang)用于產(chan)生并形成高速(su)、聚束的電(dian)(dian)(dian)子(zi)流，去轟(hong)擊熒(ying)(ying)光(guang)屏(ping)使之發光(guang)。它(ta)主(zhu)要由(you)燈(deng)(deng)絲F、陰極(ji)(ji)(ji)(ji)K、控(kong)制(zhi)極(ji)(ji)(ji)(ji)G、第一(yi)陽(yang)極(ji)(ji)(ji)(ji)A1、第二陽(yang)極(ji)(ji)(ji)(ji)A2組成。除燈(deng)(deng)絲外，其(qi)余(yu)電(dian)(dian)(dian)極(ji)(ji)(ji)(ji)的結(jie)構都為金屬(shu)圓筒，且它(ta)們的軸(zhou)心都保持在同一(yi)軸(zhou)線上(shang)。陰極(ji)(ji)(ji)(ji)被加(jia)熱后，可沿軸(zhou)向發射電(dian)(dian)(dian)子(zi)；控(kong)制(zhi)極(ji)(ji)(ji)(ji)相對陰極(ji)(ji)(ji)(ji)來說是(shi)負電(dian)(dian)(dian)位(wei)，改變(bian)電(dian)(dian)(dian)位(wei)可以改變(bian)通過控(kong)制(zhi)極(ji)(ji)(ji)(ji)小(xiao)孔的電(dian)(dian)(dian)子(zi)數目，也就是(shi)控(kong)制(zhi)熒(ying)(ying)光(guang)屏(ping)上(shang)光(guang)點(dian)的亮度。為了提高屏(ping)上(shang)光(guang)點(dian)亮度，又不降低對電(dian)(dian)(dian)子(zi)束偏轉的靈敏度，現(xian)代(dai)示波管(guan)中，在偏轉系統和熒(ying)(ying)光(guang)屏(ping)之間還加(jia)上(shang)一(yi)個后加(jia)速(su)電(dian)(dian)(dian)極(ji)(ji)(ji)(ji)A3。

第(di)一(yi)陽(yang)(yang)(yang)極(ji)(ji)(ji)對陰極(ji)(ji)(ji)而言加有(you)約幾百伏的(de)(de)正(zheng)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。在第(di)二(er)(er)陽(yang)(yang)(yang)極(ji)(ji)(ji)上加有(you)一(yi)個比第(di)一(yi)陽(yang)(yang)(yang)極(ji)(ji)(ji)更(geng)高(gao)的(de)(de)正(zheng)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。穿(chuan)過(guo)控(kong)制極(ji)(ji)(ji)小(xiao)孔的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)束(shu)，在第(di)一(yi)陽(yang)(yang)(yang)極(ji)(ji)(ji)和(he)(he)第(di)二(er)(er)陽(yang)(yang)(yang)極(ji)(ji)(ji)高(gao)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)的(de)(de)作(zuo)用下，得到加速(su)，向熒光(guang)屏(ping)方向作(zuo)高(gao)速(su)運動。由(you)于電(dian)(dian)(dian)(dian)(dian)(dian)荷的(de)(de)同性相斥，電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)束(shu)會逐(zhu)漸散開(kai)。通(tong)過(guo)第(di)一(yi)陽(yang)(yang)(yang)極(ji)(ji)(ji)、第(di)二(er)(er)陽(yang)(yang)(yang)極(ji)(ji)(ji)之(zhi)間(jian)電(dian)(dian)(dian)(dian)(dian)(dian)場的(de)(de)聚(ju)焦(jiao)作(zuo)用，使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)重新聚(ju)集起(qi)來并交匯于一(yi)點。適(shi)當控(kong)制第(di)一(yi)陽(yang)(yang)(yang)極(ji)(ji)(ji)和(he)(he)第(di)二(er)(er)陽(yang)(yang)(yang)極(ji)(ji)(ji)之(zhi)間(jian)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)差(cha)的(de)(de)大小(xiao)，便能(neng)使(shi)焦(jiao)點剛好落在熒光(guang)屏(ping)上，顯現一(yi)個光(guang)亮(liang)細小(xiao)的(de)(de)圓點。改變第(di)一(yi)陽(yang)(yang)(yang)極(ji)(ji)(ji)和(he)(he)第(di)二(er)(er)陽(yang)(yang)(yang)極(ji)(ji)(ji)之(zhi)間(jian)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)差(cha)，可起(qi)調(diao)節光(guang)點聚(ju)焦(jiao)的(de)(de)作(zuo)用，這就(jiu)是示波器的(de)(de)“聚(ju)焦(jiao)”和(he)(he)“輔(fu)助聚(ju)焦(jiao)”調(diao)節的(de)(de)原理。第(di)三陽(yang)(yang)(yang)極(ji)(ji)(ji)是示波管錐(zhui)體內(nei)部涂(tu)上一(yi)層(ceng)石(shi)墨形成(cheng)的(de)(de)，通(tong)常加有(you)很高(gao)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，它(ta)有(you)三個作(zuo)用：①使(shi)穿(chuan)過(guo)偏轉(zhuan)系統以(yi)后(hou)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)進一(yi)步(bu)加速(su)，使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)有(you)足夠的(de)(de)能(neng)量(liang)去轟擊熒光(guang)屏(ping)，以(yi)獲得足夠的(de)(de)亮(liang)度；②石(shi)墨層(ceng)涂(tu)在整個錐(zhui)體上，能(neng)起(qi)到屏(ping)蔽(bi)作(zuo)用；③電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)束(shu)轟擊熒光(guang)屏(ping)會產生二(er)(er)次電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)，處于高(gao)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)的(de)(de)A3可吸收(shou)這些電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)。

2、偏轉系統

示波(bo)管的(de)(de)(de)偏(pian)(pian)轉(zhuan)(zhuan)系統大(da)都是靜電(dian)(dian)(dian)偏(pian)(pian)轉(zhuan)(zhuan)式，它由兩對相互垂(chui)直(zhi)的(de)(de)(de)平(ping)(ping)行(xing)金(jin)屬板(ban)(ban)組成，分別稱(cheng)為水平(ping)(ping)偏(pian)(pian)轉(zhuan)(zhuan)板(ban)(ban)和垂(chui)直(zhi)偏(pian)(pian)轉(zhuan)(zhuan)板(ban)(ban)。分別控(kong)制電(dian)(dian)(dian)子(zi)束在(zai)水平(ping)(ping)方向(xiang)和垂(chui)直(zhi)方向(xiang)的(de)(de)(de)運(yun)動(dong)。當電(dian)(dian)(dian)子(zi)在(zai)偏(pian)(pian)轉(zhuan)(zhuan)板(ban)(ban)之間(jian)(jian)運(yun)動(dong)時，如(ru)果偏(pian)(pian)轉(zhuan)(zhuan)板(ban)(ban)上(shang)(shang)沒有(you)加電(dian)(dian)(dian)壓(ya)，偏(pian)(pian)轉(zhuan)(zhuan)板(ban)(ban)之間(jian)(jian)無(wu)電(dian)(dian)(dian)場(chang)，離開第二陽極后進入偏(pian)(pian)轉(zhuan)(zhuan)系統的(de)(de)(de)電(dian)(dian)(dian)子(zi)將沿(yan)軸向(xiang)運(yun)動(dong)，射向(xiang)屏幕的(de)(de)(de)中心。如(ru)果偏(pian)(pian)轉(zhuan)(zhuan)板(ban)(ban)上(shang)(shang)有(you)電(dian)(dian)(dian)壓(ya)，偏(pian)(pian)轉(zhuan)(zhuan)板(ban)(ban)之間(jian)(jian)則有(you)電(dian)(dian)(dian)場(chang)，進入偏(pian)(pian)轉(zhuan)(zhuan)系統的(de)(de)(de)電(dian)(dian)(dian)子(zi)會在(zai)偏(pian)(pian)轉(zhuan)(zhuan)電(dian)(dian)(dian)場(chang)的(de)(de)(de)作用下射向(xiang)熒光屏的(de)(de)(de)指定位置。

如果兩塊(kuai)偏(pian)(pian)(pian)轉(zhuan)(zhuan)板互相(xiang)平行，并且它們的(de)電位差(cha)等于(yu)零，那么通過偏(pian)(pian)(pian)轉(zhuan)(zhuan)板空(kong)間的(de)，具有速度(du)υ的(de)電子束就(jiu)(jiu)會沿(yan)著(zhu)(zhu)原(yuan)方(fang)(fang)向（設(she)為(wei)軸線(xian)(xian)方(fang)(fang)向）運(yun)動(dong)，并打(da)在(zai)(zai)(zai)熒光屏的(de)坐標原(yuan)點(dian)上(shang)。如果兩塊(kuai)偏(pian)(pian)(pian)轉(zhuan)(zhuan)板之(zhi)間存在(zai)(zai)(zai)著(zhu)(zhu)恒定的(de)電位差(cha)，則偏(pian)(pian)(pian)轉(zhuan)(zhuan)板間就(jiu)(jiu)形成一(yi)(yi)個(ge)電場，這(zhe)(zhe)個(ge)電場與(yu)電子的(de)運(yun)動(dong)方(fang)(fang)向相(xiang)垂直，于(yu)是電子就(jiu)(jiu)朝著(zhu)(zhu)電位比(bi)較高的(de)偏(pian)(pian)(pian)轉(zhuan)(zhuan)板偏(pian)(pian)(pian)轉(zhuan)(zhuan)。這(zhe)(zhe)樣，在(zai)(zai)(zai)兩偏(pian)(pian)(pian)轉(zhuan)(zhuan)板之(zhi)間的(de)空(kong)間，電子就(jiu)(jiu)沿(yan)著(zhu)(zhu)拋物線(xian)(xian)在(zai)(zai)(zai)這(zhe)(zhe)一(yi)(yi)點(dian)上(shang)做切線(xian)(xian)運(yun)動(dong)。最后(hou)，電子降落在(zai)(zai)(zai)熒光屏上(shang)的(de)A點(dian)，這(zhe)(zhe)個(ge)A點(dian)距(ju)離熒光屏原(yuan)點(dian)（0）有一(yi)(yi)段距(ju)離，這(zhe)(zhe)段距(ju)離稱(cheng)為(wei)偏(pian)(pian)(pian)轉(zhuan)(zhuan)量(liang)，用y表示。偏(pian)(pian)(pian)轉(zhuan)(zhuan)量(liang)y與(yu)偏(pian)(pian)(pian)轉(zhuan)(zhuan)板上(shang)所加(jia)的(de)電壓Vy成正比(bi)。同理(li)，在(zai)(zai)(zai)水平偏(pian)(pian)(pian)轉(zhuan)(zhuan)板上(shang)加(jia)有直流電壓時，也(ye)發(fa)生(sheng)類似情況，只是光點(dian)在(zai)(zai)(zai)水平方(fang)(fang)向上(shang)偏(pian)(pian)(pian)轉(zhuan)(zhuan)。

3、熒光屏

熒(ying)光(guang)(guang)(guang)屏(ping)位于示(shi)波(bo)管(guan)的終端，它的作用是將(jiang)偏轉后的電(dian)(dian)(dian)(dian)(dian)子(zi)束(shu)顯示(shi)出來，以便觀(guan)察。在示(shi)波(bo)器的熒(ying)光(guang)(guang)(guang)屏(ping)內(nei)壁涂(tu)有一層發(fa)光(guang)(guang)(guang)物質(zhi)(zhi)，因而(er)，熒(ying)光(guang)(guang)(guang)屏(ping)上受到高(gao)速電(dian)(dian)(dian)(dian)(dian)子(zi)沖擊(ji)的地點(dian)(dian)就(jiu)顯現(xian)(xian)出熒(ying)光(guang)(guang)(guang)。此時光(guang)(guang)(guang)點(dian)(dian)的亮度(du)決定于電(dian)(dian)(dian)(dian)(dian)子(zi)束(shu)的數目、密度(du)及其速度(du)。改變控(kong)制極的電(dian)(dian)(dian)(dian)(dian)壓時，電(dian)(dian)(dian)(dian)(dian)子(zi)束(shu)中(zhong)電(dian)(dian)(dian)(dian)(dian)子(zi)的數目將(jiang)隨(sui)之(zhi)改變，光(guang)(guang)(guang)點(dian)(dian)亮度(du)也就(jiu)改變。在使用示(shi)波(bo)器時，不宜讓很亮的光(guang)(guang)(guang)點(dian)(dian)固定出現(xian)(xian)在示(shi)波(bo)管(guan)熒(ying)光(guang)(guang)(guang)屏(ping)一個位置上，否則該點(dian)(dian)熒(ying)光(guang)(guang)(guang)物質(zhi)(zhi)將(jiang)因長期受電(dian)(dian)(dian)(dian)(dian)子(zi)沖擊(ji)而(er)燒壞(huai)，從而(er)失去發(fa)光(guang)(guang)(guang)能(neng)力。

涂有不(bu)(bu)同(tong)(tong)熒光(guang)物質(zhi)的(de)(de)(de)(de)(de)熒光(guang)屏(ping)，在(zai)受電子(zi)沖擊時(shi)將顯示出(chu)不(bu)(bu)同(tong)(tong)的(de)(de)(de)(de)(de)顏色和不(bu)(bu)同(tong)(tong)的(de)(de)(de)(de)(de)余輝時(shi)間，通常供觀察一般信號(hao)波(bo)(bo)形用(yong)的(de)(de)(de)(de)(de)是發(fa)綠光(guang)的(de)(de)(de)(de)(de)，屬中(zhong)余輝示波(bo)(bo)管(guan)，供觀察非周(zhou)期性及(ji)低頻信號(hao)用(yong)的(de)(de)(de)(de)(de)是發(fa)橙黃(huang)色光(guang)的(de)(de)(de)(de)(de)，屬長余輝示波(bo)(bo)管(guan)；供照相用(yong)的(de)(de)(de)(de)(de)示波(bo)(bo)器(qi)中(zhong)，一般都采用(yong)發(fa)藍色的(de)(de)(de)(de)(de)短余輝示波(bo)(bo)管(guan)。

（二）Y軸放大電路

由于(yu)示(shi)波管的偏轉靈敏度甚低，例(li)如常用(yong)的示(shi)波管13SJ38J型(xing)，其垂直偏轉靈敏度為(wei)0.86mm/V（約(yue)12V電(dian)(dian)壓產生1cm的偏轉量(liang)），所(suo)以一般的被測信號電(dian)(dian)壓都要先經過垂直放大(da)(da)電(dian)(dian)路的放大(da)(da)，再(zai)加到(dao)示(shi)波管的垂直偏轉板上(shang)，以得(de)到(dao)垂直方(fang)向的適當大(da)(da)小的圖(tu)形。

（三)X軸放大電路

由于(yu)示(shi)波(bo)管水(shui)(shui)平(ping)方向的(de)(de)偏(pian)轉(zhuan)靈敏度也很低，所以接入示(shi)波(bo)管水(shui)(shui)平(ping)偏(pian)轉(zhuan)板的(de)(de)電壓（鋸齒波(bo)電壓或其它(ta)電壓）也要先經(jing)過水(shui)(shui)平(ping)放大電路的(de)(de)放大以后，再加到示(shi)波(bo)管的(de)(de)水(shui)(shui)平(ping)偏(pian)轉(zhuan)板上，以得到水(shui)(shui)平(ping)方向適(shi)當大小的(de)(de)圖形。

（四）掃描同步電路

掃描(miao)電(dian)(dian)路產生一個鋸(ju)齒(chi)波電(dian)(dian)壓。該鋸(ju)齒(chi)波電(dian)(dian)壓的(de)(de)頻率能在一定的(de)(de)范圍內連(lian)續可調。鋸(ju)齒(chi)波電(dian)(dian)壓的(de)(de)作用是使示(shi)波管陰極(ji)發出的(de)(de)電(dian)(dian)子束在熒光屏上(shang)形(xing)成(cheng)(cheng)周期性的(de)(de)、與時間成(cheng)(cheng)正比的(de)(de)水平位移(yi)，即形(xing)成(cheng)(cheng)時間基線。這樣，才能把加在垂直方向的(de)(de)被測信(xin)號按(an)時間的(de)(de)變(bian)化波形(xing)展現在熒光屏上(shang)。

（五）電源供給電路

電(dian)源供(gong)給電(dian)路：供(gong)給垂直與(yu)水平放(fang)大電(dian)路、掃描與(yu)同(tong)步(bu)電(dian)路以及示波管與(yu)控(kong)制(zhi)電(dian)路所需的負高壓、燈(deng)絲電(dian)壓等(deng)。

由示波器的(de)原理功(gong)能可(ke)見，被測信號電(dian)壓(ya)(ya)加到示波器的(de)Y軸輸(shu)入(ru)端，經(jing)垂直(zhi)放大(da)電(dian)路加于示波管(guan)的(de)垂直(zhi)偏(pian)轉板。示波管(guan)的(de)水(shui)平偏(pian)轉電(dian)壓(ya)(ya)，雖(sui)然多(duo)數情況都采用(yong)鋸齒電(dian)壓(ya)(ya)（用(yong)于觀察波形(xing)時），但有時也(ye)采用(yong)其它(ta)的(de)外加電(dian)壓(ya)(ya)（用(yong)于測量頻率、相位差等時），因此(ci)在水(shui)平放大(da)電(dian)路輸(shu)入(ru)端有一個(ge)水(shui)平信號選擇(ze)開關，以便按照需要(yao)選用(yong)示波器內部的(de)鋸齒波電(dian)壓(ya)(ya)，或選用(yong)外加在X軸輸(shu)入(ru)端上(shang)的(de)其它(ta)電(dian)壓(ya)(ya)來作為水(shui)平偏(pian)轉電(dian)壓(ya)(ya)。

此外，為了使熒光屏上顯示的圖形保持穩定，要求鋸齒波電壓信號的頻率和被測信號的頻率保持同步。這樣，不僅要求鋸齒波電壓的頻率能連續調節，而且在產生鋸齒波的電路上還要輸入一個同步信號。這樣，對于只能產生連續掃描（即產生周而復始、連續不斷的鋸齒波）一種狀態的簡易示波器（如(ru)國產(chan)(chan)SB10型(xing)(xing)等(deng)示(shi)波(bo)(bo)器(qi)(qi)）而言，需(xu)(xu)要在其掃描電路上輸(shu)入一(yi)個(ge)與(yu)被(bei)觀察信號頻(pin)率相關(guan)的同(tong)步信號，以牽制(zhi)鋸(ju)齒(chi)波(bo)(bo)的振(zhen)蕩頻(pin)率。對于(yu)具有(you)等(deng)待掃描功能(neng)（即平時(shi)不產(chan)(chan)生(sheng)鋸(ju)齒(chi)波(bo)(bo)，當被(bei)測信號來(lai)(lai)到(dao)時(shi)才產(chan)(chan)生(sheng)一(yi)個(ge)鋸(ju)齒(chi)波(bo)(bo)，進(jin)行一(yi)次掃描）的示(shi)波(bo)(bo)器(qi)(qi)（如(ru)國產(chan)(chan)ST-16型(xing)(xing)示(shi)波(bo)(bo)器(qi)(qi)、SR-8型(xing)(xing)雙蹤示(shi)波(bo)(bo)器(qi)(qi)等(deng)）為了適應各種(zhong)需(xu)(xu)要，同(tong)步（或(huo)觸發(fa)）信號可通過同(tong)步或(huo)觸發(fa)信號選擇(ze)開關(guan)來(lai)(lai)選擇(ze)，通常來(lai)(lai)源有(you)3個(ge)：

1、從(cong)垂(chui)直放大電路引來被測信號(hao)作為(wei)同步(bu)（或(huo)(huo)觸(chu)發）信號(hao)，此信號(hao)稱為(wei)“內(nei)同步(bu)”（或(huo)(huo)“內(nei)觸(chu)發”）信號(hao)；

2、引入(ru)某種相關的外(wai)(wai)加(jia)信(xin)號(hao)為(wei)(wei)同(tong)(tong)步(bu)（或觸(chu)發）信(xin)號(hao)，此信(xin)號(hao)稱為(wei)(wei)“外(wai)(wai)同(tong)(tong)步(bu)”（或“外(wai)(wai)觸(chu)發”）信(xin)號(hao)，該(gai)信(xin)號(hao)加(jia)在(zai)外(wai)(wai)同(tong)(tong)步(bu)（或外(wai)(wai)觸(chu)發）輸入(ru)端；

3、有(you)(you)些(xie)示波器的同(tong)(tong)步信號(hao)選擇開關還有(you)(you)一檔“電(dian)(dian)源同(tong)(tong)步”，是由220V，50Hz電(dian)(dian)源電(dian)(dian)壓，通(tong)過(guo)變壓器次級降壓后(hou)作為(wei)同(tong)(tong)步信號(hao)。