在zai三san極ji管guan開kai關guan電dian路lu的de設she計ji過guo程cheng中zhong，由you三san極ji管guan所suo構gou成cheng的de放fang大da電dian路lu，其qi功gong能neng是shi利li用yong三san極ji管guan的de電dian流liu控kong製zhi作zuo用yong，或huo場chang效xiao應ying管guan電dian壓ya控kong製zhi作zuo用yong，把ba微wei弱ruo的de電dian信xin號hao不bu失shi真zhen地di放fang大da到dao所suo需xu的de數shu值zhi，實shi現xian將jiang直zhi流liu電dian源yuan的de能neng量liang部bu分fen地di轉zhuan化hua為wei按an輸shu入ru信xin號hao規gui律lv變bian化hua且qie有you較jiao大da能neng量liang的de輸shu出chu信xin號hao。而er這zhe種zhong三san級ji管guan放fang大da電dian路lu的de實shi質zhi
，是shi一yi種zhong用yong較jiao小xiao的de能neng量liang去qu控kong製zhi較jiao大da能neng量liang轉zhuan換huan的de能neng量liang轉zhuan換huan裝zhuang置zhi。

 

zaishijideshejiheyingyongguochengzhong
，sanjiguanfangdadianludeshejiyuanzezhuyaoyousandian
，xuyaogongchengshizaishejizhiqianduojiazhuyi。diyibixuyouzhiliudianyuan，erqiedianyuandeshezhiyingbaozhengsanjiguanhuochangxiaoyingguangongzuozaixianxingfangdazhuangtai。dier
，yuanjiandeanpaiyaobaozhengxinhaodechuanshu，jibaozhengxinhaonenggoucongfangdadianludeshuruduanshuru，jingguofangdadianlufangdahoucongshuchuduanshu。disan，yuanjiancanshudexuanzeyaobaozhengxinhaonengbushizhendifangda
，bingmanzufangdadianludexingnengzhibiaoyaoqiu。yaoshisanjiguannenggouzhengchangfangdaxinhao，fashejieyingjiazhengxiangdianya，jidianjieyingjiafanxiangdianya。

 

為了更進一步的說明這種三極管開關電路的設計原理，在這裏我們以NPNsanjiguandegongfashejifangdadianluweili，laijutideshuomingyixia。xiatuzhongsuotigongdesanzhonglianjiefangshishisanjiguanfangdadianluzuichangjiande
，chulegongfashejilianjiefangshiwai
，haiyougongjidianjihegongjijilianjiefangshi。

在三極管其射極放大電路中，三極管V的作用是實現電流的放大。集電極直流電源UCC則能夠確保三極管工作在放大狀態。在該電路係統中，集電極負載電阻RC負責將三極管集電極電流變化轉變為電壓變化
，以實現電壓放大。基極偏置電阻RB為放大電路提供靜態工作點。耦合電容C1和C2的作用則是隔直流通交流。當這一電路接通後，ui直接加在三極管V的基極和發射極之間，引起基極電流iB作相應的變化，通過V的電流放大作用，V的集電極電流iC也將變化。而iC的變化引起V的集電極和發射極之間的電壓uCE變化。此時，uCE中的交流分量uce經過C2暢通地傳送給負載RL，成為輸出交流電壓uo
，由此實現了電壓放大作用。

 

以yi上shang就jiu是shi本ben文wen結jie合he實shi際ji案an例li
，所suo分fen析xi的de三san極ji管guan開kai關guan電dian路lu設she計ji過guo程cheng中zhong常chang用yong到dao的de放fang大da電dian路lu的de工gong作zuo原yuan理li，希xi望wang能neng夠gou為wei各ge位wei新xin人ren工gong程cheng師shi的de工gong作zuo和he研yan發fa設she計ji帶dai來lai一yi定ding的de幫bang助zhu。