关闭

关闭

关闭

封号提示

内容

首页 贴片三极管引脚_三极管的识别分类及测量[1].doc

贴片三极管引脚_三极管的识别分类及测量[1].doc

贴片三极管引脚_三极管的识别分类及测量[1].doc

上传者: 俄要让迩永远得卜到 2017-10-15 评分 0 0 0 0 0 0 暂无简介 简介 举报

简介:本文档为《贴片三极管引脚_三极管的识别分类及测量[1]doc》,可适用于综合领域,主题内容包含贴片三极管引脚三极管的识别分类及测量贴片三极管引脚三极管的识别分类及测量符号:“Q、VT”三极管有三个电极即b、c、e其中c为集电极(输入极)、b为符等。

贴片三极管引脚三极管的识别分类及测量贴片三极管引脚三极管的识别分类及测量符号:“Q、VT”三极管有三个电极即b、c、e其中c为集电极(输入极)、b为基极(控制极)、e为发射极(输出极)三极管实物图:贴片三极管功率三极管普通三极管金属壳三极管二、三级管的分类:按极性划分为两种:一种是NPN型三极管是目前最常用的一种另一种是PNP型三极管。按材料分为两种:一种是硅三极管目前是最常用的一种另一种是锗三极管以前这种三极管用的多。三极按工作频率划分为两种:一种是低频三极管主要用于工作频率比较低的地方另一种是高频三极管主要用于工作频率比较高的地方。按功率分为三种:一种是小功率三极管它的输出功率小些一种是中功率三极管它的输出功率大些另一种是大功率三极管它的输出功率可以很大主要用于大功率输出场合。按用途分为:放大管和开关管。三、三极管的组成:三极管由三块半导体构成对于,,,型三极管由两块,型和一块,型半导体构成如图,所示,型半导体在中间两块,型半导体在两侧各半导体所引出的电极见图中所示。在,型和,型半导体的交界面形成两个,,结在基极与集电极之间的,,结称为集电结在基极与发射极之间的,,结称为发射结。图,是,,,型三极管结构示意图它用两块,型半导体和一块,型半导体构成。,,四、三极管在电路中的工作状态:platesfortanklap,notfixedProtectwiresshouldbeleftinthegroundandslotthecompensationallowanceMetalcabletraysandsupportandtheintroductionofmetalcableductsmustbedrawnorground(PE)orzero(PEN)reliableandmustcomplywiththefollowingrequirements:metalcabletraysandsupportfulllengthnotlessthaninthegrounding(PE)orzero(PEN)trunkconnectionsnongalvanizedcablebridgebetweenbothendsoftheconnectionplatesbridgedcoppergroundwire,groundingallowedminimumcrosssectionalareaofnotlessthanmmgalvanizedcablebridgeacrossbothendsoftheconnectionbetweenthegroundingwire,connectbothendsoftheBoardnotlessthanlockingnutandlockwasherfixingboltsoftheconnectionCabletraysinstalledinaccordancewiththefollowingprovisions:straightsteelcabletraylengthsnotexceedingm,aluminumorfiberglassCableTraylengthsovermwiththeslipjointcablebridgespansthebuildingsetacompensationslotthebendingradiusofthecabletraybend,notlessthanminimumtraycableallowstheturningradius,minimumbendingradiusofthecableshowninthetablebelowTablecableminimumallowsbentRADIUSserialnumbercabletypeminimumallowsbentradiusnoleadBaoGangkainursingsetsofrubberinsulationpowercableDhassteelarmorednursingsetsofrubberinsulationpowercableDPVCinsulationpowercableDmakejointPVCinsulationpowercableDmorethanmorecorecontrolcableDNote:dforcableodDangdesignnorequirements三极管有三种工作状态:截止状态、放大状态、饱和状态。当三极管用于不同目的时它的工作状态是不同的。、截止状态:当三极管的工作电流为零或很小时即IB=时IC和IE也为零或很小三极管处于截止状态。、放大状态:在放大状态下IC=βIB其中β(放大倍数)的大小是基本不变的(放大区的特征)。有一个基极电流就有一个与之相对应的集电极电流。、饮和状态:在饮和状态下当基极电流增大时集电极电流不再增大许多当基极电流进一步增大时集电极电流几乎不再增大。工作状态定义电流特征解流截止状态集电极与发射极之间电阻很大IB=或很小IC或IE为零或很小因为IC,βIB利用电流为零或很小特征可以判断三极管已处于截止状态放大状态集电极与发射极之间内阻受基极电流大小控制基极电流大其内阻小IC,βIBIE=(β)IB有一个基极电流就有一个对应的集电极电流和发射极电流基极电流能有效地控制集电极电流和发射极电流饱和状态platesfortanklap,notfixedProtectwiresshouldbeleftinthegroundandslotthecompensationallowanceMetalcabletraysandsupportandtheintroductionofmetalcableductsmustbedrawnorground(PE)orzero(PEN)reliableandmustcomplywiththefollowingrequirements:metalcabletraysandsupportfulllengthnotlessthaninthegrounding(PE)orzero(PEN)trunkconnectionsnongalvanizedcablebridgebetweenbothendsoftheconnectionplatesbridgedcoppergroundwire,groundingallowedminimumcrosssectionalareaofnotlessthanmmgalvanizedcablebridgeacrossbothendsoftheconnectionbetweenthegroundingwire,connectbothendsoftheBoardnotlessthanlockingnutandlockwasherfixingboltsoftheconnectionCabletraysinstalledinaccordancewiththefollowingprovisions:straightsteelcabletraylengthsnotexceedingm,aluminumorfiberglassCableTraylengthsovermwiththeslipjointcablebridgespansthebuildingsetacompensationslotthebendingradiusofthecabletraybend,notlessthanminimumtraycableallowstheturningradius,minimumbendingradiusofthecableshowninthetablebelowTablecableminimumallowsbentRADIUSserialnumbercabletypeminimumallowsbentradiusnoleadBaoGangkainursingsetsofrubberinsulationpowercableDhassteelarmorednursingsetsofrubberinsulationpowercableDPVCinsulationpowercableDmakejointPVCinsulationpowercableDmorethanmorecorecontrolcableDNote:dforcableodDangdesignnorequirements集电极与发射之间内阻很小各电极电流均很大基极电流已无法控制集电极电流和发射极电流电流放大倍数β已很小甚至小于(用直流电控制信号的一种方式)五、三极管的作用:放大、调制、谐振、开关、电流放大:三极管是一个电流控制器件它用基极电流IB来控制集电极电流IC和发射极电流IE没有IB就没有IC和IE只要有一个很小的IB就有一个很大的IC。在放大电路中就是利用三极管的这一特性来放大信号的。、开关作用:当三极管做开关时工作在截止、饱和两个状态。在三极管开关电路中三极管的集电极和发射极之间相当于一个开关当三极管截止时它的集电极和发射之间的内阻很大相当于开关的断开状态当三极管饱和时它的集电极和发射极之间内阻很小相当于开关的接通状态。导通状态的工作条件:UB>UE且UBEVCE结内阻很小此时电流可以从集电极经CE结流向发射极。截止状态的工作条件:UBE<V时也就是基极没有电流时CE结内阻很大此时CE结没有电流流过。硅三极管和锗三极管的导通、截止电压也是不同的:硅三极管:导通电压UBE>V截止电压UBE<V。锗三极管:导通电压UBE>V截止电压UBE<V。六、三极管的测量及好坏判断、三极管的测量三极管的极性及管型判断把万用表打到蜂鸣二极管档首先用红笔假定三极管的一只引脚为b极再用黑笔分别角碰其余两只引脚如果测得两次讲习数相差不大且都在左右则表明假定是对的红笔接的就是b极而且此管为,,,型管。c、e极的判断在两次测量中黑笔接触的引脚读数较小的是c极读数较大的是eplatesfortanklap,notfixedProtectwiresshouldbeleftinthegroundandslotthecompensationallowanceMetalcabletraysandsupportandtheintroductionofmetalcableductsmustbedrawnorground(PE)orzero(PEN)reliableandmustcomplywiththefollowingrequirements:metalcabletraysandsupportfulllengthnotlessthaninthegrounding(PE)orzero(PEN)trunkconnectionsnongalvanizedcablebridgebetweenbothendsoftheconnectionplatesbridgedcoppergroundwire,groundingallowedminimumcrosssectionalareaofnotlessthanmmgalvanizedcablebridgeacrossbothendsoftheconnectionbetweenthegroundingwire,connectbothendsoftheBoardnotlessthanlockingnutandlockwasherfixingboltsoftheconnectionCabletraysinstalledinaccordancewiththefollowingprovisions:straightsteelcabletraylengthsnotexceedingm,aluminumorfiberglassCableTraylengthsovermwiththeslipjointcablebridgespansthebuildingsetacompensationslotthebendingradiusofthecabletraybend,notlessthanminimumtraycableallowstheturningradius,minimumbendingradiusofthecableshowninthetablebelowTablecableminimumallowsbentRADIUSserialnumbercabletypeminimumallowsbentradiusnoleadBaoGangkainursingsetsofrubberinsulationpowercableDhassteelarmorednursingsetsofrubberinsulationpowercableDPVCinsulationpowercableDmakejointPVCinsulationpowercableDmorethanmorecorecontrolcableDNote:dforcableodDangdesignnorequirements极。红笔接b极当测得的两级数值都不在范围内则按,,,型管测。,,,型管的判断只须把红黑表笔调换即可测量方法同上。贴片三极管测量:正视两脚左下脚为b极(基极)测量方法同上、好坏判断按以上方法测量时两组读数在为正常如果有一组数值不正常三极管为坏如果两组数值相差不大说明三极管性变劣。测量ce两脚如果读数为说明三极管ce之间短路或击穿如果读数为说明三极管ce之间开路。七、三极管的代换原则(只适舍主板)、,,,型和,,,型三极管之间不能代换硅管和锗管之间不能代换。、原则上要原型号代换介在实际维修中很做到同型号代换主板一般采用的三极管大多是硅管所以代换时只须做到硅管代换硅管,,,型代换,,,型,,,型代换,,,型即可。、三极管的三个引脚不能弄错拆下坏三极管时要记住线路板上各引脚孔的位置。八、主板上常见的三极管型号NPN型:AM、RP、A、P、N、ZS、ZS、ZS、G、PF、CR、KNplatesfortanklap,notfixedProtectwiresshouldbeleftinthegroundandslotthecompensationallowanceMetalcabletraysandsupportandtheintroductionofmetalcableductsmustbedrawnorground(PE)orzero(PEN)reliableandmustcomplywiththefollowingrequirements:metalcabletraysandsupportfulllengthnotlessthaninthegrounding(PE)orzero(PEN)trunkconnectionsnongalvanizedcablebridgebetweenbothendsoftheconnectionplatesbridgedcoppergroundwire,groundingallowedminimumcrosssectionalareaofnotlessthanmmgalvanizedcablebridgeacrossbothendsoftheconnectionbetweenthegroundingwire,connectbothendsoftheBoardnotlessthanlockingnutandlockwasherfixingboltsoftheconnectionCabletraysinstalledinaccordancewiththefollowingprovisions:straightsteelcabletraylengthsnotexceedingm,aluminumorfiberglassCableTraylengthsovermwiththeslipjointcablebridgespansthebuildingsetacompensationslotthebendingradiusofthecabletraybend,notlessthanminimumtraycableallowstheturningradius,minimumbendingradiusofthecableshowninthetablebelowTablecableminimumallowsbentRADIUSserialnumbercabletypeminimumallowsbentradiusnoleadBaoGangkainursingsetsofrubberinsulationpowercableDhassteelarmorednursingsetsofrubberinsulationpowercableDPVCinsulationpowercableDmakejointPVCinsulationpowercableDmorethanmorecorecontrolcableDNote:dforcableodDangdesignnorequirementsF、F、F、F、F、D、D、D、D、D<=>D<=><=>RPNP型:A、F、P、DS、KN、、B<=>platesfortanklap,notfixedProtectwiresshouldbeleftinthegroundandslotthecompensationallowanceMetalcabletraysandsupportandtheintroductionofmetalcableductsmustbedrawnorground(PE)orzero(PEN)reliableandmustcomplywiththefollowingrequirements:metalcabletraysandsupportfulllengthnotlessthaninthegrounding(PE)orzero(PEN)trunkconnectionsnongalvanizedcablebridgebetweenbothendsoftheconnectionplatesbridgedcoppergroundwire,groundingallowedminimumcrosssectionalareaofnotlessthanmmgalvanizedcablebridgeacrossbothendsoftheconnectionbetweenthegroundingwire,connectbothendsoftheBoardnotlessthanlockingnutandlockwasherfixingboltsoftheconnectionCabletraysinstalledinaccordancewiththefollowingprovisions:straightsteelcabletraylengthsnotexceedingm,aluminumorfiberglassCableTraylengthsovermwiththeslipjointcablebridgespansthebuildingsetacompensationslotthebendingradiusofthecabletraybend,notlessthanminimumtraycableallowstheturningradius,minimumbendingradiusofthecableshowninthetablebelowTablecableminimumallowsbentRADIUSserialnumbercabletypeminimumallowsbentradiusnoleadBaoGangkainursingsetsofrubberinsulationpowercableDhassteelarmorednursingsetsofrubberinsulationpowercableDPVCinsulationpowercableDmakejointPVCinsulationpowercableDmorethanmorecorecontrolcableDNote:dforcableodDangdesignnorequirements

用户评论(0)

0/200

精彩专题

上传我的资料

每篇奖励 +2积分

资料评价:

/11
0下载券 下载 加入VIP, 送下载券

意见
反馈

立即扫码关注

爱问共享资料微信公众号

返回
顶部