贴片三端(duan)稳(wen)压(ya)(ya)管型号手(shou)册表与贴片三端(duan)稳(wen)压(ya)(ya)管封装尺(chi)寸图原厂正品-KIA MOS管

信息(xi)来源：本(ben)站　日期：2019-02-28　

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贴片三端稳压管

什么是三端稳压管

三端稳压(ya)管是一(yi)种直到临界反向(xiang)击(ji)穿(chuan)电(dian)压(ya)前都具有很高电(dian)阻(zu)的半导(dao)体器件。稳压(ya)管在(zai)(zai)反向(xiang)击(ji)穿(chuan)时，在(zai)(zai)一(yi)定的电(dian)流(liu)范(fan)(fan)围(wei)内(nei)（或者说(shuo)在(zai)(zai)一(yi)定功率损耗范(fan)(fan)围(wei)内(nei)），端电(dian)压(ya)几乎不(bu)变(bian)，表现出稳压(ya)特性(xing)，因而(er)广泛(fan)应用于(yu)稳压(ya)电(dian)源与限幅(fu)电(dian)路之中。

三端稳压管工作原理

因为固定三(san)端稳(wen)压器属于(yu)串(chuan)联型(xing)稳(wen)压电(dian)路(lu)，因此它的原理等同于(yu)串(chuan)联型(xing)稳(wen)压电(dian)路(lu)。

其(qi)中R1、Rp、R2组成的分压器是取(qu)样(yang)电(dian)(dian)(dian)路，从输出(chu)端取(qu)出(chu)部分电(dian)(dian)(dian)压UB2作为取(qu)样(yang)电(dian)(dian)(dian)压加(jia)至(zhi)三极管T2的基极。稳(wen)压管Dz以其(qi)稳(wen)定电(dian)(dian)(dian)压Uz作为基准电(dian)(dian)(dian)压，加(jia)在(zai)T2的发(fa)射(she)极上。R3是稳(wen)压管的限流电(dian)(dian)(dian)阻。三极管T2组成比较放大(da)电(dian)(dian)(dian)路，它将取(qu)样(yang)电(dian)(dian)(dian)压UB2与(yu)基准电(dian)(dian)(dian)压Uz加(jia)以

比较和(he)放大，再(zai)去控(kong)制三极(ji)管(guan)T1的(de)基极(ji)电位。输入(ru)电压Ui加(jia)在三极(ji)管(guan)T1与负(fu)载RL相串(chuan)联的(de)电路(lu)上，因此，改变T1集电极(ji)间的(de)电压降UCE1便(bian)可调(diao)节RL两端(duan)的(de)电压Uo。也就是(shi)(shi)说，稳压电路(lu)的(de)输出电压Uo可以(yi)通过(guo)三极(ji)管(guan)T1加(jia)以(yi)调(diao)节，所以(yi)T1称为调(diao)整管(guan)。由于调(diao)整元(yuan)件是(shi)(shi)晶体(ti)(ti)管(guan)管(guan)，而且在电路(lu)中(zhong)与负(fu)载相串(chuan)联，故称为晶体(ti)(ti)管(guan)串(chuan)联型稳压电路(lu)。电阻(zu)R4和(he)T1的(de)基极(ji)偏置电阻(zu)，也是(shi)(shi)T2的(de)集电极(ji)负(fu)载电阻(zu)。

当电(dian)(dian)(dian)网电(dian)(dian)(dian)压(ya)降(jiang)(jiang)低或(huo)负载电(dian)(dian)(dian)阻减(jian)小(xiao)而使输(shu)出(chu)端电(dian)(dian)(dian)压(ya)有所下降(jiang)(jiang)时，其(qi)取样电(dian)(dian)(dian)压(ya)UB2相应减(jian)小(xiao)，T2基极(ji)(ji)电(dian)(dian)(dian)位(wei)(wei)下降(jiang)(jiang)。但因T2发射(she)极(ji)(ji)电(dian)(dian)(dian)位(wei)(wei)既稳(wen)压(ya)管(guan)的(de)稳(wen)定(ding)Uz保持不(bu)变(bian)(bian)，所以发射(she)极(ji)(ji)电(dian)(dian)(dian)压(ya)UBE2减(jian)小(xiao)，导(dao)致T2集电(dian)(dian)(dian)极(ji)(ji)电(dian)(dian)(dian)流(liu)减(jian)小(xiao)而集电(dian)(dian)(dian)极(ji)(ji)电(dian)(dian)(dian)位(wei)(wei)Uc2升(sheng)高(gao)。由(you)于放(fang)大管(guan)T2的(de)集电(dian)(dian)(dian)极(ji)(ji)与调整(zheng)管(guan)T1的(de)基极(ji)(ji)接在一起，故T1基极(ji)(ji)电(dian)(dian)(dian)位(wei)(wei)升(sheng)高(gao)，导(dao)致集电(dian)(dian)(dian)极(ji)(ji)电(dian)(dian)(dian)流(liu)增大而管(guan)压(ya)降(jiang)(jiang)UCE1减(jian)小(xiao)。因为T1与RL串(chuan)联，所以，输(shu)出(chu)电(dian)(dian)(dian)压(ya)Uo基本不(bu)变(bian)(bian)。

同(tong)理,当电网电压(ya)(ya)或(huo)负载发生(sheng)变(bian)化(hua)引起(qi)输出(chu)电压(ya)(ya)Uo增(zeng)(zeng)(zeng)大时，通过取样、比较放大、调(diao)整等过程，将使(shi)调(diao)整调(diao)整管的管压(ya)(ya)降UCE1增(zeng)(zeng)(zeng)加，结果抑制了(le)输出(chu)端电压(ya)(ya)的增(zeng)(zeng)(zeng)大，输出(chu)电压(ya)(ya)仍基本保持不变(bian)。

调节电位器Rp，可对输出(chu)电压(ya)进行微调。调整管T1与负载电阻RL组成的(de)是射极输出(chu)电路，所(suo)以具有稳定输出(chu)电压(ya)的(de)特点。

在串联型稳(wen)压电(dian)(dian)源(yuan)电(dian)(dian)路(lu)(lu)(lu)的(de)工作过(guo)程中，要求调(diao)整(zheng)管(guan)始终(zhong)处在放大状态。通过(guo)调(diao)整(zheng)管(guan)的(de)电(dian)(dian)流等于(yu)负(fu)载电(dian)(dian)流，因此必(bi)须(xu)选用适当的(de)大功(gong)率(lv)管(guan)作调(diao)整(zheng)管(guan)，并按规定安装散(san)热装置。为(wei)了(le)防止短路(lu)(lu)(lu)或长期(qi)过(guo)载烧坏调(diao)整(zheng)管(guan)，在直流稳(wen)压器中一般还设有短路(lu)(lu)(lu)保(bao)护(hu)和过(guo)载保(bao)护(hu)等电(dian)(dian)路(lu)(lu)(lu)。

贴片三端稳压管