解析7805稳压(ya)电(dian)(dian)(dian)源电(dian)(dian)(dian)路图 7805稳压(ya)工(gong)作(zuo)原理(li)及典型电(dian)(dian)(dian)路 KIA MOS管

信息来源：本站(zhan)　日期：2018-04-16　

分享到：

一、7805稳压电源电路图

1、3～25V电压可调稳压电路图

7805稳压电源电路图

此稳压电(dian)源可调(diao)(diao)范(fan)围在3.5V～25V之间任意调(diao)(diao)节，输出(chu)电(dian)流大，并采用可调(diao)(diao)稳压管式电(dian)路，从(cong)而得(de)到满意平稳的输出(chu)电(dian)压。

工作原理：经(jing)(jing)整流(liu)滤波后直(zhi)流(liu)电(dian)(dian)压由R1提供给调(diao)(diao)(diao)整管的基(ji)极，使调(diao)(diao)(diao)整管导(dao)通，在V1导(dao)通时电(dian)(dian)压经(jing)(jing)过(guo)RP、R2使V2导(dao)通，接着(zhe)V3也导(dao)通，这时V1、V2、V3的发射极和(he)集电(dian)(dian)极电(dian)(dian)压不(bu)再(zai)变(bian)化(hua)（其作用(yong)完(wan)全(quan)与(yu)稳(wen)压管一样(yang)）。调(diao)(diao)(diao)节RP，可得到平稳(wen)的输(shu)出(chu)电(dian)(dian)压，R1、RP、R2与(yu)R3比值决定(ding)本电(dian)(dian)路输(shu)出(chu)的电(dian)(dian)压值。

元器(qi)件选(xuan)(xuan)择：变压器(qi)T选(xuan)(xuan)用(yong)(yong)80W～100W，输(shu)入AC220V，输(shu)出双(shuang)绕组(zu)AC28V。FU1选(xuan)(xuan)用(yong)(yong)1A，FU2选(xuan)(xuan)用(yong)(yong)3A～5A。VD1、VD2选(xuan)(xuan)用(yong)(yong) 6A02。RP选(xuan)(xuan)用(yong)(yong)1W左(zuo)右(you)普通电位(wei)器(qi)，阻值为250K～330K，C1选(xuan)(xuan)用(yong)(yong)3300μF／35V电解电容，C2、C3选(xuan)(xuan)用(yong)(yong)0.1μF独石电容，C4选(xuan)(xuan)用(yong)(yong) 470μF／35V电解电容。R1选(xuan)(xuan)用(yong)(yong)180～220Ω/0.1W～1W，R2、R4、R5选(xuan)(xuan)用(yong)(yong)10KΩ、1／8W。V1选(xuan)(xuan)用(yong)(yong)2N3055，V2选(xuan)(xuan)用(yong)(yong) 3DG180或(huo)(huo)2SC3953，V3选(xuan)(xuan)用(yong)(yong)3CG12或(huo)(huo)3CG80。

7805稳压电源电路图

2、10A3～15V稳压可调电源电路图

无论检修电(dian)(dian)(dian)脑还是(shi)电(dian)(dian)(dian)子制作都(dou)离(li)不开稳压电(dian)(dian)(dian)源(yuan)，下(xia)面介绍(shao)一款(kuan)直流电(dian)(dian)(dian)压从3V到(dao)15V连续(xu)可调(diao)的(de)稳压电(dian)(dian)(dian)源(yuan)，最大(da)电(dian)(dian)(dian)流可达10A，该电(dian)(dian)(dian)路用(yong)了具有温度(du)补偿特性的(de)，高精度(du)的(de)标准电(dian)(dian)(dian)压源(yuan)集成(cheng)电(dian)(dian)(dian)路431，使(shi)稳压精度(du)更(geng)高，如果没有特殊要求，基(ji)本能满足正(zheng)常维修使(shi)用(yong)，电(dian)(dian)(dian)路见下(xia)图。

7805稳压电源电路图

其工(gong)作原理(li)分(fen)(fen)两部(bu)分(fen)(fen)，第一(yi)部(bu)分(fen)(fen)是一(yi)路(lu)固定的(de)5V1.5A稳压电(dian)(dian)源电(dian)(dian)路(lu)，第二部(bu)分(fen)(fen)是另(ling)一(yi)路(lu)由3至15V连续可调的(de)高精(jing)度大电(dian)(dian)流稳压电(dian)(dian)路(lu)。

第一路的(de)电(dian)(dian)(dian)(dian)路非常简(jian)单，由变压(ya)(ya)器次级8V交流电(dian)(dian)(dian)(dian)压(ya)(ya)通(tong)过(guo)硅桥QL1整(zheng)流后的(de)直流电(dian)(dian)(dian)(dian)压(ya)(ya)经C1电(dian)(dian)(dian)(dian)解电(dian)(dian)(dian)(dian)容滤(lv)波后，再由5V三端稳压(ya)(ya)块(kuai)KIA7805不用(yong)作任何调整(zheng)就可在(zai)输出端产(chan)生固定的(de)5V1A稳压(ya)(ya)电(dian)(dian)(dian)(dian)源，这个(ge)电(dian)(dian)(dian)(dian)源在(zai)检修电(dian)(dian)(dian)(dian)脑(nao)板时完全可以当(dang)作内部电(dian)(dian)(dian)(dian)源使用(yong)。

第二部(bu)分与普通串(chuan)联型(xing)稳压(ya)电(dian)(dian)(dian)(dian)源基本相(xiang)同，所不同的(de)是(shi)使用了具有温(wen)度(du)补偿(chang)特性(xing)的(de)，高(gao)精度(du)的(de)标准(zhun)电(dian)(dian)(dian)(dian)压(ya)源集成电(dian)(dian)(dian)(dian)路(lu)431，所以使电(dian)(dian)(dian)(dian)路(lu)简化，成本降低，而稳压(ya)性(xing)能却很高(gao)。图中电(dian)(dian)(dian)(dian)阻(zu)(zu)R4，稳压(ya)管TL431，电(dian)(dian)(dian)(dian)位器(qi)R3组成一个连续可调得恒压(ya)源，为(wei)BG2基极提供基准(zhun)电(dian)(dian)(dian)(dian)压(ya)，稳压(ya)管TL431的(de)稳压(ya)值连续可调，这个稳压(ya)值决定了稳压(ya)电(dian)(dian)(dian)(dian)源的(de)最(zui)大输出电(dian)(dian)(dian)(dian)压(ya)，如果你想把可调电(dian)(dian)(dian)(dian)压(ya)范围扩大，可以改变(bian)R4 和R3的(de)电(dian)(dian)(dian)(dian)阻(zu)(zu)值，当然变(bian)压(ya)器(qi)的(de)次级电(dian)(dian)(dian)(dian)压(ya)也要提高(gao)。

变(bian)压(ya)器的(de)功(gong)(gong)率可(ke)根据(ju)输(shu)(shu)出电(dian)(dian)流(liu)(liu)(liu)灵活掌握，次级电(dian)(dian)压(ya)15V左右。桥式整(zheng)流(liu)(liu)(liu)用的(de)整(zheng)流(liu)(liu)(liu)管QL用15－20A硅(gui)桥，结构紧凑，中间有固定(ding)螺丝，可(ke)以直(zhi)接(jie)固定(ding)在机壳的(de)铝板上，有利散(san)热(re)。调整(zheng)管用的(de)是大(da)电(dian)(dian)流(liu)(liu)(liu)NPN型金属壳硅(gui)管，由于它(ta)的(de)发热(re)量(liang)(liang)很大(da)，如果机箱允许，尽(jin)量(liang)(liang)购买大(da)的(de)散(san)热(re)片，扩大(da)散(san)热(re)面积(ji)，如果不(bu)(bu)需要大(da)电(dian)(dian)流(liu)(liu)(liu)，也(ye)可(ke)以换用功(gong)(gong)率小一点(dian)的(de)硅(gui)管，这(zhei)样(yang)可(ke)以做的(de)体(ti)积(ji)小一些(xie)。滤(lv)波用50V4700uF电(dian)(dian)解电(dian)(dian)容C5和C7分别用三(san)只并联，使大(da)电(dian)(dian)流(liu)(liu)(liu)输(shu)(shu)出更稳定(ding)，另外这(zhei)个电(dian)(dian)容要买体(ti)积(ji)相对大(da)一点(dian)的(de)，那些(xie)体(ti)积(ji)较小的(de)同样(yang)标注(zhu)50V4700uF尽(jin)量(liang)(liang)不(bu)(bu)用，当遇到电(dian)(dian)压(ya)波动频繁，或(huo)长时间不(bu)(bu)用，容易失效。

最后(hou)再说一(yi)(yi)下电(dian)源变压(ya)器(qi)，如果没有(you)能(neng)力自己绕(rao)制，有(you)买不(bu)到现成(cheng)的(de)，可(ke)以(yi)买一(yi)(yi)块现成(cheng)的(de)200W以(yi)上的(de)开关(guan)电(dian)源代替变压(ya)器(qi)，这样稳压(ya)性能(neng)还(hai)可(ke)进一(yi)(yi)步提高，制作(zuo)(zuo)成(cheng)本却(que)差不(bu)太多，其它(ta)电(dian)子(zi)元(yuan)件(jian)无特(te)殊要(yao)求，安装完成(cheng)后(hou)不(bu)用太大调整就(jiu)可(ke)正常工(gong)作(zuo)(zuo)。

7805稳压电源电路图5v

如图所示电(dian)路为(wei)(wei)输(shu)出电(dian)压(ya)+5V、输(shu)出电(dian)流(liu)1.5A的(de)稳压(ya)电(dian)源。它由电(dian)源变压(ya)器B，桥式整流(liu)电(dian)路D1～D4，滤波电(dian)容C1、C3，防止(zhi)自激(ji)电(dian)容C2、C3和一只固定(ding)式三(san)端(duan)稳压(ya)器(7805)极(ji)为(wei)(wei)简捷方便地搭(da)成的(de)。

220V交(jiao)流(liu)市(shi)电(dian)通过电(dian)源变(bian)压(ya)器变(bian)换成交(jiao)流(liu)低压(ya)，再经过桥式整流(liu)电(dian)路D1～D4和滤(lv)波电(dian)容(rong)C1的整流(liu)和滤(lv)波，在(zai)固定式三端稳(wen)压(ya)器KIA7805的Vin和GND两端形(xing)成一个并不十分稳(wen)定的直流(liu)电(dian)压(ya)(该电(dian)压(ya)常常会(hui)因为市(shi)电(dian)电(dian)压(ya)的波动(dong)或(huo)负(fu)载的变(bian)化等原因而发生变(bian)化)。

此直(zhi)流电(dian)(dian)压(ya)经(jing)过KIA7805的(de)(de)稳压(ya)和C3的(de)(de)滤波(bo)便在稳压(ya)电(dian)(dian)源的(de)(de)输出端(duan)(duan)产生了精度高、稳定度好的(de)(de)直(zhi)流输出电(dian)(dian)压(ya)。本稳压(ya)电(dian)(dian)源可作为(wei)(wei)TTL电(dian)(dian)路(lu)或(huo)单片(pian)机(ji)电(dian)(dian)路(lu)的(de)(de)电(dian)(dian)源。三端(duan)(duan)稳压(ya)器(qi)是(shi)一种(zhong)标准化、系列化的(de)(de)通用(yong)线性稳压(ya)电(dian)(dian)源集成电(dian)(dian)路(lu)，以其体积小、成本低、性能好、工作可靠性高、使用(yong)简捷方便等(deng)特点，成为(wei)(wei)目(mu)前稳压(ya)电(dian)(dian)源中应用(yong)最(zui)为(wei)(wei)广(guang)泛的(de)(de)一种(zhong)单片(pian)式集成稳压(ya)器(qi)件。

7805稳压电源电路图