電源適配器的輸入電(dian)路(lu)大都采用電(dian)容濾波(bo)型整流(liu)電(dian)路(lu)，在(zai)進線(xian)電(dian)源(yuan)適配器(qi)(qi)合閘瞬間，由于電(dian)容器(qi)(qi)上的初始電(dian)壓為(wei)零，電(dian)容器(qi)(qi)充電(dian)瞬間會形成很(hen)大的浪涌電(dian)流(liu)，特別是大功率開關電(dian)源(yuan)適配器(qi)(qi)，采用容量較(jiao)大的濾波(bo)電(dian)容器(qi)(qi)，使浪涌電(dian)流(liu)達100A以上。

在電(dian)(dian)(dian)(dian)源適配(pei)(pei)(pei)(pei)器接通瞬間如此大(da)的(de)浪涌電(dian)(dian)(dian)(dian)流，重(zhong)者(zhe)往(wang)往(wang)會(hui)導(dao)致輸入(ru)熔斷器燒斷或合(he)閘開關(guan)(guan)的(de)觸點燒壞(huai)(huai)，整流橋過流損壞(huai)(huai)；輕者(zhe)也(ye)會(hui)使空氣開關(guan)(guan)合(he)不上(shang)閘。上(shang)述現象均會(hui)造成開關(guan)(guan)電(dian)(dian)(dian)(dian)源適配(pei)(pei)(pei)(pei)器無(wu)法正常工作(zuo)，為此幾(ji)乎(hu)所有的(de)開關(guan)(guan)電(dian)(dian)(dian)(dian)源適配(pei)(pei)(pei)(pei)器都(dou)設置(zhi)了防(fang)止(zhi)流涌電(dian)(dian)(dian)(dian)流的(de)軟(ruan)啟動電(dian)(dian)(dian)(dian)路(lu)，以保(bao)證電(dian)(dian)(dian)(dian)源適配(pei)(pei)(pei)(pei)器正常而可靠運行。防(fang)浪涌軟(ruan)啟動電(dian)(dian)(dian)(dian)路(lu)通常有晶閘管保(bao)護法和繼電(dian)(dian)(dian)(dian)器保(bao)護法兩大(da)類。

沖擊電(dian)流(liu)的(de)(de)大小由很多因素決定，如輸入(ru)電(dian)壓(ya)大小，輸入(ru)電(dian)線(xian)阻(zu)抗，電(dian)源適(shi)配器(qi)(qi)內部輸入(ru)電(dian)感(gan)及等(deng)(deng)效阻(zu)抗，輸入(ru)電(dian)容等(deng)(deng)效串連阻(zu)抗等(deng)(deng)。高壓(ya)開關電(dian)源的(de)(de)發展這些(xie)參數根據不(bu)(bu)同的(de)(de)電(dian)源適(shi)配器(qi)(qi)系(xi)統和布局不(bu)(bu)同而不(bu)(bu)同，很難進(jin)行估算，最精確(que)的(de)(de)方法是在(zai)實際應(ying)用(yong)中(zhong)測量沖擊電(dian)流(liu)的(de)(de)大小。在(zai)測量沖擊電(dian)流(liu)時(shi)，不(bu)(bu)能因引入(ru)傳(chuan)感(gan)器(qi)(qi)而改變沖擊電(dian)流(liu)的(de)(de)大小，推薦使(shi)用(yong)霍(huo)爾傳(chuan)感(gan)器(qi)(qi)。

串連(lian)在(zai)電(dian)(dian)路上的(de)電(dian)(dian)阻(zu)(zu)必須能承受在(zai)開機時的(de)高電(dian)(dian)壓(ya)和(he)大電(dian)(dian)流，大額(e)定(ding)電(dian)(dian)流的(de)電(dian)(dian)阻(zu)(zu)在(zai)這種應用(yong)(yong)中比(bi)較適合(he)，常用(yong)(yong)的(de)為線(xian)繞電(dian)(dian)阻(zu)(zu)，但在(zai)高濕(shi)度的(de)環(huan)(huan)境(jing)下，車載(zai)廣告機則不(bu)要(yao)用(yong)(yong)線(xian)繞電(dian)(dian)阻(zu)(zu)。因(yin)線(xian)繞電(dian)(dian)阻(zu)(zu)在(zai)高濕(shi)度環(huan)(huan)境(jing)下，瞬態熱應力和(he)繞線(xian)的(de)膨脹會降低保(bao)護層的(de)作用(yong)(yong)，會因(yin)濕(shi)氣入侵而引(yin)起電(dian)(dian)阻(zu)(zu)損壞。