變頻器包括整流電路和逆變電路，輸入的交流電經過整流電路和平波回路，轉換成直流電壓，再通過強(qiang)(qiang)電(dian)和弱電(dian)的(de)區別，主要體(ti)(ti)現在用途的(de)不同。強(qiang)(qiang)電(dian)是(shi)(shi)用作一種動(dong)力能源(yuan)，弱電(dian)是(shi)(shi)用于信息(xi)傳遞。具體(ti)(ti)而言，它們大致(zhi)有如(ru)下區別：

（1）交流頻率不同?
強電的(de)頻(pin)率一般是50Hz（赫），稱“工頻(pin)”，意即(ji)工業(ye)用電的(de)頻(pin)率：弱電的(de)頻(pin)率往往是高頻(pin)或特高頻(pin)，以KHz（千赫）、MHz（兆(zhao)赫）計。

（2）傳輸方式不同?
強電以輸(shu)電線(xian)(xian)路傳輸(shu)，弱(ruo)電的(de)傳輸(shu)有(you)有(you)線(xian)(xian)與無(wu)線(xian)(xian)之分。無(wu)線(xian)(xian)電則以電磁波傳輸(shu)。

（3）功率、電壓及電流大小不同?
強電(dian)功率以(yi)(yi)KW（千瓦）、MW（兆瓦）計(ji)、電(dian)壓以(yi)(yi)V（伏）、KV（千伏）計(ji)，電(dian)流(liu)以(yi)(yi)A（安）、kA（千安）計(ji)；弱電(dian)功率以(yi)(yi)W（瓦）、mW（毫瓦）計(ji)，電(dian)壓以(yi)(yi)V（伏）、mV（毫伏）計(ji)，電(dian)流(liu)以(yi)(yi)mA（毫安）、uA（微安）計(ji)，因(yin)而其電(dian)路可以(yi)(yi)用印刷(shua)電(dian)路或集成電(dian)路構成。

當然(ran)，強(qiang)(qiang)(qiang)電(dian)中(zhong)(zhong)也有高(gao)頻（數(shu)百KHz）與中(zhong)(zhong)頻設備，但電(dian)壓(ya)(ya)較高(gao)，電(dian)流也較大。又如(ru)手電(dian)筒與電(dian)動剃須刀雖(sui)然(ran)電(dian)壓(ya)(ya)很低，功率及電(dian)流很小，仍屬強(qiang)(qiang)(qiang)電(dian)。由于現代技術的發(fa)展，弱電(dian)己(ji)滲透到強(qiang)(qiang)(qiang)電(dian)領域，如(ru)電(dian)力電(dian)子器(qi)件(jian)、無線遙(yao)控(kong)等，但這些只能算(suan)作(zuo)強(qiang)(qiang)(qiang)電(dian)中(zhong)(zhong)的弱電(dian)控(kong)制(zhi)部分，它與被控(kong)的強(qiang)(qiang)(qiang)電(dian)還是不同的。

電(dian)(dian)子類人們習慣分為(wei)(wei)強電(dian)(dian)（電(dian)(dian)力）和(he)弱(ruo)(ruo)電(dian)(dian)（信(xin)(xin)息）兩部分。兩者既有聯系又有區別(bie)，一(yi)般來(lai)說強電(dian)(dian)的(de)(de)處(chu)理(li)對(dui)(dui)象(xiang)是(shi)(shi)能源（電(dian)(dian)力），其特(te)(te)點是(shi)(shi)電(dian)(dian)壓(ya)高(gao)、電(dian)(dian)流(liu)大、功率(lv)(lv)大、頻率(lv)(lv)低，主(zhu)要(yao)考(kao)慮的(de)(de)問題是(shi)(shi)減少(shao)損耗、提高(gao)效(xiao)率(lv)(lv)，弱(ruo)(ruo)電(dian)(dian)的(de)(de)處(chu)理(li)對(dui)(dui)象(xiang)主(zhu)要(yao)是(shi)(shi)信(xin)(xin)息，即信(xin)(xin)息的(de)(de)傳送和(he)控制，其特(te)(te)點是(shi)(shi)電(dian)(dian)壓(ya)低、電(dian)(dian)流(liu)小、功率(lv)(lv)小、頻率(lv)(lv)高(gao)，主(zhu)要(yao)考(kao)慮的(de)(de)是(shi)(shi)信(xin)(xin)息傳送的(de)(de)效(xiao)果問題，如信(xin)(xin)息傳送的(de)(de)保(bao)真(zhen)度、速(su)度、廣度、可靠性。一(yi)般來(lai)說，弱(ruo)(ruo)電(dian)(dian)工程包括電(dian)(dian)視工程、通信(xin)(xin)工程、消防工程、保(bao)安工程、影像工程等(deng)等(deng)和(he)為(wei)(wei)上述工程服務的(de)(de)綜合布線工程。弱(ruo)(ruo)電(dian)(dian)是(shi)(shi)針對(dui)(dui)強電(dian)(dian)而言的(de)(de)。強電(dian)(dian)=（380/220）、高(gao)壓(ya)不管(guan)

在(zai)電(dian)(dian)(dian)(dian)(dian)力系(xi)統中(zhong)，36v以下的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)稱為安(an)全電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，1kv以下的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)稱為低壓(ya)(ya)(ya)，1kv以上的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)稱為高(gao)壓(ya)(ya)(ya)，直接供電(dian)(dian)(dian)(dian)(dian)給用戶(hu)的(de)(de)(de)線路(lu)稱為配電(dian)(dian)(dian)(dian)(dian)線路(lu)，如用戶(hu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)為 380/220v，則稱為低壓(ya)(ya)(ya)配電(dian)(dian)(dian)(dian)(dian)線路(lu)，也就是家(jia)庭裝修中(zhong)所說的(de)(de)(de)強(qiang)電(dian)(dian)(dian)(dian)(dian)（因它是家(jia)庭使用最高(gao)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)）。強(qiang)電(dian)(dian)(dian)(dian)(dian)一般是指交(jiao)流電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)在(zai)24V以上。如家(jia)庭中(zhong)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)燈、插座(zuo)等，電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)在(zai)110V~220V。家(jia)用電(dian)(dian)(dian)(dian)(dian)氣(qi)中(zhong)的(de)(de)(de)照明(ming)燈具、電(dian)(dian)(dian)(dian)(dian)熱水器、取暖(nuan)器、冰箱、電(dian)(dian)(dian)(dian)(dian)視(shi)機、空調、音響設備等用電(dian)(dian)(dian)(dian)(dian)器均為強(qiang)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)氣(qi)設備。

智能化(hua)系統(tong)(tong)為(wei)建筑(zhu)設(she)備監控系統(tong)(tong)、安(an)全(quan)防范系統(tong)(tong)、通訊網絡系統(tong)(tong)、信息網絡系統(tong)(tong)、火災自動(dong)報警及(ji)消防聯動(dong)等系統(tong)(tong)，以集(ji)中(zhong)監視(shi)、控制(zhi)(zhi)和管理為(wei)目(mu)的(de)(de)構成的(de)(de)綜(zong)合系統(tong)(tong)；家庭內各種數(shu)據采集(ji)、控制(zhi)(zhi)、管理及(ji)通訊的(de)(de)控制(zhi)(zhi)或(huo)網絡系統(tong)(tong)等線(xian)(xian)路(lu)，則稱為(wei)智能化(hua)線(xian)(xian)路(lu)（也就是家庭裝修中(zhong)所說(shuo)的(de)(de)弱(ruo)(ruo)電(dian)）。弱(ruo)(ruo)電(dian)一般是指直流電(dian)路(lu)或(huo)音(yin)(yin)頻、視(shi)頻線(xian)(xian)路(lu)、網絡線(xian)(xian)路(lu)、電(dian)話線(xian)(xian)路(lu)，直流電(dian)壓一般在24V以內。家用電(dian)氣中(zhong)的(de)(de)電(dian)話、電(dian)腦、電(dian)視(shi)機(ji)的(de)(de)信號輸(shu)入(ru)（有線(xian)(xian)電(dian)視(shi)線(xian)(xian)路(lu)）、音(yin)(yin)響設(she)備（輸(shu)出端(duan)線(xian)(xian)路(lu)）等用電(dian)器均為(wei)弱(ruo)(ruo)電(dian)電(dian)氣設(she)備。

強電和弱(ruo)(ruo)電在概(gai)念上(shang)講，一般是(shi)容易區(qu)別的，主要區(qu)別是(shi)用(yong)途的不同。強電是(shi)用(yong)作一種動力能源，弱(ruo)(ruo)電是(shi)用(yong)于信息(xi)傳遞。具體而言，它們大致有如下區(qu)別：

⑴、交流頻(pin)(pin)(pin)率(lv)不同(tong)強電(dian)的頻(pin)(pin)(pin)率(lv)一般是(shi)50Hz，稱“工頻(pin)(pin)(pin)”，亦即工業用(yong)電(dian)的頻(pin)(pin)(pin)率(lv)；弱(ruo)電(dian)的頻(pin)(pin)(pin)率(lv)往(wang)往(wang)用(yong)高(gao)頻(pin)(pin)(pin)或(huo)特(te)高(gao)頻(pin)(pin)(pin)，以千赫（KHz）、兆(zhao)赫（MHz）計。

⑵、傳輸方式不同
強電(dian)以(yi)輸(shu)電(dian)線路傳輸(shu)，弱(ruo)電(dian)的傳輸(shu)有有線與無(wu)線之分，無(wu)線電(dian)則以(yi)電(dian)磁波傳輸(shu)。

⑶、功率、電壓及電流大小不同
強電(dian)(dian)(dian)功率以千瓦（KW）、兆瓦（MW）計(ji)(ji)，電(dian)(dian)(dian)壓(ya)(ya)以伏(fu)（V）、千伏(fu)（KV）計(ji)(ji)，電(dian)(dian)(dian)流(liu)以安(an)（A）、千安(an)（KA）計(ji)(ji)；弱電(dian)(dian)(dian)功率以瓦（W）、毫瓦（mW）計(ji)(ji)，電(dian)(dian)(dian)壓(ya)(ya)以伏(fu)（V）、毫伏(fu)（mV）計(ji)(ji)，電(dian)(dian)(dian)流(liu)以毫安(an)（mA）、微安(an)（μA）計(ji)(ji)，因而(er)其(qi)電(dian)(dian)(dian)路可以用印刷電(dian)(dian)(dian)路或集成電(dian)(dian)(dian)路構(gou)成。

當(dang)然，強(qiang)電(dian)(dian)(dian)中(zhong)也有(you)高頻（數兆赫茲）與(yu)(yu)中(zhong)頻設備(bei)，但電(dian)(dian)(dian)壓較高，電(dian)(dian)(dian)流也較大(da)。又如手電(dian)(dian)(dian)筒與(yu)(yu)電(dian)(dian)(dian)動剃須刀雖(sui)然電(dian)(dian)(dian)壓很低，功率及電(dian)(dian)(dian)流很小，仍(reng)屬強(qiang)電(dian)(dian)(dian)。由于現代技術的(de)(de)(de)發展，弱電(dian)(dian)(dian)已(yi)滲透(tou)到強(qiang)電(dian)(dian)(dian)領(ling)域，如電(dian)(dian)(dian)力電(dian)(dian)(dian)子器件、無(wu)線遙(yao)控(kong)等，但這些只能算作強(qiang)電(dian)(dian)(dian)中(zhong)的(de)(de)(de)弱電(dian)(dian)(dian)控(kong)制(zhi)部份，它與(yu)(yu)被控(kong)的(de)(de)(de)強(qiang)電(dian)(dian)(dian)還是不同的(de)(de)(de)。