Mike Krzyzewski is really a famous coach of Dream Team. She has coached north america men's basketball team for some time, that's clinched numerous medals for his country. Following Londonfl jerseys supplyn Olympic was over, Krzyzewski told The Associated Press that this game will be his final one as national coach, a job he's held for seven years. He had left open the possibility of swomen nfl jerseystaying with the team beyond the London Games, when practice on Saturday said these will be his last Olympics.When asked if he was sure, Krzyzewski didn't hesitate before again saying, "yecheap nfl jerseys wholesales," this will be his last game "If we could win it, then it might be three major championships in a row, i always do not know when that has been done because we haven't usually won http://govoriotkrito.bg/libs/nflcn08.htmthe globe championships," Krzyzewski said. "It becomes an enormous thing for the program." Whatever, he's an awesome coach. His achievement are going to be remembered by the country.cheap nfl jerseys
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    電力變壓器安裝工藝

    2014/1/21 8:32:56      點(diǎn)擊:
    電力變壓器 安裝工藝變壓器英文名稱(transformer) [trAns'fC:mE(r),tra:-]。
    變壓器是變換交流電壓、電流和阻抗的器件,當(dāng)初級(jí)線圈中通有交流電流時(shí),鐵芯(或磁芯)中便產(chǎn)生交流磁通,使次級(jí)線圈中感應(yīng)出電壓(或電流)。變壓器由鐵芯(或磁芯)和線圈組成,線圈有兩個(gè)或兩個(gè)的繞組,其中接電源的繞組叫初級(jí)線圈,其余的繞組叫次級(jí)線圈。變壓器是一種常見(jiàn)的電子元件和電氣設(shè)備, 可用來(lái)把某種數(shù)值的交變電壓變換為同頻率的另一數(shù)值的交變電壓,也可以改變交流電的數(shù)值及變換阻抗或改變相位或變換頻率。為什么需要電力變壓器。發(fā)電廠欲將P=sqrt(3)*UIcosφ的電功率輸送到用電的區(qū)域,在P、cosφ為一定值時(shí),若采用的電壓愈高,則輸電線路中的電流愈小,因而可以減少輸電線路上的損耗,節(jié)約導(dǎo)電材料。所以遠(yuǎn)距離輸電采用高電壓是最為經(jīng)濟(jì)的。我國(guó)交流輸電的電壓最高已達(dá)500kV。這樣高的電壓,無(wú)論從發(fā)電機(jī)的安全運(yùn)行方面或是從制造成本方面考慮,都不允許由發(fā)電機(jī)直接生產(chǎn)。發(fā)電機(jī)的輸出電壓一般3.15kV6.3kV、10.5 kV、 15.75 kV等幾種,因此必須用升壓變壓器將電壓升高才能遠(yuǎn)距離輸送。為什么需要配電變壓器:電能輸送到用電區(qū)域后,為了適應(yīng)用電設(shè)備的電壓要求,還需通過(guò)各級(jí)變電站(所)利用變壓器將電壓降低為各類電器所需要的電壓值。
    在用電方面,多數(shù)用電器所需電壓是380V、220V或36 V,少數(shù)電機(jī)也采用3kV、6kV等。
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