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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    軟啟動器如何實現輕載節能

    2014/8/18 9:01:50點擊:

    目前,交流感應電動機以其低成本、高可靠性和少維護等優點5,在各種工業領域中得到廣泛應用。但是,它在直接起動時,存在著兩個缺點:首先,它的起動電流可高達額定電流的5~7倍,這就要求電網裕量比較大,而且降低電氣控制設備的使用壽命,增加維護成本。
    其次,起動轉矩可達正常轉矩的兩倍,這會對負載產生沖擊,增加傳動部件的磨損和額外的維護。基于以上原因,產生了交流應電動機降壓起動設備。
    傳統減壓起動方法有Y/△起動和自耦變壓器降壓兩種,每種都有各自的特點。電動機用Y/△起動時,在切換瞬間會出現很高的電流尖峰,會產生破壞性的動態轉矩,其引起的機械振動對電動機轉子、齒輪以及負載等都是非常有害的。自耦變壓器降壓起動設備體積龐大,成本高,而且還存在與負載匹配的電動機轉矩難控制等缺點。

    籠型異步電機是感性負載,在運行中,定子線圈繞組中的電流滯后于電壓。如電機工作電壓不變,處于輕載時,功率因數低,處于重載時,功率因數高。軟起動器能實現在輕載時,通過降低電機端電壓,提高功率因數,減少電機的銅耗、鐵耗,達到輕載節能的目的;負載重時,則提高電機端電壓,確保電機正常運行。

     

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