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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时间继电器使用环境

2014/1/8 20:12:08点击:
时间继电器作为自动控制器件应用较广泛,尤其是在涉及低压电器控制

  时间继电器(图6)

网络中有较多电器设备环境中使用时电磁干扰问题更趋于严重。时间继电器组成时间继电器的内部元器件的损坏这时已不是引起时间继电器故障(失效)的主要原因,而在于应用场合中的各种干扰通过电磁耦合、电容耦合直接进入时间继电器,时间继电器干扰其正常的延时控制。时间继电器在此干扰环境下能否正常工作往往会影响到整个自动控制系统的正常逻辑功能,甚至还可能造成大的质量事故和经济损失。所以时间继电器在各种恶劣环境都应有较高的可靠性和抗干扰能力,也就是说时间继电器必须有良好的电磁兼容性能,只有这样才能完善其产品质量,提高自身的市场竞争能力。时间继电器
时间继电器在实际工作使用中,一般采用下述方法来进行抑制,提高其产品的抗干扰能力。
时间继电器采用隔离变压器;选择合适的压敏电阻;在供电输出口加高频旁路电容等方法提高产品的抗干扰能力。
时间继电器当执行继电器的绕组(感性负载)被接通和断开时。线圈中会产生一连串上升速度快,频率和幅度都相当高的尖峰脉冲电磁振荡辐射,对直流继电器绕组通常采用以下方法来减少干扰:
在线圈两端反并二极管或RC器件,如控制触点对交流感性负载的控制,也可考虑在触点并接RC 器件,从而能对触点在通断时产生的干扰进行有效的吸收。
时间继电器屏蔽能有效地抑制通过空间传播的电磁干扰,一则可限制内部产生的电磁能辐射出去;时间继电器二则可防止外来 时间继电器辐射进入,时间继电器在对内部电子线路采用整体屏蔽措施,也可对内部信号线采用屏蔽线,增强其抗干扰能力。