为什么通讯电源是-48的???
一直搞不明白,有谁明白,说来听听
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@feelbetter
我觉得第5贴说保护接地金属不被腐蚀是不对的,接地金属为正,其他负离子(可考虑HCl的氯离子)向他移动,结果与金属结合发生反应.最好看完整个贴再说.
其实第5帖说的"腐蚀"是对的,不过理由不是氧化,是原子迁移,原子移走了,铜身变幼了,慢慢的断了.抄一段 :
Subscriber-line interface cards (SLICs) provide the interface between the telephone-service provider and the telephone handset in your home. ....... Telephone-system voltages are traditionally negative to prevent electromigration from eroding the installed copper wiring.
Subscriber-line interface cards (SLICs) provide the interface between the telephone-service provider and the telephone handset in your home. ....... Telephone-system voltages are traditionally negative to prevent electromigration from eroding the installed copper wiring.
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@qaz33510
其实第5帖说的"腐蚀"是对的,不过理由不是氧化,是原子迁移,原子移走了,铜身变幼了,慢慢的断了.抄一段:Subscriber-lineinterfacecards(SLICs)providetheinterfacebetweenthetelephone-serviceproviderandthetelephonehandsetinyourhome........Telephone-systemvoltagesaretraditionallynegativetopreventelectromigrationfromerodingtheinstalledcopperwiring.
把这句话翻译过来,正是说第五贴不正确.
第五帖说:保护接地金属不被腐蚀.
注意接地的是正极,才有-48伏.
那句话:通信系统是负电压(不是接地的正极)为了阻止氧化.
第五帖说:保护接地金属不被腐蚀.
注意接地的是正极,才有-48伏.
那句话:通信系统是负电压(不是接地的正极)为了阻止氧化.
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