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原帖由 piyopiyo 於 15-4-2008 14:07 發表
04年?=.=...點解我無印象ge...我前日先做完04 =.=...
正常...
因為這是03 CE PP= ="
原帖由[S]【YU】於 15-4-2008 16:20 發表
commutator is not required in this application, because the direction of current flow makes no difference.
We need a commutator only when we want to make a DC generator.
So the essential parts should be the coil and magnet only.
那是在問essential component of motor,唔係b)果個發電機
DC motor 同 DC generator 都要 commutator
所以commutator 都 accept
(carbon brush, iron core都ok)
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