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电路如上,如果照原图的话, 将R1或R2直接短路会烧坏PCB,对此,我们在N极有加一个保险管,以保护R1或R2短路时PCB不会被烧坏,而烧断保险管.
可是图中R1,R2是2W,实际工作中很难让它们的两个脚短路呀,为何安规方面会做这种测试要求.还请各位老师指点一下了.