嘿,没说的价值?请您谈谈电源管发热及波形的特征,可好?

这里有三付图,原电源是贴片三极管,二极管.因烧毁无法辨认,用大的分立元件代替.光耦原是PC123(4脚)改用MCT2201(6脚),D5原贴片未知,用1N4148,Q2贴片改为D1027.ZD1,ZD2,Q3暂时摘去未用.IRF840在10-20W时发烫,原能达110W功率.
问两个波形愚笨问题:
1.图2波形未过零点,IRF840从未饱和过?饱和了电压就近为零了,我以为.
2.图3.波形过零了.IRF840DS极有反向电流流过了?G栅感应过来的电压?我想不出,
您说点什么.
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