| | | | | 1. 拓扑的构建与'新拓扑'的积木式组合
理解buck-boost电路的特殊性
理解电流纹波系数
BUCK衍生出正激!!! 本帖最后由 eric.wentx 于 2016-5-17 22:00 编辑
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您好, Sanjaya教授,上图中这个公式中的N1/N2的匝数比等于20是怎么来的?是不是有什么特别要求?谢谢
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| | | | | 3. EMI相关概念和测量机制
本帖最后由 eric.wentx 于 2016-5-18 08:33 编辑
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| | | | | 4. 共模噪声之元凶 开关电源前级EMI滤波器的典型配置
如何减少共模噪声
如何减少共模噪声--- 变压器屏蔽需要注意的地方:效率/短路/接地
本帖最后由 eric.wentx 于 2016-5-18 13:19 编辑
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| | | | | | | 关于AC/DC front end filter这张图上的X电容C1,我在测试的时候发现加在整流桥前面这个位置没有明显的效果,但是标准的EMI Filter配置中这个位置都是放了X电容的,文工知不知道为什么这么配置?谢谢
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| | | | | | | | | | | 刚刚没有看到这段英文解释。
Sanjaya的意思是否是说这颗电容只是power supply的解耦电容,是高频开关电路的一部分?
本帖最后由 口乃心之门户 于 2016-5-18 21:33 编辑
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| | | | | | | | | | | | | 对的,就是这个意思,纯的交流AC---功率级的解耦,我的理解是:有点像高PFC桥后的那个小CBB电容。
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| | | | | | | | | | | | | | | 文工的意思是功能可以等效成桥后的高频电容,我理解了。那我还有个问题没搞明白,就是为什么这个电容不放在桥后呢?这个高频电容靠近开关环路,使开关环路面积尽量小是否会更好?
或者说这个电容放在桥前有什么好处?
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| | | | | | | | | | | | | | | | | 桥后是DC了... 这是'AC'与‘DC’前的解耦,这是我个人的理解。 |
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| | | | | | | | | | | | | | | | | | | 还不是太明白具体的作用,但仍然解决了我多年的疑惑,谢谢文工,谢谢Sanjaya.
本帖最后由 口乃心之门户 于 2016-5-19 10:10 编辑
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| | | | | | | | | | | | | | | | | | | | | To clarify doubts: Indeed a good position for input cap is after the bridge. In all PFC circuits a small cap is present after the bridge, and as described in Fig 14-6 of A-Z/2e, this is 0.1uF per 100W. Also as mentioned in Chapter 16, a small cap, such as C1 may be placed before the bridge in low-power converters, and may be enough --- no Differential-mode EMI filter may be required in that case, and it also helps kill the noise from the diodes of the bridge. I have personally seen improvement in EMI by this small cap placed before the bridge (in addition to any cap present after the bridge), so I suggest you keep a place holder for it at least. However, this cap is strictly a decoupling cap, not really a formal EMI filter, because for that you need an L also, to produce an LC filter. So strictly, it is just a decoupling cap, if present (just try it out is all I said, and I didn't say this replaces the cap after the bridge). Hope that is clear. Eric may translate.
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| | | | | | | | | | | | | | | | | | | | | | | I understand, thank you very much!
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| | | | | | | 1.减少噪声在电路设计上还有什么方法吗
2.输出的电路的保护能智能化吗
本帖最后由 fengbin 于 2016-5-25 20:41 编辑
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| | | | | EMC,一直比较困惑的东西,希望能好好补充下自己. |
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| | | | | 资料有打包下载的吗?最好附上视频!让我们场外的小伙伴也能享受到高质量的培训
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| | | | | ppt费了不少功夫
懂得做东西,懂得展示东西
改了
本帖最后由 siderlee 于 2016-5-23 19:30 编辑
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深圳的有参加过,很精典,很不错,合肥需去不了现场,看看讲议 ,也一定很精彩。。 |
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