六樓講的另一種接法。
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' P- P/ R% a$ {$ z# SClass I AC input:
. I5 l) u' r- {8 AThis type has a three-wire input with the AC earth ground connection and provides a path to a stable reference (earth) to help minimize output common mode noise and electromagnetic interference (EMI) and immunity. Generally, this type of AC input has better performance where output electrical noise interference must be kept to a minimum. However, the availability of power sources with a ground connection may be limited or not guaranteed, and in this case, power supplies specifically designed for AC inputs without ground should be selected. Also, with a class I AC input, it is possible to provide a reference point for the load (user system) through the power supply to be ground reference for EMI and EMC performance improvements. In some applications, this is a must and provides a path to ground for ESD as well as reducing the amount of AC mains surges and electrical fast transients from reaching the load. Connecting the output to earth ground eliminates the output common mode noise.
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Linking grounds
9 g5 T) Z2 I; U, @4 Q" s, YThe link between the direct-current (DC) ground of a local electronic circuit and the earth reference potential of the mains is usually provided by the local power supply converting the line voltage into the required DC output.
Figure 1 shows a simplified block diagram of a low-cost switched-mode power supply (SMPS) typically used in personal computers, laser printers, and other equipment. Here the DC ground of the SMPS output is referenced to the protective earth (PE) conductor of the mains via the SMPS chassis. This direct link, therefore, acts as a sense conductor, establishing the PE voltage as the local DC ground potential.

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你可以在板子上  做出和螺丝连接或者外壳连接的大地  然后通过1M电租并联高压电容和你的12V负极连接   大地不要直接和负极连接

学习

我一般都是放一颗电容或者磁珠隔离开来

Mark

来看看

GND 与GND_EARTH，用电容电阻连在一起。

学习一下!

学习一下!

超級狗 发表于 2017-11-28 21:39
  B. n, k' O# f9 w6 ~' L0 EChasis Ground PCB Layout

谢谢版主

Chasis Ground PCB Layout
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板子上地接大地后，防静电会好很多。

描述问题也是学问，就像别人给你解答一样，要让别人一目了然的看懂

clp783 发表于 2017-11-28 10:28
# }% L& L' I  B3 k% h) T% W问题看不懂，只看出那字真丑

这叫草书，另外你真看不懂？
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