Transformerless Power Suppply

[Pic_User]

Hi All,

There seems to be a great deal of confusion among hobbyists and new professionals concerning ground and circuit ground.

I stopped calling the “common” connections in electrical / electronic circuits, “ground”, 30 years ago. Most of us, have worked out the dual meaning of ground. On one hand we actually mean earth ground, next we simply mean a common connection in our circuit.

This dual meaning is okay most of the time, but sometimes it causes misunderstandings and even dangerous situations. Transformerless power supplies are a common battle ground for the semantics of the term, “ground”. This is because, the misunderstandings lead to safety problems. Problems that cannot be ignored.

Melanie, as usual is the voice of reason and spot on. The TB008 application note, is right out of the twilight zone. The author, obviously has some confusion about “ground” and “common”.

I post this diagram to help illustrate what Melanie already pointed out.