Mains Transients from vacuum cleaners, showers, tumble dryers etc

[ocset]

You need to define the extreme transients you desire protection from. If you can't do that, the rest of the exercise is pointless.

Youre bang on with that.

We'd love to be able to define them, but i reckon only those who   have large scale access to the power networks of all countries in europe can really know what is the incidence rate, magnitude and duration of mains transients at any given mains outlet.
Even then i doubt anybody feels they really know.
I certainly have never seen a scoep shot of a mains transient, despite masses of google searching.
I dont hear of anybody doing a PhD in mains transients.

Only specific  companies  seem to know about mains transients, and it seems to me, that they keep this knowledge all to themselves....its their IP.

[Wolfram]

Only specific  companies  seem to know about mains transients, and it seems to me, that they keep this knowledge all to themselves....its their IP.

Mains transients are a well understood phenomenon, there are even standards in place in most parts of the world, giving both expected transient levels and circuits to generate said transients. There is even a whole industry providing test equipment to generate said transients, and an industry built around testing and qualifying equipment to said standards. Relevant standards in the EU would be IEC 61000-4-4, 61000-4-5 and a bunch of others. I would suggest setting aside some time for learning about standards if you are involved in developing consumer electronics.

[tooki]

Only specific  companies  seem to know about mains transients, and it seems to me, that they keep this knowledge all to themselves....its their IP.

Classic treez: “I don’t know about some topic, so it must be unknowable, or there’s a secret cabal holding onto this sacred knowledge, or there’s a government conspiracy against the UK electronics industry”...

[tggzzz]

Only specific  companies  seem to know about mains transients, and it seems to me, that they keep this knowledge all to themselves....its their IP.

Classic treez: “I don’t know about some topic, so it must be unknowable, or there’s a secret cabal holding onto this sacred knowledge, or there’s a government conspiracy against the UK electronics industry”...

I'm glad I wasn't drinking coffee when I read that.

[tooki]

Only specific  companies  seem to know about mains transients, and it seems to me, that they keep this knowledge all to themselves....its their IP.

Classic treez: “I don’t know about some topic, so it must be unknowable, or there’s a secret cabal holding onto this sacred knowledge, or there’s a government conspiracy against the UK electronics industry”...

I'm glad I wasn't drinking coffee when I read that.

Pffft, well obviously you wouldn’t be drinking coffee, you’re British! Be glad you weren’t drinking tea! :p

[joeqsmith]

Only specific  companies  seem to know about mains transients, and it seems to me, that they keep this knowledge all to themselves....its their IP.

Mains transients are a well understood phenomenon, there are even standards in place in most parts of the world, giving both expected transient levels and circuits to generate said transients. There is even a whole industry providing test equipment to generate said transients, and an industry built around testing and qualifying equipment to said standards. Relevant standards in the EU would be IEC 61000-4-4, 61000-4-5 and a bunch of others. I would suggest setting aside some time for learning about standards if you are involved in developing consumer electronics.

The standards can be purchased from various sources.   The cost to setup a lab is going to be a fairly large investment for a small company.   The equipment is not cheap. 

I consider the IEC standards as a guide and will typically go beyond them.  Some companies will capture data in the field and use this as part of their testing.  Once you start working in areas with industrial equipment, some strange things can happen. 

If you design and sell world wide, you really get exposed to a wide range of conditions. 

[Wolfram]

Only specific  companies  seem to know about mains transients, and it seems to me, that they keep this knowledge all to themselves....its their IP.

Mains transients are a well understood phenomenon, there are even standards in place in most parts of the world, giving both expected transient levels and circuits to generate said transients. There is even a whole industry providing test equipment to generate said transients, and an industry built around testing and qualifying equipment to said standards. Relevant standards in the EU would be IEC 61000-4-4, 61000-4-5 and a bunch of others. I would suggest setting aside some time for learning about standards if you are involved in developing consumer electronics.

The standards can be purchased from various sources.   The cost to setup a lab is going to be a fairly large investment for a small company.   The equipment is not cheap. 

I consider the IEC standards as a guide and will typically go beyond them.  Some companies will capture data in the field and use this as part of their testing.  Once you start working in areas with industrial equipment, some strange things can happen. 

If you design and sell world wide, you really get exposed to a wide range of conditions. 

It is possible to get quite far on even a small budget, as long as one is aware of which standards are relevant. The core content of a lot of these standards is described in application notes, for examle http://www.ti.com/lit/an/slva711/slva711.pdf and https://www.st.com/content/ccc/resource/technical/document/application_note/4c/2a/57/e9/43/9c/4f/2d/DM00080038.pdf/files/DM00080038.pdf/jcr:content/translations/en.DM00080038.pdf . From the expected transient levels, protection components can be dimensioned by calculation and/or simulation. This zero-budget approach is not guaranteed to result in a design that will pass transient immunity testing on the first try, but it is a lot better than nothing. With a budget above zero, one should first get an official copy of the relevant standards, and then either build, rent or buy the relevant test equipment. A lot of the needed equipment can be found for cents on the dollar used, with some luck and patience.