I contacted Schurter. They have multiple companies using the DENO on safety earth. It's designed to saturate on purpose during a fault, but when it does it appears like nothing more than 12ga solid core wire. The companies get UL and CE approval.
How do Schurter DENOs and KFA filters not infringe this? Do we all have to pay royalties for using those?
The link was to an application, not an issued patent. The Grant is here: US8988168B2 - Ground noise inductive filter
- Google Patents
On the right side of the application or grant under the blue box, there are some links you can click on. One is for 'similar documents.' The list for that looks like there are are number of people with related ideas and claims.
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Nothing I can see on this page suggests it is just an application:
US20150035620A1 - Ground noise inductive filter
- Google Patents
US20150035620A1 - Ground noise inductive filter
- Google Patents
How long has Schurter's DENO been for sale? If it predates 2013, this patent is probably meaningless. Besides that, how well could you defend an inductor on an AC application, from 5 years ago? Inductors have been used in AC application much longer than that. I have a CD player using one from 2005.
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Regarding your first question, it is necessary to read the patent carefully to see what it says. In the summary at the top it says the ground inductor is part of a system. If that is the full claim, then a ground inductor that is not a part of their system should not be covered. So, it really does depend on exactly what it says.
Regarding paying royalties, if Schurter has the right to make them either by licensing the right or because they were already being used, perhaps as a trade secret, before the patent was issued then they could keep on making them. If they have the right to make them and sell them here, and you buy from them them you are not infringing. That would be my understanding, but I am not a lawyer, and cannot, and do not give legal advice.
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And what if you are building an AC distribution box? Does it have to be part of their system with their special dielectric transformers, or just the fact that it's in a box with others?
From earlier in this thread predating sales invalidate patents. If you want to patent something do it before you sell it. It was mentioned not to tell anyone without a disclosure.
Predating sales do not invalidate patents under current rules. Public disclosure of the technology is required. If sales of a trade secret device were made that does not mean there was public disclosure. It only means whoever was using it as a trade secret before the patent was issued can keep using it without license.
Even if there was public disclosure, it does not invalidate the patent. A court or the patent office would have to determine the patent was issued in error. In other words, the patent holder would still have rights to sue, and you could then use the public disclosure as a defense.
Again, I am not a lawyer and the foregoing is not legal advice.
Even if there was public disclosure, it does not invalidate the patent. A court or the patent office would have to determine the patent was issued in error. In other words, the patent holder would still have rights to sue, and you could then use the public disclosure as a defense.
Again, I am not a lawyer and the foregoing is not legal advice.
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Hopefully that is the most important thing that everyone can agree on
Do the safety grounds from multiple chassis have to be run in parallel, or can we link chassis and have just one system PE connection?
This suggests chained PE is not allowed, although it doesn't specifically mention consumer appliances (there doesn't seem to be any webpage which does):
Connection and choice for protective earthing conductor - Electrical Installation Guide
EDIT: It seems consumer appliances are addressed under LV terminology:
Low-voltage consumers - Electrical Installation Guide
Connection and choice for protective earthing conductor - Electrical Installation Guide
EDIT: It seems consumer appliances are addressed under LV terminology:
Low-voltage consumers - Electrical Installation Guide
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Hopefully that is the most important thing that everyone can agree on
Do the safety grounds from multiple chassis have to be run in parallel, or can we link chassis and have just one system PE connection?
It's ok to link them, but I wouldn't recommend defeating the safety ground in their power cords.
This is done with pro audio gear sometimes because they struggle with awful problems. For that reason rack mount gear may have special ground posts on the back of them, which they may also connect to the rack.
What you don't want to do is mix ground connections of drastically different potentials. When I say drastic, I mean a lot more than the difference between a 14awg and 12awg cable.
I'm obviously not a lawyer either... I just intently read what people post here because they have experience with patents and electronics.
As someone who wants to use DENO's in everything I will make commercially... I do have a vested interest. I'm actually not worried, but I need to know what potential problems I'll have to get around because of this stupid patent. I've already contacted Schurter.
While I doubt this patent could hold weight in court for application not specifically including their other patents with transformers, court fees are how they hurt people not the technical side
It doesn't say you can't do both. Which is consistent with what I've seen in pro audio gear. And why I say I wouldn't defeat the power cord's PE.
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