What is the site policy on posting a reverse engineered circuit diagram like in this question: short circuit or disconnect to bypass a compressor


Please correct me if I'm wrong, but isn't it general wisdom that the schematic is the intellectual property of the actual creator of the schematic?

If someone reverse-engineered a schematic from a PCB, than that person is the creator of the schematic and therefore creator of that particular intellectual property.

Any patents which cover the finished product are a different matter completely. Patent enforcement is between those who manufacture the device and the patent holders and it has nothing to do with reverse-engineered schematics. Do keep in mind that patent claims need to be made public in the patent itself, so they are not a secret to begin with.

One more thing that I feel should be mentioned here are schematics and PCB layouts taken directly from service manuals. Such actions can be considered intellectual property infringement, since someone is directly copying existing work made by another author.

Do note that some parts of a schematic could be a trade secret, but unless the creator of the reverse-engineered schematic is somehow affiliated with the company which originally created the circuit, he has no obligation to protect the company's secrets.

Therefore I see absolutely no reason why we should not accept properly reverse-engineered schematics in our questions and answers.

  • \$\begingroup\$ The Wikipedia article on this topic might be interesting as well. \$\endgroup\$
    – AndrejaKo
    Feb 23 '14 at 15:24

You cannot copyright FACTS. The factual arrangement of a circuit is not I.P. Same as a recipe. The factual parts of the recipe is not copyrightable, the ingredients, the portions, the base instructions. What is copyrightable is the expression of those. The exact words chosen, pictures, etc. Idea vs Expression.

Technically, an official schematic from the manufacturer might be considered copyrightable if a court think's its creative enough (imho, that's bs) but a redrawn one with different symbols or routing would not be an infringement (Again, it's the Expression). A reversed Engineered one would offer even more protection than a redrawn one, because a reversed engineered one might not be 100% accurate.

See also Baker v. Selden:

Copyright does not protect facts or useful information. The Supreme Court established this principle in the 1879 case Baker v. Selden.

  • \$\begingroup\$ However, you can patent circuits, and keep people from making widgets with that schematic. \$\endgroup\$
    – W5VO
    Feb 24 '14 at 22:38
  • \$\begingroup\$ @W5VO Patenting a circuit is costly, and requires you document that circuit. So an official schematic becomes publicly viewable meaning that reverse engineering is not needed. \$\endgroup\$
    – Passerby
    Feb 25 '14 at 12:12

I've seen similar questions on Meta.SO about copyright, mainly relating to code but I believe the same rules would apply to a circuit schematic. Despite the title this is probably the best example because it links on to a few related questions:

Please add anchors to the sections on the /legal page

So the general consensus seems to be for legal reasons the only people who should deal with copyright issues are the individuals or company that owns the material and it should be done via a DMCA takedown notice.

With regard to patents and copyrights if someone else decides to begin manufacturing a product based on the schematic it's up to them to determine its legal status. For that matter if I posted my own original schematic there's nothing to say what I thought was an original idea really wasn't and is covered by an existing patent. Although once again that only becomes a problem if anyone (including myself) decide to start manufacturing it.

  • \$\begingroup\$ . regarding patents : In the USA, the laws changed a few years ago regarding "offer to sell". Now, it is not only patent infringement to manufacture and sell, but the "offer to sell" ( i.e. a quotation) is not permitted. A bit off the topic on this question, but an important addition. \$\endgroup\$
    – Marla
    Jul 2 '14 at 23:18

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