Where to find credible circuit diagrams/schematics

[kuzm1nsk1]

Hello, as said in the title, what are some of the best websites or resources to find high quality circuit diagrams/schematics meaning that they are tested and proven to work reliably. For example, if I type subwoofer amplifier circuit on Google, I get bunch of results that don't give much confidence that they work and have very little or no information about the design or working principle.

[JustMeHere]

Peer-reviewed scientific documents.  Just like the rest of the science community.

For amplifier circuits, highly reviewed textbooks.   Look for ones that are used in university classes.

[coppercone2]

you find those on a prototype

[selcuk]

You may check open source projects which have photos, measurement and test results of their prototypes.

Or you may read articles on magazines like Elektor or similar. This topic is related:

https://www.eevblog.com/forum/chat/know-of-any-good-bookssources-of-useful-electronic-schematics

[golden_labels]

Old electronics magazines. Patent applications.

With textbooks for complete newbies: some caution needed. They are tested and work, but may have serious shortcomings. The diagrams are meant to show principles, not be blueprints for practical devices. This is why so many cheap devices are poor designs: they’re literal copies from textbooks.

[Infraviolet]

Horowitz and Hill is quite a good source of circuit diagrams in general, but as said in regards to textbooks in a previous post, it can be a bit limited in the descriptions it gives. Some circuits it shows without any suggestion of what equations you need to solve so as to find the appropriate components values to give desired behaviours.

There is also a series of pdfs I've seen based on old books called "Circards", the old books were compiled from the idea of a "deck of cards" each with a sample circuit on them. Someone on here gave me the link to them initially, they are a bit old in places in terms of the default ICs they often make use of, but many of them translate straight across to more modern devices (when something calls for an op-amp a modern one is usually "better" on almost all relevant performance metrics, so will usually give overall circuit performance as good as the old IC they specify would).

[SmallCog]

Magazines, I've already seen Elektor mentioned but also consider Silicon Chip

There's also a lot of issues of "Electronics Australia" available on the internet archive

https://archive.org/details/electronics_australia?page=3

And some of the stuff from their website (files etc) are available here

https://electronicsluckydip.com/2019/Electronics_Australia_File_Archive/

[themadhippy]

plenty of old magazines and books to  choose from https://www.worldradiohistory.com/index.htm

[Andree Henkel]

Magazines: Elektor was mentioned.

Not mentioned so far: ELV Journal: they had complete schematics, article describing work. They sold kit for selv build and complete device based on same design.

But this is long gone, no longer feasible to compete as a kit for selv buid today will be priced similarly to complete device from china.

[kripton2035]

ELV had very good designs, they are now free to download. but they are in german, and if there is any microcontroler in it, you won't get the compiled code, nor the source code so all these with microcontrolers can't be built.

[DL1DLZ]

Hi,
Yes I confirm too: Magazines.

The Web is a huge source of information, but it is unfortunately polluted - as we know - by fakes, misinformation or incorrectness used only for engangement share, clicks for pay and interaction.
And filtering is not easy if you are not very experienced

Do you speak or understand a bit of Italian? Here is a magazine from a long time ago, Oldies but Goldies, which in its two volumes of Electronics lessons from scratch, is full of useful, simple and even advanced diagrams.

Obviously, it is not up to date with current times, but we should bear in mind that the laws of physics "do not change with fashion" and even if progress is advancing, the Laws of Physics, of Electronics and above all the operating principles of circuits, are the factors that drive progress forward

Greetings from an Italian in Bavaria 

https://archive.org/details/imparare-l-elettronica-partendo-da-zero/Imparare%20l%27elettronica%20partendo%20da%20zero%201/

[tggzzz]

Schematics on their own are little use. You also need to know what they do and don't do.

That was the problem with John Markus' set of books in the early 80s.

There is no substitute for understanding your requirement and understanding the circuit.

[MK14]

Service manuals.  Which in some cases, will include the full schematics, and sometimes, can be found as free downloads on the internet, and possibly even on manufacturer's (especially for older, now obsolete things) websites.  E.g. HP and Tektronix.

[Circlotron]

Plenty of well sorted circuits here.
https://sound-au.com/index.html

[Picuino]

For audio amplifiers: Audio Power Amplifier Design Handbook

https://www.amazon.com/Audio-Power-Amplifier-Design-Handbook/dp/0750627883

https://books.google.com/books?id=Qpmi4ia2nhcC

You can "find" it in internet.