Is there something similar like Project Euler for electronics?

[Ranayna]

Hi,

lately, I am realising that I am missing a lot of basics, and maybe more important, also a lot of practice.
Now I wonder if there is something similar to https://projecteuler.net/ for electronics? I.E. some page that sets electronic design tasks with solutions available, with raising difficulty.

I know of www.tronclub.com since I saw it in one of Dave's videos, and it seems I can finaly subscribe to them without a credit-card, but is it worth it? That is not cheap, and I already have quite a stockpile of basic components, so I do not necessarily look for something that ships hardware, but on the other hand it does not have to be totally free.

Are there maybe any good online courses that I could use? Preferrably those that do not bind me to a tight schedule.

[bd139]

It's a short one but look at "A Designers Guide to Innovative Linear Circuits" (google it there's a PDF).

Page 3 onwards "test your analog-design IQ".