Capacitors

Capacitors hold a 'capacity' of electronics. You may want to take up Meditation if this is confusing.

Tips/Techniques

AC Impedance

I put an article about this in my book. At AC frequencies, certain caps (usually around 1uf or lower) start to get higher impedance. This can be a problem if you want to, e.g. pass audio across a DC blocking cap, but you choose a small ceramic as opposed to a 10uf electrolytic.

Resonant Frequencies of (input/output filter) Caps

Capacitance will differ based on the frequency. One reason why LCR meters have two different frequencies to test at. You can take it a step further though, and setup something like an analog discovery to do a full frequency vs. reactance characterization. See: https://tahmidmc.blogspot.com/2024/03/electrolytic-caps-over-frequency-why-is.html per Hackaday: https://hackaday.com/2024/04/01/why-is-my-470uf-electrolytic-cap-more-like-20uf/ http://web.archive.org/web/20240402042237/https://tahmidmc.blogspot.com/2024/03/electrolytic-caps-over-frequency-why-is.html This has been discussed on the amp hour, referring to this article http://web.archive.org/web/20231208203302/https://www.signalintegrityjournal.com/articles/1589-the-myth-of-three-capacitor-values and if my memory isn't completely trashed, it came out to be: "most of the time you just throw a couple different values of caps on there and don't investigate unless necessary (but you should be aware of this trap)" or something like that. And that the signal integrity blog was 'technically correct' but for all practical purposes not something correct. I can't find the amp hour episode at the moment. Around 400.