Passive RC Filters

#220 In this video I start looking at one of the most basic forms of filters - the ones implemented as resistor-capacitor networks. Contrary to their apparent simplicity, these filters can be made to have a wide variety of response shapes and are usually used in low frequency applications.
Filter series:
Ep1 - Intro : • Intro to Filters
Ep2 - Passive RC Filters: • Passive RC Filters
Ep3 - Active RC Filters: • Active RC-filter Basics
Ep4 - More Active RC Filters: • MORE Active RC Filters
Ep5 - Introduction to LC Filters: • Introduction to LC Fil...
Ep6 - LC filter limitations: • Limitations of LC Filters
Further reading:
www.realnfo.co...
sound-au.com/a...
K-sim tool:
ksim3.kemet.co...
Special Thanks to all my supporters on Patreon!
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[@andymouse]

Awesome tutorial !! I have looked at the Baxandall tone controls with great interest but I have never had a definitive answer to the question of whether the pots used should be log or linear, to me I think It's obvious that they are linear and that log is for volume although if you used log pots it would still work ? how close am I please ? once again thanks.............cheers.

[@kentswan3230]

Thanks! I know understand more fully how many of the filters I've used over the years actually work. I'm beginning to think that LSpice or equivalent should be used as the fundamental pre-laboratory tool when teaching this in schools and universities. At the upper levels teaching the incorporation of the parasitics, manufacturing variance effects (Markov) as well as environmental comes into play especially when you get into RF. At very high RF everything is a parasitic capacitor or inductor to an extent and thus creates unexpected filters when it's not deliberate design.

[@FesZElectronics]

I fully agree that some sort of circuit simulation tool should be used in the teaching environment. Unfortunately, in my experience at least, schools and universities end up using tools that are sponsored by some company, so they cannot really be used "for fun", only in the work environment, since these are tools that are quite costly...

[@kentswan3230]

@@FesZElectronics LTSpice is under the auspices of Analog Devices while QSpice is out of Qorvo. |Open source software stability, evolution, and maintenance need a funding source as well as an enthused cross-trained core team at a minimum. along with clear public use case documents Over Over-dependence on a single or small set of core development leaders is a problem that can lead to the support and development going cold and eventually disappearing.
You have an extensive background using LTSpice but some have indicated that the support team has moved on and updates and improvements will likely peter out. Given that what xSpise versions are you holding out hope for in the near and far future.

[@rubenhidalgocarrillo]

Hello, and welcome back :)

[@albertpalau35]

Macho!! Este tio rumano, tiene uno de los mejores canales de la temática. Un fiera ❤

[@rubenhidalgocarrillo]

@@albertpalau35 Si, lo se. Es un crack, todo lo que hace tiene una calidad espectacular.

[@objection_your_honor]

Thank you for this video.
Will you be doing any videos on active filters? Both transistor and opamp versions?

[@FesZElectronics]

Indeed, active filters are planned next. However, I mostly focus on the op-amp version

[@johnwest7993]

Thank you. Yours is the best electronics learning channel I've found on UA-cam, clear and complete.

[@BalticLab]

Great video, as always! 😉 Question: What's your time overhead for making such videos? The video is just under 16 minutes, what would you say was the time from idea to publishing for this video?

[@FesZElectronics]

Well I started planning this series on filters last year :D

[@BalticLab]

@@FesZElectronics Haha, okay, that seems to line up with my own experience on making videos 😅 I think this enormous time overhead is something the viewers hardly realize. But I won't complain, if it bothered me, I would start a Vlog 🤣

[@FesZElectronics]

Quality takes time; if you want the outcome to be good, you need to put the effort into it. To some extent, I find the long time a good thing since I have time to think and re-think how to properly present and explain the subject. On the other hand it does also mean multiple projects need to run in parallel. Keep up the good work with your channel!

[@mr1enrollment]

another excellent discussion, thx

[@sergepetrov8598]

With Baxandal filter, it is a problem to get those logarithmic pots. I once considered taking stereo volume pot and flipping its resistive plates, but ended up just tuning it in reverse.

[@andymouse]

I have simulations and stuff that tells me you don't need log pots for the Baxandall tone controls so I'm confused, guess I will ask the expert above. To me the pots are changing the ratio of resistance to capacitance to adjust the corner frequency, this has nothing to do with our ears log response to volume :)

[@electroquests]

I've been waiting for this episode!!!

[@ganopterygon]

Really nice video!

[@artemdavinci]

Cool!

[@michaelalex5235]

Excellent as usual, thank you!

[@steveoffer2917]

Snubber?

[@ahmedzafar-xp3kb]

Very informative content.

[@aduedc]

Great presentation.
It would have been better, if you put together a written note so we kept as a reference.

[@tomyorados974]

Hi FesZ, some notes:
1:39 The curve for the capacitor should have a 1/f shape. Instead, it is shown as linear.
13:50 I believe, ESR should always increase with rising frequency (skin / proximity effect). Why is it increasing for those low frequencies?

[@FesZElectronics]

The impedance of the ideal capacitor does vary linearly on a logarithmic scale; I guess I should have also pointed out the type of scale; The ESR is also impacted by the dielectric and materials used around the capacitor which can have leakage.

[@nathaniel9184]

Very informative!

[@bob_mosavo]

Thanks, FesZ 👍

[@bobby9568]

😂