Thevenin's Theorem, Output Impedance, and Input Impedance

How output and input impedance interact

[OMNI_INFINITY]

THE OMNIPRESENT AETHER here. Thanks for acknowledging ME.

[yusufronco]

As an electrician, these videos have filled in so many knowledge gaps I had about electricity

[TheManzico]

Welcome back Bob. We will work with you to achieve the the viewing numbers. I am sharing the videos. Keep it up!

[ertreri]

Super informative, really good. This is a must see video for people that play the guitar out there. You see a lot of times the question about amp head to speaker cabinet impedance matching. Your video explains it all. In short using speaker cabinets of higher input impedance works fine with amp heads of low output impedance, except you waste power if you do not match impedances. Thevenin s theorem does simplify massively circuit analysis.

[borisdorofeev]

Absolutely brilliant. This is the right way. I get the teachers that start teaching Thevenin Equivalents with "short the voltage sources and open the current sources".
That method is algorithmic and helps build a process that will work immediately for students, but it won't help with intuition. This method of "just meaaure the voltage across this element, then measure the current" is way more intuitive.
It's like a special case for node analysis, which can work as any general purpose case. It's an incredible tool and a part of practical physics and electrical engineering that brings a ton of concepts together.

What I love most about Thevenin Equivalent Circuits and Thevenins method of analysis is how it takes the high complexity of Electronics and stands it on it's head by using it's own logic in his favor.
Think of it like this:
Every element in a circuit, including the conductor, will have parasitic components which cause it to behave as a partial resistor, capacitor, inductor, etc. Imperfections are everywhere so, beyond theory, we can think of any circuit with inherent reactance.
So even though transisitors and maybe ICs and other elements have been introduced (and we can still examine and appreciate each individually), it will still all simply down to some complex reactance with a source of power.
It is really a marvelous realization and a gigantic contribution to circuit analysis.

[fuha_edits]

Excellent explanation! This finally made it click for me.

[J-Eagan]

Thanks Bob! This really helped me intuitively relate the Thevenin equivalent circuit to the calculations.

[mcameron]

It’s important to understand at the beginning that when he attaches the current meter, it is no longer an open circuit. The current meter has low impedance and so “closes” the circuit so that current can flow and can be measured. So the volt meter with high impedance measures voltage across an “open” circuit while current meter measures current flowing through a closed circuit. Just a clarification for those who are confused between how a volt meter works and current meter works. Great video though.

[tomaskorenek]

simple and logic, very well put together even if english is not my first language, bravo

[inamaman]

You are a great teacher perhaps the best I have ever seen, my question is how to analyze if two voltage sources are connected in parallel to a load

[ex-genaumproject]

Great video that helped me to clarify some doubts I had about antenna's impedance matching. I work usually with audio devices and I knew that low Z mics works good with preamps with an input Z of at least 5 times the output impedance of the microphone because you don't need too much current on the preamp input circuitry as they are voltage amplifiers and not current amplifiers, but I wasn't understanding the impedance matching of the antennas, now I can understand that.

[cemox]

Best video on the subject. Thank you so much. 🙏

[snort]

This is among the best stuff on Youtube. U of YT

[bahaaalaagmail]

Thank you for such great explaination 👍

[makiskouloumparitsis]

excellent video and very understandable. thank you sir!!

[noelcastle]

Great video explains alot of complex sounding terms simply . Talking of input impedances and output impedances, early professors specialising in electrical circuits and circuit designs also used these theories with power generators internal impedances matching load impedances. These ideas forced early electrical power designs to be series connected external loads usually arc lights. These worked ok but required very high voltages and difficulty in switching individual loads within the circuits being series connected . It was taught that the impedances must match to allow maximum power transfer from generator to load. Edison with a non mathematical brain and needing to have lower voltage and individual loads being able to be switched in and out without effecting other loads for his carbon filament light globe circuits went against these scientic laws . He advocated for a extremely low generator impedance and parallel loads across the generator output . This allowed varying loads and still maintaining reasonable low voltage for his incandescent lighting supply networks. This went against theories taught at the time but worked as he invisaged without a huge knowledge of mathematics what the system needed. Of course he was 100% correct and proved the input must match output laws not really suitable for power distrubution .

[markusfischhaber]

I wish I could upvote the video everyday

[randyanders]

MATHAMAGIC, I LOVE
That, it has a ring to it

[bjorntheviking]

Luminiferous aether you say... a man after my own heart, popped this on for my kid, aether is a no longer postulated theory which has fallen out of fashion, but explains a lot

[OMNI_INFINITY]

Is that the dad of the math and science DVD guy?