Impedance, Back EMF, AC Resistance

[@TheCrunchbird]

This is an exceptionally good explanation of an inductor. Showing the fields across the individual turns of wire in the coil was a brilliant idea.

[@HitAndMissLab]

This explanation deserves 1 million views.

[@8yerbrain]

I'm fairly new to all things electrical. So the concepts of impedance, back EMF, etc. (even AFTER watching your video once) are difficult for me to work my head around, but I'm making progress and am ever so grateful for individuals like yourself who take the time to teach...for FREE no less. How amazing is that? Thank you very much!

[@AllAmericanFiveRadio]

8yerbrain Thanks

[@AllAmericanFiveRadio]

8yerbrain Thanks

[@michaelstreets7816]

Excellent. Explained with precision and clarity. Thanks for posting this.

[@fullwaverecked]

Thank you. This helped a lot. My brain has always resisted understanding impedance.

[@AllAmericanFiveRadio]

Thanks. It is important to have some idea of how impedance works.

[@fullwaverecked]

@@AllAmericanFiveRadio In a way, AC is to impedance as DC is to resistance. Everyday the fog clears a bit.

[@johnallenrichter]

Thank you again Rick for explaining a very difficult topic like EMF so that a novice like myself can begin to understand it. I truly appreciate all the hard work that you put into your videos....

[@AllAmericanFiveRadio]

John Richter Thanks

[@alchemy1]

Excellent detailed, nice slow, and meaningful explanation. This gentleman is a wonderful human being. Thank you for who you are.

[@AllAmericanFiveRadio]

THANK YOU!

[@tauseeqhaider650]

This is simply brilliant,precise and interesting,guy sounds like Marlon Brando

[@Asyss_Complex]

Your diagrams are really easy to understand, and the demonstration at the end was interesting. Excellent video!

[@AllAmericanFiveRadio]

Thanks

[@EngenheiroEletricHyanGontijo]

Thanks a lot! Now, I undernstand this!! The experience was fundamental.

[@AllAmericanFiveRadio]

Thanks, and your welcome.

[@skycarl]

Thanks Rick. Once again a great explanation of a pretty sticky wicket. Well done and thanks. Carl

[@AllAmericanFiveRadio]

skycarl Thanks

[@AllAmericanFiveRadio]

skycarl Thanks

[@kolinevans9127]

very good video !

[@gary.richardson]

Thanks for the share. This helped me understand CEMF much better.

[@n1chp]

Hi Rich, Thank you. This was a big help. 73, Mike

[@AllAmericanFiveRadio]

n1chp Thanks

[@sandragrehl4117]

Great work, thank you

[@TonyButchT]

Tremendous help...Thank You! It took me long enough to understand what Bias meant. Impedance is next!

[@AllAmericanFiveRadio]

Tony T. Thanks

[@AllAmericanFiveRadio]

Tony T. Thanks

[@wandawong]

Kudos for precise and consistent use of language. That's where most attempts to describe impedance fail.

[@AllAmericanFiveRadio]

wandawong Thanks

[@AllAmericanFiveRadio]

wandawong Thanks

[@GroverCricketDaisy]

Excellent video explaining back EMF thank you

[@AllAmericanFiveRadio]

Thank you, and your welcome.

[@spetro3387]

Excellent video. Thank you very much for that sir.

[@AllAmericanFiveRadio]

Sam Petrocelli Thanks

[@AllAmericanFiveRadio]

Sam Petrocelli Thanks

[@garyjellen8039]

excellent tutorial and good demonstration.

[@AllAmericanFiveRadio]

Gary Jellen Thanks

[@AllAmericanFiveRadio]

Gary Jellen Thanks

[@JimGriffOne]

Ah, so this is what causes the low-pass filter effect of an inductor (Inductive reactance). Great video!

[@tectalabyss]

Thank you Rick. Very useful information.

[@AllAmericanFiveRadio]

***** Thanks

[@AllAmericanFiveRadio]

***** Thanks

[@tectalabyss]

AllAmericanFiveRadio You are very welcome Sir. I hope to see more videos soon. Take care. Bobby

[@bernardocisneros4402]

Thank you! Very good explanation to go along with the visuals. I know that impedance is made up of resistance and reactance in the circuit. What opposes the flow of the source current in the coil when the magnetic field is growing? Is it the back EMF or the induced current that's in opposite direction to source current or the inductive reactance?

[@AllAmericanFiveRadio]

Thanks You! Yes, the inductance produces the Back EMF = impedance.

[@hammzahammza7914]

Thank very much for your time to make this magnificent video. It's very informative. I wish if you can make a video like that about " joule thief ". Thanks again 👍😊

[@AndyDaviesByTheSea]

Hi Rick that’s a lovely introduction into of AC theory, I'm sure that your KZbin videos will be a great source of inspiration for many years to come, I'm sure that, like me, you’ll remember the classic film ‘The Time Machine’ (originally made in the 1960) where the knowledge of the earlier wise men were stored on spinning discs for future generations. 73’s Andy . . . GWØJXM

[@AllAmericanFiveRadio]

AndyDaviesByTheSea Hey Andy, Yes, I do. I have the original movie on DVD. It's still fun and entertaining to watch The Time Machine. Rick

[@AllAmericanFiveRadio]

AndyDaviesByTheSea The Time Machine, I have that movie somewhere. That movie made it very clear how fast knowledge can be lost. Knowledge that takes many generations to acquire could be lost very quickly. Some things that archaeologists have found, that were produced thousands of years ago, still have them puzzled as how they did that. Thanks Andy.

[@dictare]

Thank you! That is the best, most easy to understand info I have ever seen on impedance. Can you please go on about Inductive/ capacitive reactance?

[@AllAmericanFiveRadio]

dictare Thanks @user/dictare

[@AllAmericanFiveRadio]

dictare Thanks

[@amywegner1183]

Very informative and thank you!

[@AllAmericanFiveRadio]

Your welcome and thanks.

[@atas525]

very simple and informative.....thank you

[@AllAmericanFiveRadio]

Aras Mahmood Thanks

[@AllAmericanFiveRadio]

Aras Mahmood Thanks

[@billybonewhacker]

great job with a difficult subject.

[@AllAmericanFiveRadio]

billybonewhacker Thanks

[@AllAmericanFiveRadio]

billybonewhacker Thanks

[@ТатьянаДубинина-и5ш]

I'm confused about this: there are no other impedances in the circuit shown other than the coil. So all voltage of the signal generator should be dropped across the coil in any case, increasing coil's impedance only affects the current. But since oscilloscope registers more voltage, the only option is that voltage was previously dropped across generator's internal impedance, and when coil's impedance increased, it took more voltage. Is that correct? or I am missing something?

[@AllAmericanFiveRadio]

I can understand your confusion. I’m thinking about a video to demonstrate the effects of impedance. I’ll reply to this comment when I put up the video and give you the link.

[@AllAmericanFiveRadio]

I just uploaded this new video. Impedance Back EMF Practical Demonstration kzbin.info/www/bejne/gKOsaHxvaL2tj80

[@grovve8960]

An a/c coil cancel each other out as the the electrons and currents flows back and forth?

[@AllAmericanFiveRadio]

When the magnetic field cuts across a wire it produces electron flow in the opposite direction opposing the main flow, this is call impedance. If the magnetic field is not moving you only have resistance of the wire. Here is another video that may help. Impedance Back EMF Practical Demonstration kzbin.info/www/bejne/gKOsaHxvaL2tj80

[@jasmany19]

couldn't you also say that by adding the iron core to the coil you are also increasing the inductance and thereby increasing your induced voltage as shown on the oscilloscope?

[@AllAmericanFiveRadio]

+Mejia Yes

[@atco21117]

Very good theory lesson, thanks! -- Atco

[@AllAmericanFiveRadio]

atco21117 Thanks

[@Greg_Chase]

To explain why Nature initially UNDERMINES the growing magnetic field in a coil as supply current INCREASES, then turns right around and tries to keep the magnetic field around when the coil's current is decreasing - I tell students this: 1) Faraday's law of induction and Lenz's law show that increasing current will induce an opposing current that undermines the growth of the original current. Nature seemingly says "I don't like growing magnetic fields - and I'm inducing an opposing current to limit the magnetic field you're trying to grow in that coil" The second part, when supply current starts decreasing, is tricky. Because Nature tried to limit the magnetic field, if Nature was consistent, it should be quite happy to see the original current and magnetic field drop back to zero. Instead, Nature turns around and seemingly says "you know, I've discovered I like your magnetic field - I see you're trying to reduce the current and make the magnetic field go away - I'm going to resist that action" and Nature establishes a current to bolster the existing magnetic field, instead of trying to kill it like it did when the power was first turned on. I tell students that when the supply voltage and supply current begin decreasing, think of that decline in current - as actually INCREASING in the opposite direction. It's like stepping on the brakes in a car, You are actually ACCELERATING - *in the opposite direction* of the car's motion. "I'm putting on the brakes, but I'm accelerating in a rearward direction?" CORRECT. If current has changed its direction, Nature, by Faraday and Lenz's laws, induces an opposite current to the change in direction of the supplied current. And that bolsters (props up) the original magnetic field. If the supplied voltage and current moved left to right in a wire or coil, and begin to decline, this decline is just an increase in the opposite direction. .

[@AllAmericanFiveRadio]

Make some drawings, then make a video.

[@Greg_Chase]

@@AllAmericanFiveRadio I work with a small team developing sets of metal layers with the Lorentz force causing coherent accelerations of the charged particles in the metal layers. Our hands are full. The devices have a vertically-oriented magnetic field, and eddy current coils adjacent to, but not touching, the horizontally-oriented layers of thin metal. We drive the eddy current coils at very high frequencies. The 90 degree orientation of the vertical magnetic field and horizontal eddy currents in the metal layers leads to immense coherent accelerations of the charged particles in the metal layers due to the Lorentz force. As a break from work I like to watch other experts like you who deal with the subject matter of electromagnetism - it's relaxing. You do a good job - the pacing is good.