THIS IS the best JLPCB advertisement among all JLPCB advertisements :)

Man, you're a legend, wish I had professors half as interesting and clear in expression as you are.

I spent my career working with digital, now I’m jumping over to analogue for my midlife crisis. Coils... bugged the hell out of me because I just didn’t get them. After watching this video, I get it! Thank you for a very well explained and demonstrated video! 👍🏻

Inductors have been quite a mystery for me this far. Your excellent demonstrations helped a lot in understanding them better. This was likely the best practical intro to them I've seen. Keep up the great work, thanks!

Loved that "if flyback were a person" thing. I wish I had a physics teacher like you 🙏 🤓👨

Yes mate, a no nonsense, straight to the point, clearly described presentation bursting with facts in a perfectly digestible format.... This is a gold standard introduction to inductors and their properties. Perfect.

This is the best video tutorial on Inductors I have seen thus far. Much appreciated, thanks.

I've watched so many inductor tutorial videos and I swear none of them were even close to being as informational as this one. Thank you.

Fantastic to see some real life practical examples of inductor usage. Inductors have always been a bit of a mystery to me. Love the analogy of a coiled spring.

Nice theoretical and practical demonstration. In the same manner I would like to have a look at chokes!

I recently started winding my own toroids for some low-power ham radio kits. It's worth mentioning that even on a high-end RF-rated toroid (e.g. type 43 ferrite) the proximity of turns can make a pretty big difference in the final inductance; if they're all bunched together, you get more inductance but lower efficiency, and if they're evenly spread out, the inductance is lower but the efficiency is higher. Not having a component tester, though, I had to come up with an alternate way to test inductances; the simplest way is to build a resonant circuit with a known-value (measured) capacitor and see what frequency it resonates at. With a decent oscilloscope, this should be a lot more accurate than a component tester.

this is my first time watching your channel, and man, you didn't hold anything back with picking wild PCBs, that was fantastic!

I am a starter mechatronic and stuff like this is really helpfull...not every proffessor explains stuff like this...love your content!

Before watching this video, I had a basic understand of inductance, coils, magnetic fields, etc., but now after watching this video, I not only feel I finally understand inductance, but how it's used and dealt with! Thank you!!

Between the natural grown PCBs and the flyback "as a person" demonstration, you have earned my sub and like good sir. I don't often audibly laugh from youtube videos, let alone electronics related ones, but this one really got me. As a budding electronics enthusiast and (hopefully) future Electronics engineer, I hope to learn alot from this channel!

the best inductor/inductance explanation since my days of electrical engineering at Tulane.

Best possible explanation of inductors I have ever came across.

You're very articulate...and make it nearly effortless for others grasp the content. I highly recommend your approach. You will make a great mathematics lecturer 👌

That was such a clear and concise description and explanation as well as providing many useful pointers. Thanks.

I've just started working on superconducting magnet coils as a technician. And asked the team leader about inductance, long story short your explanation is awesome.

THAT PCB INTRO WAS GENIUS!!!!

Fantastic display , after 30 yrs learning and still playing with automotive electronics, in my field opening up and repairing modules are not preformed any more , But I still open and find that trying to solve basic faults , which I’m successful, and surprisingly high rate of repairs work , are simple as understanding basic principles, post like the one you have shown are a excellent learning and teaching Aid , well done !!!!! Your excellent skill and passion are shown through your well explained and simplified teaching, very happy to subscribe and view all your post, Sadly my world of repair is mostly software and this greatly confuses a Tech as simple software fault can imitate a hard Eletricial issue / fault with a clients concern is brought to a dealer ship , Thus , weeding out a software fault from a ‘ hard ‘ Eletrical issue can be trying , but it is just a elimination path I take , Your post show very importantly the understanding and it’s fantastic that you’ve taken the time to do so , Thankyou and looking forward to seeing more post , keep it up ! :)

Extremely well explained. I love the comparisons you do.

Excellent and extremely thorough presentation (technical content and instrument results) plus totally understandable physical speech and phraseology!!! Plus, plus, plus - no bloody annoying and distracting music!!! Previously subscribed to your site - cheers from Down Under.

Love your presentation. I am glad that I am not the only one to notice the "black hole" in one's workshop that gobbles up all erratic kinetic objects never to be seen again. LOL. Like other commenters here, I have always been perplexed by inductors, but you make the concepts crystal clear. I guess the birds in NZ do not like PCB seeds which allows the PCBs to grow in the wild.

This helped me with inductors more than any other video I've seen. Thank you!

you just killed me over here with the god dammed spring bouncing all over the place LOL good one.

These ads are actually great. Most KZfaqrs make the ad spots boring af, but these are hilarious

Interesting for sure. Nice to see the factual results with the scope, between the different inductors. Thumbs Up!

This is the best video of concepts of inductor. I really undestand when you make analogy with spring. The diference aboult capacitor and inductor is very interresting. Thank You!

Wasn't even searching for this topic but I'm glad I found it, super interesting 👌

I would like to re-iterate a previous comment. You are so easy to understand and don't leave anything out. Which a lot of Electro tech tutors have a tendency of doing.

Excellent explanation of theory and good examples.

Thank you for concrete simple and clear teaching on inductor.

The PCBs growing in the forest like mushrooms were great

Don’t need to overkill catch diodes. When sizing catch diodes, remember that current doesn’t increase with fly back. The inductor does what is needed to keep the previous current flowing briefly, however much voltage it takes to do that. So if your 70mA relay coil is switched off, it will continue to pass that 70mA briefly. A 1N4148 catch diode will handle that easily! And with your power inductor at 1A, a IN4001 will do the job just fine.

Very informing!! I am in the process of learning more and indulging in projects involving inductors

One thing that you can also use for the winding of the inductor is "layered" enameled copper wire, it can handle more current at higher frequencies * layered enameled copper wire just means multiple enameled copper wires put side-by-side (aka in parallel) and then wrapped around the core; only electrically connected at the ends. Hope this helps!

Omg that spring reference changed everything for me! Subscribed mate 🤙🏻

Your video & Demonstration has relief me from some misunderstanding the nature of inductor. Thanks for the video.

Very nice video. The simple explanation of how an inductor works by using examples of things that are far and away more complex than a simple inductor seems counterintuitive.

Your examples of flyback at 5:15 and 5:30 are... absolutely perfect 😎❤👍

Looking at inductor's for antenna matching and came across this video. Very interesting especially about making them and the difference between the two with the same inductance. Tnx mate

Thank you. Very informational video. I am a complete rookie in electronics and I am just beginning to find the fun of this hobby. Thank you for your Lesson.

The first video to lay it simple and clear to me. Ever. Instant sub...and now I dream of a PCB forest :-)

Great video. One of the clearest explanations on how coils work and what they’re used for. Thanks 👍

Gotta love your Widlariser at 5:30. 👍

I love the intro. "I happen to live in a part if the world where pcb's grow wild". 🤣🤣🤣🤣

I studied this at university in New brunswick. The prof who taught the subject was very good explainer. so this video.

That flyback person demo is awesome. Well done video. Thanks!

Very good Intro to inductors! Best in helping visualize Flyback effect! Thanks!

Finally I got proper knowledge about inductor and it's used nice video 👏👏 thoroughly practical enjoyed your video Thanks 👍😍

Nice video! I especially love the JLCPCB advertisement. I also love how you showed how flyback would be if it was a person.

Excellent presentation and explanation! Best I have seen. And please continue with using and explaining terms ("flyback", etc). This is very helpful in establishing a basis in overall understanding. I am now going to look for your follow on video which, hopefully, will go into more filtering aspects.

Best inductor video on KZfaq! Thanks!

Great video and information, thank you very much! FYI, I haven't sanded or burned the insulation from this kind of wire for many years now. Modern coated wire is made to solder through, at least on all the wire I've dealt with. Just hold the soldering iron and solder on it for a few seconds and it works like magic, instantly tinned.

A true Eureka moment for me watching this! Absolutely superb! Subscribed!

Love it! Very well explained with detailed presentation and comparisons. Great job!

Excellent explanation. Loved your approach , pragmatic and with humor , a great combo.

That's one of the best demonstration of flyback ..

Never watched a Schematix video I didn’t like and that I didn’t find instructive. Thank you for taking the time to share this.

Best video about electromagnetics I've seen so far

The best inductor video on KZfaq!!!

In RF parlance, especially in the amplifier arena, capacitors and inductors are labeled as tank blocking capacitors which pass RF current and block DC, while the plate chokes block RF current and pass DC, unless they're making up the tuned resonant tank circuit, where you want the cap to charge and discharge, and the inductor to ring, forming the flywheel effect in class B and C amplifiers. Another choke is used off the load capacitor to ground, which is for safety if the plate cap fails, connecting the HV to the tank. This, of course, blows the fuse before allowing HV into the antenna circuit. However, that choke's ringing causes HV to appear across the tuning and load cap's plates, and they have to be rated for that. In the plate power circuit of tube amps, the cap passes the anode's RF to the tank circuit while blocking HV DC, and the RF plate choke blocks the RF from entering the HV power supply. It's like using two types of check valves in a hydraulic circuit, and very similar to a diode's action.

Sir you are a genius at explanation and teaching. Your video was so clearly done and while interesting. I applaud you. Well done.

- probably already in the comments somewhere, but I'm not going to read over 600 comments to find out: The peak current at turn-off of an inductor can *_never_* exceed the current at the instant turn-off starts. This is a fundamental property of inductance. If a relay coil operates at, say 100 mA, the current at the instant of turn-off will be 100 mA and decline from there. For small relays a 1N4148 or 1N914 or similar diode is entirely satisfactory. If the coil current exceeds half an amp then you might go to something rated at 1 amp. I've used dual transistors in surface mount packages for driving relays. One transistor is used as the switch and the other is used as a diode (collector-base; the base-emitter diode has some better properties for some applications but small reverse breakdown voltage, typ. 6 or 7 volts for common types). This makes things very compact. ~~~ That HY-2 inductor core is a Micrometals Type 52 powdered iron material, or a counterfeit thereof.

i have to sincerely thank you for this, it's what i needed to know, and you've done a good job of making this easy to comprehend. thank you.

thank you, a very good tutorial on inductors mike

As someone who's fried a few boards early on in my days of home building CnCs, this a huge resource.

This is by far the best sponsor acknowledgement I have ever seen :D

Best explanation of inductor Thank you very much.

This video is of high educational value and was a pleasure to watch. I came away knowing things I didn't know I wanted to know!

Very good, easy to follow

Excellent explanation. I mainly deal with AC, but your clarification of DC circuits is massively helpful. Small point of contention though regarding definitions, an inductor I believe doesn't so much "resist" current so much as "impede" it. The definition and distinction I was taught is that resistance is work done that produces heat, whereas impedance doesn't. But then I guess no matter the length of copper wire you are using it will have some inherent resistance to it. Great video!

I have that very same component tester. It doesn't work too bad. The LCD screen lost its seal on mine shortly after I bought it, but still works. Every once in awhile it will give some erratic readings. I bought mine and assembled it. I had to come up with my own case for it.

Awesome... waiting for next inductor video that it can cause issue in circuit with practical and theoretical explanation...

*Finally, an inductor tutorial that makes sense* 👍👍👍👍👍

Beautifully explained. So electrically an indicator is like capacitor that has had its two parallel separate conductors shorted together at the end. And would become a capacitor again if "unshorted".

How can i build something like that inductor tester? Am so much at the right place. This is the best ever tutorial after i wasted my two years on other channel to keep on feeling like quiting electronics.

Excellent class professor!

I wish I know all this at my university, it is so clear and visual thank u👍👍👍

I really enjoyed your flyback to a spring example! I need to find out the opposite of what you showed after that, however... I need to figure out how to best protect any other circuitry while, at the same time, getting the highest possible flyback voltage. It doesn't help that my limited amount of electronics background is close to 50 years old ~ with a LOT of "water under the bridge" during that time... (I'm having to go back & start over from scratch via youtube, etc.) Fortunately, I DO remember enough to have a healthy respect for HV & how to discharge scavenged flybacks, capacitors, & condensers without "knocking myself into the next county ~ if not the next life..." I'm wanting to set up at least 3, horizontal shaft, Briggs & Stratton 4 stroke motors with to run off of HV produced HHO on demand. These motors, in turn, would spin "smart drive" stator/rotor motors, rewired to be generators, with a bit of the output getting diverted to charge the flyback system for HV/LC... Any suggestions on how to protect the other circuitry withOUT reducing the flyback voltage???

From the coil32 page......Another case is the inductor in the switching power supply. The commonly used ferrites have a relatively low value of saturation flux density (about 0.3 T), so in the power switching circuit the inductor is switched between the maximum value of the field when it almost gets a saturation and zero-field value, when it is demagnetized to a value of residual induction (curve [4]). As we can see the slope of the major axis of the ellipse 4 is much smaller than that of the ellipse 3. In other words, the magnetic permeability of the core in this mode is greatly reduced. The situation becomes worse if the choke core has DC bias (curve [5]). The major hysteresis loop of the real ferrite is more rectangular than on our schematic image and, in the end, the dynamic magnetic permeability of the power inductor on a ferrite ring falls to several units. As if there is no the ferrite! In the end, the inductive reactance of the inductor decreases, the current increases dramatically (which results in an even larger decrease in µ!), the key transistor heats up and burnout. The calculations of Coil32 for this choke give an absolutely wrong result. Because, we used to calculate the value of initial magnetic permeability, and in a real circuit, the permeability is two to three orders smaller. You will get the same situation if you will measure the relative permeability of the toroid by the trial winding. The solution is to use a ferrite core with the interrupted magnetic circuit. In the case of the ferrite ring, it is necessary to break it in half and then glue that two half with the non-magnetic gap. The major hysteresis loop of such a core becomes more sloping [2], the residual induction is much less [B'r], the effective magnetic permeability is also less than that of the core without a gap. However, the curve of magnetization [6] shows that the dynamic magnetic permeability of this inductor is much higher than that of similar, but with a core without a gap. It has permeability about 50..100. Coil32 also is unable to calculate this choke, since it does not take into account the non-magnetic gap. Another solution is the use of special rings for the power supply as powdered iron toroids (not ferrite). Such toroids can be found in pulse power supply units and motherboards of computers. The non-magnetic "gap" in such ring is distributed along its length. Conclusion. The Coil32 program calculates only low-current ferrite toroid coil working in low magnetic fields. For the power chokes calculation, it is necessary to use a completely different methodology.

This is probably one of the better videos I have seen you make. Quick quick question I am building speaker crossovers and found Inductors are very expensive. I wanted to ask what type of Toroid would you suggest for this purpose. I am thinking I can save a lot of money if I just build my own inductors. I want to use iron core inductors for the large woofers rest could be air core but I guess I could use iron core for those too as I could use less wire. I will probably be using 18 awg (1 mm2) wire. Could I even use an iron bolt?

Excellent demo and explanation ! Glad I found your channel !

the pcb foraging is fantastic haha

I love your style of teaching !👍

I built a 60 watt transistor stereo from Heath kit back in the day. I would bridge a 47 mf Disc capacitor across each speaker output To keep from hearing my neighbour talking on his CB radio through my speakers, It worked!

I had to pause to comment, "oh my god," as you smashed LED, resistor and cap, and I'm an atheist. You are a Kiwi treasure. I salute you with subscription, sir.

I work on refrigeration systems. We put vfds on the condenser motors a while back. They were blowing up motors left and right. Aside from the motors not being rated for vfds at the time (over a decade ago) they added these electric filters on the outputs of the vfds. I'm no electronics guy, but are those filters we added essentially just inductors for taking out the spikes like you mention in this video on the buck converters? The output of vfds are dc that mimic ac as far as I understand. Which isn't much.

Thank you very much for your explanation and presentation. Great video.

Thank you for an awesome explanation.

It's PCB season here in Australia. I'll be heading to the hills to pick a few bags worth next weekend.

Excellent subject, very well covered. Thanks for sharing.

A good presentation with a clear explanation of what's happening. Thanks.

When you released the spring and it bounced around the entire shop, i burst out laughing. XD 4:12

Awesome video thankyou for such a detailed insight!!!!

Amazing class! Thank you!

Thank you for educating me on inductance. Peace, VF