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No such cajon anywhere

You need to squeeze the top. It will stay crushed and will not expand. You'll get even better results. Done it 100s of times

Genius level.

Very interesting experiment and very helpful as I am arguing about this with my friend right now <3

500 ms per division, not screen.

Great demonstration. Would have been ideal if you'd turned of the room's primary light source.

capturing that back emf and using it to power the same light, by pulsing the switch at about 200 hertz.

dude why are your fingernails so long and why you have nail polish on them?

You should have done a capture on the scope!

Howdy. Yeah. The "free wheeling" diode over the coil or an inductor is a proven remedy. But, as one commentor pointed out, it makes the turn off of magnetic valves and locks sluggish. One may consider using 5 diodes in series over the coil. This will allow the backfiring emf to rise to 5 x 0,7 V = 3,5 V. The dissipation of the magnetic energy will be faster. There will be contact arcing, but way less. A smarter way is to connect a diode and a zener diode in anti series and connect this over the coil. One may choose a suitable zener to which level one will let the backfire emf to rise. There is one problem though. Zener diodes are slow. The backfire emf slew rate must be moderated. This moderation may be done connecting a capacitor too over the coil. Suggested values. A magnetic lock, 1 uF. A DC contactor coil, also 1 uF. A relay coil or a small magnetic valve coil, 100 nF. Regards.

Wait a minute -help me here: how do a bunch of charged bits of any size get pulled together? Any two bits of "dust" must be oppositely charged, to attract each other. Now, what charge is the 3rd particle, to attract the other two?

All talk and no show. Now I see why they say that space comes like religion. Although it sounds like bullshit many people still believe.

You didn't mention, that coil also affects rising edge on circuit close. It makes rising edge slightly rouded - stretched in time.

If you understand the physics, the the same blip you see will be missing at the beginning of the on , the same stored energy, is lost, it s called reactance, same applies to capacitors

Hi, Michael ! I just wanted to comment on your video called : "Testing the Yoidesu Schumann pulse generator for electromagnetic wave output." The comments were turned off. From a scientific standpoint, considering the footage carefully, I noticed that the testing procedures that you apply to the magnet were not applied equally to the Schumann pulse generator. To be more specific, on the conventional magnet, you waved your detector over several times in order to obtain/observe a reading. But on the Schumann generator, you did not. Therefore, the test / review results, including your statements at the end of the video, in my opinion and consideration, could not be determined as scientifically truthful and your findings are based in your opinions and feelings and disappointments about the product during the limited amount spent testing / reviewing the product. Another variant to be considered could be the possibility that the device malfunctioned because of an unforeseen circumstances such as, but not limited to: Shipment of a damaged product or human error during manufacturing of the item.

Explained by E = - dA/dt

Hey Michael! I found your video while searching to do the same repair as yours. The funny fact here is that my dyna-sonic was my father's snare and I realized a long time after I began to play that this snare was sth very special and good sounding. I alsmot share the same story as yours! Since I'm a little broke, I'll try to fit a 14' instead of original Rodgers way more expensives 14.5' wires, too. I feel like I might end with buying the real thing already. Thanks for sharing your experiment!

What is the R of the coil? is it not negligible?

Uggh... Thank God for little coils!

With relays I know that often to counteract this back EMF sometimes a diode is placed across the coil in the reverse direction of the main current flow and that captures the back EMF and allows it to dissipate in the coil instead of going back into the circuit where it might cause damage.

Great explaination!

yo dawg y yo nails look shiny?

This is a great video. I am an aviation maintenance instructor and I teach this in my magnetos class. The collapse of the magnetic field of the primary winding (a few hundred turns of thicker wire) moves the field across the secondary winding which has several thousand turns of very thin wire and this is able to generate tens of thousands of volts that get applied to the high tension leads which lead to the spark plugs inside the cylinders of the engine to provide ignition of the fuel air mixture. The amazing thing about this (amazing to me at least) is that this is all done with a relatively small magnet that spins to create the initial current flow through the primary and the entire device is self contained (requiring no outside electrical input).

Why you didn’t use the trigger once on the oscilloscope to freeze the signal upon the opening and closing of the switch? It would have given a better image that can be zoomed to show what did happen. A missed opportunity.

It was a missed opportunity to not end the video with a diagram of a diode in anti-parallell to deal with back EMF :)

Nice man

great idea! I'd say, you pulled it off!

How can I buy those mini incandescent bulbs with alligator clip hookups? Not blocked by the general incandescent ban?

Lol. Yeah. I noticed that as well. Good in theory but will never work. Just go out and buy a Rogers snare wire replacement

Current is Lorrentz. Magnetic field is lenz. Lenz is with a coil is inductively coupled, with a magnet on rotor on magneto if you want. The coil field change the polarity → ← or ←→ always stop the magnetic field pole and reverse for this with charge by the field of the magnet. The Back EMF on a coil is the discharge capacity of the wire and impédance on the system...never the capacity in the coil are on the maths for this... . On a coil you have R L and C if timing is introduce is another history, capacity of the coil Discharge...Tesla work on this, Best Regards

Hi mike, I can't comment on th e other video so I'll do it here. I've tried many methods with the Viking sunshine and none were that great. Some didn't work. Your method and explanation work just great! Thanks man!

Thanks a lot this video really helped for my school project

Legend says that he's still here... and he is!

The tychos model updated by Simon Shack (Tychosium) destroyed the heliocentric model. For example.. on nov 5 2018 and again on may 4 2020 (546 days later) Earth and Mars were aligned with star Delta Capricorni. In the Copernican model this is physically impossible. According to this observation.. in the copernican model 300 millions kilometers produce no parallax at all.

Title is misleading, there is no analogy for superposition in this video. It is entirely about basic wave interference.

Cool. This is the first time I've seen how the angles work so clearly explained. Thanks

Wonderful demonstration! Will have to check out your Channel for other such instructive videos. Thanks

Wow 👏 😮 so is there anything that continues amplifying constructively from a intersection? Like maybe a black hole and its ring? Isnt a black holes job destructive and always growing? So to a black whole perspectives via objective be constructive energy wave? Would gravity be able to do this destructive interference?

why don't you show how to capture that and feed it back to the batteries? capture the spike and gain energy.

its called the flyback voltage , specifically the reverse flyback , so the inductor flips polarity when it fly back

can you stick a magnet on back of the coil? And test it in both directions of the magnet (N/S) and let us see the results? I'm thinking if that back EMF Spike will be greater or smaller. (but you need to stick the magnet so it won't move)

With that paraphernalia you put on top of that poor drum you might as well drill it it'll sound better you don't know what the hell you talkin about these people that play drums that think they know how to have no clue at all! As my drum teacher said Joey cats the original drummer from the Four Seasons who taught me how to play 40 years ago said all that other b******* should be taken away stop with all the s*** basic stuff works you don't need all that paraphernalia that sounds like s***!, and Joey cash knew his stuff he rocked out God Rest his soul!

By doing that piece of Hardware you are ruining the sound of your Kick Drum you might as well drill it at that point. Hanging symbols or Tom's anything off your Kick Drum takes away from the actual sound when that is done it's not the drill that rooms it it's all the b******* that you put on top of your kick that room's the sound. Like to Tom's and assemble hanging off your drum that changes the sound that totally sucks! Like I'll say again it's not the whole that you drill that changes the sound it's all the bulshit you hang off your Kick Drum that changes the sound drastically you people don't know what you're talkin about!

It might have been more obvious to see the negative going spike if you set the scope to trigger on level change and used a faster time base sweep, since you're using a digital scope. You could also put the coil in series with the circuit and put the scope across the coil. Or instead of the light, use a relay as the coil but still scope the coil of the relay.

Professor Sam Ben Yaakov, you the best on explaining the stuff, thank you for this walk-through , cheers from Tanzania , I appreciate your infomative and intuitive videos

Interesting demonstration. Thanks for sharing.

I am not sure that is what back EMF is. Secondly, a coil essentially goes short after it is fully magnetically charged and thus should short out the globe as it is in parallel. WTF????????????

Counter emf

Back EMF is such a bad term. It's actually the current carrying forward in the same direction it already was... Like if you put a ferrite on a wire it suppresses the ripple because any increase in current generates a larger magnetic field but then if the current to the wire decreases then the field collapses a little and allows the current carry forward. If that was in some way opposite to the current that was in it then you would amplify ripple rather than filtering it out. And you'll find that the voltage going negative is just the current continuing to pass forward in the same direction that it was before but now there's nowhere for it to go so it registers as a negative voltage. You know the electrons stack up in the same direction that they were already going. There's nothing going in an opposite direction.

An important part that 'back EMF' experimenters pay close attention to is the delta T in the denominator - see the (dPhi/dT) formula of Faraday's law at time 5:00 in the video. The complete formula is E = dPhi / dT, Voltage (EMF) equals changing magnetic field / change in time. The "E" in this case is the back EMF voltage spike. As the time of the change in current tends to zero - ie., as dT drops to zero in the denomintor - the voltage "E" grows inversely. This is why the huge number of 'back EMF' experimenters on youtube and elsewhere seek out MOSFETS with the fastest switching times possible - to cut current flow to the coil in the briefest time possible. *_A PHYSICAL ANALOGY_* - a large water tower is filled with 1 million gallons; a release valve is opened a tiny amount and the water drains out slowly. You can stand beneath the tower as it drains with a trickle and be in no danger. - the time span for the draining is shortened immensely: the entire bottom section of the water tower is removed instantly and 1 million gallons falls to the ground. It's not safe to stand beneath it As the time to interrupt current flow to the coil tends to zero, the voltage spike grows inversely, and with a very steep rise time and large magnitude, like emptying the water tank quickly. Faraday's Law. .