DIY METAL DETECTOR, Gone Wrong and Right!!
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- čas přidán 28. 04. 2024
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With few incidents, I think I made what is called a BFO metal detector, which actually works very well over a large distance.
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By: Mehdi Sadaghdar
0:00 Wrong Way of Detecting Metal
1:48 Theory Behind How Metals Effect Inductance
6:10 More Fake and Real Metal Detector Video Tutorials
7:32 Designing a “Simple” Metal Detector Circuit
15:48 Testing the DIY Metal Detector Circuit - Věda a technologie
YO! I'm still waiting to HEART a comment! in the meantime, ALUMAGNETIC FOREVER! Paramagnetic, diamagnetic or antimagnetic properties of non-ferromagnetic... sorry, ALUMAGNETIC metal are very week magnetic properties observable in DC fields, which I don't care about. They are overshadowed by MUCH greater Eddy Current magnetic forces in AC. ALUMAGNETIC focuses on great AC forces of whatever that is not ferromagnetic!
k nerd
do mine then
heart me
Because it's AC...?
Check mine out hope it answers your question
05:16: The core splits itself apart because the flux lines pass through each laminated layer. Since there is a gap between each layer, you end up having the said layers behave like like-oriented magnets, thus they repel each other
I gave the same answer 2 days earlier and never got a heart :(
@@RavenLuni you can have my heart ❤
@@RavenLuni❣
CHAT GPTTTT
Yeah what mobs chan said
Does this count as one of electroboom’s hair-raising electrifying shocking adventures?
Yes😂
Hello fellow electrifier you are electreofing my elecroballs
My hair was standing on end the entire time!
Haha, nice throwback! 😂
Because the core is made of plates that are isolated from each other
It’s crazy how smart Electroboom is but still keeps it funny with the fails and stuff.
He looks like the wizard from the smurfs
@@user-fs6xp3hl8w 🤣🤣🤣 he kinda does now that I think of it 🤣
Failing is a big part of being smart. It's just not often the part you see.
Mr beast
A true expert knows how to suck intentionally
I love how when I was a kid being fascinated by his knowledge in electronics and thinking he's a man of magic and now that I'm studying my bachelor's in electronics understanding everything he says and recognising circuits. When I look back I see I've grown a lot and will also be a magic man to future generations
Please go abroad for better opportunities. Unless u wanna work in the IT field
@@manan-543 How in the hell would you know what country he lives in or what opportunities are available there?
@@jayesgazebobecause of his profile picture
The hobby shall heretofore be called _"metal detectoring"_ and I will be taking no questions at this time.
Metal detectorists. 😂
U got the heart
the metal detectioner
Even better: Metal Detective.
@@Smashcolors3dmaster -_- there are two main reasons 1# she is a women 2# she is super confident 3# she looks like a dracula
Mehdi, you did a fantastic job, covering 2 types of metal detectors (energy theft and BFO) in just 20 minutes, with no loss of fingers or eyesight. Well done, and thanks for the shout-out. As for the cross-coupled transmitter, I've used that in a metal detector design (White's TRX) and did not use any bias resistors on the transistors. You should not need them.
On the transformer plates, they push apart because the eddy current generated in each plate (across the thin cross-section) interacts with the coil's magnetic field to produce a force which is the cross-product of the two, and is perpendicular to both. This means that at the surfaces of the plates, the forces oppose each other and try to push the plates apart. Hard to explain in words, easy to illustrate. Any decent EM book explains it. A dangerously impressive example of this force can be found in coin shrinkers, where a sufficiently strong EM field creates enough radial force to literally shrink a coin. If you were to do a video on coin shrinkers, I would not dare to wager that you have 10 fingers at the end.
Edit: I couldn't remember the name of the force so I had to look it up: Lorentz force, where F = J x B (cross product).
That coin shrinker sounds cool and scary at the same time.
i believe what you're describing should be the Laplace force. the Lorentz force for a continuous charge distribution, which i assume you mean from the use of *J* , should also include a term ρ *E* , where ρ is the charge density of the volume in question.
@@matthewbertrand4139 The general equation for the Lorentz force is f = ρE + JxB, but E=0 inside the conducting plates, so we're left with the eddy currents interacting with the B-field. I think the term "Laplace force" is synonymous with Lorentz force for cases of current flowing through a conductor, like we have with the plates.
Do you think that the GPZ7000 using zvt is somewhat applying that same concept of a design like Mahid did with his zvs ?
@@mmmk1414 No, not even close. Mehdi's circuit is continuous wave BFO, something that was popular in the 1960s and 70s. The GPZ uses a form of pulse induction called constant-current PI.
You sir deserve your own Netflix series. I have been entertained all day watching your videos. You are genuinely likeable.
@@BigDuke-6 Broke boy
@@lil_applejuice3456 Nah dude he's right, if you have Netflix you either have a ton of money to spare or you don't know how to properly handle your finances
I like your sense of humor, your integrity in owning when you make a mistake and your selflessness in promoting other CZcams pages that also get it right. It shows you will always be about the facts
Sometimes, the explosions make you forget how intelligent this man is 🤓
I think, the explosions not killing him, because it was all planned, make him look even more intelligent
he can plan ways to make the explosions without seriously injuring him _and_ make it seem accidental. A genius with an oscar.
should be wearing safety glasses
Well. It’s electro boom. It has to have explosions.
@@tomservo5007 Barring that...at least a Safety Tie? But that requires being around potentially fast spinning objects...
For 4:56, due to the core having multiple individual pieces, each producing its own magnetic field in the same direction, it makes them repel each other. Maybe that's why core pieces are tightly stuck together to avoid vibration due to repelling.
Thats definitely got it. Here before heart. :)
@@Dvplexx No. They are lined up in the right direction to to stick together, so that isn't it.
@@KnightsWithoutATable it doesnt matter once you break apart lets say a permanent magnet, it wont stick together ever again because it will form its own magnetic field around itself
In addition, each piece produces its own magnetic field because the eddy currents that are generating the magnetic field won’t cross an air gap.
@@SethPentolope Magnetic fields do cross air gaps.
Hello ElectroBOOM, I love your platform. I’ve been laughing and learning from you for a couple of years now. Please keep it up!
Is there any chance of getting a schematic and materials list for this tutorial?
Finally some awesome proper electric design content we needed this
Everybody love to understand how things works and how to make them using basic electrical knowledge
Mehdi, this was one of your best videos in a long time!!!! Is so amazing to see the electronic circuit forming before our eyes and see all the logic behind it and the reason for each component!!!! Do more content like this one
15:49
Mehdi you made a Geiger counter 😂😂😂
though I had some problem with sea water It also czcams.com/users/postUgkxa-FNYUOM93a388gi9a4brtSCEVmrHgJH land for finding any things very easily. (thought it would work as normal due to it being water proof within certain parts of the detector), on dry land and sand worked well. My first one, so still have lots to learn
This one is one of those videos of him that showed his engineering knowledge and design abilities. He make them look too easy. Thanks. Please do videos like these once a while.
2:55 yum, high voltage
4:57 the magnetic flux is concentrated in the iron core. The separate plates are aligned with the field axis, and so adjacent plates will always have the same polarity and repel. Like lining up a set of bar magnets next to each other in the same orientation
I had the same idea, but I didn't offer to comment because I couldn't think of the right terms, I'm not a master at this kind of stuff but I like learning about it
Was about to write the same - at least that is what my mind would deem the most plausible ^^
9:44 you can use a cheap half bridge gate driver (such as IRS2153D) with the bootstrap pin tied to ground. i've used it in this arrangement for induction heating. this way you get quick transitions & dead time without wasting power. great video!
I honestly wish Mehdi was one of my college professors for EE. Even though I graduated with a BSc in EE I still struggle with circuit design and control systems. I learned more from Mehdi videos than the entire last 2 years in college :)
I'm just starting college, planning on going for EE.
I'm finding Mehdi's videos fascinating even though I only half understand it.
Any tips for a new EE student?
@@galacticviper4453 In one word: RUN! I went to school studying EE while having a full time job and a wife with 2 kids. The EE program ASSUMES you're totally OK with not having a life whatsoever and that it is "Reasonable" to work 14-hour days studying, assignments, etc. And no I am NOT exaggerating. Furthermore, the first 2 years of EE is a walk in the park. The third year gets a bit challenging but still manageable with some grit. The 4th year though is totally insane. The instructors switch into the "we're not here to educate you but we're here to grade you and try our best to make you fail. YOU have to prove yourself worthy to breathe the same Oxygen in the room we occupy. Oh, and did we mention that while you were reading this sentence there is a 10% penalty on your assignment because you turned it in 2 minutes late?". By the way, I am in no means exaggerating. It is THAT bad! Now what's the good news? The good news is that if you go through it and make it out and graduate you have "proven" yourself to be an engineer and therefore can qualify for entry level positions that start somewhere in the 65K to 100K range. Not too impressive when compared to some entry-level IT jobs, especially in data mining and AI that can have a STARTING range upwards of 125K. You do the math. And btw, I really do mean i t. IT is a PHENOMENAL amount of work. Legalized slavery that is, to finish an EE program! :)
@@galacticviper4453go to trade school instead, save your time and money
I love all of your videos, but for some reason this one really stood out. Watching you develop different circuits, showing them and then improving on them taught me a lot on the development process. Thanks!
6:55 hertz😂
Comedic and electrical genius. A rare combination of talent.
In general I did well in school, and in school I found physics to be quite easy. Chemistry took some effort to follow. Electricity just seems like a totally foreign language comprised of multiple languages at the same time lol. I always disregarded it as something I could live without. Cut to me in my 30s now really invested in computer tech and watching LTT videos and broadening my interest in tech and I find myself needing to understand electricity more and more. Not to mention it seems to be a useful thing to know when it comes to other things like cars and homes.
So I'm glad you're as entertaining as you are. I've decided I'm just going to watch a few videos of yours every day and hope I just start picking things up over time lol. Because otherwise I have no real idea where to start that won't either bore me to death or be overwhelming... tbf this one got close to overwhelming in the last 3rd as you were talking about converting all of those signals in order to make the data presentable to the human ear lol.
WOW! This video was incredible. It started out with your usual style, but going more into it, you demonstrated how educated you are and became on the topic and in the field of electronics.
I love how you were able to walk through every step in the process of designing this circuit: Research, testing, refining, etc. To make something resembling what you see in stores all around the world. And still made it digestible enough for me and a lot of other people understand. You show all the complex stuff, yet explain it simply, catering to both audiences.
I absolutely love your content Mehdi! ❤️🇮🇷❤️🇪🇬❤️
1:28 Detector showed us that Mehdi is made out of metal.
So that explains why Mehdi gets schocked faster than the average human
Real iron man
It's actually crazy how much this kind of field of work relates to music/sound design with basic waveforms. Even the terms used are the same. Math really does connect everything.
This has to be ElectroBoom's most challenging and satisfying project yet.
0:57 lamp catapult
yes😂😂
It looks epic on 0.25x speed
@2:20 if you count fiber optic, we've been using infrared lasers for networking for a while now. I don't think coax cable can carry anything other than radio though.
Aluminum is paramagnetic, but the funny part is that now there's a term on urban dictionary alumagnetic
I’d like to see him make a voltage controlled oscillator kinda like the Original Moog Synth.
Heck maybe he can make a synthesizer
I was thinking theromin
He should go full custom Eurorack!
lookmomnocomputer is your guy.
Of course he can make a synth! It's just an oscillator!
I love how you've shown the process here. A complicated electrical circuit is, fundamentally, a bunch of sub-circuits stuck together. It sort of reminds me of a project I did in undergrad, and I solved each step in the signal chain by reading The Art of Electronics to get the signal processing right!
"The Art of Electronics"... oh it's been a long time I didn't hear this book title. Brings me back to the time I spent in the library.
Exceptional and very effective way of teaching. Keep it up!
Never fail to get a chuckle from me multiple times every video. And I occasionally retain information i learn lol. Thanks Mehdi!
Fascinating, i never knew how those clicks and tones were generated, being a computer guy i just figured it was just a digital tone generator mapped to some signal and not the actual signal (if that makes sense)
Makes sense
Yeah, I thought exactly the same - the clicks were generated by a microprocessor when it gets a matching, programmed signal. Apparently it's more simple and complicated at the time (for me at least).
Same. It's satisfying to learn something that was completely out of my imagination radar.
I wouldn't be surprised if thats how modern or more expensive detectors work, but the old WW2 ones were probably very similar to what Medhi has built here.
Modern tech, being at such a high level interface, obfuscates what the computer's actually doing behind the scenes, which is the reason I love looking back at analog circuitry and the computers of the past where you can see a direct correlation between all components.
This feels like the classic electroboom type of content which I love. It's chaotic enough, it's got simple educational parts for us non-EEs, it's got some damn massive schematics that give me flashbacks for those that understand them and there's a complete working project at the end, love it
Yeah, I got the part about the need to multiply frequences to make the change when metal is brought closer noticeable but the rest needed some EE studying I guess XD.
Bro I’m so tired I didn’t understand the most simplest thing you said
@1:04 Even though I've been watching & enjoying Electroboom for years and I know what to expect, I still jump out of my seat once in a while! Bravo. 👏👏👏
@@ElectroBOOM09 Thanks for your pathetic attempt at scamming. Reported.
Too bad this video didn't come out half a year ago when I started learning to design and make videos on my own DIY metal detector to originally find lost keys in the snow. I eventually decided to build a more serious project designed around pulse induction PI detector type after trying other designs and schematics but this video gives a great introduction to the principals that are used in beat frequency oscillator BFO detectors which are the simplest to wrap ones head around how it works. VLF dual coil types can detect a bit better at depth and discriminate metal types while PI mono coil types have no discrimination but detect the deepest of all three types because of a different and more complex detection method used. Professional units are always VLF or PI types, but the BFO types like shown in this video were widely used in the early days because of their simplicity and low cost of design.
I built a Pirat detector circuit but it didn't work.
Man, I had zero idea that metal detectors are this complicated
Not more than my life
i mean this is very interesting since its going to deeper dive on those detectors
And this is the most simple type of metal detector, it falls in the BFO type (beat frequency oscillator). Other more precise and accurate like pulse induction or induction balance can become way more complicated
or using coils
@@bhabok20 At least life has a logical destination, Jesus, who makes our lives simple, but the field of magnetometers is a never ending rabbit hole.
Mehdi is no longer just an electrical engineer, he is also a sound design master!
whod of thought sound is created by coiled copper wiring too LUL
he should collab with Andrew Huang to make a synthesizer. Ultimate collab and challenge
@@ThunderBlastvideo a great idea honestly
The landmine bit killed me 🤣🤣👌
@@papagrounds oh god I had tears in my eyes XDDD
Very interesting and informative. Keep them coming!!
I love this video. Refresh my knowledge on designing RC filter.
This is actually quite impressive. I don't know how well this will hold up to long-term use, but as a proof of concept it's remarkable. Thank you :)
Usually, long term use is just beefing up the mechanical connections, adding weather proofing (if required) and generally making the circuit hard to kill or to be injured by. He could probably pack the circuit into a project box, make sure the solder joints are top notch, and have an actual legit metal detector.
You were going crazy with your engineering skills on this one! It's so cool to hear the technical stuff 😊 thanks for another great and highly entertaining video!
😂😂😂 this video is funy
I just discovered your channel. Your videos are amazing ! Keep going. Your videos are so funny. It made my day.
Man, I saw this guys videos when he started.. What a huge improvement and he now has sponsors!!; I love it
16:14 Why does it sound like Geiger Counter
The joy I gain watching you demonstrate how not to do things is the gift that keeps on giving. Seriously, I worked as an electrician for a decade and it never fails to make me laugh when shit pops. Thank you 😀
You are actually the ONLY guy that i can really trust not just making up crappy stuff to steal our time just for their sick amusement 🙂😂 because you actually really know what you are doing when making stuff. Very good and informative as always.🙂😗
This was very interesting. So how would you go about increasing the depth of detection? It seems like it would involve multiple factors.
Really loved this video. Nice to see the analog logic and math. Would love a series on this…
Electroboom 101 is entering circuit logic already (he has videos on relays, and relay logic) and I wouldn't doubt further episodes in that series will eventually dive into such topics as analog math, digital math, signal processing and others.
It just seems to take Mehdi ages to produce those videos. Probably because of all the extra research, fact-checking, error corrections, and editing he needs to do.
There are more than enough extant channels that cover the theory in detail. Like EEVBlog. We come for the boom and the doubletakes. And the unibrow.
@@Mr.Sparks.173 I hope Medhi makes a video on logic gates that use LED transistors!
I hope this series includes Medhi making a Hall sensor or explaining why it is not used in a metal detector.
This came at the best time, lol
I've been struggling to build a metal detector for a land mine detecting robot, its honestly looking like ground penetrating radar would be easier to build
16:17
Wow, that's actually impressive its clicking at that distance with such a small coil.
17:35
Yeah, that's one of the problems we had, and if you're actually using it in the real world, you gotta deal with changes in soil (i.e. mineral deposits) which can throw off the coil's dynamics.
What I found works good is using a microcontroller. You can use the PWM for a fairly stable signal. That's how I'm running mine, just a simple on/off circuit powered by an IGBT used to run a car ignition coil, then we just probe a leg of the coil with an analog pin. I'm still using low voltage, though. 28v, you might want to throw a capacitor in line and add a clamping diode after it or something
The cool thing with using a microcontroller is that you can do the filtering with the controller and have it run a decay function that slowly increases or decreases coil sensitivity to account for changes in the environment.
The big problem we're having is trying to figure out what is a piece of metal and what is just environmental noise, also the fact a lot of landmines have very little metal in them at all.
I do think we are going to go with GPR though, it's just better able to detect objects underground, but before we go that far I want to try one more time with the pulse inductance and maybe a VLF
Just throw 240VAC through it and you should detect things meters apart lmao
HI
I had the same problem on a metal detector project a few years ago : the sensing coil had to fit in the palm of a hand. The electrical circuit was very similar to this one (pair of oscillators, listening to the beat frequency) and it was very sensitive to human body proximity, including to the hand ! We got around by going towards a completely different circuit, the pulsed induction you mentionned. The time it takes for the voltage spike (following a sudden current cut in the coil) to decline indicates the presence of a metal, and it's much more selective than the beat frequency method, i.e. very insensitive to surrounding moisture, and even to small deformations of the coil
GPR doesn't work well on wet ground etc. A metal detector is your better option.
A good rule of thumb is that a metal detector can only see into the ground about the same as the diameter of the sensing head.
This is why a lot of stuff used for UXO (UneXploded Ordinance) is so big.
Land mines of the antipersonnel type are about the size of a can of cat food and have almost no metal in them. They use trained pouch rats to sniff them out. The critter is light enough not to set them off.
@kensmith5694
GPR should work just fine in water logged soils. It measures the difference in the refractive index of materials, and we don't need to sense very deeply, just a foot or so.
The main issue is a lot of the landmines (e.g., the butterfly mines) are just sitting on top of the ground, so we'd have to deal with soil reflection.
Another idea we're toying with is to just give our robot a hammer or spike and tell him good luck.
Realistically, we can make a dumb robot for under $100 to just go trigger mines. It'd still be cheaper than what it costs now per mine, but at a certain point, you're better off just driving an RC car through the minefield
@@noahw4623 Microwaves don't travel through mud.
Some guy in Africa made a thing that gets blown by the wind to stomp across a field.
It’s really cool to see all of this stuff actually work
This feels like oldschool classic electroboom. I would never request you to shock yourself- but showing mistakes in a comical way is genius.
Now this is what I call quality content! Really love the in depth design process. It gave me the "why use this and not that" and the "if that is unavailable, this can also work" insight, which I find very rarely explained on other channels. THANK YOU, MEHDI!!!
Okay, I thought I understood how metal detectors worked - to the point of being confident when I sell them at work. But now... Man, you just opened up a lot to me. There are people who just want to know how the thing works, and there are people who want to "KNOW" how it works. Now I can explain so much better.
That's awesome! They'll be amazed by your knowledge.
so what makes the difference between a 5k metal detector and a 500 detector then their signal goes deeper they have a larger battery ?
Man, thanks for the frequency lecture. Needed to refresh it anyway 😊
It's great how he shows how intelligent he is through simply not dying each time he plugs into mains electricity.
I love the practical explanation of the circuit and how it generated sound along with the oscilloscope display. I know there was product placement involved but it was also very educational and instructive. Thanks for the video Mehdi!
One suggestion boss, use switch , not teeth 3:00
2:55
I haven't seen your videos in so long that I had to check to see if you were still kicking. Glad you are and haven't fallen prey to any electricity or wayward gadgets!
6:24 The grumpy indian man with a bucket water heater got me😂
wow, thank you medhi, this might be one of my favourite videos of yours, i love lerning about the desing proces of anything in general, and circuit design always has buffled me, but seeing you go through it made me understand how it can be done, thank you :D
Hi Mehdi.
The 24 amp maximum current of the IRFZ24N Seems massive especially if you're planning on a PP9 type, battery powered portable metal detector.
I'm therefore taking my clue from this as I'm unfamiliar with the MOSFET and Schottky type of astable multivibrator you've used in this example.
So I'm hoping for a Mehdi induced heartfelt like with my idea of what you're hoping for.
I Do go on to mention how I learned because the learning curve was such a massive moment especially after being at college and coming no where.
I hopefully explain why I'd be employing such an experimentalist approach and, if I'm wrong I was wrong but not for the want of having an estimated guess.
Anyway.
A two transistor BJT astable multivibrator is possibly the answer.
TIP41 or TIP42 transistors should supply enough current through the 100uh + the series of the 115uh search coils.
I hindsight the resistor supplying the emmiter follower regulator seems to verge around the 1 amp current region so I'm more inclined to believe this.
Ditch the Schottky diodes and I'd replace them with an experimental value of around 220nf then the 150 ohms might be used in series with the search coils
(in case of over load)
and in their original place I'd insert something like a 2.2k ohm resistor to be used for the Resistor in the CR timing network.
OR leave the 150 ohm resistors where they are to act as a voltage limit stop resistors and cut the connection between the 100uf switch spike surprising capacitors positive terminal to the 150 ohm resistors shared common connection and insert a 10k pot to change the voltage and therefore speed the 220nf capacitors charge up times.
Therefore giving experimental frequency change.
I'd choose this experimental method because I'm not to good with theory especially with frequencies.
I have been a self taught electronics enthusiast since the age of 13 finally teaching myself digital fundamentals whilst I designed and constructed a Radio Controlled up / down step encoder into a Resistor divider DAC utilizing a toy car Remote control and receiver chip.
1 "Nudge Turn" of the remote would notch 1 up / down control on the encoder and therefore Digitally control the amount of resistors in the resistor adder and give Analogue control for the timing function of the mains cycle for the 240 volt ac bulb to dim or brighten up.
Obviously timed to coincide with the correct part of the phase during the 50hz cycle.
Cheers and TTFN. ;)
The peak current rating of the MOSFET will not impact the battery drain. However the voltage dropped across the FET when saturated is less than the BJT, so you end up with more voltage across the coil and therefore more current through the coil, so for the same supply the MOSFET will yield a better field.
The MOSFETs can handle more current for the same package type (TO220) in this case, because it does not get as hot because of less voltage drop across the transistor as previously mentioned.
@@NCmountainview Absolutely understood but I mentioned the BJT astable as I'm more familiar with its turn
on / off characteristics having made many LED flip flops I'm also more familiar with the 0.7 volt saturation voltages of the BJTs being a lower sensitivity than that of the FETs which MAY cause weird oscillator results than I could positively say I knew about as I've never built a variable frequency MOSFET astable.
I'm not saying the FETs would use more current, this would be limited by the one amp rating of the main regulators feed resistor.
I also realise the exceptional sensitivity of the gate junction of a MOSFET and with that realization
I can also theorise the BJTs tendency to give a rounder top to their waveform especially when the transistor base goes below its saturation voltage, this does cause more heat but one amp is within the rating for the type and possibly achievable without adding a heatsink. (If not bung a pair of BU508s in there.) LOL.
The sinusoidal wave shape at the waves peak must give a better all round smoother electro magnetic RF flow.?
@@Electrodoc1968 The BJT does not have a saturation voltage of 0.7V, as that is the ideal junction voltage and usually associated with the base emitter region in forward bias. The saturation voltage is measured across the collector emitter and varies depending on the load, but it is generally larger than the channel voltage for a FET under the same load.
There is some merit to your point, as FETs can have issues with linear response because of the transconductance profile. However, the reality is that you can design stable oscillators with either. In fact the higher input impedance of the FET can make the oscillator much more stable when under load.
This was a top-notch video👌 Took me back to the 90s when I used to fiddle with analog oscilloscopes. Breadboard remains the best tool to play with:) Very well done and instructive with a great result:)
after 2 years i came back to this channel and now I am amazed about myself to finally understand the technical stuff🤧
a good portion of my mining geophysics course dealt with metal detection at various scales/depths. it is nice to see this stuff discussed at a more accessible level.
That's the old Mehdi in first 2 minutes 😂😂
Always love your informative sessions❤
This man has something hug to share.❤
bro your the best, every time i watch a video of yours i just crack up, keep up the good work!!!!
Amazing. Its really motivating mehdi put together this very complex circuits and concepts and show that its not that complicated. Makes me feel like i can too build and learn these awesome things.
I was studying a metal detector to modify mine last night. Good thing you posted it and really helpful. thank you professor boom. i'd like to see its final form for next video 😅
05:16 Imagine your transformer or inductor as a stack of really thin sheets, like a deck of cards. These sheets are there to guide the invisible magnetic lines that make everything work.
Now, these lines don't like to hang out too close together, and that's where the magic happens. There's a small gap between each sheet, and when the magnetic lines pass through, it's like a bunch of tiny magnets trying to push each other away.
Think of it like having a bunch of magnets on a table, all facing the same way. You push them close, and instead of sticking together, they go "Nope, I don't want to be near you!" That's what happens between these layers in your device.
This pushing away is a smart move by designers. It helps to avoid wasting energy and makes your device work more efficiently. It's like turning a potential mess into a well-choreographed dance, where each sheet knows its role, keeping things smooth and efficient. And that, my friend, is the secret behind why your device splits itself apart but still does its job beautifully! 🚀
5:16 core is laminated to reduce path for eddy current, since flux through each ring is same , similar currents are induced which creates a like like magnetic field
Having built metal detectors with my dad as a kid, the only thing I would change is do a flat coil like an antenna instead of a regular coil. But that is more difficult to wind up. Another thing you can do to make it extremely sensitive is to have two coils, one above the other running half off phase signals and sum them in the end to essentially make an EM interferometer.
How does having two coils out of phase make it more sensitive?
@@locinolacolino1302 Instead of measuring the changes of one coil's frequency and peak, you're measuring the difference between two. After amplifying, I could detect 0.01% difference between the two. But it's super finicky, the coils have to be perfectly aligned, the frequencies have to be on spot. It's a fun experiment, but probably not worth it for practical use.
Those professional detectors that have the coils shaped like an 8 use two of them already, but they work by being a coupled oscillator. You can detect coins 30cm away with those easily.
@@locinolacolino1302 As they hinted at this design is based on interferometry. When there is no metal present the two 180 degree out of phase signals destructively interfere to produce a constant potential. In essence your output signal is the result of recombining those two waves, when nothing is interfering with the field they will destructively interfere and cancel out, when there is however the two coils being in different physical locations will cause them to experience a different change in frequency thus recombining the two will produce an interference pattern that can be detected.
Do you have a circuit
@@chinnapank No, it has been 20 years. But if you look up for two phase shift oscillators leading to an amplifier, it is pretty much the same thing. Just need to adapt for the coils and voltages you will be using.
I am by no means new to this channel.
But I can barely watch these videos with him so bravely handling... Everything that he does, lol. When I saw that lightbulb I already knew. My heartrate was already skyrocketing, haha!
The core is split in many layers so each separate layer acts as a separate magnet thus opposing each other. If the core is in a piece the field lines pass through it making it 1 big magnet.
love ur work thank u
I absolutely love watching your videos, it is fun, educational and makes me realize how happy I am now that I made it into my final year of studying electrical engineering and only have 1 semester left.
Nice! I just finished my PhD in EE, and although the work I do is mostly theory and simulation, it was love of circuit building and tinkering with electronics that pushed me into the program initially. EE is a huge field with a lot of really cool opportunities!
Now this is a very cool and informative video. The Core is repelling because of laminations between the slits of core material. two slits have the same direction of eddy current causing the magnetic field to be generated to repel each other. Its the same as one piece of mage is solid but when it breaks the two pieces repel each other.
That's somewhat similar to what I proposed, but i don't think eddy current has anything to do with it as the core is split up like that specifically to avoid eddy current, aka the core doesn't act like a short-circuited coil. But i do believe it's similar to the broken magnet thing.
I wished you ve made this before cause i had a similar project "car mine detector" this year would have helped alot , btw it a great vid anyway.
You could also get a program in a smart device to interpret the signals so you don't rely on hearing and can that way increase the sensitivity of the system
Well that was illuminating. Especially when the light bulb blasted out of the holder! But seriously, this was a great illustration of how metal detector oscillators can be tuned and filtered. I think I finally understand how the "discriminator" on my ancient Radio Shack Micronta metal detector works. Since the circuitry is no longer a mysterious "black box" to me, I think I can use it more effectively.
9:28 I suggest you put a free-wheeling diode in parallel to the 100uF capacitor. This is just to avoid the Collector terminal of KSB596Y from going too negative by the inductors when the current through the PNP is throttled by the 2N2904 (when trying to limit the current).
@ElecroBoom, or anybody else for that matter, is there a schematatic and parts list for this, I'd love ti learn a bit by having a go making it. Awesome video as ever.
What is the difference between parallel and series resonance?
Which one should you use when driving inductive loads like antennas vs capacitive loads like piezos or ultrasonic sensors.
This is the best diy tutorial video you've made. Just loved how the analog electronics working without any microcontroller rubbish! Such a beauty, Joy forever!
Agreed that it is fun to see an analog only design but an MCU could've allowed for fine grained identification of metals just by switching between frequencies automatically and by not being annoying to hear. This is actually super impressive because you don't need more than a single MCU to do that with the way he designed it
@@amogusenjoyer yes, you're right. I'm a microcontroller person and if I had to design a metal detector like this, I would've used a microcontroller. My analog electronics skill is - well, questionable.
This video sparked my interest in analog electronics again.
There are numerous solutions for the gate bias resistors:
1. At low frequency, don't worry about it. Scope the gate waveform: if the rising edge is fast enough, you're done. At 25kHz, probably some kohms is acceptable.
2. Add a buffer. I've done this before, add a complementary emitter follower (just a simple class C one will do, no biasing components) between the pull-up / diode connection, and the gate. Use a pull-down resistor at the gate, to bias the follower (this is necessary for startup, because this is a linear amplifier at its heart -- it won't start up at the right frequency, or at all, if there is too much gain or distortion in the feedback path!). I've done this before, on, let me get it out here -- I had 2 x FDP33N25 for the inverter, and 2N3904/6s for the buffers. Oh, I didn't use a pull-up resistor with the diode, I used a PNP current source, fancy; well, about 470Ω pull-up would be equivalent. It ran over 600kHz with good gate waveforms as I recall, so it doesn't take much as you can see. That suggests 27k would be enough for IRFZ24N down at 25kHz! Call it 10k for good measure. Maybe 1k or less without the buffer circuit.
3. Use different devices in a related circuit. The original Baxandall* circuit, I believe used a feedback winding, with bipolar transistors. This separates bias and feedback from the output voltage, giving more freedom to design the gain and drive strength. Example circuit in following comment.
*The common "ZVS" oscillator configuration is actually due to Baxandall, the same one of audio tone control fame; published back in the 50s or 60s when transistors were new, though I don't have the exact citation handy unfortunately. It's commonly called "Royer" by the amateur/HV community, but this is erroneous -- Royer refers to a non-resonant (specifically, saturable core commutated) oscillator. (Occasionally even professionals make this error: for example, Jim Williams (of Linear Technology) in AN49; the correct citation is even given (Royer, et al; in the title, "in saturable core circuits" -- but these are resonant, non-saturating circuits!). So, go figure, even the best of us make mistakes.)
!@QSDRD
I like, when people copy paste stuff from Wiki.
@@tuff_loverikr
Man typed out a whole dream tweet
Mehdi, can you explain how static charge sparkle in acrylic?
It's pretty spectacular!
0:49 THIS metal detector looks like a *gun!!*
15:30 doing redstone i guess
i rlly love how he teaches science whilst putting alot of entertainment into his vidoes.
5:00 : The core splits itself apart because the flux lines pass through each laminated layer. Since there is a gap between each layer, you end up having the said layers behave like like-oriented magnets, thus they repel each other
YOU all make US laugh and learn.
Im Happy that your still here.....
.....you made my day😊
🎉CONGRATULATIONS🎉
🎉ELETROBOOM!!!!!!!🎉
Wow, that video is one of the most impressive videos I‘ve seen. The amount of electrical knowledge is impressive. The difference of the first and last experiment is astonishing!
As a metal detecting enthusiast, this is my favorite video, Mehdi!
Ótimo trabalho amigo parabéns 👏
If you want to reduce power consumption overall in this circuit, my suggestion would be to use some sort of class B or C amplifier and place your entire circuit on a clock. The coil doesn't need to be hot all of the time, it just needs to be on frequent enough to find the stuff underneath of it. So make a dial to tune the polling rate of the coil to match your walking speed, this would reduce the constant power consumption of the resistors in your circuit at 9:26 to just peak power consumption allowing you to use lower rated components, as well as reducing the overall power consumption of the device.