So my friend and I actually managed to build this today, but as you pointed out tuning it is very difficult as it is extremely sensitive. Occasionally we were able to detect a coin from around 20-30 cm, but one issue we are having is that the LED and buzzer are on continuously while in steady state. So when it detects metal the buzzer frequency actually decreases. My uncle has an oscilloscope I will try and figure it out tomorrow. Anyways thank you so much for this awesome project!!!
Your schematics and explanations are SO clear and understandable. At first glance it does look like an analog nightmare, but you explain it in a way that makes a lot of sense to me.
I watch alot of metal detector youtuber the last month and like it that you show how it works. most is over my head but i understand the simpler parts. thanks and keep up the good work.
DGW, I'm afraid you have misinterpreted the "nulling curve," and also drawn it incorrectly. The slope of that curve represents sensitivity to the overlap null, it does not represent sensitivity to target detection. The induced signal from a target is about the same no matter where you null the coil, but the target is easiest to "see" when the coil is at maximum null because then the target signal is relatively largest compared to the null signal. The curve is incorrect because there is a phase inversion right at the null point; it is not flat there with minimum slope, but rather has a maximum slope. Hard to say in words, easy to show in a graph.
i love how you tied pin 7's resistor into the PNP transistor that's connected to the oscillating BC547c instead of to the power rail & into the 555 timer. that was very cool. & a new one for me. never saw that been done before. AWESOME... CANT WAIT TO MAKE THIS PROJECT... : )
Danke! Thank you very much for this work. After alll this years ..once uppon a time 😂 We are waiting for resin or more rosin on the DD coils XD Maybe some more ideas to improve it. Some guys wrote about kind of metal detection as you suggested or real world openfield tests on soil (or the pot of your Chili pepper plant😂). Still watching your videos. I love your content. The quality and how deep you explain the circuits and function.
I have successfully replicated your receiver and managed 25cm coin sensitivity with only 8cm coils and much weaker transmitter (I use simple LC oscillator with single transistor and it only takes 3mA at 5V), however I had stability problem in receiver. I had 2Hz oscillation on rails (2.5-5mA so almost 50%) which was causing almost constant beeping. I started removing parts while retaining the oscillation, I reduced it to first 4 transistors, I even removed the search coil and it still oscillated. When you look at the first 4 transistors of receiver, the collector resistors are 2k2 0 10k 2k2. I think the 10k or 2k2 could not cause such a deep oscillation on rails so the only culprit is second transistor which has direct path to ground via 4.7uF cap. I tried larger resistor and larger cap but it only delayed the oscillation. I added 6V regulator (78L06, because I power receiver from 9V battery) and power first two transistor from it and it seems to stopped. Later on I also increased Rc of fourth transistor to around 5k. I also used separate 6V regulator for 555 stage. I also changed 100k resistor and 100k pot from base of 5th transistor to 2k2 resistor and 100k pot. This allowed me to lower sensitivity even further using pot. I encased coils in epoxy and tested it outside and found some metal plate and one bottle cap around 5cm underground.
this is interesting since ZVS is used in one of the expensive minelab detectors and to watch diodegonewild make from scratch using his own understanding of electronics is truly fascinating. i wonder how it will perform on soil and if there will be ground balancing added and coil shielding. the materials used for shielding are like an RF absorption paint and can be home brewed using a glue binder and the black goo from a carbon zinc battery , graphite or a mixture of both. it needs to be made into a glue suspension that will dry leaving or cure with a specific ohm per square centumeter value...i dont recall the range but perhaps there will be some info in the geotech archive of metal detection technologies. I made some of the RF paint about 10 years ago and was PVA based with battery goop and graphite and made a very good shielding for a probe coil i made. i have seen graphite and epoxy based shield paint in a standard minelab 11 inch coil. so the binder works with either water based or organic.
Saw a few comments below regarding Metal Detector‘s and showing interest in the Hobby. Or folks talking about how they’re going to get rich if they build one of these 😂 I thought I would post this reply here, and maybe more people would see it. I definitely don’t want to discourage anyone from the Hobby, but as someone has been doing it every week for 20 years…. Stuff like gold and jewelry and treasure is really hard to find. And gold registers exactly like trash aluminum and llead. Gold registers exactly the same as small aluminum trash targets. Even on the nicest and most expensive Metal Detector’s… A big fat gold ring will show up on the screen, and sound, exactly like an aluminum soda can tab, or small shard of other trash metal. They also have the exact same acoustic signature and sound like a small piece of lead. And considering a lot of your gold will be found around swimming holes… You’re also going to dig thousands of fishing sinkers… Because they sound identical to a gold ring. Source…..i own about 15 metal detectors. Been Detecting for the past 20 years. From cheap to expensive. My main machine is a minelab CTX 3030… I have several other minelab machines that are even more high-end than that machine. But the only reason I have such high end machines, is because of build quality, waterproof ability, and ruggedness. You can do almost the exact same thing with a $300 machine that I can do with a $3500 machine. I do a lot of hunting for Civil War artifacts, old coins, and gold jewelry. Best place to find gold jewelry is at old or new swimming holes, when people get in the water their hands shrivel up… Their jewelry slides right off. Especially with all that slick sunscreen. Second best place is next to a tennis court, Public pool, or basketball court. That has grass all around the edges. If you drive around your town and look at the basketball courts and tennis courts… You’ll see people playing. And if you look closely you’ll see they lay all of their belongings, wallet, jewelry, hats… Stuff like that… In the grass right next to the court. And then very often, the basketball will hit their pile of stuff, or they’ll forget they put their ring on top of their wallet… And when they go to move it they drop it into the grass. I metal detect on average two or three afternoons a week for a few hours each. Both On dry land and in the water. On average… You have to recover about 2500 trash targets for each piece of gold jewelry you find. And About 400 targets for each piece of silver jewelry. That sounds like a lot, and it is a lot of work… But still totally worth it and a lot of fun. However, even the best case scenario… If you live in a neighborhood or somewhere with tons of rich people or you have a swimming hole that’s been active for 100 years… More than likely other Metal Detector’s have already cleaned it out. And even if nobody’s detected it… And you find tons of good stuff… It would be better getting a minimum wage job. You would make more money per hour . Sure I might have $5000 or $6000 worth of gold and silver at the end of each year… But I Guarantee i spent A few thousand hours finding it. Maybe if I’m lucky, and I count all of my gold, silver, and usually somewhere near $1000 in regular pocket change each year… Maybe I’ll make minimum wage. MAYBE!! But that’s not counting gas, equipment, stuff like that. But it’s definitely possible to break even… Which is good because if you really get into the hobby it can get dang expensive fast. A single coil for my machine could be $300-$500. I have several coils for each machine because you need different types of coils for different situation’s. If you’re interested and want to learn more you can check out the “friendly Metal Detecting forum”… I’ve been a member on there for over 10 years, and I post my end-of-the-year totals with pictures, weights, and values. Most folks on there do the same. I’ve always kept a very meticulous journal every day, of my Detecting trips, how many targets are dug, how many decent targets, how many trash targets, and how many hours and location. It’s fun to do that, but it also allows you to go back and see patterns, and you become better at locating good stuff. Half of a hobby is definitely research. And when I’m saying it takes an average of 2500 trash targets to find one piece of gold…that’s using some of the best modern metal detectors out there, costing upwards of $3500. They definitely make Detecting easier in some aspects, but I can do the exact same thing with a 200 or $300 machine. Especially if you get the machine super capable and sensitive like the Fisher F2. Which is an extremely good machine that can perform as well as any $1500 machine out there. But you can pick them up for really cheap. So although you’re not going to strike it rich… it’s absolutely worth it! And it’s a lot of fun! I paid for most of my machines with the gold , Silver, and pocket change I find every year. You’d be hard-pressed to find another hobby that would completely pay for itself. However… When you consider 1000 pounds of pocket change every year, and at the bank and coin star machines won’t take dirty corroded coins… You have to clean them. But that’s pretty simple just put them in a bunch of big 5 gallon buckets with vinegar for a little while. But it’s still a pain in the butt dealing with well over 100 pounds of change every year 😂
@@vaclavtrpisovsky I live in the USA, but yes at least 100 pounds of loose change. Or “clad” as it’s called in the Detecting community. When you’re digging a few hundred holes each trip… And taking 2 to 3 trips per week year-round… You end up with well over 100 pounds of pocket change. We call it “clad“ in the Detecting community. Because most of our coinage is a cheap base metal like zinc, plated in a thin “cladding“ of copper or other metal. However, the term doesn’t apply to points from before 1964. Because before then, most American coins were 90% silver. And all pennies were solid copper before 1982. I’ll have to check my year-end tally on my forum posts and journal.. but think I ended up with approximately 130 something pounds of clad coinage. Probably a few thousand of them were pennies made after 1982, and since they are zinc with almost no copper at all… They very easily erode into nothing and become almost unrecognizable. Because we have very acidic soil. So those I’ll go in the trash. For the other stuff… I used to clean it with vinegar and shake it around in a 5 gallon bucket after separating into the different types of coins. But since I do this so often, and have s large quantities to process… I invested in an extra large rock Tumbler so that I could make them look brand new without any work. I also use the rock Tumbler for other things, so it was worth the purchase. Tell you what else is wild… last year I recovered about 160 pounds of lead. From fishing sinkers mostly. Maybe 5% of it was from fired bullets and wheel balancing weights. I do a lot of detecting in the water… in old swimming holes… Because that’s where a lot of the gold and silver is. But i find loads and loads of lead.. especially where people catfish, because they use a very large lead weights to hold their live bait near the bottom. And you have to recover the lead targets if you’re looking for gold. Because a big gold ring will sound exactly like a large lead sinker, and give the exact same numerical signature to the “brain“ of the detector.
@@vaclavtrpisovsky also, considering a large amount of that pocket change is quarters and dimes, (because they give off a signature similar to silver jewelry or brass/copper buttons from the Civil War or other highly conductive relics)….. So if I see those numbers on my detector screen….., even if I’m not looking for pocket change…. I dig them. So that’s why I end up with predominantly quarters and dimes. I can have anywhere from a few hundred dollars to a bit over $1000 each year. I would say on average each year I find around $750 in pocket change. Some years much more, sometimes it’s more like $450. It’s according to what type of hunting I’m into that particular year. Because obviously if I’m detecting old Civil War sites in the middle of the woods, I’m not going to find loads of pocket change.
Its such a pleasure listening to a real expert in his area! :-) Honestly i didn't understand everything but i got the overall clue! So would be interesting to compare the sensitivity and effectiveness of your detector to a good professional one! The distance you are amining at already with small objects is very impressive!
What a crazy world, I'm working as an employee doing boring circuits than I contribute to another engineers income so he can to have all the R&D fun :) But the quality of the your work and videos is worth every penny! I really liked you idea for the phase shift compensation.
I'll be honest. This is treasure of insight. Do you think it would be possible to make more such a in-depth projects? This is as far one of the top best content on electronic subject on yt
You may use a little adjustable coil in series with the receiver coil so that you can tune the tank circuit easily. You can scrap it from old CRT TV or PC monitor. You may need re-wind it maybe. I follow the project!
This is a very interesting subject for most people. Please consider designing and building a discriminating metal detector. There are some projects on the web, but I enjoy your builds and videos.
exelent performance! and you can use small ferite transformer to translate the low(max500pf) variable capacitors on to a nF capacitor by choosing a right turning ratio
Я делаю как раз вариант с Push Pull, но тогда лучше мотать катушку с отводом от центра. Тогда можно использовать микроконтроллер типа STM32 для раскачки передачтика и обработки результатов.
A very fun project for sure! The material detected can be determined from that phase shift.( ie. silver will shift it almost 180 degrees. Aluminum block will shift it more than aluminum coin or sheet) :-)
My friend and I are trying to replicate this, but we are stuck trying to wind the transformer that feeds the coil. Is there any transformer we can salvage? Or any tips on winding one ourselves?
you can use almost any flyback transformer of a similar size. Wind 32 turns, then make the centre tap, then continue another 32 turns. Then wind 16 turns for the feedback. Mind the direction of the feedback winding, otherwise it won't oscillate.
@@DiodeGoneWild Tremendous Thank You!!! We were able to wind a transformer with the same turns and roughly the same induction measurement. We tried multiple times to build the circuit on a breadboard but it didn't work. When we went and soldered it to perfboard, it worked. Using the AC setting on a multimeter, we got 12V-AC across the transmitter coil. When we brought a large metal object, the 12v decreased. Tomorrow God willing we are going to build the reciever circuit.
I would only use a duel coil on a discrimination detector mono it's fine for what your doing there is a site I'm a member is geoteech metaldetecting where we have a community on what your doing lots of info there and help
Is there a design I can use to install a metal detector inside the under carriage of a robot chassis? I came across this "Double D" design some years ago that used a PLL chip. Was published in a magazine article and looked promising. Like many projects, it got canned for lack of knowledge about metal detectors and which ones to go with.
@@daveherd6864 I've seen one operate in San Diego, CA by the beach. The dude used a metal shield separating the coils from any interference from within the robot. He was finding jewelry right left and center. I've seen some that use a trailer type sensor, where the coil is pulled behind a robot. But that's not what I'm looking for.
I made one years ago and had the second coil run at 5 x the frequency of the main one. they were then mixed and the audio amplified to a speaker. was quite sensitive it could detect anything coming towards the coil.
Autor detektoru je skutečný pašák. Zapojení jsem postavil a dosáhl jsem téměř přesně stejných výsledků, dokonce jsem na test našel stejnou minci, 5mm LED detekuji na vzdálenost 18cm. Vyrobil jsem (3D tiskem + epopxy) několik různých cívek, ale téměř vždy s podobným výsledkem. Nemám jiný drát a tak jsem navinul cívku RX 40 závitů drátem 0,3mm, TX 30 závitů drátem 0,3mm. Transformátor do oscilátoru jsem navinul na toroid. Jednu RX cívku jsem navinul 40 závitů 3x drátem 0,3 mm jako VF lanko a opět výsledek přibližně stejný. Na místo NE555 jsem použil PIC12F675, což umožnilo mimo jiné rozlišit barevné kovy a železo a maskovat různé stavy. V zapojení jsem tisíckrát změnil většinu kapacit a odporů, ale nikdy jsem nedosáhl lepšího výsledku. Nepoužil jsem poslední tranzistor a potenciometr na řízení zisku je zapojen na místo odporu 100 ohmu. Chápu sice na co jsou v zapojení 1N4148, ale při jejich zapojení, nebo odpojení nepozoruji na funkci subjektivně ani na osciloskopu žádnou změnu. Kmitočet oscilátoru mi vyšel na 17kHz. K zamyšlení: 1. Jako limit pro větší citlivost vidím vlastní šum zapojení, který roste s každým stupněm zesilovače a je přítomen i při odpojené cívce. 2. Při přebuzení velkým kusem kovu trvá asi 4 sekundy než se detektor vrátí do pracovního stavu a nepodařilo se mi vymyslet jak to vyřešit. 3. Když cívku naprosto totálně dokonale vybalancuji, tak je citlivost přibližně poloviční, než když je trochu rozbalancovaná a také nelze jednoduše určit druh kovu, protože první kmit výchylky na výstupu je vždycky kladný.
Your project will work but when you will put on field you will be disappointed: ground itself have capacitance so you have to shield the coil and you will start to pick up soil itself (gorund minerals) so the distance at you will sense a coin will be very short and you experience a lot of false signals. Unfortunately the ability to build a good detector is the ability to deal with those drawbacks. I suggest you the book of Carl Moreland - George Overeton, Inside the metal detector. keep experimenting in any case your channel is amazing.
Hello, question please.. If technology was invented that could replace the copper wiring in coil disks without loosing performance..would it be valuable?
actually, the idea of using a variable capacitor with the coil is doable, just not worth while in this case. if you make your own, it's not that hard, really. I had to get hold of a 100 pF capacitor with ~ 2000 volts A.C capable of working at around ten MHz. Rather than buy one (expensive) I just used the cap formula and used a 30 cm length of PVC tube about 4 cm diameter, about 3 mm thickness. What I did was wrap the outside of the tube with Aluminium foil, with a length of multi strand wire touching the foil I wrapped it fairly well with tape. For the inner electrode I used a 30 cm length of thin copper foil, with a wire soldered to it. The copper foil was rolled around the same size of the PVC pipe, then the rolled up copper tube was inserted inside the PVC tube, it was springy enough so that it hugged the inner surface of the PVC pipe. And that's it. You can slide any amount of the copper tube in or out for it to act as a variable capacitor, probably not worth the effort for this low voltage application, but when using 2000 plus volts it certainly is ! It was for a plasma candle.
Hello dear brother, thank you very much for teaching us how to make a metal detector. I ask you, if possible, to teach us a metal detector to build two meters of metal underground, because in our area, all gold is less than one meter to three meters. May God grant success to you and your dear family, and may you always be victorious and happy in life, brother
You might want to check out phase shift of high frequency received signal. You should have a phase shift with the transmitter that correlates with the type of metal. That way you can tune receiver to for beep for gold but ignore mostlhy iron or whatever. Of course measuring phase shift with amplitude makes it a lot more complex, especially when you start putting limits on phase shift to ignore some metals. Did you try differect receiver coils already or estimate Q of the receiver tank? That can affect receiver selectivity and sensitivity.
What if you used a hugh voltage dc converter to charge a 200v rated capacitor, tobbe used as the current for the search coil, running at about 120v -180v. To pulse the coil with. Along with higher current. With a low duty cycle to allow dead time for reading for metallics. Think its possible, also cover the high voltage side with PCB board with solid ground plane. And seam covered with copper foil conductive tape, to protect the sensory circuits from the EMI,. With the actual peak current of the ping going to the search coil being 5amps or more then dropping off to around 2 amps then 100ma before ending the pulse. With a strong pulse, with a quick, ever changing magnetic field should make small metallic bits ring like a bell caught up in a bicycles wheel! Compared to someone ringing it and sitting it down! The sense during dead time could possibly sound interesting. I'd like to attempt using a stand alone coil and try listening to a small piece of metal being rang by a detector, possibly record the sound play it back at 25% speed so humans can hear the frequency. I want to attempt using a tiny coil with tons of copper a 2ohm dc coil hit with nearly 200vac. The instantaneous current would be amazing, sky high, yet quickly falling. I really want to experiment with some metal detecting circuitry. And especially experiment with coil types and shapes. It would be awesome to be able to drive metal rods into the ground with coils on them and wires going tovthem from s contol box, have 3-4 of them around a search area. Then sweep. The area inside the rods say 3-4 meters from them. Using a detector coil, connected to the cintrol box, or operating wirelessly. And having the ability to find metallic bits down to or smaller than 1/10 of a gram, as deep as the rods can be driven into the earth. Possibly slightly deeper around 100 mm roughly, with the rods capable of going 1.5-3 meters deep. Possibly deeper with soil type and rocks effecting performance, i belive this tech is possible. Possibly only usong the rods with the electronics. They can find voids in the earth with similar tech. Had the ability for many years. It could work like radar, or sonar use it similar radar or sonar by reading the electromagnetic returns from multiple pings, send energy intothe ground with the rods and listen to the earth after the ping, do youbhave an opinion? Any ideas about a pi detector, awesome video..
if you had bigger coil then could you add extra turns to fine tune it but smaller coil you need less turns so you can tune it is that correct or did you never test
Very nice video. The front end is very impressive, but I think the performance could be much higher if you digitized the signal after the front end, rather than going through the peak detector and the following circuitry which is very retro...
Awesome work! It's certainly a difficult task to make it work properly. I'm wondering, how it would detect metal objects that are dug in the ground. I'm thinking that if you would add more of these demodulating capacitors with slightly different capacity and connect one you need so it would be possible to somewhat change the sensitivity.
1n4148 is low current FAST silicon diode.. Can't replaced in high circuits with the slow 1n4001 to 4007 Standard rectifier diodes. On the other hand: Search datasheets and make main attention to breakdown voltage Forward voltage drop current reverse(leakage) current Aannd powerdissipation over all xd
hello, i've build it and it works, prety well! But there is problem for me, it is extremly sensitive to my hand with no metal, i guess capacitive things... If someone has a solution to it i will be gratefull.
How about schematics on EASYEDA and then you can order the circuit boards!? So that you solder the components and its much easier. Of course you need some copper and the 'CD thing' (I have it randomly). The problem is that a lot of copper is required... I have some transformers from some SMPS power supplies but the wires in them will still not be enough... Maybe I can buy it somewhere but it's quite expensive.... And of course you will the resin and a container for it... But still maybe you get lucky and you find real treasures with this thing... It's also a very nice project!
I feel like to improve it further, you probably need to start adding opamps everywhere. Especially if you wanted to replace some of the potentiometers with automatic adjustments.
Hi, very good explanation but I know nothing about electronic, what I want is to build one to find gold, I got no money to buy one metal detector. Can you made a video with all part soldering together and making coil from start to end for starters, so that I can follow......Thank you
you know nothing but you want hunt for gold to become rich. good luck with that great plan. You maybe want go invest some money in bitcoin, heard that everyone who invests make more of his investment
nice project. how this work on soil? air test are nice but soil makes a lot of interference.... not like pulse induction.... pi doesn't respond to ground interference.... greetings, keep working💪
Interesting video and nice project to learn metal detector technology, could you please improve this circuit by adding discrimination and ground balancing techniques.
I have some suggestions and some questions you can put one transistor phase shift to improve the receiver Also, is the transmitter required to be zvs or zvt I mean, can the transmitter circuit be replaced with another and put a controller or chip like 555 timer or tl494 or bfo tx?
This is great but I guess with this sort of ' tuned circuit ' stuff designing a PCB would be a nightmare as a lot of the values would then be select on test or do you think once its finalized it would just work ? as I would like to design the PCB but don't have the skill set to diagnose at your level ! at least not at the moment, but it's all absolutely fascinating anyway....and no salt cheers.
Everything that oscillates and has a coil, is a tuned circuit. 10KHz is low enough frequency that's not really affected by wiring. It can even be breadboarded. I don't use PCBs. Only perf boards and solder wire them. Just like you see Great Scott make his prototypes.
@@piconano Thats why I called it a ' tuned circuit ' if your happy with perf and you dont use PCB's thats great...enjoy ! I am discussing PCB's...cheers.
In this video: _I haven't used any resiiiin._
In the next one: _…and even more resiiiiin…_
I think resin is gonna be the new rosin ...
@@HazeAnderson or the new saaaalt! ;D
So my friend and I actually managed to build this today, but as you pointed out tuning it is very difficult as it is extremely sensitive. Occasionally we were able to detect a coin from around 20-30 cm, but one issue we are having is that the LED and buzzer are on continuously while in steady state. So when it detects metal the buzzer frequency actually decreases. My uncle has an oscilloscope I will try and figure it out tomorrow. Anyways thank you so much for this awesome project!!!
hello, do you have any updates on how your assembly is going? I'm trying to do this but the same thing happened here
Incredible sensitivity!
Hello Dr. House. Did you take your Vicodin?
Your schematics and explanations are SO clear and understandable. At first glance it does look like an analog nightmare, but you explain it in a way that makes a lot of sense to me.
I watch alot of metal detector youtuber the last month and like it that you show how it works. most is over my head but i understand the simpler parts. thanks and keep up the good work.
*Low budget high quality metal detector ❤️❤️👍🏻👍🏻👍🏻*
DGW, I'm afraid you have misinterpreted the "nulling curve," and also drawn it incorrectly. The slope of that curve represents sensitivity to the overlap null, it does not represent sensitivity to target detection. The induced signal from a target is about the same no matter where you null the coil, but the target is easiest to "see" when the coil is at maximum null because then the target signal is relatively largest compared to the null signal. The curve is incorrect because there is a phase inversion right at the null point; it is not flat there with minimum slope, but rather has a maximum slope. Hard to say in words, easy to show in a graph.
i love how you tied pin 7's resistor into the PNP transistor that's connected to the oscillating BC547c instead of to the power rail & into the 555 timer. that was very cool. & a new one for me. never saw that been done before. AWESOME...
CANT WAIT TO MAKE THIS PROJECT... : )
you are a genius. One of the best or THE BEST in what you doing. Thanks a lot for sharing.
Danke!
Thank you very much for this work.
After alll this years
..once uppon a time 😂
We are waiting for resin or more rosin on the DD coils XD
Maybe some more ideas to improve it.
Some guys wrote about kind of metal detection as you suggested or real world openfield tests on soil (or the pot of your Chili pepper plant😂).
Still watching your videos.
I love your content. The quality and how deep you explain the circuits and function.
I have successfully replicated your receiver and managed 25cm coin sensitivity with only 8cm coils and much weaker transmitter (I use simple LC oscillator with single transistor and it only takes 3mA at 5V), however I had stability problem in receiver. I had 2Hz oscillation on rails (2.5-5mA so almost 50%) which was causing almost constant beeping. I started removing parts while retaining the oscillation, I reduced it to first 4 transistors, I even removed the search coil and it still oscillated. When you look at the first 4 transistors of receiver, the collector resistors are 2k2 0 10k 2k2. I think the 10k or 2k2 could not cause such a deep oscillation on rails so the only culprit is second transistor which has direct path to ground via 4.7uF cap. I tried larger resistor and larger cap but it only delayed the oscillation. I added 6V regulator (78L06, because I power receiver from 9V battery) and power first two transistor from it and it seems to stopped. Later on I also increased Rc of fourth transistor to around 5k. I also used separate 6V regulator for 555 stage. I also changed 100k resistor and 100k pot from base of 5th transistor to 2k2 resistor and 100k pot. This allowed me to lower sensitivity even further using pot. I encased coils in epoxy and tested it outside and found some metal plate and one bottle cap around 5cm underground.
this is interesting since ZVS is used in one of the expensive minelab detectors and to watch diodegonewild make from scratch using his own understanding of electronics is truly fascinating. i wonder how it will perform on soil and if there will be ground balancing added and coil shielding. the materials used for shielding are like an RF absorption paint and can be home brewed using a glue binder and the black goo from a carbon zinc battery , graphite or a mixture of both. it needs to be made into a glue suspension that will dry leaving or cure with a specific ohm per square centumeter value...i dont recall the range but perhaps there will be some info in the geotech archive of metal detection technologies. I made some of the RF paint about 10 years ago and was PVA based with battery goop and graphite and made a very good shielding for a probe coil i made. i have seen graphite and epoxy based shield paint in a standard minelab 11 inch coil. so the binder works with either water based or organic.
Nice work!
Really interesting to follow. Detecting that small coin from 35 cm is really impressive :)
I'm curious to see at what distance gold coin would be detected. In order to use it for treasure hunt.
Saw a few comments below regarding Metal Detector‘s and showing interest in the Hobby. Or folks talking about how they’re going to get rich if they build one of these 😂 I thought I would post this reply here, and maybe more people would see it. I definitely don’t want to discourage anyone from the Hobby, but as someone has been doing it every week for 20 years…. Stuff like gold and jewelry and treasure is really hard to find. And gold registers exactly like trash aluminum and llead.
Gold registers exactly the same as small aluminum trash targets. Even on the nicest and most expensive Metal Detector’s… A big fat gold ring will show up on the screen, and sound, exactly like an aluminum soda can tab, or small shard of other trash metal. They also have the exact same acoustic signature and sound like a small piece of lead. And considering a lot of your gold will be found around swimming holes… You’re also going to dig thousands of fishing sinkers… Because they sound identical to a gold ring.
Source…..i own about 15 metal detectors. Been Detecting for the past 20 years. From cheap to expensive. My main machine is a minelab CTX 3030… I have several other minelab machines that are even more high-end than that machine.
But the only reason I have such high end machines, is because of build quality, waterproof ability, and ruggedness. You can do almost the exact same thing with a $300 machine that I can do with a $3500 machine.
I do a lot of hunting for Civil War artifacts, old coins, and gold jewelry.
Best place to find gold jewelry is at old or new swimming holes, when people get in the water their hands shrivel up… Their jewelry slides right off. Especially with all that slick sunscreen.
Second best place is next to a tennis court, Public pool, or basketball court. That has grass all around the edges.
If you drive around your town and look at the basketball courts and tennis courts… You’ll see people playing. And if you look closely you’ll see they lay all of their belongings, wallet, jewelry, hats… Stuff like that… In the grass right next to the court. And then very often, the basketball will hit their pile of stuff, or they’ll forget they put their ring on top of their wallet… And when they go to move it they drop it into the grass.
I metal detect on average two or three afternoons a week for a few hours each. Both On dry land and in the water.
On average… You have to recover about 2500 trash targets for each piece of gold jewelry you find. And About 400 targets for each piece of silver jewelry. That sounds like a lot, and it is a lot of work… But still totally worth it and a lot of fun. However, even the best case scenario… If you live in a neighborhood or somewhere with tons of rich people or you have a swimming hole that’s been active for 100 years… More than likely other Metal Detector’s have already cleaned it out. And even if nobody’s detected it… And you find tons of good stuff… It would be better getting a minimum wage job. You would make more money per hour
. Sure I might have $5000 or $6000 worth of gold and silver at the end of each year… But I Guarantee i spent A few thousand hours finding it. Maybe if I’m lucky, and I count all of my gold, silver, and usually somewhere near $1000 in regular pocket change each year… Maybe I’ll make minimum wage. MAYBE!! But that’s not counting gas, equipment, stuff like that. But it’s definitely possible to break even… Which is good because if you really get into the hobby it can get dang expensive fast. A single coil for my machine could be $300-$500. I have several coils for each machine because you need different types of coils for different situation’s.
If you’re interested and want to learn more you can check out the “friendly Metal Detecting forum”… I’ve been a member on there for over 10 years, and I post my end-of-the-year totals with pictures, weights, and values. Most folks on there do the same.
I’ve always kept a very meticulous journal every day, of my Detecting trips, how many targets are dug, how many decent targets, how many trash targets, and how many hours and location.
It’s fun to do that, but it also allows you to go back and see patterns, and you become better at locating good stuff. Half of a hobby is definitely research.
And when I’m saying it takes an average of 2500 trash targets to find one piece of gold…that’s using some of the best modern metal detectors out there, costing upwards of $3500. They definitely make Detecting easier in some aspects, but I can do the exact same thing with a 200 or $300 machine. Especially if you get the machine super capable and sensitive like the Fisher F2. Which is an extremely good machine that can perform as well as any $1500 machine out there. But you can pick them up for really cheap.
So although you’re not going to strike it rich… it’s absolutely worth it! And it’s a lot of fun! I paid for most of my machines with the gold , Silver, and pocket change I find every year. You’d be hard-pressed to find another hobby that would completely pay for itself.
However… When you consider 1000 pounds of pocket change every year, and at the bank and coin star machines won’t take dirty corroded coins… You have to clean them. But that’s pretty simple just put them in a bunch of big 5 gallon buckets with vinegar for a little while.
But it’s still a pain in the butt dealing with well over 100 pounds of change every year 😂
@@hullinstruments 100 pounds of change? As in, 45 kg of assorted coins or £100 of British currency?
@@vaclavtrpisovsky Well his name is "Hull Guitars USA", so I'd bet you a gold ring those pounds are in weight. :P
@@vaclavtrpisovsky I live in the USA, but yes at least 100 pounds of loose change. Or “clad” as it’s called in the Detecting community.
When you’re digging a few hundred holes each trip… And taking 2 to 3 trips per week year-round… You end up with well over 100 pounds of pocket change.
We call it “clad“ in the Detecting community. Because most of our coinage is a cheap base metal like zinc, plated in a thin “cladding“ of copper or other metal.
However, the term doesn’t apply to points from before 1964.
Because before then, most American coins were 90% silver. And all pennies were solid copper before 1982.
I’ll have to check my year-end tally on my forum posts and journal.. but think I ended up with approximately 130 something pounds of clad coinage. Probably a few thousand of them were pennies made after 1982, and since they are zinc with almost no copper at all… They very easily erode into nothing and become almost unrecognizable. Because we have very acidic soil. So those I’ll go in the trash.
For the other stuff… I used to clean it with vinegar and shake it around in a 5 gallon bucket after separating into the different types of coins.
But since I do this so often, and have s large quantities to process… I invested in an extra large rock Tumbler so that I could make them look brand new without any work. I also use the rock Tumbler for other things, so it was worth the purchase.
Tell you what else is wild… last year I recovered about 160 pounds of lead. From fishing sinkers mostly. Maybe 5% of it was from fired bullets and wheel balancing weights. I do a lot of detecting in the water… in old swimming holes… Because that’s where a lot of the gold and silver is.
But i find loads and loads of lead.. especially where people catfish, because they use a very large lead weights to hold their live bait near the bottom. And you have to recover the lead targets if you’re looking for gold. Because a big gold ring will sound exactly like a large lead sinker, and give the exact same numerical signature to the “brain“ of the detector.
@@vaclavtrpisovsky also, considering a large amount of that pocket change is quarters and dimes, (because they give off a signature similar to silver jewelry or brass/copper buttons from the Civil War or other highly conductive relics)…..
So if I see those numbers on my detector screen….., even if I’m not looking for pocket change…. I dig them.
So that’s why I end up with predominantly quarters and dimes.
I can have anywhere from a few hundred dollars to a bit over $1000 each year. I would say on average each year I find around $750 in pocket change. Some years much more, sometimes it’s more like $450. It’s according to what type of hunting I’m into that particular year.
Because obviously if I’m detecting old Civil War sites in the middle of the woods, I’m not going to find loads of pocket change.
Its such a pleasure listening to a real expert in his area! :-) Honestly i didn't understand everything but i got the overall clue! So would be interesting to compare the sensitivity and effectiveness of your detector to a good professional one! The distance you are amining at already with small objects is very impressive!
This video is full of interesting ideas, great job
This series had better end with Danyk finding a treasure chest.
What a nice project. Thanks from Brasil!
What a crazy world, I'm working as an employee doing boring circuits than I contribute to another engineers income so he can to have all the R&D fun :)
But the quality of the your work and videos is worth every penny!
I really liked you idea for the phase shift compensation.
Nice circuit
I'll be honest. This is treasure of insight. Do you think it would be possible to make more such a in-depth projects? This is as far one of the top best content on electronic subject on yt
How about PCB for this project after tuning it?
i would buy one!
We always watching your tutorial.
You may use a little adjustable coil in series with the receiver coil so that you can tune the tank circuit easily. You can scrap it from old CRT TV or PC monitor. You may need re-wind it maybe.
I follow the project!
This is a very interesting subject for most people.
Please consider designing and building a discriminating metal detector.
There are some projects on the web, but I enjoy your builds and videos.
exelent performance!
and you can use small ferite transformer to translate the low(max500pf) variable capacitors on to a nF capacitor by choosing a right turning ratio
2:50 forbidden chocolate
I think we can use push-pull amplifier for transmitter output, so we don't need anymore use the transformer that struggling to find on the market.
And use the phase shift for the different sound that inform us what metal it is.
Я делаю как раз вариант с Push Pull, но тогда лучше мотать катушку с отводом от центра. Тогда можно использовать микроконтроллер типа STM32 для раскачки передачтика и обработки результатов.
@@stalkerfromvoronezh4493 да, то, что ты делаешь, прекрасно.
A very fun project for sure! The material detected can be determined from that phase shift.( ie. silver will shift it almost 180 degrees. Aluminum block will shift it more than aluminum coin or sheet) :-)
I'm impressed by your English
What about episode 3?
My friend and I are trying to replicate this, but we are stuck trying to wind the transformer that feeds the coil. Is there any transformer we can salvage? Or any tips on winding one ourselves?
you can use almost any flyback transformer of a similar size. Wind 32 turns, then make the centre tap, then continue another 32 turns. Then wind 16 turns for the feedback. Mind the direction of the feedback winding, otherwise it won't oscillate.
@@DiodeGoneWild Tremendous Thank You!!! We were able to wind a transformer with the same turns and roughly the same induction measurement. We tried multiple times to build the circuit on a breadboard but it didn't work. When we went and soldered it to perfboard, it worked. Using the AC setting on a multimeter, we got 12V-AC across the transmitter coil. When we brought a large metal object, the 12v decreased. Tomorrow God willing we are going to build the reciever circuit.
I would only use a duel coil on a discrimination detector mono it's fine for what your doing there is a site I'm a member is geoteech metaldetecting where we have a community on what your doing lots of info there and help
Is there a design I can use to install a metal detector inside the under carriage of a robot chassis?
I came across this "Double D" design some years ago that used a PLL chip. Was published in a magazine article and looked promising.
Like many projects, it got canned for lack of knowledge about metal detectors and which ones to go with.
@@piconano no because the electrics will interfear with the detector you would have to have the coil away from the vehicle
@@daveherd6864 I've seen one operate in San Diego, CA by the beach.
The dude used a metal shield separating the coils from any interference from within the robot.
He was finding jewelry right left and center.
I've seen some that use a trailer type sensor, where the coil is pulled behind a robot. But that's not what I'm looking for.
I made one years ago and had the second coil run at 5 x the frequency of the main one. they were then mixed and the audio amplified to a speaker. was quite sensitive it could detect anything coming towards the coil.
Autor detektoru je skutečný pašák.
Zapojení jsem postavil a dosáhl jsem téměř přesně stejných výsledků, dokonce jsem na test našel stejnou minci, 5mm LED detekuji na vzdálenost 18cm.
Vyrobil jsem (3D tiskem + epopxy) několik různých cívek, ale téměř vždy s podobným výsledkem. Nemám jiný drát a tak jsem navinul cívku RX 40 závitů drátem 0,3mm, TX 30 závitů drátem 0,3mm. Transformátor do oscilátoru jsem navinul na toroid.
Jednu RX cívku jsem navinul 40 závitů 3x drátem 0,3 mm jako VF lanko a opět výsledek přibližně stejný. Na místo NE555 jsem použil PIC12F675, což umožnilo mimo jiné rozlišit barevné kovy a železo a maskovat různé stavy.
V zapojení jsem tisíckrát změnil většinu kapacit a odporů, ale nikdy jsem nedosáhl lepšího výsledku. Nepoužil jsem poslední tranzistor a potenciometr na řízení zisku je zapojen na místo odporu 100 ohmu. Chápu sice na co jsou v zapojení 1N4148, ale při jejich zapojení, nebo odpojení nepozoruji na funkci subjektivně ani na osciloskopu žádnou změnu. Kmitočet oscilátoru mi vyšel na 17kHz.
K zamyšlení:
1. Jako limit pro větší citlivost vidím vlastní šum zapojení, který roste s každým stupněm zesilovače a je přítomen i při odpojené cívce.
2. Při přebuzení velkým kusem kovu trvá asi 4 sekundy než se detektor vrátí do pracovního stavu a nepodařilo se mi vymyslet jak to vyřešit.
3. Když cívku naprosto totálně dokonale vybalancuji, tak je citlivost přibližně poloviční, než když je trochu rozbalancovaná a také nelze jednoduše určit druh kovu, protože první kmit výchylky na výstupu je vždycky kladný.
The cat is Smart. You need to start listening to the cat right meow!!
Your project will work but when you will put on field you will be disappointed: ground itself have capacitance so you have to shield the coil and you will start to pick up soil itself (gorund minerals) so the distance at you will sense a coin will be very short and you experience a lot of false signals. Unfortunately the ability to build a good detector is the ability to deal with those drawbacks. I suggest you the book of Carl Moreland - George Overeton, Inside the metal detector. keep experimenting in any case your channel is amazing.
Hello, question please.. If technology was invented that could replace the copper wiring in coil disks without loosing performance..would it be valuable?
Velmi pěkná práce, možná by bylo dobré pro korekci několik závitů spínat - přidávat/ubírat elektronicky. Každopádně se těším na výsledek :)
actually, the idea of using a variable capacitor with the coil is doable, just not worth while in this case. if you make your own, it's not that hard, really. I had to get hold of a 100 pF capacitor with ~ 2000 volts A.C capable of working at around ten MHz. Rather than buy one (expensive) I just used the cap formula and used a 30 cm length of PVC tube about 4 cm diameter, about 3 mm thickness. What I did was wrap the outside of the tube with Aluminium foil, with a length of multi strand wire touching the foil I wrapped it fairly well with tape. For the inner electrode I used a 30 cm length of thin copper foil, with a wire soldered to it. The copper foil was rolled around the same size of the PVC pipe, then the rolled up copper tube was inserted inside the PVC tube, it was springy enough so that it hugged the inner surface of the PVC pipe. And that's it. You can slide any amount of the copper tube in or out for it to act as a variable capacitor, probably not worth the effort for this low voltage application, but when using 2000 plus volts it certainly is ! It was for a plasma candle.
Hello dear brother, thank you very much for teaching us how to make a metal detector. I ask you, if possible, to teach us a metal detector to build two meters of metal underground, because in our area, all gold is less than one meter to three meters. May God grant success to you and your dear family, and may you always be victorious and happy in life, brother
Absolutely amazing, Dan!
Will you plan to do some tests in the wild/out of lab?
It's very good please post the schematic of circuitr
You might want to check out phase shift of high frequency received signal. You should have a phase shift with the transmitter that correlates with the type of metal. That way you can tune receiver to for beep for gold but ignore mostlhy iron or whatever. Of course measuring phase shift with amplitude makes it a lot more complex, especially when you start putting limits on phase shift to ignore some metals.
Did you try differect receiver coils already or estimate Q of the receiver tank? That can affect receiver selectivity and sensitivity.
Does anyone know what the affects of using this over soil/dirt with high iron content would be?
Are you going to share the pcb and the components list when you refine everything. Please do I love your work. Thank you.
15:17 😚 🐈❤️ Thank you Mr DGW !!! Great explanation!!!
Please give me the schematic of the 12V 50A chinese power supply...
What if you used a hugh voltage dc converter to charge a 200v rated capacitor, tobbe used as the current for the search coil, running at about 120v -180v. To pulse the coil with. Along with higher current. With a low duty cycle to allow dead time for reading for metallics. Think its possible, also cover the high voltage side with PCB board with solid ground plane. And seam covered with copper foil conductive tape, to protect the sensory circuits from the EMI,. With the actual peak current of the ping going to the search coil being 5amps or more then dropping off to around 2 amps then 100ma before ending the pulse. With a strong pulse, with a quick, ever changing magnetic field should make small metallic bits ring like a bell caught up in a bicycles wheel! Compared to someone ringing it and sitting it down! The sense during dead time could possibly sound interesting. I'd like to attempt using a stand alone coil and try listening to a small piece of metal being rang by a detector, possibly record the sound play it back at 25% speed so humans can hear the frequency. I want to attempt using a tiny coil with tons of copper a 2ohm dc coil hit with nearly 200vac. The instantaneous current would be amazing, sky high, yet quickly falling. I really want to experiment with some metal detecting circuitry. And especially experiment with coil types and shapes. It would be awesome to be able to drive metal rods into the ground with coils on them and wires going tovthem from s contol box, have 3-4 of them around a search area. Then sweep. The area inside the rods say 3-4 meters from them. Using a detector coil, connected to the cintrol box, or operating wirelessly. And having the ability to find metallic bits down to or smaller than 1/10 of a gram, as deep as the rods can be driven into the earth. Possibly slightly deeper around 100 mm roughly, with the rods capable of going 1.5-3 meters deep. Possibly deeper with soil type and rocks effecting performance, i belive this tech is possible. Possibly only usong the rods with the electronics. They can find voids in the earth with similar tech. Had the ability for many years. It could work like radar, or sonar use it similar radar or sonar by reading the electromagnetic returns from multiple pings, send energy intothe ground with the rods and listen to the earth after the ping, do youbhave an opinion? Any ideas about a pi detector, awesome video..
interesting video, waiting add discrimination and ground balance features!
Very interested ,low cost in high quality detection
zdravim, budu neskor aj nejake podklady na stiahnutie? schema pcb? inak uzasny projekt, klobuk dole
Impressive, I love those good old analog circuits!
Also, very nice explanation!
Exelente detector me gustaría echar un vistazo a este diagrama como podré adquirirlo.
Can i use c1815 instead of the bc547
thaks for the video it was full
but could yoy please drow one circuit diagram including all parts
Nice project , Why you didn't used tow or three opamp instead of transistors i think it will be more sensitive.
You have amazing knowledge bud what’s your credentials, just really interested.
Would that make you respect him more? Is actually irrelevant.
Because you asked, and since Google is our friend, danyk.cz/ja.html and also danyk.cz/
@@rogeronslow1498 Does it bother you?
if you had bigger coil then could you add extra turns to fine tune it but smaller coil you need less turns so you can tune it is that correct or did you never test
Very nice video. The front end is very impressive, but I think the performance could be much higher if you digitized the signal after the front end, rather than going through the peak detector and the following circuitry which is very retro...
Awesome work! It's certainly a difficult task to make it work properly. I'm wondering, how it would detect metal objects that are dug in the ground. I'm thinking that if you would add more of these demodulating capacitors with slightly different capacity and connect one you need so it would be possible to somewhat change the sensitivity.
Because there is a phase shift between phases maybe it's good idea to make a phase detector instead of amplitude detector?
Best accent in the world 😁👍
Please I want one electronic circuit map
where can i download the diagram cause your description doesnt have it?
i dont find the capacitor 250nf and 1 uf can you send the code or symbole for all capacitor that you used on your video
can you make this project on the pcb please sire help me i need to make this metal detector
very creative
Hi sir, this detector can reject iron nails? LIKE 👍
hello i make it but not working i have a problem on the capacitor that you used please give me the code of the capacitor
Sir can i use transistor c1815 all for this diagram?
Please ,Can i replace a diode 1n 5819 by 1n 4148 or 1n4007 and thank you.
1n4148 is low current FAST silicon diode..
Can't replaced in high circuits with the slow 1n4001 to 4007 Standard rectifier diodes.
On the other hand:
Search datasheets and make main attention to
breakdown voltage
Forward voltage drop
current
reverse(leakage) current
Aannd powerdissipation over all xd
Why you don't use op amp for minimize the circuit
Hi. What’s size of wires are you using on the transmitter and receiver coils.?
Hi can i skip the 555 timer ic? I dont have it and i cant get it anywere
Is there a more common chip than 555? :)
hello, i've build it and it works, prety well! But there is problem for me, it is extremly sensitive to my hand with no metal, i guess capacitive things... If someone has a solution to it i will be gratefull.
Boost the voltage for more sensitivity
How about schematics on EASYEDA and then you can order the circuit boards!? So that you solder the components and its much easier.
Of course you need some copper and the 'CD thing' (I have it randomly). The problem is that a lot of copper is required... I have some transformers from some SMPS power supplies but the wires in them will still not be enough... Maybe I can buy it somewhere but it's quite expensive.... And of course you will the resin and a container for it... But still maybe you get lucky and you find real treasures with this thing...
It's also a very nice project!
I feel like to improve it further, you probably need to start adding opamps everywhere. Especially if you wanted to replace some of the potentiometers with automatic adjustments.
Even more opamps...
Hi, very good explanation but I know nothing about electronic, what I want is to build one to find gold, I got no money to buy one metal detector.
Can you made a video with all part soldering together and making coil from start to end for starters, so that I can follow......Thank you
you know nothing but you want hunt for gold to become rich. good luck with that great plan. You maybe want go invest some money in bitcoin, heard that everyone who invests make more of his investment
Plz explain proximity sensor
nice project. how this work on soil? air test are nice but soil makes a lot of interference.... not like pulse induction.... pi doesn't respond to ground interference.... greetings, keep working💪
I still have to test it with soil...
sir ....final map plz tell me
Very very nice job wooow :-)
That 555 is overkill.
All 555s are overkill.
if it is used only to detect gold, how is the circuit?
Interesting video and nice project to learn metal detector technology, could you please improve this circuit by adding discrimination and ground balancing techniques.
the base legs of the transistor are 1-2 UF or nf ???
it's uF
Are you gonna put it in a case?
I have some suggestions and some questions
you can put one transistor phase shift to improve the receiver
Also, is the transmitter required to be zvs or zvt
I mean, can the transmitter circuit be replaced with another and put a controller or chip like 555 timer or tl494 or bfo tx?
Now you can go out for hunting some dodgy electronic.......
By the way how to increase sensitive more....
Where did you buy that orange ink pen? The marks on the pen are terrible !!
Perfektní 👍👍👍
This is great but I guess with this sort of ' tuned circuit ' stuff designing a PCB would be a nightmare as a lot of the values would then be select on test or do you think once its finalized it would just work ? as I would like to design the PCB but don't have the skill set to diagnose at your level ! at least not at the moment, but it's all absolutely fascinating anyway....and no salt cheers.
Everything that oscillates and has a coil, is a tuned circuit.
10KHz is low enough frequency that's not really affected by wiring. It can even be breadboarded.
I don't use PCBs. Only perf boards and solder wire them. Just like you see Great Scott make his prototypes.
@@piconano Thats why I called it a ' tuned circuit ' if your happy with perf and you dont use PCB's thats great...enjoy ! I am discussing PCB's...cheers.
@@andymouse That's what I was trying to tell you. The PCB would be like any other. This is not RF design.
@@piconano cheers.
DiodeGoneWild based and collectored, as always. 😎
Genius.
How can you make it stronger?
Reinforce with fibreglass
@@godfreypoon5148 or cement
Nice! Only discrete, no scary op amp technology)
Just a tip for anyone trying this. Don't power it from a powerbank without any protection. The high voltage spikes killed mine
NE555 or TLC555?