Microwave Oven Transformer Spot Welder 1

Let's build a spot welder from a Microwave Oven Transformer (MOT). In this episode I talk about MOTs, do some tests and experiments, I remove the high voltage secondary winding from a big MOT and I prepare it for a low voltage high current secondary. In the next episode I will wind the secondary and try to use it as a DIY spot welder.
The next episode:
• Microwave Oven Transfo...
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[@edgeeffect]

There's literally hundreds of MOT spot welder videos on KZbin... but none of them explain what's actually happening as well as you do. Looking forward to part 2.

[@Basement-Science]

Yeah, they are all just copying each other and usually add nothing of value to it. Same goes for tons of other projects. Danyk is one of the very few people who knows what they're doing and actually explains the relevant concepts.

[@johncoops6897]

Like many other people, I am currently considering various methods of spot welding. Since I am unsure how much I will use it, I certainly want to keep the initial costs low. I have proper welding transformers, lots of MOTs, and I could even build a lithium battery bank with sufficient current capacity (if I had a spot welder LOL). I am very interested in learning if the MOT is the best solution, and seeing how Danyk will control the impulse current and duration.

[@jeffm2787]

This guy puts so many so called electronics KZbin channels to shame. I've studied electronics all of my life and still manage to pick up new information here. Then again I'm getting old so perhaps I just forgot it 😎

[@cagmito76]

I agree never fail to learn here.

[@hadireg]

true! DGW is a real state of the art Electronics & Electrical Engineering knowledge sharing! + a bonus sense of humor 😊

[@itsevilbert]

This is engagement, I am engaged, engaged is me. Hail the algorithm, may you bless this video for many more eyes.

[@powerelectronics7544]

Lupin what are you on about

[@nikiamz6501]

Wtf

[@piconano]

I made one exactly as yours to get 30V output for a power supply! I quickly found out I can't use these for more than an hour before it got hot. You explained why, beautifully.

[@Basement-Science]

These are designed to be cooled by a fan. So add one to your PSU.

[@piconano]

@@Basement-Science I tried that but the heat build up is deep inside the core. These transformers are not for constant duty cycle. Just like welders. They need cooling time.

[@marco56702]

@@piconano you can rewind the primary with more turns, or lower input voltage. Plenty of resources online to calculate

[@therealjammit]

I wish I read your comment before posting. I had a similar issue. I used two MOT with the primary wired in series. I also removed the magnetic shunts. Where I live the mains is 120vac. Since the transformers are in series they're only getting about 60vac each. I also had to double the number of secondary turns to get the right voltage. With a lower input voltage it's harder to go into saturation.

[@Speeder84XL]

@@therealjammit It surpriced me that they run at all with the core driven that hard into saturation. Toroid transformers for example, behave almost like a short circuit if the core is saturated (I have accidently done that while trying to wind my own transformer, before I had knowledge to calculate how many turns are needed on the primary). I guess the magnetic shunts and a relatively uneven distribution of the magnetic field in the core, due to it's shape and, helps a lot (since all iron doesn't saturate at the same time). But of course, it's still causes a lot of inefficiency. They simply rely on the mass of the core being so large, that for normal microwave oven running times, it never get too hot before it's allowed to cool down, when not in use.

[@SarionFetecuse]

Not only do you get invaluable information nobody else explains you ALSO get it through a beautiful Czech accent. With intonations going high to low as the mountains go to the plains in the prestine Czech Republic countryside!!

[@johncoops6897]

AND you get a cat. Don't forget the cat, Gūðsang !!

[@warmarin]

Oh, first time hearing a czech accent, before reading your comment it sounded to me like an Indian russian american mix.

[@Killeroz]

Oh shit a je to tady :D Tak na to se těším :)

[@skyes9461]

:D

[@NikiBretschneider]

No to já taky, ale pobavila mě jiná věc - cca 1V na závit. To je totiž opravdu hodně (čekala jsem tak polovinu), takže při nějakých 3-4 závitech jsou tam 3V určitě, ale spíš víc, což už pasivaci prostřelí naprosto spolehlivě a pak už platí, že čím méně závitů, tím větší proud, přičemž čím méně závitů, tím větší průřez, čím větší průřez tím menší úbytek na kabelu a tím víc energie se vyřádí ve vlastním sváru. Otázkou zůstává jak najít optimum, ale myslím si, že je jasné, že těch závitů tam moc nebude.

[@to220]

@@davidpolacek4902 Človeče Ty si fakt mimo. Takto urážať človeka ktorý poukáže na reálnu problematiku že prečo to nefunguje, je fakt úbohé !!! keby si mal základné elektrotechnické vzdelanie, hneď by si vedel kde bola chyba u Kill.. (a to v nízkom napätí !!!) Na Danyka určite nebudem reagovať keďže on použije podstatne výkonnejší MOT a dokonca s medeným vinutím !!! Takýto MOT určite len tak niekto ľahko nezoženie. A keď si už takýto inteligent tak nám láskavo vysvetlí že prečo všetci čo majú 650W, 700W MOT tak museli previnúť z 50 káblov na tenší kábel a použiť viac závitov (aby im to vôbec bodovalo). Prečo ? PS. A keďže mám ešte nejaký MOT doma a mám ešte originál 50 kábel, tak ukážem rozdiel medzi dvoma závitmi 50 a štyrmi závitmi 25.

[@Zek205]

@@to220 Tobe to proste neda spat :) Hosi, nechte si to jinam. Sem to opravdu nepatri.

[@to220]

@@Zek205 Ja len som musel reagovať na jeho komentár keďže ma urazil😥

[@alex-r2pi]

5:00 Yay, thousands of jumper wires - all over the place :-D

[@johncoops6897]

Looks like the floor of a barber shop after a biker gang comes in for a trim.

[@454cassul9]

Vrey informative videos, & I also love the way he speaks English, thanx! ))

[@nortenhardenberg1598]

Super explained. Love this guy!

[@peter.stimpel]

transformer masacre, next level

[@enzoperruccio]

This can't be a coincidence. Yesterday I finally decided to make a spot welder with a microwave transformer I've had for a while. And now diodegonewild uploads a tutorial on how to make it? Wow

[@454cassul9]

Definitely "go ahead" sign!)

[@enzoperruccio]

@@454cassul9 For sure :)

[@frogz]

i just cut the secondary off a MoT with a recip saw and chisel!

[@Samurai38135]

Me too. I've found the vertically wind type.

[@taka4059]

The prophecy is true.

[@Peterjames3535]

Save a lot of money a home built spot welder, very handy tool to have. Thanks for the idea.

[@Hellhound604]

Have re-purposed quite a few old microwave transformers, but always wondered about the magentic shunts. Some people make a huge issue about it, but I can’t see how to remove it on the transformers that I have… good to see you leave it in too.👍👍👍btw, only recently discovered your channel. Absolutely love it since you also analyze and reverse engineer stuff…

[@albertolaurella9168]

"this video is not for the layman" Me an absolute layman: "I could do this"

[@plainedgedsaw1694]

Me an absolute layman: I did it.

[@roseelectronics4582]

You both are above laymen rank. If you were, you wouldn't be able to do it.

[@michaelwynne2801]

Awesome build Mr Wild

[@jp040759]

Lots of great info. Thanx for your efforts. Great job.

[@RODALCO2007]

Good video and explanation of the workings. Thanks.

[@TaRg3t222]

Nice video, thank you for your effort!

[@NullPointer]

Excellent explanation!

[@Random_4400]

I really enjoy your videos

[@thehumbledabbler]

I love his cadence and delivery.

[@XarkoCZ]

Drink everytime he says traaansformer.

[@KatouMegumiosu]

Just stretch vowels.

[@Steelplayer59]

I believe the removal of the windings was a foley sound effect of eating potato chips, lol!

[@socialbeat2587]

Hahaha u made my day bro 🍻🤣

[@Buzzhumma]

Nice lesson on mot effeciency👍🏻

[@nativoneto9763]

Great project. I did something similar, I used some pcb(diode gone wild style) for timing the welder. I did with 16mm^2 copper wire, it get hot very fast. Wait for the next episode.

[@jyojycorpuz5834]

I Knew it 😊. Great Explanation 👌⚡

[@andymouse]

Look forward to part tchew....cheers.

[@TopBabyWOW]

Amaing channel for my kids! Thay love to spend time in the grage!

[@TBL_stevennelson]

This project is something I would like to learn and try.

[@t_Gecko]

this is gonna be my next project 👍

[@saschakolb7102]

What a coincidence 🤔 last week My brother asked me about a transfirmer to build a spot welder 😅 I gave him my old 24V 2500 W Iron core transformer which has a weight of about 25 Kg. It is continues power stable because it is from an industry machine. The next few weeks I think we will built the spot welder with a pedal from a sewing machine

[@franzliszt8576]

25 kg's?! Bloody hell!!

[@aivansama6265]

Pedal from sewing machine? Super dodgy!

[@frogz]

25 kg sewing machine pedal? bloody hell thats dodgy, the foot pedal has a microswitch in it, rated at 5? 10? maybe 15 amps if you're lucky, maybe 1 amp if you arnt, you will literally need to replace the switch in the pedal

[@Basement-Science]

Guys, I'm sure OP can figure out if they need to use a relay for it, dont you think? ;) I'm a bit skeptical about those MOT-based spot welders since I believe real spot welders use significantly bigger transformers, but a 25kg one will definitely be good!

[@Pirelli.]

Great! Thanks mr. DGW 👍🏻 One Beer 🍺 for YOU and one KISS for your CAT 😘 😊

[@ithalkomedi1513]

Nice 👍. I am waiting for second video.

[@jankindl915]

Luxus, z tvojí angličtiny chčiju :D Palec nahoru i samozřejmě za obsah ;)

[@Speeder84XL]

Very interesting! I have wondered how they can get them so small while still getting so much power thru (compared to for example a few toroid transformer that I have with the same or lower power rating) - now I know and also (as I suspected), since they in simply use the fact, that the run time is usually short and the core has a large mass that take a while to heat up. But, never taught it would run at all with the core driven that hard into saturation (as your wave form showed), but it apparently do - at direct cost of efficiency, of course.

[@mernok2001]

Your clamp meter probably also showed a higher current because its close to the MOT and there is a quite strong magnetic field around the core of it.

[@hadighaemipoor6354]

Thank you for good thiching

[@Asraful_x]

True intelligence.♥️♥️

[@PiratCarribean]

I have the same big MOT and am also planning to make a spot welder out of it :D

[@DrAVRECEIVER]

Which side need to remove the winding, primary or secondary???

[@f4tboy99]

@@DrAVRECEIVER Secondary to put a bigger wire with less turns (less voltage and bigger amperage) 🔌

[@DrAVRECEIVER]

@@f4tboy99 thank u for clarifying the doubt

[@Basement-Science]

Watch out for false readings from (AC) clamp meters when they are so close to an energized transformer. They will show an AC reading when they get close to it because of the leakage magnetic field.

[@DiodeGoneWild]

Well, you're right, I forgot about it this time. But anyway, an RMS meter tends to show higher currents than a rectified average meter when measuring this kind of current with short peaks. The same applies to switching power supplies with no PFC.

[@Basement-Science]

@@DiodeGoneWild yeah an RMS meter is always better, especially when measuring current. There's not that many devices that ever draw sinusoidal current, so there's really not many opportunities where it doesnt give significantly more accurate results. They are also cheap enough that I dont think it ever makes sense to buy something else when buying new.

[@therealjammit]

I needed to make a transformer that the output needed to be low voltage and high current. I also needed it to be a little more efficient so I could run it continuous without getting too hot. What I did was to use two MOT with their primary in series and wind both secondaries in series. Basically instead of running them to their limits (120vac here), each one was only seeing about 60vac. It gave me enough "wiggle room" to prevent saturation.

[@HIDLad001]

These transformers (with the dangerous high-voltage secondary removed) are perfect for learning how transformers work and how to wind your own. They can be obtained very cheaply, and they are large enough that there is enough room that you can make mistakes and you don't need to disassemble the core to wind your wire. Your experiments would also be safely isolated from mains as well!

[@sinister6116]

Great experiment :o) every elecronic device , has to do with E=mc2 i guess ..

[@fbi_gunner]

WHERE IS PART 2 PLS PUBLISH SOON AS POSSIBLE!

[@electronic7979]

Super

[@AlexforTruth]

The spot welding machine you plan to build will be used to weld the connecting strips between Li-ion batteries, or in other application?

[@augustus4711]

I'm getting very nervous just by watching him play with those MOTs. Stay safe DGW :(

[@lumsdot]

so is the ac high current better than a dc high current for spot welding. i think it is since dc spot welders can make big sparks and blow holes in the metal

[@UBsLab]

Diodegonewild: uses microwave transformer for spot welding. Meanwhile Microwave oven : Am I a joke to you?

[@edgeeffect]

Microwave oven is not a joke.... it's a parts store. ;)

[@andrezinatech]

Niiiiceeeee!

[@Random_4400]

English subtitles: "y in a ding"

[@azislo]

I have tried the same, but used a bigger transformer from actual (failed) old-school metal welder transformer. And used welder cables for winding. It was too strong for spot 18650 welding, even though dual pulse controller (you can find on Ali, Ebay) was used. You could see black burn marks on the nickel strip. I have tried with 2 turns instead of 3, but still burn marks were visible on nickel strip. I wanted it clean. I will try with microwave transformer and a bit thinner wire - did not had that transformer then.

[@alexistexas5018]

I actually reused the secundary coil for a Tesla coil

[@RespawnRestricted]

Got 2 1000w and one 1300w ones laying around gonna make a micr power supply some day

[@jpius1017]

Hellow dan which is best power suppy for phone and laptop repair liner power supply or switching power suppy is the best ?

[@RoGameReview]

dangeruuuss

[@christiancarassai9540]

Nice explanation, your videos are very satifiying and informational. Regards from Argentina!!!!

[@techtheguy5180]

there weeee goooo

[@justin8894]

Put a Dremel tool on your Christmas list!

[@Purple431]

What does the vaccum tube tesla coil look like? ;)

[@mrfrog8502]

Excellent explanaition, thanks for another fascinating video.I was really scared looking at you holding 1970's single insulation wires with bare hands. Please ba careful, we need you to stay alive.

[@TechGorilla1987]

@12:00 or so - That looks like a piece of a degausing coil from a CRT television. Good copper there.

[@DiodeGoneWild]

Yes, in the 2nd episode I will test it with a secondary made of a degaussing coil.

[@Zebra_Paw]

You can disassemble the core, it is made of ferrite sheets. Most of the time they have E and I shape. This allows you to rewind the transformer a lot easier!

[@k.kivenmaki8431]

It wont be the same again😟

[@Zebra_Paw]

@@k.kivenmaki8431 it still can run nicely. I have done it once, and the transformer is still fine. I rewound it to be 35-0-35V output for a Hi-Fi amplifier!

[@ProdigalPorcupine]

Iron, not ferrite!

[@Zebra_Paw]

@@ProdigalPorcupine you right, sorry

[@techno0b467]

The easiest (and the least likely to damage the primary) way I have found to remove the secondary of these transformers is to take a big screwdriver or a chisel if you have one and sharpen it and hammer it on the windings. It cuts them like a hot knife through butter.

[@sklepa]

Please make some weld energy measuring in Wh or joules so microcontroller can adjust time of each weld to make them even and elegant :)

[@valamilamasag]

Hm, why wasn't the transformer's winding encapsulated/infused? All the ones I converted had the secondary infused with epoxy or something similar, was a huge pain to remove it.

[@frogz]

why do you do this a few days after i cut the wire off a MoT??? i need a 48v/3a supply or maybe 1-3v/100a

[@trebushett2079]

If you're going to keep making sparks and smoke, you'd better enter the ElectroBOOM contest.

[@RicoElectrico]

4:26 nice ASMR

[@krnlg]

Wow, a lot of copper in those transformers!

[@ProdigalPorcupine]

Sadly not. MOTs almost universally use aluminium windings.

[@DiodeGoneWild]

the primaries are mostly aluminium, but ony 1 out of 25 MOTs I examined had an aluminium secondary.

[@ggcmod]

Hi, diod...how to measure power consumption with multimeter? I imagine that the yellow tester showing in another videos, you have modified it for that.(?)

[@gacherumburu9958]

👍👍

[@git-push]

Can you spend a bit of time in the next episode explaining how to do the power factor correction of that transformer? It would be intresting! Thanks

[@johncoops6897]

You can't do power factor correction of that transformer. It's creating a distorted current waveform, not a phase shift that can be corrected with capacitance. In any case, the Amps drawn are not from Apparent Power (phase shift) but because of LOSSES in the core. It's all explained in this video.

[@hadireg]

👍👍👍

[@davidca96]

thadits nyyyyyyyycee

[@catalinbadalan4463]

Very rarely you get to see a mains transformer these days. Are they more advantageous than switched mode variants for the spot-welding application?

[@undefinednan7096]

It's a lot simpler to build a MOT-based spot welder than a switched-mode-based spot welder, although the switched mode one should be vastly more efficient if designed properly, and probably less expensive when built in large volumes (silicon costs less than iron these days, and higher frequencies allow the use of smaller transformers).

[@Felix2417425]

Why is magnetic shunt needed in these transformers?

[@manikmaity1651]

Can you explain the primary winding of microwave transformer......

[@rollbot]

DiodeGoneWild: Can you tell me what country you are from? / What is your native language? Thank You! I love all your videos!

[@gamecrafterl3659]

He is the Czech ElectroBOOM XD

[@jmr]

You can make a wig from that copper.

[@uksuperrascal]

Nice to see you joined Lbry and Odysee, See my reply on your odysee channel under your Community Icon

[@MiamiMillionaire]

👍

[@k.kivenmaki8431]

I wish i hadnt done it the wrong way around. I thought it would work better by replacing the primary and running mains from secondary.

[@DiodeGoneWild]

I you use the 2100V secondary as a 230V primary, you get just slightly above 0.1V per turn and a very low current (because the magnetic flux density is loo low).

[@bashaaksema94]

cool video but what a weird isolation on the big wire in the last minutes

[@godfreypoon5148]

Here is what I did to reduce the magnetizing current to something more sensible, and not push the flux density so high. Ideal for general usage (don't bother for spot welder). 1. Patrol the streets until you collect two microwaves / transformers of the same type. 2. Use an angle grinder to unweld the "I" blocks from their "E" blocks. 3. Remove the secondaries. 3. Assemble the two "E" blocks together, with the two primaries and a new secondary as you please. Weld as desired. 4. Happy days.

[@godfreypoon5148]

You can also reduce the flux density excursion by taking your 50 Hz transformers and moving to a place where there is 60 Hz.

[@eDoc2020]

You could also add extra turns and put them in series with the existing primary. I plan on doing this with a large (non-microwave) transformer I have to reduce its no-load losses.

[@Felix2417425]

@@godfreypoon5148 Or you can reduce input voltage, gives same result as increasing frequency.

[@-Crash-Nebula--]

continue to use your welding machine made with the inductances of 2 lamps ... that works fine

[@AmatorElektronik]

Can You show Your DIY Power Meter?

[@zebo-the-fat]

What is the point of the magnetic shunt??

[@TechHowden]

Why do 4 of the outlets on your outlet strip have an x

[@niemam5825]

What will happen if You use HV secondary winding as a 230V primary (of course with disconnection one of the terminals from transformer core) and cut-off the original 230V primary to make high current secondary for spot welding? What with the transformer ratio? What with core saturation?

[@DiodeGoneWild]

if you use the secondary as a 230V primary, you get a very low voltage per turn (about 0.1V), very low flux density and the voltage on the new secondary tends to drop a lot even under a light load. I tried to reverse a MOT and use the primary as a 24V secondary. It works, but only for very low power.

[@niemam5825]

@@DiodeGoneWild Thanx for Your quick answer!

[@jayvadgama3703]

Can it possible to melt this copper wire using induction heater??

[@johncoops6897]

Yes if you get a big enough one. But it's a lot cheaper and easier to just use Propane or other gas to create the heat.

[@physicsandmathemathicssimp833]

How do you measure real power with your multimiter on volts? Please tell me seems useful .

[@DiodeGoneWild]

danyk.cz/wmetr_en.html

[@physicsandmathemathicssimp833]

@@DiodeGoneWild Thank you :)

[@ToBeDefined85]

@@DiodeGoneWild Isn't it worth a separate video :) ?

[@TheComputerGuy96]

It's mad how some people would throw away a perfectly good microwave oven just because it's dirty. My family has had the same microwave oven for over 10 years, it still works fine, and when it gets dirty we just clean it.

[@1pcfred]

Microwave ovens do not last forever. They lose power over time. Your oven should have a spec of how long it should take to boil a quantity of water in it. Usually it is about a cup full. Generally it should take under two minutes for a 1,000 Watt unit.

[@krnlg]

@@1pcfred Sure, but they can last way longer than a few years. Throwing one away because it takes a few seconds longer than it used to take is just as bad as throwing it away because its dirty :)

[@1pcfred]

@@krnlg if a MWO is taking longer that is indicative of it failing. They're not worth servicing either. No one uses MWOs to take longer either. I've had a MWO crap out on me. Once they start to go they die out quickly. It was days from noticing it was slower to it doesn't do anything at all.

[@erikhansen4681]

Hello I have difficulty on my refrigerator board with no DC output can you help me with this please !!! Thank you in advance.

[@fourkings7897]

What would happen if we combine two or more iron core.. Can it make big transformer...???

[@f4tboy99]

If you wire them in parallel you get a bigger amperage. In series a bigger voltage. You can mix them too.

[@fourkings7897]

@@f4tboy99 thank you. I have a lot of iron core transformer from old Stabilizer and Computer UPS. I'll try as you said..

[@vitcenek8611]

Tak obří MOT jsi vytáhnul z čeho? To snad musela být nějaká Ruská mikrovlnka z 80. let :D

[@DiodeGoneWild]

Ne, to byla stará Moulinex.

[@user255]

TransfooormEEEEeeeer

[@Atetus94]

Do real welding machine from that type of transformer - Maybe on some SCRs?

[@patrikjankovics2113]

he has one iirc. He had to weld his muffler, so he made a welder quickly

[@mubashirbhat8041]

Why you put cross on the extension

[@therealjammit]

To turn it into a power to voltage adapter, he disabled and removed those outlets to make space for the necessary circuitry.

[@eDoc2020]

I actually guessed the current would be about three amps. Do I get a prize?