I boiled one of the transformers in a pan and made a youtube video with that process (I wanted the core to expand a bit and the resin that holds the coils to soften). MOT s (Micro Oven Transformers) make this world a better place :D Very nicely done transformer conversion! Thank you for sharing!
My friend and I have been staring at a transformer for two months, trying to pluck up courage to saw into the weld. And now you come up with the [obvious when you see it] solution. Many thanks!
Thank you, soo much. You are an amazing engineer. I was watching you from USA. Good job. I got a bunch of those microwave transformers. I always believe there is something that can be done using them.
Hi Bob! Over the past few years, i have often stumbled on your videos, and always enjoyed them. But this one takes the cake. I was currently stumped by the EXACT problem that you explained here so nicely. In fact only a few hours ago, I rewarded a workshop mechanic with some prize money to suggest a way to remove the secondary, but he just said No, I have tried and tried, and never succeeded - they are built and sealed in the factory so tightly, it is impossible. I was planning something close to what you showed, and felt so happy for the encouragement! I have always felt that posting nice, informative videos on the net is like broadcasting seeds of help in the wind - you never know or imagine how much even a tiny bit of your kindness and effort can mean to some one! (Sorry for going on so long.) By the way I am a retired Civil Engineer, having the best time of my life, tinkering and making in my house which is more of a junkyard than a decent house! Thanks a lot for all your videos, and best wishes for every thing good in life (and beyond)!
Btw, if you build a spotwelder out this, then it's better to use a chromium copper alloy for the tips, as it will stick less to the welded parts. Cheers mate !
Your program is very helpful I had seen others run loops to the transformers I didn't know it increased the power Very interesting thank you Joey Cotton Houston Texas
6:30 great tip! most use 1 turn since its seems logical, but 2 turns are in practice way better. Yesterday I converted my 800 transforemer from 1 turn to 2 turns, and its amazing - like 4-5x more power. ( i use a chinese 2000W(2$) AC Motor regulator, and i can melt nails when the Potentiometer is only at 20% power)
nice presentation, just one comment: You have to add the external loop also, so when you say you have one turn, there are actually two turns ther, one of then inside the trafo and the other is the one that includes the load.
I worked in a transformer, choke and inductor making factory for a while. We made devices so that they didn't vibrate and make noise, to improve insulation performance, and to improve efficiency. Some of the final construction steps were to immerse the devices in a bath of varnish, in a vacuum chamber. This sucked the varnish between the core laminations, the bobbins, and all of the coil windings, when the vacuum was released. Then they were drained and baked in an oven to harden the varnish. A similar process is used worldwide, using other varnish or wax. The downside is that transformers treated in those ways are very difficult to dismantle nondestructively. We often had older transformers, made by many different manufacturers, sent in for reverse-engineering and rebuild. That could be done least destructively by immersing a device in solvent for a couple of days, and then its core could be dismantled. The first 'E' or 'T' (for either 'E-I' or 'C-T' laminations) of the transformer or choke core would be drifted out with a thin drift, and then the dismantling became progressively easier. Bobbins could then be unwound, measured and turns counted, before being cleaned and rebuilt. In the light of this, your destructive method is perhaps the easiest one to adopt, if a winding can be sacrificed.
Does the transformer not hold a larger charge ? And thus is it not possible to die from such a comtact with it ? Or is your version just a steady voltage that doesent build ?
So with only 2 turns on the primary coil he gets a low voltage but a high amperage? And you can only spot weld using a high amperage? A normal transformer needs to achieve the exact opposite. Did I get that right?
Would a power cord from an oven (240v outlet) on a 60 amp line work as a solid base for an Arc Melting Furnace? (iron/steel/aluminum) Or do I need two such leads, cobbled together with two modded transformers for such a melter?
Love your smarts lol and when the unexpected happens lol I got a good laugh too it's good to learn new stuff or just look at it and wonder wow amazing always smile my brother cheers mate I'm from usa but knowledge is universal
Can you do a video with converting a fan cooled transformer to a transformer submerged in oil to cool it. I have seen it twice but the fear is naturally put into you about the obvious electricity and liquid, though the wires are insulated. So can it be done ??
I don't know how helpful this is, but mineral oil is used in transformers (like the ones up on the pole outside your house) and capacitors (like the one I just had to replace in my emergency generator). I don't know if you can use just any mineral oil (like at Walmart), so order the stuff that's made for it and you should be OK. Just make sure conductors aren't touching the sides of the container.
Hi Rob. Afternoon from Az. Great video! I've got a resistance soldering iron transformer left to me by my Dad that works very similarly from what I can gather. It's a 115 v to 3-4 v 400 va beast. As you might imagine it's a tad tricky to control for anything smaller than 16 awg. (Melts through bolts rather nicely just like yours! :) Any chance you might pop up an short addendum vid. on how to easily vary and control the power without changing the number of coils?
I'd considered a light dimmer, but In looking into them, it seems that there are several different kinds with varied internal methodologies affecting there operation. Also as you mentioned finding one that can handle the 1200-1600w the power supply can draw has proven to be a bit of a challenge & as Rob rather humorously noted in this video, "WOW haha! Didn't expect that to happen!!" I figured he might be headed in the "taming the beast" direction anyway. :) As I'm far from an EE, If you happen to know of any of those 4-5 component circuits that can handle 1200-1600w that you could recommend, that'd be much appreciated!
it depends which side you want to control mate - if you look at the input side you can control the input voltage which will 'down' the output voltage but if you want to control the amps on the output side you will need a power resistance that can cope with high 'burn off' - a liquid rheostat works well for that
I go well out of my way to salvage MOT's. Microwave Oven Transformers. Getting quite good at pulling the secondary winding's out of them. 20 minutes flat now. Slide a sheet of plastic between the two sets of winding's as protection for the primary. Hack Saw the secondary off both ends. Punch out what's left with a wood dowel. Here in the U.S.A. One 360 turn of wire provides 1v. 6 AWG Wire provides One (1) volt on secondary. Three turns makes fine Spot Welder.
Your input voltage in the USA is 110v ours is 240v so you have more turns on your primary that's why I need 2 turns on mine to do the same thing that 1 turn does for you.
I’ve got a Panasonic CT55JW it’s working fine apart from it’s Display, and then this .. fantastic , At least I know it’s all good parts !! Apart from the display walloped lol
Thats usefull. I small spot welder I can use to connect strips to batteries ... for example. Now, If I wanted a step down transformer to 20V or so I could attempt to use the original secondary winding as the primary and the primary as the new secundary. I know that is not working. But why ?
yes mate that is exactly what you do - it's a bit like sewing at scale - just feed it in and loop it round then feed it out and you keep on doing that until you get the number of turns you want - or will fit
Im sure they were plenty warm, but as far as the bolt, it's a relative bottleneck in between two other conductors with a likewise relatively/proportionally much, much lower resistance. For that bolt to "keep up", and it clearly can't, it must dissappate a wholllllee lot of that excess energy screaming through it faster than it's able to handle gracefully as heat. Lots and lots of heat. You'd get *exact* same effect if you were to have those same grips connected to some ~4AWG from the transformer, no bolt and just touching *them* together. Different magnitude, same relative bottleneck.
It's more resistive - remember V=IR. Current and resistance are directly proportional, increase the resistance and the current will increase. In this case it's localized in a smaller cross-sectional area at a higher resistive value = molten metal lava.
i wanna make a AC to DC welder conversion. i hear i need a inductor or a choke. how can i build one for 220v arc welder. i already have a full bridge rectifier
Hi Robert, great video thankyou. i have a wind generator that is producing 400v dc max spin. Would that transformer method work with dc? i need to bring voltage down from 400 to 14volts ish if possible.
We were often taught as small children to test electrical batteries such as the square ones by our tongues however when using bigger electronic devices i will say this isn’t the correct way. I kno someone who actually received a large sized jolt on there tongue from this and resulted in no taste for some food. Even some smells you wouldn’t be able to detect. Over time it has gotten better but i suggest making a simple light which can detect power. As we do not all have complex electrical detectors. This is my recommendation so always use caution. Also i have found its best to use a nice size rubberized shoe to protect one from things when working with high power such as electrical plugs. Hope this helps , voltmaster.
Please be careful with those things! You of all people don't need to be told about with microwave Transformers, it only takes one time! Looks like you're having fun stay safe! 👍😆
I guess I am a little eccentric I like to stick my tongue on my mot gives a nice numbing effect on the front of my brain thanks for letting me know its dangerous now I guess I will have to go back to smoking crack
no indeed - I do take the appropriate precautions but the danger here is the heat - on the bare wire side you have 2 volts - that's no where near enough to do anything to you - the 240 volt side is isolated from me - this is much safer than the original transformer was
HI THERE! How's it going my friend? I really liked this video!! I've been looking for a cheap welder and now I have one!!! Thanks buddy °° You're the best!
They should force all kids across the world. To learn from this man. He is doing amazing things here. I learned more in a hour watching his videos. Than all of school.
2 thumbs up and 5 out of 5 stars for you! Great description and very nice demonstration. You have answered the question I've always had regarding turns in the top coil and effect of putting more turns.. Thank you
I wonder how efficient one of these would be as a base for a power supply for a whole house LED power supply for exterior lights... Instead of running 120VAC around the eaves of the house for the typical LED bulbs, have actual LEDs mounted in the eaves ever couple of feet with a MOT powered low voltage line feeding all of the various LED locations...
The MOT I pulled out was wired backwards or something. The input coil was made of smaller wires and such and the output was the larger wires, so I ended up cutting the wrong one off
I want to tell you that if you apply mains to the high voltage winding you can then get 50v ac out of the old 250v winding without doing any taking to pieces. You should know that taking out the shunt core reduces the inductance and the mains winding then takes a lot of current and the transformer will get very hot even with no load.
thanks for the video. I've watched dozens of videos on this particular subject and yours is the best that I've come across so far. Thank you very much.
6:50 i thought 1 turn is better since it has more amps, but as shown 2 turns is in practice is better :) 3:30 i came to the same conclusion , this way is the best when you have to do it multiple times i used a round steel rod for hammering the wires out, but square is better offcourse.
Yeah, I thought 1 turn would produce more amps as well. I guess it's because there's more efficient transfer of total power (Watts) when more windings on both sides share the same field. In other words, that 1 turn would produce more amps if it enjoyed the same efficiency of transferring power (from primary to secondary) as 2 turns.
@@charlesrichards5389 no , the explanation is that at 1 turn (~1volt) the voltage losses are too hight at the contact point which reduces the currentflow. 2 windings are 2x the voltage and solve that issue
The nail melts and breaks and the result is Rob shitting himself as he jumps back in a split second. Fantastic video. I have been playing with transformers lately and they are great all purpose devices. I am wondering what would happen if you used a microwave oven transformer using the secondary as primary and visa versa. What would the voltage be? Also could a microwave oven transformer be used to make a large inductor heating element, turn any screwdriver into a soldering iron in seconds, lol
Yes, pull any current through a coiled up extension lead and it will heat up and melt the insulation. Big no no there, pull all the cable out and flake it on the floor, much cooler and a lot less induction..think of an air inductor !!! All the best Tony
@@ThinkingandTinkering First thing I noticed in Your setup - whoa what a big coil You've got standing there. My dumbass boss melted my extension cable being too lazy to pull the cable out. There should be an information how much wattage the cord can take extended and how much coiled, it's about 1/2 of the power whan coiled, before melting. Don't burn the shop down and keep up the great vids!
No - the currents in the line wire and the return wire inside the cord are equal and in opposite directions, so their magnetic fields will be equal and opposite, and will cancel out. (Google 'non-inductive resistor'.) Resistive heating only in extension cords.
@@brianspencer6397 Correct, you saved me from having to answer that one. Just think of the lawsuits that every retractable cord reel maker on the planet would be facing if they were susceptible to self-induction heating. Resistive only, spot on. I knew an electrician a few years back who liked to coil up about 2 feet of extra live and neutral wire (separately) in the ceiling when he installed lights - on every single can light, and he called them 'service loops.' I explained to him that the only service that was helping with was the fire department. He made them nice and tight too, then zip tied them up into neat little inductors. **facepalm** Not exactly what the NEC meant when they mention adding a service loop lol.
I have watched a lot of vids with mircowave transformers. The best really is a welder. However no one has really taken the time to look at the potential of this device. First it offers a household electrical system can be use to weld. Ok it would be considered mirco welding . And considering the millions of people who may actually just buy a mirco welder for home use welding the one millimetre thick steel for projects. The real question is after the device is worked out to be able to give amps and volts flow to the manufacturer to make some rods for it to be tested. Once tested this device could be manufactured by anyone as a business and rods then can be used to do anything for creative to amateur and professional tasks. I am really thinking ask you local rod manufacturers for some mirco rods to be made off the data collected. It is a win win for business and meets whatever demand is generated. Capacity to weld at home off a normal system is mindblowing. Let alone the vast creative projects it could be used for. If manufacturers don't help you contact the minister in your country or ask someone to just make them who has knowledge of how to make rods .I can see this device one day just being sold S a tool like any other.
It's not a single turn! The external connections complete a second turn. (you cannot make a half-turn BTW.) Same with what you called 2-turns, it is really 3 turns.
love that I found your Channel, really enjoy your videos, would you know of any other sources for such transformers, would the old TVs from the 80s have them inside? I'm a total newb to electronics and just trying to learn, my current fascination is with AC motors
hi there question because you stepped down the input voltage you got a high amperage which is why it melts the nail. You had a reading of about 2.3 V. That means you could safely touch both wires at the same time correct as long as it wasn’t hot previously of course.
All ya gotta do is cut one of the loop ends off drive a chisel or wedge behind other end with a hammer and even a wooden wedge will work, and presto it comes right out. I've stripped literally thousands of transformers for scrap copper.
Spot on, I've a scrap piece of teak cut to shape which I use in the same fashion. Mouse Milk also works a treat if you're not in a hurry. Coat coils and let sit overnight.
