Great Scott : experiments in this video show dangerous mains voltage... ElectroBOOM : so here I have a microwave oven transformer

Short answer: no Long answer: it depends *kurzgesagt bird breaks through the window*

I use these videos, to understand stuff taught in my high school where there is no demonstrations to motivate children to learn practically. I highly appreciate these videos...😍😍😍😍😍😍❤️❤️❤️❤️❤️

Ah, I spent hours trying to make transformers and having no one to explain it so well that it looks simple and logical. I wish you would’ve make this video 30yrs ago :)

I would like to see this guy collab with electroboom

I just learned more about transformers in 11 minutes than I have in 50+ years. I didn’t understand all of it but it has given me a foundation to build on. Thanks!

The conundrum of hysteresis, magnetic flux, resistance, and heat for the sake of electricity! Very well done video. Thank you. I love this subject.

This really could have saved my grade in Energy Conversion last semester

Super cool! I was just thinking that the layering "flaw" that happens when you 3d print something might just be an advantage when making a transformer core! Can't wait for part 2

3D printed xfmrs! Really looking forward to that video,

Wait,does this mean I won't have to travel to Cybertron to get a transformer?

Can you maybe bild a bike security system which makes a loud noice if somebody want to steal it? And yes I know that you've already built something similar for your motorcycle, but in my opinion it's too complicated and uses up too much power for a normal bike because you do not have a battery like a car or a motorcycle. I thought of a small circuit that you can activate with a switch and then beep when the bike is moved after activation.

Yay I was waiting for this great scott! Nobody likes to mess with custom transformers. High five and thumbs up!

3:52 : Smoothly introducing one of Maxwell's Equations without scaring anyone...

My first transformer was a rewound MOT for a 100W 808nm laser. Added linear current control with an output of 110A @ 2.5v. Was a fun project 🍺

It depends, do you think that tedium is hard? In all seriousness, I gave this a like, but there's a couple of things that people should be aware of. Your current draw on onside effects the current draw on the other side of the transformer, and it's oppositely proportional to the voltage change. Using the example mains transformer: if you draw 1 amp on the primary side, you're secondary side might have as much as 17 amps pushed through it. This is why the MOT spot welder took off a couple years ago on KZfaq; One high voltage path with an intermediate current draw can become a low voltage path with very high current, and thus heat, output. Also.. this is hints at some general best practice stuff: put lots of current limiting devices on a transformers primary, and voltage regulator stuff on the secondary side. Second, The UK limits the number of wire wraps you can get on a single transformer, and that can be good, because it's meant to limit parasitic capacitance. Without getting into a super long explanation, test your transformer for inductive spiking. A transformer isn't a motor, but it's still a large inductor. It has an inductive spike associated with rapid changes in voltage, and depending on current draw at the moment of power cut off, that can cause a significant voltage spikes on either side of the transformer. So types of transformers are prone to issues with inductive spiking.

I just remember my first power pack which was variable 1.5V, 3V, 4.5V, 6V, 7.5V, 9V, 12V with 300mA which i used to power almost every thing in my childhood! Finally it got very hot and magic smoke came out!

One semester of Electromagnetic Machine Theory didn't explain the subject as well as you did. I had to reteach myself almost every electrical engineering class when I studied to take my PE exam. Students would do well to watch your videos.

Perfect video to watch just before going to sleep 👍🏻

NEVER EVER hold one live pole in one hand and and another one in the other hand like this guy does! The current can stop your heart!

Hi GreatScott, overall a very nice video, good to see this kind of education content! I would like to offer some small technical corrections if you’re amenable. At 5:00, you say that the EMF induced in the primary which opposes the applied voltage is the reason the primary current didn’t agree with your complex impedance based calculation. This EMF _is_ self induction, and is exactly what your meter measured, and if the measurement were taken under the appropriate conditions, the complex impedance formula would give you exactly the mains current. The reason you didn’t get agreement is that electrical steel is a highly nonlinear magnetic material: your meter’s excitation current simply wasn’t high enough to replicate the (nonlinear) inductance that the mains voltage sees at higher excitation. You could point at the chart at 6:30 (or a similar chart) to show this: the line approximating the slope of the 0.3 T B-H loop is less steep than the one approximating the slope of the 1.2 T B-H loop. Or, a current probe/oscilloscope measurement of the magnetizing (no load) current would show the extreme nonlinearity of the typical mains frequency transformer. Also, at 7:52, you say that increased load current can push the transformer closer to saturation. This is a very common misconception. In fact, at higher loads, a transformer is operating farther from magnetic saturation. The reason is that the secondary current’s flux opposes the primary current’s flux, as you said. This ends up lowering the total core flux. You can work it out from the lumped element model by seeing that the load current reduces the total AC voltage across the mutual inductance part of the winding system, and causes larger voltages across the resistive (and leakage inductance) parts of the primary winding impedance. So the dPhi/dt integral of the mutual flux (which is equal to the mutual voltage) must be smaller, and peak mutual flux is actually lower. At 8:29, the formula you show is the formula for induced voltage in terms of _net magnetizing current_ (the flux that links both windings), not primary current. Magnetizing current is the difference between primary and secondary amp turns (at least ignoring leakage inductance, which is usually fair for mains frequency transformers). So that “I” should really be labeled “Im” or “Ip - Is”. Referring to the T model at 5:44, you can see how (in the lumped element model at least) the Lm element sees less voltage as the load current is increased, and so the flux linking Lm is reduced. The model is just a model of course, but the real behavior is captured correctly in this case. Edit: also, worth mentioning that the reason high power transformers use larger cores is really just so that the primary (and secondary) windings can be made with fewer turns of thicker wire, reducing the ohmic resistance and therefore reducing conduction losses, while still avoiding saturation at no load conditions. It's also worth noting that the volt-second product seen by a mains frequency transformer winding is a super fundamental parameter that drives core flux excursion as a function of winding count, and that practically we always use this method of calculating the core flux, and never use the induction formula, because the induction formula depends on the nonlinear resistance while the volt-second product applied to the winding is directly proportional to the change in flux linkage, and so tells you exactly how many turns and square centimeters you need to hit a particular operating flux.

A (almost) 3D printed transformer ? Very interesting ! About 15 years ago I was going to build a transformer, but the materials required (metal sheets and wire) are impossible to buy in my country if you are not a business (they only care about big money), so, I abandoned the project. Thanks for sharing !

😃😂 Lollll. I started laughing when you illustrated the winding of the transformer directly on the core. Genius, use a bobbin, even one built from paper will be helpful.

I've seen russian guys on KZfaq make a transformer core out of tin cans, it worked. The teaser you applied with winding a transformer-It's far easier if you build a bobbin out of thick solid cardboard, fiber glass or 3D print it, and as far as I know it is necessary for the windings to be winded tightly next to each other. Also you can easily calculate the number of windings by rhe cross sectional area and a few more sizes.

You have penmanship qualities better than most people I know. That with English not being your primary language(assumed) AND you're left handed. (That last bit being most impressive)

Now we are making transformer, awesome Scott

Well you pretty much summed up the bulk of my mechatronics course I took for my ME degree

This video was very dense with information. good. I will save it for future projects.

All Hail the great and powerful Sir Scott! Without you I would not have a job.

Great Video! One correction though: When you increase the load, the efficiency drops mostly because of the resistive losses (copper losses) in the windings. The more current you draw, the greater the voltage drop, and the less voltage the primary inductance "sees", therefore decreasing the flux density and reducing the saturation, not increasing it.

I love mains not switching transformers because they can do a lot of crazy stuff and their 50hz buzz is really calming

Scott finally came with a video that most KZfaqrs dont prefer to make ....Thanks scott

You might have measured the inductance with a frequency that's too high, iron core transformers are very dependent on frequency and will read a lot less when tested at higher frequencies. But I can't really see the frequency setting because it's blurry.

Useful video 👍 I like it

I love your content. You always explain everything perfectly and with proper maths. I have learned more from your vids than I did in college lmfao. Ty for your time and knowledge my friend.

there are some wrong information at 8:00 the saturation is not dependent on the current, it is the saturation that causes the high input current

In Argentina we learn to calculate and build your own transformer at the age of 15. It's part of a car battery charger completely made at state school. Mine has 13 year now and still working perfectly. Tip: coils are first winded up in a cardboard structure and then you insert the metal core.

Excellent video! Kudos on the clear language to explain the workings of a transformer and the sometimes pecular behavior and power consumption you get from them.

you are my go to for learning electronics

I have done an experiment with UPS transformer Connected 220volts mains to low voltage winding, the power draw was about 2KW And after i have brought the high voltage wires close to each other, it made a spark 1 cm long, and the watt meter showed around 7KW, most probably that would be greater than that. Within half of the second MCB shutdown And the experiment ended with a little smoke of glues used in the transformer.

Thanks For Covering Transformers. I always wanted to make one, particularly high-frequency-audio-split-center-tap (on 2ndry side) transformer with 1:2 ratio. Hope to cover more advance about transformers in future.! #StayCreative

Short version: The principle is simple. Putting it into practice isn't so simple, especially if you need a particular voltage and current. Basics: More turns of wire on the secondary than on the primary equals a voltage step-up with a reduction in abilty to supply current. The opposite is also true. And that's only the beginning.

For a 50hz/60hz sine wave transformer (the kind of transformers you plug directly into mains), you measure the surface (not the volume) of the core you are winding copper around (for an E-I core transformer, only the middle) in squared centimeters and then you divide 42 by your result, and it gives you the number of turn you need for 1 volt! If you don't understand you can ask me a better explanation by answering this comment!

YES ! .....This ‘ADVENTURE’ is the BIG ONE I have been waiting so long for ! I can not wait to see his efforts and final product/work ! 🧐🇬🇧🤔👍🏻❤️🤝🤓🤓🤓😍😍😍

Great video as always...... Waiting for long time for this type of video related to transformers and there calculation...... well want to see a video related to core saturation and how measure saturation point of an unknown core...... Well finally very informative video just of seconds but knowledge of hours.❤️

There are two main problems that you cannot avoid with "home made" transformers. First , you cannot get the core lamination properly done. I mean you cant tide the core properly and you cannot cut all laminated slabs at same size.Second, the coil/winding will be loosely winded around the core. All these problems are going to create noise and make transformer hot.

really complex formulas that took some people years to figure out, all brought into one video. and broken down so my dumb ass can actually understand it... thanks this is exactly what i needed. I have a transformer calculation app on my computer but it is really hard to use and doesn't explain the formulas....this was so good..and they thought i was never gonna need algebra again..lol

JLC PCB has sponsored a huge amount of videos uploaded by you I seeee, Great video 😃

5:45 it "uses" reactive power, which goes back to the mains. Actual dissipated power will be very very low when the secondary isnt hooked up

Nice video thank you keep making useful video information about electronics

I always wondered about this. I once tried to build a transformer out of a nail and some enamel coated wired. Except the wire was only 0.2mm diameter and the lowest voltage transformer I had was 16v. I apparently forgot that joule heating was a thing and the enamel coating melted and the primary winding shorted. Guess I could try again with a resistor to limit the current. They have really bad hysteresis, but for some reason I love the idea of making a transformer or inductor out of a nail. I even tried making an RC oscillator with a nail and enamel wire for the inductor and a capacitor I made by sandwiching a piece of plastic wrap between 2 sheets of aluminium foil and folding it up to take up less space. But unfortunately the capacitor was too leaky to be any use. But I was able to measure a capacitance of around 500nf. Rimstar is a good channel to browse for stuff on making your own capacitors.

Even on a masters degree, you will only touch on some of this theory, to design them, you really need to develop a program or excel spreadsheet to put in approximate values and use LUT from wire gauge charts. good luck.

I haven't studied electronics yet but I did understand what you said. Your a great teacher

I specially love that last line"Stay Creative"

Transformers are a type of toy robot that has become popular all over the world. They are easy to create and can be made from materials that are easily accessible. In this article, we will provide you with all the information you need to create your own Transformers. The first step is to gather the necessary materials. You will need some metal tubing, a hot glue gun, and some scraps of plastic or other materials that can be used for the body of the Transformer. The metal tubing can be found at any hardware store, and the plastic can be found at most craft stores. Once you have gathered the materials, it is time to start creating your Transformer. First, cut the metal tubing into two pieces: one piece that is about 10 inches long, and one piece that is about 6 inches long.

Waited for a long time for this video 😍

You are one one of the best electronics youtuber

My understanding is that most professionally built transformers actually wrap their coils around a paper or plastic "bobbin", itself put on a form of the same dimensions & shape as the part of the core that the coils will go around, so that they can be wrapped in a more convenient way before being transfered onto the actual core.

I used to make my own transformers baxk about 20 years ago, they worked well. Mine were designed for 25khz and up tho for switching power suppliy use. Calculated about 88% efficiency average on my diy transformers. Used to take the core out of commercial ones and rewind it for what i needed

Ah, glad to find this video.

Great video! Can you please show what happens when you put a capacitor across an inductor that exactly cancels out its reactance? For example the 1600 ohms reactance you calculated for your primary is +J, what would happen if you used a 1600 ohms -J reactance capacitor for that frequency? Does the output voltage continue to grow on each cycle until it arcs?

9:18 Alright mate, calm down 😂

@8:00 in the video: overloading a transformer DOES NOT lead to magnetic saturation! The flux density is the HIGHEST at NO LOAD condition & LOWEST at OVERLOAD condition. All of the voltage "sag" is due to resistance losses in the primary & the secondary. Overload condition: iron's job is EASY, the copper's job is HARD. No load condition: iron's job is HARD, copper's job is EASY. You can make a transformer transform CURRENT (to serve as a sensor). You wind a heavy wire only 1 (or a few) turns as your primary. You wind finer winding (with more turns) as the secondary. You put ammeter across the secondary winding, essentially SHORTING it. The current in the sense winding will be the meter reading x #primary turns/ #secondary turns. Because the secondary is shorted, voltages will be almost zero & so will be the core flux.

GREAT channel and awesome content as always

I'm confused by the explanation of why the current through the primary winding is less then V/Z. Because the back EMF induced by the current in an inductor is nothing else than the phenomenon responsible for the reactive part of its impedance in the first place. And a transformer with the secondary winding open is just an inductor. So, there must be something else that is causing that discrepancy. Maybe the inductance measurement was inaccurate, or done at a frequency other than 50Hz.

this is way of engineering, i enjoyed thank you ❤

at 4:29, you don't have to measure the resistance of primary like this: the value displayed on the voltmeter is impedance equivalent of your body and primary impedance of the transformer. the correct method is to supply the primary of transformer with a DC voltage and read the current value, therefore the resistance is the ratio voltage/current. thank you ;) .

I was looking for a vid to show me how to make a transformers transformer, like Optimus prime, but still, cool

What a great explanation! Thank U Scott!

6:41 Is that resistor the same Tomary used in his video of a heated table to keep the meal in the pot warm?

Fantastic presentation, thanks from Colorado USA.

I have done this before, Its very possible. But Like Great Scott Said, You basically have to Gut a Transformer and Rewind it to meet your specifications.

All hail the perfect machine, the transformer!

A long time ago, while trying to wind my own transformer I relaized that the efficieny gets much lower when you just try to randomly wrap the wire turns on to the core! The way you turn the wire around the core must be sequenced properly and in a way which strengthens the collective field of coil. This video repeats the same mistake which will definetely take a toll on the machine's efficiency.

Can't understand why anyone feels the need to dislike your vidz. I remember looking at most of this theory at college many years ago, but this is a fantastic refresher. Your explanation is concise, detailed and easy to follow, a powerful mix. And your diagrams are beautiful too.

Pls make a high voltage converter DIY or BUY video

Well that was great Scott 😁👍☮

Great introduktion..... ;-) Thanks for sharing :-)

Use a toroidal core and wrap wire around that. 1000x easier.

. You are a great teacher.

I enjoyed your presentation, thank you.

After watching the full video, it's feel like an electrical theory class by a professor.

I enjoy watching videos. I was also searching through internet to how to calculate winding turns. There were various formulas and calculators. But values they giving does not match nearly for transformers we saw in old televisions and ups transformers. Hope you can do a video about how to calculate number of turns and core area for specific power of transformer.

I was going to suggest that you use iron filament from Proto-Pasta, to 3D print an iron core. But right at the end you said that you're going to do that. Looking forward to seeing that video!

Microwave transformer is little bit weird... Its core is welded together and draws more than 1kW with no load but the output frequency shape is not a perfect sinewave but it's more like a square wave signal. This could be bypased by adding a second identical transformer , secondary in series because the number of turns in secondary is adound 240 maybe 250T so that makes the core sooooooo oversaturated and producing a lot of brumm ( this is maybe that reason why is welded ) and producing a looooots of heat even without the load.

2:05 Nice drawing. So perfect.

Hello, can you make a video on "ferrite-core" transformer... How to make a simple smps/adapter circuit with it (ac->dc)... and how to check it's properties... Please... There are very less info on that... Thanks...

I was waiting for this video Thank You Very much scott

Thanks for yourbexplanation i made my own small transformer,(step up).and it works well,thanks.

I was about to wind a transformer and your video shows up. Thanks for your precise timing i will buy a pre wound one instead of diying it

Thank you for the video =)

Thanks for your very good contents. Just one request please. Could you please create content about audio output transformer for tube (valve) amplifier (both of single ended and push pull)?

This video is so awesome. At my work we built a couple of Three-Phase transformers that were designed to transform 110VAC to 50VAC at 125Hz. We were struggling with saturation and we had to adjust the design of our system, thus increasing the operating frequency from 125Hz to 250Hz (not such a big deal since we were going to use a three-phase rectifier for those phase-phase voltages) This video was very educative. Can you please make a video explaining Generators or Alternators? That would be so awesome

More than meets the eye.

Also a winding technique that makes large magnetic flux but focused,in a different way

You can get steel sheets from Delatsch electronics.

Grazie per la lezione

Great video, I wish you did it a couple years ago! I can't wait for more!!

Video idea: Circuits/techniques to measure high resistances in the 10M to 10G ohm ranges? I'm currently looking into this myself and would love to see your approach.

Just discovered your content 🙌🔥🔥🔥🔥🔥🔥🔥