12V 50A 600W power supply - (re)winding the transformer

Today, let's rewind the faulty transformer of my 12V 50A 600W switching power supply. I wound it partially the original way (with some original shortcomings), just using copper instead of aluminium, and splitting the secondary into more parallel wires, leaving the original design of the primary. Of course it could be redesigned much better, fitting higher cross section of copper into it to reduce the current density. It could also use many more of thinner wires to further reduce the skin effect. The returns that waste space could be eliminated by winding each section in two layers. The secondary could be a copper strip which is more space-efficient for high current low voltage windings.
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• 12V 50A 600W power sup...
Previous episode - failure analysis & transformer autopsy:
• 12V 50A 600W power sup...
First episode - the teardown of this power supply:
• 12V 50A 600W power sup...
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[@MegaSunRise3]

It was fascinating to see you working on that transformer. Very good job fitting all those turns in there!

[@DiodeGoneWild]

I think I could have fitted 50% more copper into it :). But it's always tricky and you never know if it fits or if it hits the ferrite core :D. The layers always take more space than on paper.

[@raffaellobottoni871]

@@DiodeGoneWild i do agree with you.

[@I_like_some_BG]

​@@raffaellobottoni871*me too*

[@FulvioGa]

Yours is the best electronics channel on KZbin for me.

[@RubixB0y]

This channel is seriously the best practical knowledge channel I've found on KZbin. Taking the dark arts like switching power supply failure analysis and actually making it understandable to those with some background. Not to mention the presentation is so entertaining and engaging! Thank you so much for your work, it's appreciated greatly :)

[@brookerobertson2951]

Learnt more about transformers in this one video than i have watching all other electronic videos for the past 10 years.. big Clive and eev blog must have been letting me down... Lol... Thanks for another informative video.. you rock dude.. 🤘

[@xcross8537]

Dr Donkey is the best 👌

[@leeselectronicwidgets]

I’m addicted to your videos, partly to see when you say ‘dodgy’, and ‘bloody hell’ in your melodious tones!

[@WagTsX]

I am still wanting to know how many amps is that mains fuse that didn't blow up when the PSU got shorted and tripped the 16A breaker. Can you check it?

[@DrHouse-zs9eb]

Highly underrated comment. I hope he will read it. He could test it quick in the intro of the next video...

[@iaaqob8318]

Something like 10A probably, fuses in power electronics are usually the last thing to blow though :P And, with dead short circuits like that, the circuit breaker operates significantly faster than a regular fuse, not giving it time to melt.

[@SianaGearz]

@@iaaqob8318 Ya but still curious whether fuse is genuine or whether the uncle from the back street behind Shenzhen market sold you fake ones.

[@omsingharjit]

@@iaaqob8318 yes , right it only blows whenever Rectifier gets internally shorted

[@keithking1985]

@@iaaqob8318 i was about to same the same thing. you said it perfect. in England and here in Ireland we normally have 13A fuse's, but this been a China job its hard to know they have put in there!

[@ERIC-65]

This Transformer became a piece of ART!

[@ERIC-65]

@Agustinus Reynaldi 🤜👊🤛

[@Random_4400]

Yeah definitely

[@brancarr1]

I have never seen anyone, who does videos on KZbin about electronics, explain in such detail every step like you do. Thank you for your videos. Your knowledge is astounding! Cheers from the USA!

[@d-riuz7402]

This is simply unsurpassed professionalism!

[@prathikprashanth2932]

im so glad that you re-wound it. that was so cool.

[@tim0steele]

Very pleasing to see you rewind the transformer instead of just scrapping the power supply.

[@zx8401ztv]

You have just improved that switchmode :-D Less loss in the wire. Any slight difference in the turns will be cancelled by the opto feedback voltage correction.

[@crusaderanimation6967]

DGW: This transformer is super dogy ! Viewers: Them do it better ! DGW: Do it better. Viewers: Aren't surprised but are happy.

[@zaidhussain5206]

Agree , can you do it better please ?

[@IkmalRusli]

why I like this channel 1. Cats 2.Funny accent 3.Your freaking genius

[@rastapaez3992]

We all already know this is the best channel on youtube. But just incase, he made this......... pure GOLD.

[@Miata822]

Fantastic video! We've seen lots of dodgy coils. It's great to see how it should be done properly and to understand the difference.

[@Shmbler]

Excellent video! Its a shame that the transformer died before you could do any efficiency measurements. I would have loved to see a before-after comparison ;-)

[@DiodeGoneWild]

I kept roughly the same cross section of the windings, so the losses in the windings would probably divide by 1.6 (thats how much copper is more conductive than aluminium). The core losses would remain. But the losses in the transistors and secondary diodes are probably an order of magnitude higher that the transformer losses. I think I wouldn't even notice the difference in efficiency. The transformer losses are not the most important factor for the overall efficiency, but they are important for the reliability of it.

[@Shmbler]

@@DiodeGoneWild Thinking twice about it - yes you're right. The transformer losses can't be generally very high, as it could hardly get rid of the heat anyway. So it only takes comparably small losses/little heat to destroy the transformer.

[@joinedupjon]

I was sure it was going to end up too fat to fit back into the same core, which is what happens to me... it's probably cos I don't have a cat to supervise my work.

[@claytonmorgan8625]

I'm a noob when it comes to electronics, always enjoy watching your videos. Keep them coming. Thx for educating me!

[@BogdanSerban]

The end tape is called "margin tape", they sell it on ebay/aliexpress. By the way, can you do a video on calculating the number of turns for a transformer?

[@peckelhaze6934]

I, also, request calculating number of turns.

[@johncoops6897]

@@peckelhaze6934 - Ratio. For example, 10 turns primary and 20 turns secondary = 1:2 so that would step up the voltage by a factor of 2.

[@khayyam741]

Yes No. of turns calculations please.

[@iaaqob8318]

Good idea, a short tutorial for designing own transformers. If interested in that though, I recommend reading the "Power Supply Cookbook", all important information contained therein.

[@ToBeDefined85]

Yes, please a video how to calculate the number of turns for primary and secondary for a given transformer core. BTW: I love his videos!!!!!

[@adaniel69]

No fire extinguisher????🍻🍻 Thanks for rewinding the transformer! I've requested in last video!

[@rajendra2345]

Love your voice....bro...the way you speaking....i loved it and....Enjoying every video of you...nice and unique information every time...and I m from india...

[@andytipping70]

incredible - i learned so much - thank you for acceding to our request.

[@zaidhussain5206]

Thank you for doing the winding with a lot of useful notes regarding .

[@Ricksp65]

I’m a woodworker but I am learning tons about electronics it will come in very handy in the future thank you very much.

[@datech6274]

You're the best I have seen on KZbin. Congrats, keep it coming.

[@antibrevity]

Thanks for the awesome and informative transformer rewind! This is currently one of the best electronics channels on youtube and that's coming from someone who watches a lot of them. You obviously know a lot about this stuff and I like your unique presentation and editing style; even the drawings are great.

[@esunayg]

i will be a patron for doing this. love you!

[@RicoElectrico]

7:41 Kapton tape (the real one at least) won't melt. Back when I was an intern at some company I'd try to burn it with soldering iron, but to no avail.

[@godfreypoon5148]

I got fake kapton tape once that actually burned with a flame when I put a 400degC iron on it.

[@chrisg6597]

You're right, it wont melt. The first time I saw Kapton tape, (about 40 years ago) it was being used to cover the gold plating on pcb edge connectors prior to the boards being wave soldered.

[@SianaGearz]

This material cannot melt fundamentally, also Chinese KOPTAN tape. But it can degrade in high heat. After a long time, more molecular bonds are broken, and it becomes brittle and crumbles. It can be rated for long term use at 150-200°C and short term use to 350°C or so, very short use for higher temp yet. Adhesive can give up with temperature too and turn darker, it's basically latex.

[@iaaqob8318]

The smell when it burns, tho Ugh!

[@omsingharjit]

250 ℃ rating of Polyamide Tape

[@GAURAVKUMAR1019]

Great video! Sir You are a rare combination of genius and hard work at once. Please make a video explaining fast chargers(20w, 30w, 65w) for mobiles.

[@AdemirSoares294]

parabéns amigo! você é o unico que teve sabedoria e esforço de nos presentear com sua inteligencia aplicada nas fontes chaveadas ou seja power supply switing

[@DuroLabs85]

World's most safest transformer :D

[@voltlog]

Really useful info showed in the rewinding process of this transformer!

[@keithking1985]

very happy to you fix that one! : ) and as always knowledge been shared... THANK YOU!! D..

[@micaiahadams659]

This is my best electronic tutoring channel. You're doing a great job keep it up! By the way, am really looking forward to the working principle of the oscillator and schematics thank you.

[@MikeB_UK]

Really great that you took the time to do this for everyone who commented. A super non-dodgy job! Well done.

[@krahaborowski]

Great! I would leave the connection between parts of primary at the other end of a bobbin, to avoid that return-run back to first side. That connection would not even need a pin, it should be easy to join and isolate it somewhere far enough from secondaries connections. That would make windings smaller and easier to fit inside the core.

[@anshchawla566]

Damn you never dedicated so much time toh a single topic

[@hullinstruments]

Would be fun to see you wind a massive DIY isolation transformer. Like one of those huge one that sits on the floor in a lab. There are some great videos on KZbin showing guys making huge 5 to 10 kV transformers using cores purchased from eBay. Would be awesome to see you make one for isolation for use in the lab. Your attention to detail is great… And some of us could really use a massive isolation transformer in our laboratory

[@mik310s]

Best vid I've seen regarding how transformers work

[@florabee9283]

I learned more on this video than I did in a month of college physics!

[@peckelhaze6934]

Koptan Tape, hahahaha! I am researching winding my own SMPS Flyback and within minutes you have taught me things I didn't know.

[@LucasPereiradaSilva]

DGW mastered High-frequency black magic. As a technician, I find it scary.

[@snakezdewiggle6084]

Great vid, thank you. Many years ago I re-wound a transformer. It had 18kg of copper.

[@f4tboy99]

Good job! Don't worry with the transfo, this one is like 54% bigger than the original so it can handle 50 amps easily! 🔌 💡

[@l_szabi]

That's some really satisfying work! Thanks for responding the comments and making this video!

[@two_number_nines]

21:03 I thought so when I was younger, because it sounds logical that the turn ratio*current trough each turn should be the same constant, therefore the cross section sum should be the same, but it turns out not to be the case. The more windings a coil has, the more cross section it needs, because more turns=longer wire, therefore you need to compensate with thickness. This problem is very underlined in microwave oven transformers and any high voltage transformer. Furthermore, when making arc welder mod for MO transf. if you put 3 turns secondary with half the cross section of the primary, the primary will overheat faster.

[@barnabasnagy9595]

I love how he says bobbin :D

[@jmikronis7376]

When winding switch mode transformers, one must use a copper coated wire due to what’s called the skin effect where the electron flow occurs only at a thin layer at the top of the conductor. By using solid copper wire, the inner portion of the wire is not being used. This skin effect becomes pronounced at all radio frequencies. This is what caused the development of Litz wire. At higher power levels, copper tubing is used.

[@omaralkassab9079]

I can't wait to see the schematic of this SMPS, and listen to your great explanation of the SMPS. Please do it with your new camera :)

[@ronniepirtlejr2606]

Electrical Magic done, Diode Gone Wild Style!👍 Amazing job!💡🐈

[@jstro-hobbytech]

You should do a series where you make a series of low power psus showing the different topologies. Use parts that are harvested from old psus and use the tny297 ic as the controller. It would be cool to build reference designs that are safe and simplified. Id love to build a few 5v smps circuits. I understand the feedback through the opto but biasing it correctly and where to place the snubber network is what gives me pause. I have tons of parts and an isolation transformer for testing. Id never implement the circuits but id fully understand them when i repair vintage psus for game consoles. There have been times where i should have built a simple psu instead of replacing all the parts that degraded over time. I do it as a hobby so they dont end up in the trash. Ive saved all the transformers and have the tny297 ics on hand. Ive replaced most of my components with ones from digikey or authorized resellers. Id be willing to buy some diodes and such off you if you want to make a few hundred bucks. I build guitar pedals as well and testla diodes cost a fortune. Haha. Sorry for rambling but i love psu design.

[@Tigrou7777]

18:44 SCAAAAARYYY !

[@garrygemmell5676]

I was thinking the same!

[@bottering_one]

NIIIIICE

[@alancordwell9759]

That's done properly, as it should have been to start with. Nice job!

[@jjcaruso44]

Great job. You are a great engineer.

[@MrAREZ3]

Excellent video, I love your work and the manner you present it each time, thank you !!!

[@BrucesWorldofStuff]

Wow! Nicely Done! That is a thing of beauty the way you laid those wires!! :-) I have a 30 amp version of this supply but never pull more that 12 or so amps BUT I will save this video in my "Watch Later" In case the transformer goes poof! Then I will know how to fix it... LOL Thanks for rewinding it and making it work again. Made for a great series! Thanks for the video! LLAP

[@randydicotti3975]

Subscribed. Love your explanations and your accent. Very good stuff. Thank you!

[@PrasetyoMuhammadDwiBiology]

this video deserve to be in youtube rewind😁

[@mcg6762]

Would be very informative and enjoyable to watch you try to increase the efficiency of that power supply by replacing components for better ones, using more in parallel, increasing conductivity of traces etc. Really liked the video!

[@stanimir4197]

The power supply lack active power factor correction, that should have been the 1st thing to address. I doubt he'd go to lengths of adding rectifying mosfets on the secondary.

[@sidyajv]

19:28 what are those medals for behind the cat?

[@englishrupe01]

Feline oversight achievement awards!

[@laurilink7512]

You can put also little pill of aspirin and then put wire on top and heat this wire with soldering iron which is coated with tin. It generates no very good smell, but cleans this lacquer from copper and also makes a nice tinned result. You can't remove lacquer from very tiny cables with knife without damaging wire.

[@garrygemmell5676]

Haha you never talked liked this when you started - its a perfect example of exaggeration for effect and it has worked remarkably well for you Diode! To je dobré, môj český priateľ, veľmi inovatívny pre anglických divákov / zemiaky! >;o)

[@Sonic-sv5gp]

Danyk please, how do you determine the orientation of the individual coils (green dots in your drawing)?

[@Mladjasmilic]

By looking into it. There is left hand and right hand coil. For example, normal bottle caps are right hand, but for dangerous stuff, like chlorine acid, are left hand. Direction of coil winding is not important as long as their relative winding orientation is as specified. Dots mark this.

[@Sonic-sv5gp]

@@Mladjasmilic Thank you for answer.

[@ZeroExperienceWelder]

Hey, Drop that gorgeous ETD and switch to PQ core - you'll love yourself for it!

[@TomaszStachewicz]

the judgmental cat needs his own voiceover 😀

[@franzliszt8576]

Her

[@nirajsomai9957]

Very Great efforts Sir. I really Appreciate your Efforts.

[@noanyobiseniss7462]

Why are toroidal transformers not used in these fast switching applications?

[@jimadams7765]

Great tutorial on transformer windings. Thank you.

[@jeanlesueur6936]

I was pretty sure that you'll try to rewind it. Nice job !

[@crusaderanimation6967]

7:24 Oh yea, i know this feel bro, i wind some time a go my first Switch mode transformer and after winding primary, secondary BARELY fit inside ferrite core.

[@godfreypoon5148]

And you use secondhand wire and try to pull it tight to make the wire straight and neat, but you break the bobbin... I know these feels too.

[@crusaderanimation6967]

@@godfreypoon5148 or when you try to remove licker using sandpaper but you hold it too tight so when you make a another pull instead of grinding licker you brake peace of precious wire. I know there is trick with soldering iron, to remove licker and thin at the same time but somehow i'm just not able to to do it right and licker stands still.

[@godfreypoon5148]

@@crusaderanimation6967 Oh yes! The trick is to turn your temperature controlled iron up to 480degC... but then you forget and it ruins the tip...

[@anmolkumar6704]

Make a video on the schematic diagram and explanation on how two switch forward work?

[@TerryLawrence001]

Awesome! It's like you can read my mind! I am pondering buying cheap dodgy stuff just for the fun of fixing them! You do great work :-)

[@hullinstruments]

This is what KZbin should do at the end of each year….. they could call it ……”rewind“ 😂

[@Throttler007]

Thanks lot dear friends good knowledge you have shared lots of love and thanks for sharing this❤❤❤❤❤

[@piconano]

Can't wait to see the next video on this.

[@hernancoronel]

Loved it! Thank you!

[@andreluizpiva39]

Greetings from Brazil, nice video!

[@6siqueira]

You are the best of the best

[@saadr2208]

Good work Dan. Thanks for the video.

[@ManuelGonzalez-tc1bl]

good job rewinding that transformer and improving it!!!!!!!!

[@Agent24Electronics]

Nice job, nice video! I enjoyed it greatly and some good tips on transformer winding. Also, it seems wise to de-rate eBay power supplies to about half the labelled current!

[@peterpiso7384]

Great video very glad to see you rewire that transformer. Keep up the great content.

[@DigitalBhangari]

KZbin archive now contains “how to wind a transformer like a pro"

[@richardnanis]

In older books for transformer formulas you can find the max. current density on the copper windings with a factor of 2,5 per mm2. So for 8 x 0,8 mm2 windings you have 2,5 x 6,4 = 16 Amps max. continous! So the 50A are even much too much for pure copper! It would last quite a bit longer but is still not enough copper for 50 Amps cont. One small correction on the power dissipation of aluminium over copper: The resistance of alu is 1.6 times that of copper - but the power increases with the square of the resistance, so its 1,6x1,6 = 2,56 :-) The efficiency increases by a factor of 2,5 - nice!

[@TradieTrev]

You mad man! Love your work!

[@RavenLuni]

Nice - very informative :) I'll put this knowledge to use rewinding some transformers from my drawer full of old chargers (which everyone has) - nothing dangerous of course though :)

[@undefinednan7096]

Thank you for making this video, it was very informative.

[@hisheighnessthesupremebeing]

With that thick accent I was looking forward to "It's alliveeeeE"

[@eded8045]

After so many requests thanks....can you rewind the inductor now and pre and post test on supply efficiency tabulated would be a great exercise )))

[@snhongo1]

great video .have learn a lot

[@ChervyakovTheodor]

Excellent video! All the best

[@omsingharjit]

What is the impedance and inductance of MOT primary Winding for 220volt 50hz Ac 1000 watt ?

[@Shadow_of_STLKR]

17:45 I think this will make opposing magnetic field in wire and cancel current or make heating choke. I think electroboom mention that. As always teaching video, thx

[@undefinednan7096]

He's still winding it the same way, just going downwards instead of upwards (so if he started counterclockwise he'd still be going counterclockwise, just downwards).

[@lgiannatasio]

gostei muito, vi o alto rendimento do seu trabalho Luiz do Brasil

[@lmwlmw4468]

Great work with that transformer.

[@keithcookman2918]

Your so proficient at winding transformers. Would you ever wind your own speaker voice coils, to discover limitations? I believe flat wire is used... maybe not always copper, sometimes other alloys.

[@michaelfisher9671]

Very interesting thanks Dany. I know you probably don’t want to risk your newly wound transformer but it would be interesting to see you test this at 100A, even if just for a short time, to see if it starts to heat as far as the original. You say “of course” too much.

[@sidewinderam9m]

Where do you get copper strip for this application? I have never been able to find it. You can get a pretty good idea of temperature rating of the coating by holding a lighter to the lacquer of a known temperature rating and then on the unknown wire (it takes significantly longer to burn high temp coating). Also after a few times of doing this you can begin to tell the difference between PU and polyimide coatings, they burn off differently and smell a bit different as well.

[@johncoops6897]

He actually TELLS YOU IN THE VIDEO where he got the copper wire.

[@sidewinderam9m]

@@johncoops6897 I didn't ask where he got the copper wire.

[@johncoops6897]

@@sidewinderam9m - Your sneaky edit to change the word "wire" to "strip" doesn't change what you originally wrote (and what I replied to). OK, so he didn't use "Copper Strip".... so why ask your (new) stupid question?

[@sidewinderam9m]

@@johncoops6897 He actually TELLS YOU IN THE VIDEO that he if he wanted to be more serious about it and further reduce the original shortcomings then he would use copper strip as one improvement.

[@ithalkomedi1513]

Finally 😁 i was just waiting this thanks a lot diodegonewild 🙏