How does a modern Power Supply work?! (230V AC to 5/12V DC) DIY Flyback Converter!

[@realdragon]

Wurth Elektronik: Do your best Great Scott: *Cuts transformer in half*

[@robert_g_fbg]

DIY == Destroy It Yourself 💥

[@legominimovieproductions]

Flextape can't fix that XD

[@Mr_REBA]

kzbin.info/www/bejne/j6WsY2xqmM9-g8U

[@jainvibhore1997]

"Do not build this circuit! With that being said, here's the schematic" -Great Scott XDD

[@greatscottlab]

Everyone should have the access to knowledge ;-) But a warning was still necessary ;-)

[@Paul_EEB]

It is not a bad circuit to build. It just missing parts that make it a compete power supply unit, and it should not be used as a power supply.

[@oraszuletik]

Dodgy! 😉

[@tvishmaychoudhary69]

@@oraszuletikDIODE GONE WILD!!

[@VijayaLakshmi19807]

@@greatscottlab Hi sir. Sir please hack an AR glasses to work on a HDMI input even if the whole setup becomes bulkey. Bigg fan. Love from India ❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️

[@melchiortod29]

That's like marketing to the next level! Love that!

[@greatscottlab]

Well, I wanted to do a video about SMPS and they wanted to show off their transformers.....I would say that is a good match ;-)

[@analoghardwaretops3976]

.." this is not a promotional pitch..but in all fairness I can say this ( though we were really small customers ) Wurth Elektronik do have " high quality & reliable components and are real serious business partners... despite we using a limited range and quantity of their products...they went " all out " to respond to our doubts/queries/ end use applications..and sent their team over with substantial dev. kits/ catalogues etc. besides follow ups..

[@nickwallette6201]

I am ALL FOR THIS. I have a pet project I'm trying to learn up to... I've got a shelf full of game consoles from the Famicom to PS4 Pro. I want to install a high-power 24VDC supply and use isolated switchmode supplies to step down to what each machine needs... 3.3V, 5V, 7-9V, 12V, and so on. (Isolated to prevent ground loops and issues with systems that raise "ground" to a diode drop above one leg of the input jack, like the NES.) In my research, I've seen planar transformers that use stacked PCB layers to provide galvanic isolation. Since the design is kind of tricky, they're also available as drop-in modules from trafo manufacturers. But, magnetics selection is non-trivial, and I still feel completely lost on this topic. It's really the last domino to fall before I can start building some POC designs. So, please! MOAR TRAFOS!

[@inothome]

Great video as always!!! Ignore the YT analytics, if they still show poor results. It's not you, it's them and please don't change your style to try and appease the algorithm. . We're all here for the quality of videos you have always done and this is a perfect example.

[@greatscottlab]

Well said! Do not worry. I will keep making such videos as long as I can ;-)

[@WarriorRev6300]

Those waste fake yt videos with crazy thumbnails are making it to yt algorithm.

[@nickwallette6201]

I would love it if content creators banded together and created a wash of "Shorts" that were titled "do not watch this - nobody asked for it, nobody wants it, this is a waste of time." 30 seconds of vertical video paint drying, grass growing, and similar pointlessness. When the viewing stats are complete garbage, maybe YT can butt out of trying to dictate content.

[@eepydragonloaf]

Already suggested your channel to all my nerd friends :) great videos. Keep up the great work!

[@thebamplayer]

Can you make a video about active power factor correction, because it's an important topic with switch mode power supplies. Due to it's big capacitors.

[@greatscottlab]

It is on my to do list :-)

[@user-qf6yt3id3w]

Active PFC is fascinating. I think it's just using PWM to draw a sinusoidal current so the current is in phase with the voltage but there might be some more clever stuff going on. What would be interesting would be to use a microcontroller to do sinusoidal PWN synchronized to a zero crossing detector and see if that performs as well as a commercial APFC chip. I suspect the commercial chip is doing something a bit cleverer than this but it's not well documented. Basically a 'Buy of Build' for active power factor correction.

[@axelBr1]

About 10 years ago I had to simulate an oil refinery electrical power grid. Was a struggle trying to understand how a generator's AVR goes from changing the generator's voltage when it's the only generator on the grid to changing the reactive power supplied when there is more than one generator.

[@sulochanakharat9033]

@@greatscottlab sir please make vedio on "how to use lab bench power supply basic to professionally"🙏🙏🙏 (I request you)

[@user-qf6yt3id3w]

@@greatscottlab Awesome! Looking forward to it.I don't suppose you know any good discussions of Actice Power Factor Control algorithms?

[@fuadmammadzade1213]

Wow, I have watched dozens of videos about SMPS before, but this one really made the subject to click.

[@greatscottlab]

Brilliant :-)

[@sumitkumar12]

So true, this was the best explanation

[@NilsRohwer]

Fascinating, I'm very happy to have this video from you. I have wondered about Switching mode power supplies for ages, and to have such detail is great - to be fair, I'm 1:03 in, but I know it'll be good. Edit: I was not disappointed! Thanks.

[@greatscottlab]

Glad it was helpful!

[@edoardocastellaneta271]

hi, great video as always. just keep in mind that in case of flyback topology, we aren't really talking about a transformer: since there is a high reluctance gap, a flyback trasformer is more like two mutual inducitors with a very high coupling coefficient.

[@kelvin1316]

Me: "hmm yes, I see" My mate: "you have no idea what's he is talking about do you?!" Me: "nope he lost me at 'reluctance gap'!" Hehe 😇 💚

[@Henry-fv3bc]

Meh most would still consider that a transformer. RF transformers can be completely air core and we still call them transformers.

[@edoardocastellaneta271]

@Joseph Bunn great explanation, thanks!

[@The-Master-of-None]

When Scott says "RIGHT?" The answer is "NO". Great content as always! Thanks for sharing your knowledge.

[@L2.Lagrange]

8:56 what an absolute madlad lmao. Props man

[@chuckthebull]

I have been fixing these for years by changing some of the caps..I had a good idea how they worked and you defiantly boosted my understanding of them even further... lots went into the design technically.. thanks

[@MrTacoSr]

sometimes I have to rewatch these videos because I get so caught up in him writing and labeling so perfectly with no mistakes

[@samim6523]

I am helping with KZbin algorithm, I am watching again and again. LOVE YOUR CONTENT

[@greatscottlab]

Thanks for the help :-)

[@samim6523]

@@greatscottlab my pleasure

[@TotallyNotJason101]

Thanks Würth elektronik for us to learn more about Switch mode power supplies!

[@ucan-diy]

Great work! One of the best channels on KZbin!

[@greatscottlab]

Thanks :-)

[@David-zu5tp]

9:24 Full Bridge rectifaiaa Good job GreatScott!!

[@greatscottlab]

Thanks :-)

[@MrJugsstein]

I'm coming to electronics later on in life. Your tutorial have to be the clearest and most well explained. Really enjoy and get so much from your videos. Thanks for your time.

[@greatscottlab]

Glad it was helpful!

[@vidulabeywickrama7852]

U really deserve more sponsors.

[@FINALASTXTN]

Finnally somebody goodly explained a flyback converter

[@greatscottlab]

You're welcome :-)

[@LimbaZero]

I usually use bare wire to do these prototyping circuits. Saves some solder and less headache of solder bridges.

[@philipatkinson1532]

Thank you. I have a big box of these I bought eBay as a mixed bag for £1 ages ago and having tested the coils resistances was puzzled. The box remains! I will try testing them with low voltage at 60kHz Might be more informative. Very good explanation. I vaguely knew how they worked. Now I know more :)

[@thatoneguy99100]

I really love Würth Elektronik's products, and I love them even more for sponsoring you!

[@mohammadrezamim272]

Best channel in this topic is DiodeGoneWild.

[@hobbyelectronics2121]

The best description of flyback transformers ever :)

[@varunrmallya5369]

"..........with that being said here's the schematic."- the reason I love your videos

[@heatsingh2205]

That's if you want to build a professional one users descretion is required

[@twistedshadowsaf]

This makes understanding those circuits I copied down from circuits I worked with before alot easier..

[@DonkenAndToivolaRR]

Just can't wait for the video on the TL431. I'd love to see, how I could use it, to regulate the output of a dc-dc converter (which aren't so different from smps). For example to battery power a microcontroller based temperature logger.

[@sauritinfo2248]

Great, I was looking for this topic from may days.thanks to German friend from India. 😀😀😀

[@GeertGoossens]

well despite the fact I know how a SMPS works in theory, I didn't know about the specifics about the transformer windings being opposite and the fact it's basically using the charge / discharge of such transformer... I always thought it was due to high frequency switching that it worked like a regular transformer but was just smaller because of the higher frequencies and the square wave... :)

[@greatscottlab]

The more you know ;-)

[@analoghardwaretops3976]

....windings being opposite... is for " flyback " mode only...also duty cycle cannot/ should not exceed 50%...

[@ShinyMajor]

@@analoghardwaretops3976 The flyback can go to as high of a duty cycle as you like within the practical limits of maintaining control, as long as the switching transistor can handle the reflected voltage. I think you're thinking of the forward converter, which is one where you can't exceed 50% with the standard design

[@analoghardwaretops3976]

@@ShinyMajor exceeding 50% , the volt/ sec. balance in off- to -on may not be achieved..and can lead to core saturation even in boost/ flyback modes.. leading to gradual residual flux buildup... so when it's @ the extreme limit of the hysterisis curve..the next turn on pulse ..in its first few hundreds of nanosecs.can destroy the sw. with uncontrollable current.. Chips for flybk./ boost have an internal divide by 2 f/f to limit max. duty to 50 % .. example..compare data sheet for internal blk.dia. of 3842/43 or other..

[@__MINT_]

6:23 Well, actually the mosfet can get overvoltaged even if the leakage inductance is zero. Here's an example: we built a flyback SMPS, that converts 325V DC into 12V DC. The transformer's ratio is 20:1, and Vd-s(max) of our mosfet is 500V. Whet the mosfet opens, the energy from the core gets transfered to the secondary side, where we have 12V, so the voltage on the secondary winding is about 12.6V (due to fast diode's voltage drop). Knowing the transformer's ratio, which is 20:1, we can calculate, that the voltage on the primary winding is 12.6V * 20 = 252V. This voltage adds to 325V, that we already have on the mosfet's drain, so at the end we have 577V there! As you can see, the 500V was exeeded. Even the 600V mosfet wouldn't be enough, because of the leakage inductance, which also adds some voltage to our 577V. To solve the problem, we could use a transformer with lower ratio, for example 2:1. But here another problem begins: when the mosfet turns on, the voltage on the secondary diode will be 12V + 162.5V = 174,5V. Our diode have to maintain this quite a high voltage. That is why we have to be careful when it comes to choosing a transformer, a mosfet and a secondary diode for our flyback power supply. In a described example, optimal transformer's ratio would be 5:1

[@analoghardwaretops3976]

Voltage wise factor of safety..2.5 x.. (+20%consider input o.v. condition) so( 325+65 )× 2.5...but now new device rDS " on" will be higher...

[@IrishSkruffles]

Very good points, thanks for sharing

[@AnilChoudhary244]

From all of your video, this is the first video which i felt has less content and knowledge. I think it can get more informative... Apart from this, i love your video, always get something to learn.... Thank you sir.... ☺

[@SudhirKumar-bq4xz]

Man you are my virtual teacher.... ❤️

[@greatscottlab]

Happy to help!

[@mirko4757]

Feel like a traitor for missing out on your content lately, you still do an amazing job but I have a long way to become an engineer(like 2 years)

[@johnemanuel5593]

Clearly understood.... It was too hard to understand about smps.... Thank you it was helpful... 😊😊😊

[@alext5310]

Nice, something interesting to watch while waiting for the F1 GP to start, haha

[@InterFelix]

Exactly...

[@JSPHism]

I already lost hope lmao I honestly want to see a good race without rain

[@SERAFINARODRIGUES]

Same here hshshshshsh

[@analoghardwaretops3976]

Yes in this demo it was built without any " soft start ".. unlike the G.P. races that can Never begin with a soft start 😂😂😂

[@swapnilbandgar8730]

I m following last 2-3 years... and learn a lot from every video... also tried many circuits... please make next video on TL431...

[@greatscottlab]

Thanks for watching :-) I hope I will get to the TL431 video soon.

[@TheUnknownCatWarrior]

KZbin: DIY power supply without explanation Great Scott: *explains everything thoroughly*

[@williamcraig6377]

Excellant explanation to a topic I have been wanting to understand for years. Yes, please cover the topic of voltage references. You are my inspiration to build electronics.

[@greatscottlab]

Glad I could help :-) I hope I will get to this video soon.

[@patstine2741]

Video includes FULL BRIDGE RECTIFIER 10/10

[@electromatic2014]

Stay creative , and I will see you next time. Always brings a smile to me, great video as always, only getting better and better

[@greatscottlab]

Thank you! Cheers!

[@TopDedCenter]

Looking forward to more videos about this. I've been trying to fix a switch mode power supply for a KORG keyboard and my knowledge in the feedback loop is very limited. This video has been a huge help and i think I'll take another look at repairing it after your next video.

[@electronic7979]

Very helpful video. I liked it 👏

[@sahilsingh1]

Amazing video. I always wondered how usbc PD is able to achieve different voltages, and this video is the answer - PWM with different duty cycles.

[@johnathanasiou9284]

Awesome video GreatScott!. To help newbies who may not be always fully aware of how oscilloscope measurements should be approached especially with mains connected circuits, can you please do a follow-up video showing exactly how you had connected all devices, especially the isolation transformer & scope ground leads. If you can also demonstrate scope differential probes in such situations, this would be super

[@greatscottlab]

I did a video about how to use an oscilloscope properly. There all those things are explained.

[@Slushee]

I love this! I have always wanted to make a switching power supply. My next big project is going to be one of these thanks to you. Wish me luck!

[@greatscottlab]

Be careful though

[@Slushee]

@@greatscottlab Yes! I watch DiodeGoneWild, and my intention is to make the most absudly safe power supply ever built. If you know who he is, he always critiques PSUs for missing safety features and such. Not going to miss any of those. I will be using overkill air gaps and components, and cables too thick. Thanks for the reminder though!

[@EasyOne]

Very well explained ❤

[@greatscottlab]

Thanks a lot 😊

[@Zebra_Paw]

Actually the voltage dropping at the output is due to the flyback topology. It’s just like a forward of halfbridgd, the output is averaged out, but no need for an output inductor, the transformer does that itself when used in a flyback configuration. But obviously it isn’t a stable voltage, so a flyback loop is needed, and usually it’s made with a voltage reference and an optocoupler for galvanical isolation!

[@analoghardwaretops3976]

Flyback/ boost.. as the name implies..is mostly for " boosted" output voltages...I e. volts higher than input level..so current is usually lower ... The boost inductor is in series with the transistor switch...on Input power side .....and "THIS" current is measured...in the control circuitry..,here it's not the " load " current that's being measured..even though that's what we need... However in some critical apps. the freewheeling diode current... ( partly it's some of the of real load current ) is measured and used for control... it involves more mathematical derivation and additional equalising circuitry...

[@TechBuild]

Press F for the poor transformers. Great video by the way!

[@greatscottlab]

Thanks!

[@gabrieldai88]

1:02 ElectroBoom is proud

[@sethunthunder]

😂✅

[@criticalthinking2603]

Thank you. More videos like this are welcome.

[@Richie_]

I'm still learning and haven't used AC yet. I got a 220v - 9v AC to try the AD-DC circuit when confident enough.

[@oneRella]

I love your videos but I wish you had longer versions with more in depth explanations so that idiots like me could keep up.

[@fixnreview]

Im watching Scott from Philippines

[@jeronimonunes]

Valeu!

[@jeronimonunes]

I just got really curious about the optocoupler, I thought they were digital devices but in this video it's seem like it can work like a variable resistor. I guess that makes sense since they are a transistor in which the gate is controlled by an LED, but, can the LED be turned on partially with linear correlation with voltage? I guess I need to do more research!

[@greatscottlab]

Thanks for the support. I will talk about the optocoupler working behaviour in the video with the TL431.

[@stormz4040]

Thank you. Your videos are amazing.

[@greatscottlab]

So nice of you

[@wgm-en2gx]

As always well presented. Someone below asked about PF correction. Along with that, maybe do a video that turns this into a true power supply with PF correction, filtering, in rush limiting and isolation. That would be an interesting follow up !

[@greatscottlab]

Thanks for the feedback :-) Let's see what I can do

[@SkyhawkSteve]

It might be a good experiment to build the same circuit on copper-clad board with a good ground plane. That should cut down a lot of the ringing at the switching transitions. This sort of ringing is what causes a lot of the EMI in switching regulators.

[@sdlion7287]

a good ground plane needs to be on a separate copper layer? or just having more area (on the same side) is enough? (with those other design considerations, but I want to know how important are ground planes on independent copper layers)

[@SkyhawkSteve]

@@johndododoe1411 I don't think so. I've spent years troubleshooting EMC problems, and ringing in switchers is a classic issue.

[@ToniPlays_]

It's nice to understand how these things work. Sounds complicated but really isn't. Also preparing my moped project for 1.6kw charger integration. So exciting stuff. Great Scott!!

[@greatscottlab]

You can do it!

[@mr.skeleti4038]

Another quality video from the best quality creator on this platform(BTW pls can you make another video using a raspberry pi ?)

[@greatscottlab]

Thanks mate :-)

[@keyem4504]

That's a type of video I like a lot. Lots of stuff to learn. Thank you.

[@MCsCreations]

Pretty interesting! Thanks a lot, dude! 😃 Stay safe and creative there! 🖖😊

[@CppExpedition]

WONDERFUL EXPLANATION❤🎊🎊🎊

[@lpt2606]

Very informative 👏 thanks

[@ansonvattakunnel5297]

"This is super dangerous, don't rebuild it, now here's the schematic " I couldn't stop laughing

[@thetrcg]

Thanks for the great content! Always wanted to know how power supplies worked and now I know, I think

[@insoft_uk]

That TL431 sure gets around a lot.

[@6935g]

Maybe you could try to build a differential probe in a DIY or Buy episode. They are very expensive yet not too complicated.

[@semphony100]

Thanks a lot scot that subject is much clear to me now

[@marcdraco2189]

Major injuries... I think death is worse than just a major injury! Damn that board was terrifying, but thank you for the explanation I finally understand how these little beggars work.

[@midnightgadget3459]

At least half of that went over my head. That being said, i was really interested to see whats inside, and how all my 12V DC adaptor power supplies that i use for various projects actually work. Out of curiosity, i would love to see in your opinion what a basic VS a well engineered design would look like for one of these circuits. Would be a nice reference if i ever get curious enough to open some and see if they are high quality units or cheap and nasty. Thanks for the video :P

[@greatscottlab]

Thanks for the feedback :-) I will see what I can do ;-)

[@laboratoryoperationsmanage5079]

Most of that went over my head, too...

[@pierreretief]

Please build a switch mode power supply with all those features you spoke about, the inrush current protection and such. Would be awesome!

[@johnathanasiou9284]

Looking forward to follow-up videos on TL431 & the switcher IC also. A trick I had picked up from Haseeb Electronics to troubleshoot faulty optocouplers in SMPS is to use a diode on the output of the opto, which helps isolate any feedback circuit issues

[@IrishSkruffles]

Hi, could you explain a bit more about adding a diode to the opto output? How does that help to diagnose an issue? I work with SMPS sometimes so it'd be great to learn a new way to find problems :)

[@brucewilliams6292]

Great video. I love learning about electronics and your explanations are very good.

[@darshandodal1889]

Just at the right time😍🔥... Eagerly waiting for the next video🔥

[@gendragongfly]

Great video, there aren't many video's about propper modern powersupplies out there on KZbin and reading about the subject tends to get complicated fast 😁

[@greatscottlab]

Glad it was helpful!

[@dinushkam2444]

Wish you did more videos on switch mode power supply. Anyways great video, keep it up

[@greatscottlab]

Maybe there will be more..... ;-)

[@ricardoserrano-smith5571]

I definitely agree

[@dexattech]

Awesome as always ❤️‍🔥

[@ThriftyToolShed]

Great video! Thanks for all the work you put into this.

[@uditfand817]

very nicely explained

[@my3dprintedlife]

For learning purposes only, smart!

[@SFInspector2211]

I kept looking at my phone because your background music sounds like one of my ringers. LOL

[@KillianTwew]

I keep zoning out on your perfect handwriting... You were saying something about fly...

[@NiHaoMike64]

The flyback converter was the first switching converter used in a mass produced consumer product - the automobile. It likely got nicknamed when someone got shocked by the high voltage and was thrown back. Note, however, that some modern automotive ignition systems (e.g. Kia/Hyundai) use a forward topology for the final output since it gives a more powerful spark which allows engines to run more efficiently.

[@DanielsGameVault]

As soon as I saw that fuse popping in the intro I thought "Yup: I'm staying till the end" :)) I was hoping to see what happened. High inrush current most likely, since the main cap is big and there's no NTC to limit it....

[@nickwallette6201]

Haha.. I remember building my first AC mains supply. I brought it up on a Variac, and all worked perfectly. After thorough testing, I plugged it into the wall directly, and predictably... I popped it.

[@apon1279]

Very Nice.... ❤️❤️from Bangladesh!

[@greatscottlab]

Thank you so much 😀

[@susmittayade4643]

Nice video !!! Really loved it!!! Will you make a detailed video how these power electronics produce harmonics in systems and their remedies??

[@greatscottlab]

Watch my video about power forms.

[@robertwillemsen368]

Thank you. Nice and clear explanation!

[@prathameshraikar5428]

😍😍😍great explanation

[@ElektronikelAcoustics]

Really a great video as always 👍👍

[@rashidak7821]

👍👍👍 good video

[@greatscottlab]

Thanks 👍

[@linuswulff03]

Thank you! I've been wanting to learn more about flyback converters recently!

[@greatscottlab]

Glad I could help!

[@LabArlyn]

I was also looking for an SMPS tutorial, glad I could find this video.

[@legominimovieproductions]

I am from germany but I still prefer ypour video in english

[@darrylkinslow5613]

AC is great for power transmission, but at the wall we should have a universal DC outlet that can switch from 1.5v up to 24v. It makes sense for electronics that use a lot of power to be AC,but something like a game console should be DC and should be completely portable. All of our Ac devices, actually run on DC, and not AC. They rectify AC to DC, then use a transformer to step it up to high frequency, then output through a couple of mosfets to the DC side of the board, that is what you'll find in pretty much all AC electronics. They typically run on about 12v DC on the DC side of the board. I have gotten into the habit recently of tracing the path and removing the AC side of my smaller electronics so I can run them on a DC power supply and have them portable.

[@kdcreativity6201]

finally a video on smps🤩🤩😘. thanks :)

[@huhufbez]

🤩🤩 Good work 🔥🔥

[@walterwhite237]

Hi GreatScott i would like to see a a video made by you about PFC system on power supply how they work what happen if they fail. thanks for sharing the knowledge!!!

[@ahmadsaeid]

Would really love it if you make a video explaining why there are both 3v and 5v powered devices, why there aren't (almost) any 3v power supplies in existence, and what is the easiest way to transform 5v to 3v to use those nasty 3v devices?

[@jhunmichaelibanez2362]

Hi! Can you do in your next DIY or Buy a cellphone signal booster? I really want to know how wifi/internet and other communications work but don't understand any information I came into so far. I always watch GreatScott everytime I want to DIY something!

[@b.mandal]

"diode gone wild" is best in this subject

[@BRUXXUS]

Love DiodeGoneWild !

[@umakanthbojanapalli3240]

Valuable information sir