How SMPS works | What Components We Need? Switched Mode Power Supply

[@ELECTRONOOBS]

Sign up at ELECTRONOOBS.io: electronoobs.io/ Follow me on FACEBOOK for more: facebook.com/Electronoobs help me on Patreon: www.patreon.com/ELECTRONOOBS

[@thearchetype9829]

Hey electronoobs you can CREATE SHADES USING SIERPINSKI'S TRIANGLE AND YOU SMART PHONE kzbin.info/www/bejne/en68n5JmqrmJeJo same as I have done

[@ugetridofit]

Something is strange here. At time 8:30 in the video its showing 2, 560uf @ 200V. After the bridge the DC voltage will be way higher than the input of 230vac, so how can those caps be so underrated?

[@ELECTRONOOBS]

@@ugetridofit there are 2 capacitors in series so 400V

[@chanchukumar3562]

Can you give me its circuit diagram

[@shashankshekharverma6151]

Bro why did we use high frequency transformer,cant we just take output from mosfet and connect it to secondary filter?

[@saikittang7450]

I honestly can’t imagine how much time and effort must have gone into making these videos man. Appreciate it!

[@shailendrarajput9533]

Time does not matter when you doing something interesting 👌👌👌😍😍😍

[@learningcorner4597]

Now imagine how much efforts it would take to produce an smps

[@garyhogue7990]

@@learningcorner4597.

[@FixDaily]

All his videos are filled with errors. For example, in this video he says that after the bridge rectifier is still AC. It is pulsating DC! Which is a very ugly mistake for someone that called himself "Electronics Engineer" on his webpage.

[@Boffin2002]

I've been in the business for quite a while and can honestly say this is a very well presented explanation. Not too technical but accurate enough and to the point. I'd have no hesitation recommending your material to anyone that wanted to learn. Well done

[@jeremiahchamberlin4499]

This is my third video today on switch mode power supplies. It was most informative. As an English (American) speaker, I had no problem with the verbal instruction, I understood you very well. As a student, I deeply appreciated the waveform transformations across sections. Of the power supply. A lot of repair videos assume the viewer is familiar with how a SMPS works; I was not (and wondering for years): you explained it very well. You focused on the main components without getting distracted by how individual capacitors, zener diodes, and resistors could affect performance. If I were to repair an item, I would need that information, but BEFORE I need to make the repair, I need the information you present. Thank you very much.

[@FixDaily]

And he didn't explained it well. He assumed that the SMPS works with the same principle as a linear power supply. Most things he said right but there are a lot of mistakes he said. For example: After a bridge rectifier he says that it is still AC and the capacitor is responsible to transform it into DC. This is a clear mistake that he doesn't know what he's saying. After a bridge rectifier you have pulsating DC. Also the induction on the transformer doesn't work the way he describes it. It is called a flyback transformer for a reason.

[@bashaaksema94]

The EMC filter is also really important to make sure the power supply doesnt make interference on the line

[@pssh23]

also know as line filter, if your speaking of filter at the input side.

[@Samuel-km5yf]

Dark Angel - Electronoobs is wrong here and you are right. The EMI/EMC filter is primarily for filtering out the conducted emissions *back* into the source supply.

[@bashaaksema94]

@@Samuel-km5yf thanks are you an expert on it btw?

[@Samuel-km5yf]

Dark Angel - I’ve designed, built and tested satellites for over 15 years and have SMPS designs currently in orbit above Earth... so, yes? You are obviously well educated yourself because many EEs I’ve worked with would not be able to tell me what the input filter of a SMPS is primarily for 😉

[@bashaaksema94]

@@Samuel-km5yf well in that case. Im working on my own smps right now maybe we can have a chat?

[@gonzalomeabe5256]

Great video! Just a little thing I want to mention, at 15:34. The control circuit is on the low voltage side, but the power transistors are still on the high voltage side, so you need a way to controll them withouth loosing your insulation. That's the purpose of that smaller transformer. I'm pretty sure that it is used to control the power mosfets from the low voltage side. I asume that the main transformer have 4 pins on the left, two pins for the main HV winding, and two for an auxiliary winding, used to power up the control circuitry (and in some other desings, an auxiliary winding is used as a voltage feedback instead of using an optocoupler, as its voltage should be more or less, proportional to the output winding voltage). If you watch close, near the small transformer, there are two small transistors used to drive the primary side, and on the other side, there is a bunch of capacitors, resistors and diodes used to drive the gates of the power mosfets; those are needed to reduce the time they take to turn off, and therefore, to reduce the power loss. And two diodes to form a snubber network, to protect the transistors against reverse high voltage spikes, due to commutation. You can tell where is the division between high voltage and low voltage side, by looking at the bigger gap that separates the copper traces from one side to the other.

[@RoadRunnerMeep]

Probably one of the most indepth videos I've seen for SMPS that simplifies it :)

[@zsigmondsinventions5201]

I am an electrical engineering student, and learn more from your videos than from university :((

[@ELECTRONOOBS]

Well I'm happy that you learn from.my videos :)))

[@felixwurm1467]

Well then you have a Problem. The video ist good but also very very Basic. I would recommend the KZbin Channel Diode gone wild cause He also goes Info the math an Transformer Design, an some different Typs OS SMPS (flyback ....)

[@alejandroperez5368]

@@felixwurm1467 he doesn't have any problems. This is more electronics engineering than electrical engineering stuff. And even in Electronics engineering they won't give you these clear explanations as shown here. They will teach you what a buck and boost converters are at and advanced level but will not teach you what a SMPS is.

[@coloradowilderness3139]

Zsigmond's , Bcz you never attend class lectures !

[@makkanelectronics]

Good job bro ✌️

[@mdaraphiri6767]

You are really a genius. I usually don't comment. But today I feel the need to leave 2 or three words. As I am watching, I am sitting with my 4n charger open trying to figure out why there are so much components. You nailed it.

[@cecilandrews1875]

This has to be the best description of power supplies design I have ever seen you have a new follower

[@ameristanbouli5063]

i was waiting for someone to explain why high frequency transformers are smaller but can handle the same power as the low fequency one with iron core thank you 💙💙

[@Amirzackyproduction]

Am now becoming expert since i started watching your vedios Waiting for more sir You pretty motivate me since am an EE student

[@dawsonrichards6363]

This channel is amazing and underrated. Somehow you manage to read my mind and teach me exactly the things I need and want to know. Please keep up the amazing content!

[@ehsansoleymani2394]

This has to be the best description of power supplies design

[@kwhp1507]

Best smps explanation I’ve found to date. You described things nobody else has. Thank you

[@zikermu]

Thank you very much for this excellent video which allows, with average knowledge in electronics, to approach the SMPS without using abstruse terms like forward, buck, etc... (this terminology is obviously not to be denied but is not needed to understand how it works). Your course is very educational and icing on the cake, it is excellently illustrated with videos with ad hoc comments.

[@Xlife018]

The most comprehensive yet easy to understand SMPS video I have seen. Well done!

[@RoshDroz]

I'm sure you've seen this correction a million times, but it's *linear power supply, not lineal. Your English is excellent in general, and you're a great teacher!

[@yopdiesel80]

Thank you so much for this video! Please don't stop creating such content, humanity needs it.

[@ismail_aydemir_youtube]

sen ne güzel bir anlatımda bulunmuşun. çok güzel alkışlıyorum. Bu anlatım smps devrenin sırasıyla, özellikle de; ac ve dc sinyallari ile birlikte tam zamanlı anlık anlatmanız çok güzel olmuş.

[@thanatosor]

So we filter out a lot 😂 1 - AC >> Fuse, EMC filter & main filter to smoothen high FQ noise. 2 - AC >> Full bridge rectifier to chop off negative side to become DC >> PWM controller & MOSFETs to boost frequency into transformer coils to be AC again. 3 - AC >> Half bridge Rectifier chop-off AC again into >> DC controlled with pwm signal & filter the noise again with low-value Cap to smooth out the output. 4 - DC >> Then optocoupler will send feedback back to high voltage part while remaining isolated, to keep the voltage steady.

[@BobWa43]

Best explanation of how switched mode power supplies work I have seen anywhere. Clear, concise and explained in terms that a layman can understand. Thank you, just what I had been looking for.

[@shawncalderon4950]

The best instructional video on the topic. Universities should pay you to make their electrical engineering videos:)

[@big-boss-404]

Great video bro, you spent much effort on this. You're better than my lecturers. Anyway, I think the DC output voltage of the output LC filter should be controllable by changing the pulse width of the signal. So, the DC output should change due to the change of duty cycle of the signal. You might mean it, but you misrepresented it in your video. Great job anyway bro 🔥

[@uwezimmermann5427]

Nice video and good explanations, however, some comments: Noise on the ac input voltage is not so important, since the ac will be rectified and charges up the primary high-voltage capacitors. At least as important is the filtering of noise which is generated within the power supply so that it is not emitted out onto the ac grid. Also the voltage on the high-voltage primary capacitors is not 240 Vdc but sqrt(2)*240 V or about 300 Vdc since the capacitors charge to more or less the peak voltage of the ac grid.

[@cheeseschrist2303]

That is why these capacitors are usually 400V.

[@uwezimmermann5427]

@@cheeseschrist2303 and they make a lot of noise when discharged through a well insulated pair of pliers 😈

[@charlesslagal3353]

He states the output voltage at the large caps after the rectifier is around 320V.

[@mikevultaggio9589]

One of the best electronic learning tutorials I have ever seen!!!!!!!!!!! thank you..

[@jarrod0987]

Been learning about SMPS for years. Watched a lot of video's on them. This one is the best I have seen so far Thank You.

[@peterlethbridge7859]

At last, someone who has explained an SMPS in such detail that it's easy to understand. I thank you sir. A wonderful job. I have a couple of questions as a noob: 1) on the EMC filter, I thought coils (chokes) blocked A/C voltage? 2) Why is only a half bridge rectifier used on the second stage instead of a full bridge. Isn't there a loss in efficiency by throwing away the negative component? Many thanks again for your superb explanation.

[@peterlethbridge7859]

@@Adhithya2003 thank you so much for spend time answering my questions. It’s greatly appreciated.

[@d614gakadoug9]

The inductor used in the EMC filter is called a "common mode inductor" or "common mode choke" ("choke" is a rather old term for an inductor, but it is still used). A common mode choke is designed with two windings. The windings are arranged such that the low-frequency current in one winding is equal to and opposite in polarity to that in the other winding at any instant. The magnetic fields of the two windings cancel each other and there is very little inductance for that "differential mode" current. However, if there is high frequency noise that is the same ("in phase") on both of the windings, there is no cancellation and you get high inductance to this "common mode" noise. In the filter you use capacitors across the AC line connections on both sides of the inductor. This more or less makes a short circuit for high frequency noise between the two sides and makes sure the high frequency noise is common mode. In the circuit in the video there _is_ no AC at the output of the transformer. His description is simply wrong. This is almost certainly a forward converter so the voltage at the secondary side is unipolar pulses. The diode doesn't really act as a rectifier in the usual sense, but rather as a way of preventing the output filter components from discharging through the secondary winding of the transformer. If there really were symmetrical AC at the secondary you certainly would use a full wave rectifier. Half-bridge, full-bridge and push-pull converters do produce symmetrical true AC on the secondary and you do use full-wave rectification. Usually you use a centre tapped secondary so full-wave rectification requires only two diodes, but sometimes you use a simple untapped winding and a full-wave bridge rectifier. These types of converter are more complex but you make much better use of the transformer because of the true AC excitation and you can get nearly double the amount of power for the same size transformer. There is some chance that I am wrong and the circuit is actually a half-bridge converter, but I doubt it.

[@aussieboy77]

This is the best explanation of SMPS I've seen anywhere.

[@harivignesh]

This is the kind of videos we want. very Informative with very good graphical explanation

[@rusty1187]

FINALLY!!!! Someone who could explain these to me in a way i could understand!

[@hoyschelsilversteinberg4521]

I'm 9 minutes in and you've just solved so many mysteries for me. I've read up on so much, so many tutorials out there are just plain SHIT. Talking about lemons powering LEDs to absolutely incomprehensible jargon laden nonsense. You just created here something so incredibly easy to follow and understand. Your breaking down of the sections in a PSU is so logical and well thought out. You must have been in the same position as myself at some stage in your journey to have created such an easy to follow video. Thank you so much! subscribed and liked.

[@lucast3006]

Your channel as well as Learn Electronics Repair are my absolute favorites. Everything is always so clear!

[@ninadtaralekar]

The video is very detailed and have niche explanation of each block step by step... That's amazingly made and appreciate your peculiar points for the each block from application perspective

[@ajeethsuryash5123]

This man deserve a best teacher award.

[@habtamusium8646]

I could cleared out my confusion on how potentio-opto-ic work together for attaining a constant output voltage . many thanks for well explanatory vid .

[@styrishrodrigues]

Even a noob can be master after watching your videos.... ❤️❤️❤️❤️

[@bteentalk]

I've learned this for many year and still confusing but I can understand what I've learned exactly by this 16 mins vdo. Thank you so much.

[@Den_Electro]

Hi, friend. Watch my video! kzbin.info/www/bejne/aILVZ32Zop2qmKM

[@blueunicorn807]

*Sir, please make the world's simplest but powerful SMPS and of course without any chips. We need to learn this. As often we need a power supply. You are a great teacher, Love you from India.*

[@usertogo]

pretty good- the real pleasure is too look into a high performance telecom rectifier where multi phase intermediary transformers are used to achieve 90+ percent efficiencies!

[@jagdeepsekhon9006]

The effort you put in and the amount of time you have spent on making the video is really commendable. You are doing a really amazing job!!

[@grahamhall2662]

Excellent, I am learning all the time and your explanation is aimed at just the right level for me. Gives me a stepping stone from which to learn more. Thank you.

[@anthonyvolkman2338]

Very well done! On the bigger PCB that little transformer is a Gate Drive Transformer, it used to have isolation from the main FETs in case they short (example, from gate to drain sending tail voltage straight into the gate drive network). However the transformer allows galvanic isolation between which allows the pwm controller and gate drive network to (generally) be preserved during a fault. Those transformers are generally gate drive only and those little transistors near it are for driving the GDT. Coilers use GDTs (same as I) for Tesla Coil gate drivers with dedicated gate drivers such as the UCC3722 or TC4420 gate drivers.

[@h.matiin]

Wanna evaluate the quality? check if you feel the time passing or not. Thanks for this beautiful and comprehensive video

[@conradh7659]

Great detailed explanation of how a SMPS is designed and works! Excellent video!

[@ELECTRONOOBS]

Thank you :)

[@beauhanson3318]

This was such an amazing video, so many people have tried explaining this, but your animations and examples were so effective. Thanks!

[@Richie_]

Explaining the use of each component is brilliant. It's how I like to learn and it's how I look at circuits. Thanks. 👌

[@sauravbhegde]

Seconds back I was sitting with an open PSU looking at two blasted Capacitor, wishing I had some guidance. Thanks🙏

[@donaldfilbert4832]

Must be great for you that life works that way - laugh !!! ;)

[@sauravbhegde]

Really it was like "angel👼 sent a notification check out son" moment

[@techview6933]

Great !!! Your explanation method is A to Z , You explain all steps and working principle of all components !!! Thanx!!!

[@gouraviki]

Best ever explanation of SMPS...really a great job...keep it up

[@Engbic]

This is really amazing. Your video is the best about SMPS in YT.

[@rickpontificates3406]

A couple things… the 230AC input is obviously for Europe, but since you didn’t mention a PFC stage, then the power supply will typically have a 110/220 switch, which is not needed in a power supply with a PFC. The secondary stage (PWM} is powered by a DC voltage (typically 250-400VDC) which is the output of the PFC if it has one, and which is higher than the VAC RMS of the bridge rectifier (VIN x 1.414). The secondary pulse transformers operate at about 100khz and the output is usually rectified back to DC with a DIAC which powers the output load.

[@peddersoldchap]

Best video on power supplies on this site, for sure! Well done and thank you!

[@jkj1459]

VERY NICE THE STYLE OF LANGUAGE .. EASY TO UNDERSTAND EACH AND EVERY WORD .

[@chandrab373]

how was the control system designed with feedback to assure stable equilibrium i.e. in order to reach steady state ? , in the sense , after supplying (feedback) the driver circuit with the necessary voltage to start controlling the gate , what assured u with the confidence as to see no ripples in the output signal from the desired signal output from driver section ? and also if u can please explain transient analysis for choice of tolerances of parts on the "to be used components" while designing an SMPS it would be very kind of u

[@DiscoverRajivVlogs]

Man this video is so easy to understand... Good job...

[@sanjalon]

Amazing job in laying out the material so clearly and logically that it is simple to follow and even fun. Thank you!

[@adhossain]

Really apprechiate. I had no idea how SMPS works and now I fully understand it

[@ibrahimethemdere5518]

Thanks for your short and explanatory narrative🙏✋

[@farabielec]

Thank you dear. The best video I have seen explaining SMPS 👍👍

[@mrsmarty7894]

Electroboom, Electronoobs and Greatscott are great

[@GemunuJayasinghe]

Best explanation . Sir , thank you so much . I am from Sri Lanka .

[@AD34534]

That recap/summary at the end was amazing. Great video man.

[@HmEMusicRemixSongsHmE]

That was a great video you us by simplifing and that was pretty understandable video Thank you 👍🏻

[@tomallen6073]

Awesome! Great explanation. I have a few I’d now like to try to troubleshoot. Videos like this really help move the world forward.

[@matthewrampersad8185]

This Video was so helpful especially during this time of online learning where I'm unable to get any hands on experience with these stuff but your video really helped thank you!

[@666aron]

Thank you for another anazing, informative video. On the topic of SMPS, it would be nice to see a tutorial on building the transformer for feed-back, feed-forward, push-pull. I remember that in university we've learnt the control of SMPS, but but the design.

[@sahilyadav998]

Finally your videos started showing up on my suggestion page. :-)

[@sri198904]

At 7.55 You forgot to show the dots of the choke used in an EMC filter and also forgot to mention it. There is a reason why there are two coils, one at the input and a second one at the return part.

[@recenttechnology2952]

Good job, once again a great video! Sometimes a power factor correction (pfc) is applied to avoid harmonics.This would certainly be an exciting topic for another video ;)

[@zeitgeist909]

Great video - I have watched quite a few videos on SMPS, this is the first where I feel like I am getting an actual grasp on them from the ground up.

[@borakilerci1299]

Nice video. I wish to learn how to filter and decrease the rf noise of smps from you. I am using smps for HAM RADIO because i can't afford high price, high power lineal power supply. Keep doing great job.

[@basitimran3368]

Excellent demonstration bro👍 I just want to ask... "What if i feed 230V DC instead of AC to a switch mode power supply? What will be the impact on circuit? Will it work or not? Or will it burn out?..." Please don't ask about WHY i wana do this.

[@Vinaykumar-bf8hj]

Brilliantly Explained with seriously impressive animations🧡 i loved it

[@tonymai124]

very ...very good explaintaion to people who not really good in electronic field like me, big thanks Bro !

[@Adhithya2003]

extremely good video. Love it great combination of theory and practical knowledge. Chef's kiss.

[@0MrENigma0]

Thank you for this video! It will make more sense in time, as I get a better grasp of the components, and re-watch this video over time, but this is so appreciated to be able to have even a basic understanding now.

[@kamaljoshi9102]

You are talented and hard working person. Thank you for making so informative videos

[@ve2zzz]

The EMC filter also protects the grid side from noise generated by the high frequency curent choppers inside the SMPS. Also important: The large toroidal inductor after the low voltage rectifier allows output voltage control with PWM. Otherwise, voltage control becomes quasi-impossible despite PWM.

[@030H]

Thank you! That is definitely the best video on SMPS! 👍

[@nadavnatan2320]

perfect tutorial. very clear. i show your demonstrations in my classes

[@milindkhurd]

Thank you for the section by section details with animation, excellent video!

[@arunmalik790]

nobody can explain this topic better than this

[@Elikaee]

Hello man, this video was very useful for me. Everything had been clearly explained. WAY TO GO

[@taylorboultinghouse8296]

What an amazing video! Thank you for putting in all the work to make this video so clean and concise. Take care!

[@voxluke]

The best explanation video I ever heard

[@unosec]

very brief demonstration tutorial, thanks for video production😀

[@erygion]

Great video! I'm new here and I've seen all the Great Scott, ElectroBoom, Andreas Spiess, ect and I think you're one of the greats just like them and I'm going to get all caught up, sorry I've been sleeping on you.

[@derekhyps2821]

I have my doubts regarding your explanation for what the EMC filter coil does. You say it filters the AC mains coming in that contain high frequency noise. I not so sure about that. I don't think there's high frequency noise on the mains coming in. I believe the coil is used to filter the high frequency noise generated by the SMPS from feeding back into your house mains. Your thoughts? Other than I think your presentation is excellent.

[@dougsteel7414]

How is the positive half wave leaving the rectifier still AC? I can see it's still a voltage moving at the mains frequently, but it doesn't reverse polarity?

[@sundarbe]

At 8:45 you show peak-peak voltage but saying it is 230 V, which is Vrms. Peak to peak is 325 V, when rectified half of that would come to be 162 V that’s why they used 200V caps.

[@ajaikumars6948]

Great content and you way of explaining is so easy to understand. Keep it up Bro. Support from TAMIL NADU.

[@ELECTRONOOBS]

Thank you very much!

[@anmolkumar6704]

Thanks for this video man I was just building a tl494 based SMPS 😃

[@aungkyawminoo9386]

Great Sir Your presentation and explaination are very valuable. Thanks.😍😍😍😍

[@ahmadmaaz2566]

As always, the best video.... Man keep up the good work... I always get excited for your video

[@saxhorn1508]

Excellent explanation and graphics. Thanks.

[@kevinjacob7464]

Awesome ! Please make more of these types 👍

[@tonign80]

Magnifico vídeo explicativo!!!... la info gráfica del las distintas etapas, funcionamiento y el recorrido de cómo actúa es didácticamente perfecto!!!... menudo trabajo!!!... gracias por compartir conocimientos

[@chandrab373]

on a whole it was an extraordinary video , cuz it was useful at the right time , (based on viewer situation) , it helped me a lot , very informative. looking forward to seeing more videos in electrical involving control systems techniques of circuit designing.

[@harshdesai1932]

You did a great job. I appreciate your work. But I have one query in this tut. If we give square wave to the transformer, we will not get the square wave on the secondary. That will be impulse signal. Then how in this SMPS we get the square wave at the secondary?

[@Samuel-km5yf]

Harsh Desai - You’re correct, the secondary waveform is not a perfect square wave, but at high frequencies, it looks close enough to consider it a square wave.

[@harshdesai1932]

Okay, now I got it. It also depends on the winding's inductance. Higher the inductance, wave looks closer to square wave.