Howto repair switch mode power supplies #1: basics, and block diagram of a PSU

[@Drvanosdrand]

Finally someone explains what the parts do and in what order they do them , Thanks !

[@paulrichard4945]

hi everyone ,if anyone else needs to find out about remote computer repair try Saankramer Electronic Magazine System (just google it ) ? Ive heard some pretty good things about it and my mate got excellent results with it.

[@cwguy8960]

Why are you watching electronics vids? I thought you were an architect...!

[@victorzedwings]

start from 5VSB check

[@taricwalters8750]

Yes indeed

[@djarty1164]

@@paulrichard4945 scammer

[@gordonemery6949]

Understanding electronics in layman's terms ,I've learned more in this video than hundreds of other ones thank you 👍

[@retrohd1_]

If you’re reading comments to know whether to watch this video, I’d say go for it 👍🏻 Literally amazing! I feel like I can say with confidence that I understand circuits a lot more now.

[@hassanburrows8535]

For someone brought up in the valve/tube era, this type of tutorial is simply excellent. I very much like your step by step approach, and am really looking forward to subsequent videos. Thank you very much for sharing your knowledge in this way. Saludos!

[@DonkeyLearningIT]

Valves were the real deal. For audio they are still *the best ever!* I started out with valves, since as a kid I had no access to books on transistors, and even Germanium transistors were hard to get from used Russian electronics ;) Just keep on watching the series, I will make more videos for sure.

[@kiswahilikitukuzwe2547]

Much respect and appreciation from Kenya for the time, dedication and patience you have put in this wonderful series to impart this invaluable knowledge in such a simplistic and holistic way!!!

[@michaelkelly1251]

You Sir took the time to explain some of the components that have been a mystery to people who would like to think they are born smart, and only want to know, and speak one language. They see those round capacitor looking devices, but they are bright blue, or flat black. Most think they are capacitors. You have done a great job in this video you deserve the respect, for going out of your way to teach, and explain it all, and not just hold on to old secrets. That is rare! It should be appreciated by all who watch this. While it wont make people who don't have the skills repair a power supply, it will help those who have skills, but are short on component Id's and understanding to actually repair a switching power supply. Caution: "High Voltage", and Highly complimentary comment. You remind me of a good friend I used to work with. I am glad I found this. Subscribed ready to learn.

[@tashgur9901]

Are you serious? Where have you been my whole "electronics" life? Definitely the best video on components ever made!! Very Much Appreciated!

[@maxwarfield6699]

FINALLY! This is the BEST electronic tutorial video, that I have found online. I'm not an expert, I'm just a hobbyist who enjoys attempting to repair Tvs and electronic devices around the house. You speak CLEARLY and you don't speak too fast, that is very important for beginners like me, because the technological jargon is difficult enough as it is. I've now subscribed to your channel, and I hope you will make more videos, as they are REALLY helpful, to non-professionals like me. Kudos and thank you kindly

[@boredwithusernames]

This came up on my recommended channel list (on 2024) and I have to say that this is the absolute best explanation of how these circuits work, thank you so much for uploading this, it has given me a lot of confidence in moving forward to trying to repair these power supplies. Thank you 😎👍

[@TampaTec]

so true 1:30 I went to tech school too and they gave us math books instead of showing us real world troubleshooting steps. I wasted 30k, 2 years of my life, and that school closed so my degree is worthless but still have to pay off that gov loan. On job experience, license or certifications I highly recommend. thanks for sharing your knowledge 👏👏👏👍

[@DonkeyLearningIT]

Finally someone who thinks the same as I do! When I give people advise that nowadays schools often tend to be a *huge waste* of time and money, they think that I just want to stop them from reaching their dreams. I wasted several years from my life looking into textbooks for almost nothing... As you wrote, experience counts more than a degree! One can get a degree *after* if it is required by the employer. Especially in the field of tech and IT, certifications are the real deal.

[@SilverMoonJoe]

Back in my days "1980" when I took electronics, was the same way. The only difference with me was that my dad was an electronic technician Radio/Television... He taught and showed me the how's,when and why. But I agree Tampa Tech.. my books which I still have them was too much math and little hands on... am sorry to know about your unfortunate event. A personal note.. I love Cleveland Institute of Electronics!! my dad always spoke highly of them. In any event you are great Tech Bro!! Joe-K4JGA - JGA Electronics Repair Center - Fl

[@TampaTec]

Donkey Learning IT so true, billionaires will say the same thing and they have. The government wants us to go to college because they make money off of that loan interest but reality is that experience, certifications and licenses are more valuable in tech field.

[@nazishkhan3362]

Samsun lcd

[@jerrythefisherman94]

Sounds like ITT to me. I went there 2 years. On the job training gives much more valuable experieince.

[@ibanix2]

Came for basic info on switchmoded PSUs, got a whole series on design and parts. A++ thank you.

[@BomJimmy]

Nothing can be better explaining SMPS than this video. Core level and clear explanation.

[@DonkeyLearningIT]

Thanks for the positive comment. I am happy that you liked the video!

[@msdesignru]

The best video I have ever watched about psu's. Thank you, appreciate it.

[@bobl78]

the best video about how switch mode power supplies work

[@DonkeyLearningIT]

Thanks for the positive comment!

[@MrLiquidArrogance]

Went through 20+ videos before finding yours -- by far the most helpful for a newbie like me. Thank you!!

[@DonkeyLearningIT]

I am glad that you like the vids. The idea was exactly to create a series which is different compared to what is available on KZbin. Making the same material looked kind of pointless, this is why I try to go through step-by-step.

[@wamimuswamimus3496]

Great teaching method, looking outside the frame before you digging in . Knowing the whole image before going to details helps the brain to map course and connect the dots without using much energy. I call it green teaching.

[@rsattahip]

Thanks, your videos are among the best on KZbin for the practical repair of electronics power supplies.

[@DonkeyLearningIT]

Well, so far I am presenting mostly theory, and many people are complaining about this. However, explaining practical repair without basic theory is impossible.

[@endotype2286]

Absolutely brilliant. I love the diagrams and your abstractions are spot on for me.

[@DonkeyLearningIT]

Thanks for the comment. Please go through the whole series (I am still producing new episodes) because it will describe the whole SMPS step-by-step for hobbyist repairers and for repair technicians.

[@Dexter101x]

You mean that your teacher never taught you well?

[@ankan2088]

Finally found you again! The most comprehensive playlist on smps working. I am so thankful to you. :)

[@boblewis5558]

Great video. Much better dealing with the blocks before having to delve directly into the countless variations of schematics. Top level view and back to basics is always a better approach. One word of extra caution however, especially for the UK (and potentially, previously British colonies) the nominal 220-230v European mains, in the UK tends to be 240v nominal (still within the European spec limits) but is OFTEN sitting at 250 volts AC (my own domestic mains supply certainly is). This means the the rectified mains DC bulk capacitors frequently have a static DC voltage of over 350 (!!) volts (250 X 1.414)! Please use great caution when "playing" with such supplies. Also, PLEASE DO NOT do what many people advise and simply short the capacitor terminals with a screwdriver! This is potentially lethal to your eyes and skin! The stored energy (0.5 CV^2) can easily exceed 15 to 20 joules or more and is MORE than sufficient to blow the end off the screwdriver as molten metal!!! Use a voltmeter FIRST, a sufficiently high value resistor SECOND of say 5 megohms and 0.5 watt and suitable for the voltage (yes, resistors have a voltage rating too). If in doubt use multiple resistors in series instead to "bleed" the energy from the capacitor. Strictly speaking GOOD designs will incorporate such a resistor anyway, but never assume that. ADDITIONALLY, using a screwdriver or other short circuit can easily cause hidden internal damage and or weakening of the capacitor which will simply cause long term unreliability!

[@alok20001]

Very informative comment.

[@muzikman2008]

Especially microwave oven capacitors ;-)

[@marc49lewis]

Yes, I've seen damage to switching FET''s and IGBT's due to this foolish practice. At my bench, since I deal with large linear and switch mode supplies, I utilise a 200 ohm 20 watt resistor that has old volt meter style test probes attached to it to discharge these primary filters.

[@sirgigamight7703]

After all these years on KZbin, I have only subscribed to 2 channels... until now. I am subscribing to your channel for the simple reason that you are not trying to impress everyone with how brilliant you are, and thus avoiding simple explanation of basics. Thank you. Please keep doing what you are doing. Thorough in depth discussion with basic terminology and component description.

[@DonkeyLearningIT]

Than you Sir Gigamight for the comment! I am glad that you liked the style of the presentation. What people do not understand is that the educational system is so broken, that students are not though about the most important *basic and useful* stuff, but instead they are stuffed with things what they could easily look up in a book. This is why I am trying to cover the basics.

[@Washburn-rr5eh]

So very true!!!!

[@brutusjb3814]

​@@DonkeyLearningIT you should try to activate the KZbin version of patron, I bet people would send you those KZbin super thanks. I tried but I can't. Thanks for the video

[@manaharlotia7233]

Excellent tutorial I have ever seen by anybody.You have tried to explain each n ever components in a excellent manner. your given slides itself show what it is for including their clear images.really great video. Awesome. thanks for your hard work.

[@kakadu89]

This is the approach I've been needing and trying to find online without luck until now. You make great videos and explain wonderfully, thank you for this!

[@nosafetyswitch9378]

You are doing a great job. I am an EE and I would say you are explaining things very well and accurately, bloody well done!

[@DonkeyLearningIT]

Thanks for the good words! I try to make explanations which contain a some minimal theory of operation without much mathematics for the general public.

[@nosafetyswitch9378]

@@DonkeyLearningIT You are doing a great job, dont worry. I am actually learning too since the EE field is vast so it takes a life time to read everything on yourself but videos like these can quicly narrow down the particular thing that someone is missing in order to proceed in, for example in this case, fixing a PSU. More particularly, I got two answers in this video (and some reasearching afterwards), why passive PFC requires a manual switch for 115/230V and why would a fuse blow but nothing else did? Your explanation about the MOV shorting the fuse to protect the rest of the PSU answered my 2nd question :) Cheers! Your accent is a welcome bonus :D

[@DonkeyLearningIT]

@@nosafetyswitch9378Many thanks for the feedback. I am glad that the video was somewhat informative even for an EE student.

[@lamtatyan]

By only watching this part 1, I already think I am no longer being ignorance in electronics. Thanks! Looking forward to learning more from your video!

[@DonkeyLearningIT]

Many thanks for the positive comment. I hope that by watching the other videos it gave you more insights as well.

[@rocoroco15]

Wow! This is one the best video I have seen describing the working a a switching power supply - Nice simple graphic but very precise information - Thank you!

[@logiccom511]

One of the best tutorial video ever on this topic.... thanks a lot for sharing

[@mattymuc]

Best video I have seen for explaining how a PSU works. I'm looking forward to watching the next parts! Thank you!

[@DonkeyLearningIT]

Thanks for the comment. Since I have the slides all done, it should not take too long to make the video. On Friday it should be out if all goes right.

[@ali37]

Superb, at last an explanation I can understand , explained in plain english with no recourse to all the confusing tech-speak found elsewhere, keep up the good work !

[@DonkeyLearningIT]

If you found the video easy to follow, it means that I am going in the right direction, because that was exactly the main purpose: simple videos, with explanations of what happens in an SMPS and why.

[@ali37]

For me anyway your definitely heading in the right direction , very refreshing to find and explanation I can understand, well done and I hope there's lots more vids planned ?

[@irongastelum6202]

I am so happy to have come across your video! you can probably guess this is my 1st time watching one of your videos, so i just wanted to tell you i love thee way you show whats going on from one component to the other.I really enjoyed watching and really enjoyed the format. Thanks see you in your next one!!!!

[@yesplease1000]

Excellent tutorial. Very well explained. The school teachers should learn from this tutorial on how to teach. Once you listen to this tutorial you will remember electro magnetic theory all your life.

[@DonkeyLearningIT]

Many thanks for the positive comment. The truth is, that many things regarding the theory are being presented by me in a way too oversimplified manner. However, even this oversimplified explanation is ofter better than nothing for people who are just starting out.

[@prenumenume7498]

Sir, your series of videos about power supplies is absolutely perfect. Thank you very much for explaining everything. Give this man a cookie.

[@peckelhaze6934]

A very good video. Clear and concise and the use of block diagrams make it very easy to follow. Thanks very much for the time taken to create this.

[@johndoo1265]

You should definitely teach as a teacher. It makes me sick to see all the people who call themselves teachers reciting material from the textbook. You're definitely one of the rare teachers we'd like to see in the teaching profession. 👏👏👏

[@Anesu98]

Thank you thank you. I'm watching from Zimbabwe Africa. This what I was looking for. I love your video.

[@dgsujeewapriyantha211]

The best explanation of circuit board of power supply. Thank a lot sir,. Pls. keep it up. Much helpful for the beginners of the subject.

[@a.wagner9479]

Information and explanation = Amazing Accent = Priceless Keep up the good work! I'm a huge fan!!!

[@milanhorvat6494]

I think he's Romanian.

[@carlnikolov]

@@milanhorvat6494 Austrian

[@shvideo1]

An incredibly useful video. I have been longing to learn the uses of all the components that I've been seeing on these power supplies for a long time. Thank you, thank you.

[@WayniKlaru14344]

Love it Bro!! Keep it up.,You got my honest subscription.Finally explain spot on the building blocks of the circuitry. I hope i can watch some of your videos that i can lean electronics as a novice hobbiyist. Ever since I was younger I am facinated how a radio or tv works or even my remote control cars. Now I think i am mature enough to learn at least the very basics of electronics. I am now in my 50’s learning new knowledge is a bit of a challenge with a good teacher like you who can breakdown where to start and perhaps persuade myself to research and venture out even deeper just for a hobby in thinkering old electronics such as small stuffs in the house. Thank you..👍 Watching in the Philippines.

[@payspayson3795]

Yes. Very complete and basic instruction. All thumbs up for an excellent thorough job. Thank you so much. I look forward to more of your videos.

[@Torreiro]

Thank you very much my friend. I'm trying to learn about power supplies and you saved me! Thank you very much for your video class! Congratulations from your Brazilian friend!!!! 🇧🇷🇧🇷🙏🙏🙏😁😁😁

[@klaasklapsigaar1081]

This was exactly what I was looking for. Helps so much to understand the schematics and identification of parts as a rookie :) Thnx a ton for making the video, liked and subbed.

[@W1RMD]

Me too!

[@RickinICT]

This comment will probably be buried where no one will see it, but on the off chance someone comes along and reads all the comments before embarking on this playlist, be advised that while there is much to learn in the videos that are already posted, as of April, 2021 there have been no new videos posted in over 2 years and the playlist stops while still explaining theory of operation. It never actually made it as far as beginning to describe the repair of SMPS. Hopefully @Donkey Learning IT will someday return and finish the series, what's already here is great and I learned a lot!

[@surfernorm6360]

Rick your only about 5 lines from the top so your comment is not wasted. I read it and i make note. Even though its not finished Donkey does a real good job of explaining electronic circuit blocks for beginners like me he has given me enough basics to look around youtube for other tutorials on electronics and there lots of those that don't explain basics. Thanks for the heads up. I specially like the way he explained the block diagrams very slowly. to help beginners understand every step. see I'm already babbleing. Cheers

[@ohmedarick1]

This is the best tutorial on switch mode power supplies. A++ Thank you

[@josephsirois2353]

Thank you so very much, you are so clear and concise, I've been out of electronics repair since 1990 and trying to get caught up!

[@DonkeyLearningIT]

You are welcome. Since 1990 some things have changed, but most things stayed the same, as usual. Are you interested mostly in digital or in analog/power electronics? Namely, nowadays everything have become digital.

[@patagualianmostly7437]

Same here Joseph...I gave up with the introduction of the microchips.... But when you consider now, that most problems are directly down to the power supplies.... this stuff here is extremely useful. The microchips, after all, are dealing with currents that are so infinitesimal, the problems, generally, are 90% of the time somewhere in the power supplies...Where heat & current levels are high...and there are lots of them..... I strongly recommend the videos of TAMPATEC.

[@vubur7742]

Thanks so much for taking the time to make such an informative video!

[@leonalexander26]

You teached me so much! Your diagramm is really easy to undertand aswell! Greetings from Germany. Leon.

[@DonkeyLearningIT]

I'm glad you liked it! Though, this is just the first part of the series, most likely you want to go through the videos in the playlist. Grüße aus Österreich!

[@Vidya1939]

Let me tell U ,I feel U R the best teacher in my opinion. I will follow u r next video. Tks for this first part.

[@samuellourenco1050]

It was about time to see such videos. This subject was never well explained before. Thanks for sharing!

[@DonkeyLearningIT]

Thanks for watching and commenting as well!

[@weerobot]

Awesome better than all Universities in the World....!!

[@DonkeyLearningIT]

Thanks for the positive comment. Though, I really hope that university education will never degrade below the level of a random video done by a donkey published on a social media platform. I still have hope in higher education...

[@weerobot]

@@DonkeyLearningIT lol...ok

[@prabaitzme3811]

everyone can understand ur teaching method....fabulous

[@3niknicholson]

6:58... semiconductors are named after their half way position between insulators and conductors, not because of a preference for DC. Apart from that, thank you for a very good, useful and instructive video.

[@TheMadMagician87]

Great video, and excellent approach to breaking the system down to explainable sub-components.

[@imampermana1800]

Great vid. Im a newbie who try to fix my totally dead projector, and it is what im googling for, can't wait to have the next vid. Thank you

[@DonkeyLearningIT]

The follow up video will be up next week. Btw, is the lamp of the projector actually being fed by an SMPS? Just asking, since in the more simple projectors which I have seen had no regulation, and they used just a special high pressure incadescent halogen lamp.

[@tibitec8008]

Thank you very much! Very good explaining. I am electrican and repair TV s for fun/ hobby. i don't like the way of the manufacturers nowadays. They want that we buy every 2-3 years new insted of repairing the items. Your video is the best that I found in the last two years. I am looking forward to the next video

[@imampermana1800]

It is sony vpl-dx140, the stand by led doesn't come up. If i disconect the mainbord there are only fluxtuating 1 to 3 volt, 8 to 11 volt, at the output meauserment of the SMPS.

[@DonkeyLearningIT]

Are there any voltage levels shown on the PCB? I mean on the PCB mask are there any explicit levels defined, like +5V or +3.3V for the standy-by? If there is an explicit stand-by voltage shown, track it down, and try to figure out where does it go on the PCB of the SMPS. First thing what *must work* is the stand-by power (it will be covered in the second video, which I have already half-way done). Be *super* careful of not to touch anything due to the high voltages present! By fluctuating voltage do you mean that you move your multimeter on different output leads, or you keep it on the same lead, and the voltage fluctuates? In the latter case the SMPS might be just turning the high power stage down, since it detect no load on the output.

[@DonkeyLearningIT]

Thanks for you kind words. The second part of the video is almost done. The audio is a bit messy since I am having a cold, but it should be still informative. Regarding the 2-3 years, I disagree. Most manufacturers want you to buy a new product *every year*!

[@scroopynooperz9051]

This is pure gold - thanks for the upload mate

[@surgingcircuits6955]

IMHO, very well done and well explained. You create a "real" learning experience. Keep up the good work!

[@sirronnijames2997]

great mate, simply great. also loved your comment about mathematics nonsense in university and any education about what you really need.

[@DonkeyLearningIT]

Yeah, nowadays sadly they pump you full with stuff what you will almost never use, and things which you can easily look up in a specialized engineering book. In contrast, the basic ideas, working principles and showing you the rope of designing stuff are almost never given, which is a shame when we consider how expensive "education" is. From some YT videos I learn more in 5 minutes, than I was from sitting through a 50 minute lecture.

[@patagualianmostly7437]

Couldn't agree more regarding useless mathematics: They tried to teach us how to calculate the capacitance of a component given its physical dimensions & the material used as the dielectric..... I still have the ridiculous formula somewhere, including all the factors for the various possible dielectric material....ranging from air to blackberry jam! (Only joking with the jam....but you see my point.) Why? Just why? Complete waste of time. We were training to be 1st Aiders on electronic equipment...not designers. And it still is this way today: Seems to me, they are just extra hurdles put in the way of practical guys with great common sense, but not necessarily with fabulous mathematical skills! The 3-year course I took could have been easily cut by 50% without the totally Useless-In-The-Field mathematical aspects.

[@SODA-iz8lc]

Thanks mate. This was a great vid. I'm looking forward to the next one.

[@OrinSorinson]

Never thought I'd spend so much time learning about SMPS but here I am. I'm trying to repair a blown up original Xbox PSU and I've gotten to the point where it's outputting voltage over the 5V line but it's oscillating. So I know there's a fault somewhere else and it's triggering the protection on the (new) IC and that it might be on the output side.

[@masterofnone7823]

5 seconds into the video i became a new subscriber...good job....

[@DonkeyLearningIT]

Thanks for the feedback! Btw, I hope that after you watched the rest of the video, you have not pressed the unsubscribe button twice, the unsee button and the thumbs down button as well ;)

[@Sirvirgilio]

Wow, really good, really basic but highly informative and well prepared presentation. Thanks for sharing your knowledge. Well done. I cant wait to see the rest of your series.

[@DonkeyLearningIT]

Thanks for your positive comment! Meanwhile there are multiple vids in this series, next week I will upload more. I am making the whole series on purpose to be *very basic*, but to actually give the viewer the information needed to understand how SMPS work. Once this is clearly understood, I will make videos on real repairs, because I can reference the basics and explain why I am measuring/changing the given part out.

[@shafi420]

Great video. Just amazing. You made it so simple. Can’t wait to watch the part 2 of the video.

[@iRevnant0420]

Awesome video, Sir!!! You absolutely, positively ROCK!!! Thank you so very much for making this series. Please keep making videos like this. I will watch and rewatch every one of them for sure. I love your approach to teaching and I can actually learn from you. I have been driving myself Mad over the past few years trying to understand the tech world were rushing into but I have learning issues and in most of the stuff I've studied or watched out there on these topics quickly confuse and frustrate me. I LOVE the way you walk is through this with full explanation and slides and everything without making my head hurt by hitting me with university level equations and doctoral language. (Advanced math is my kryptonite and my mental kill switch.) But you kept it simple yet made it all make perfect sense!

[@DonkeyLearningIT]

I am really happy that you found the videos informative. This means that my work what I put in them was not in wain. Btw, trust me, the problem is *not with you* since as I mentioned, even if you attend a University, they will tend to push you full with totally over-the-top useless math, without just explaining the basics. Practically after you get your degree, you have to sit down and learn things on your own. The degree is there just to get a job with it, which is really sad considering that one will spend 4-5 years for a degree, and lots of money...

[@DIYeverything513]

LOL

[@norwoodd]

very helpful, schools need to really start teaching practical theory of how things really are.

[@Paul-gz5dp]

From many years of college, schools are a business there to make money off of people, they do not teach practical skills such as how to do things to earn a living. They do not help people with actual skills to get a good income, or anything else other than theory and have not since John Dewey was involved with education. In the 1800's and was completely removed after 1980's as there were classes in the 1970's and 1980's as I had taken a few. But when all the shop classes were removed along with adding none left behind the complete education system is there only to program people to think a certain way, and no practical skills. I say this from knowing a number of teachers from grade level to college classes. Also I have a masters in engineering, and have passed the exams to be a teacher, and engineer etc. Even when I was taking the hands on classes it was not directly the school but ROP. Think about what no child left behind is, it means the classes are designed to bring everyone down to the level of the lowest student and not put them in the special classes that they belong. Also students are taught to pass a test instead of get the life skills that they need and with those skills they could pass ANY test. There is a big difference between helping and programming, when people ask for things that the ones in charge do not like they get thought programming. The best thing is to have community home schooling and get back to just a couple books as was used in the 1860's when those people could do things that most people with a doctorate would have a hard time doing. That is someone with a single room school can and did the things most are unable to do with a bachelors degree. It involves thinking for ones self, and not thinking to what someone else has put in a book. This is dangerous thought to those who pull the strings in this world. This world from what I see is there far more to promote harm than good. It is more of a crime to attack those who harm us than to harm others. This goes against everything that many of us have been taught for thousands of years.

[@aros007z]

P R you are 100 % right! ROP student here too.

[@MichaelVx]

even that im repairing Power supplies i was have no idea about the detailed things in how things are working together thanks so much for that detailed videos

[@DonkeyLearningIT]

That was exactly what I had in mind, namely, repairing these SMPS is not that tough, but once you understand more their principles-of-operation, it make repair/debug a lot easier.

[@MichaelVx]

some how yes :) because i still trying to learn things into my region since im not an English but im sure i will understand everything soon :)

[@DonkeyLearningIT]

For sure you will learn a *lot* if you keep going at it. Also, if you focus on the applied theory side, and keep away from complex mathematics, you learn a lot-lot faster the important details for repair. Designing new stuff is a different issue, for those one must look a bit deeper into the way things work...

[@Lifeless11111]

wow , best explanation i've seen on youtube so far .. good job!

[@jlwmrblack]

Very nice and detail video,can't wait for the follow up videos

[@DonkeyLearningIT]

Hi, thanks for the feedback. I got the slides, but had no time to make the video before a short vacation. After my vacation I will produce more videos, so stay tuned.

[@cameronyoung6769]

This is exactly the video I've been looking for!

[@tyronenelson9124]

When the main fuse blows on the input it is usulally down to the switching mosfet on the hot side failing, (high voltage dc side) it usually takes out the coupling resistor and the pwm driver ic

[@DonkeyLearningIT]

Agree with you. I would say that about 30% of the time the PWM IC will be dead, since on its output the +310V DC will be directly connected. However, in the other 70% of the time I still *do not trust* the PWM chip after the FETs have blown, so I almost always change the PWM controller as well. Only on those cases I try to skimp, when the switching FETs are dirt cheap, and the PWM controller is an expensive part.

[@tyronenelson9124]

and also other common failures can be down to bad caps on the low voltage dc output side, ive repaired enough power supplies in my time

[@keithatkins9394]

I suggest you make a video with your knowledge instead of comments on others.

[@muzikman2008]

Fantastic lesson on SMPSU's thanks for sharing your knowledge, I already knew how they worked, but some info is really useful that i never knew in depth. Great video.

[@DonkeyLearningIT]

I am always happy to hear that my content has helped somebody understand electronics better! Glad you liked it.

[@bjdejesus7223]

Thanks, highly recommended to my colleague your videos. 👍🏼👍🏼👍🏼

[@Bige4u]

Experience and hands on are the greatest teachers.... books, not so much other than giving you a basic idea on how things work for knowledge sake, luckily i never took the tech/trade schoold route, nothing but rip offs.

[@DonkeyLearningIT]

Well, I think that in schools nowadays very little is done for educating people. Especially the young kids just sit in the class, without knowing why they are even studying the material they are supposed to learn. Universities and trade schools in the meantime have became purely businesses, where the one and only goal is to make money, no matter at what cost for the students...

[@stm3252]

Great video!!one of the best tutorial of SMPS on youtube

[@DonkeyLearningIT]

Thanks for the feedback. This is just the first part, introducing the power input circuit. If you find the video helpful, go through the whole series. More videos are coming up, part 7 should be uploaded soon as well.

[@stm3252]

thanks for this great work.keep it up please!!

[@abdulparada6664]

Woowooh!!! Amazing step by step explanation. With diagrams and everything

[@DonkeyLearningIT]

Thanks for liking the video. I hope that if you go through the content you will learn something.

[@paulcortes5725]

Great video! Very well explained which made it easy to understand. Thank you!

[@practicemakesbetter7132]

Great video, I hope to watch all your videos, thanks for sharing!

[@stephendianda1543]

Thank God I found your channel.

[@isaactodzi939]

Great explanation on SMPS. I really love it Can't wait for the next video #7

[@alfawasia9036]

Excellent...i wanna know the difference between NTC wich used to limit inrush current and the viaristor whic used with fuse in protection srave?

[@robj7481]

An MOV shorting and popping a fuse is called a “crowbar circuit”. And the 110VAC and 230VAC mains input voltage is irrelevant to a SMPS power supply that has a “power factor” stage (you can tell if it has a power factor by the lack of a 110/230 switch). The PFC will always regulate B+ on the bulk cap (large cap) to roughly 300~400VDC. If you see (mains input voltage * .707, VRMS) voltage on the bulk cap (77VDC for 110VAC operation), then you lost the PFC stage. If it’s there, then you lost the secondary output. If the secondary is there, but drops out within seconds of power on, then you either have an under/over voltage or a feedback problem to the secondary output’s oscillator (usually an opto coupler). If the secondary is totally gone, then you’ve usually lost a MOSFET or the oscillator is dead (check the gate of the fet for oscillation). A bad “boot capacitor” can cause a power failure in a supply that’s been operating perfectly and doesn’t come back on after power down. Bad caps can also cause every problem in a power supply.

[@HandymanBe]

❤❤❤ good explaining about how this works

[@hadireg]

Great way to organize ideas!! well done👍👍

[@anthonyreyes2417]

Thanks boss now I know the basic step by step ..hope to see the next video soon...

[@AladarEdits]

Very good information for me. I have a question : My Panasonic music system create noise like humming on radio mode when I power on my house led bulbs, chargers etc. What is the solution to get rid of humming noise. Thanks in advance

[@stevosteve]

Superb description. Top man.

[@ThriftyToolShed]

Excellent video, thanks for the time you put into this! Explained very well.

[@fredcrayon]

Thank you for your brilliantly clear lesson, well done!

[@rosco4659]

Great video. finally i understand switch mode

[@DonkeyLearningIT]

Ahh, you just got started understanding the Matrix, but this is just the beginning ;) There are several more videos in the series, and next year I will upload more until I cover all parts.

[@viz8390]

Very easy to understand. Thank you sir.

[@jessuelangue2761]

Very informative and easy to understand. Thanks

[@Khujandiho]

I was looking for your video for 3 weeks)😊

[@bernarddoherty4014]

Absolutely positively Superb! Very well done. Great teacher.

[@InterRad1]

I could not agree more with tampatec. The series of videos is absolutely fantastic. I will be sending links to my friends who might be interested. Thank you very much. Your presentations are wonderful and even for my puny brain they will be imprinted for a much longer period of time than would have been the case with all the math and a book. My undergraduate degree is in mathematics but this is much better. Having watched your series of videos I fully understand why you have broken this information down this way and have this much detail in your presentations. Thank you so much for all of your efforts. Do you have a patreon account?

[@jayjwin1178]

this is a helpful series. thanks.

[@misterbonzoid]

The reason semiconductors are so called is because they are less conductive than conductors and more conductive than insulators. Not a preference for DC as you suggest around 7:00

[@Solder_it]

Ok, you are right, but dont just skip all the good info he said to catch him on this only, everyone makes mistakes, there is another mistake he said when he was talking about the NTC values but its fine everyone makes mistakes and im sure he learned from it. Thanks to him for the good video

[@rmanzanog1]

Part of these these power supplies is directly connected to line, so there are floating high voltages that could be dangerous to manipulate, especially in places with 220 volts. Even unconnected because of the charge of some capacitors.

[@yenal5258]

The best teacher....

[@cakeinfo6510]

Thanks you sharing, very impactful knowledge

[@1973jdmc]

If you were a super hero you'd be MR FANTASTIC - a massive THANK YOU

[@DonkeyLearningIT]

Thanks for the comment, made my day. Related to Mr. Fantastic, I was thinking about that famous Frank Zappa song ;) Cannot write that refrain from the Bobby Brown song here, because KZbin would censor it out.

[@relanandrew2308]

really u have done a great job bro, we are waiting for new electronic tropic from u in future.

[@DonkeyLearningIT]

Thanks for the comment. I am just editing a long (30 min) video of a teardown, detailed analysis and repair of a 450W Cisco switch mode PSU. It should be interesting for a large portion of my subscribers ;)