How A Switching Power Supply Works

[@jordannaumceski2269]

Never mess with a man who draws and writes with both hands 💪

[@jazieltripp1040]

i guess im asking the wrong place but does anybody know of a trick to get back into an instagram account..? I somehow forgot the account password. I would appreciate any tricks you can give me!

[@OFDM-network]

34:13 Capacitor passes AC to ground and blocks DC keeping it at the side of input power line, not letting it to ground. This produces even DC voltage at power line. This is the best education channel on KZbin :)

[@bblackdogg4352]

Thank you, Master Sorin. I Certify/Repair Air Traffic Control Systems for FAA in the USA and learn much from you. I have great respect! People like you make the world a better place!

[@barcatalin8346]

Best electronics teacher, lesson for everyone, specialy for smart kids, beginners in electronics. We all need your lesson in electronics. Cel mai bun profesor de electronica, Sorin tine tot asa, cu totii avem nevoie de tine, de lectiile tale unice.

[@francismannion7075]

Sorin with each view of this video I understand more. Thank you.

[@Dr.muthanna]

Thank you Sorin you are not only a practical person you’re an academic teacher

[@zoltankecse991]

It's true.

[@Tomtech29]

Sorin you will have to correct it because not to confuse transistor opening with with a lock as it does here but it's understandable when you say open you mean is able to lead (Transition status) position of the switch (N.O) means normally open -you're doing a good job Gentlemen, take this opportunity to learn

[@steveolsen2164]

Great explanations. I've been in electronics since the mid 1960"s and have grown up with tubes, transistors, IC's, etc., etc., etc. BUT always the basics stay the same. Devices get smaller, power demands increase, but the theory (and physics) stays the same. It's not magic (usually). Keep it up! We are never to old to learn. We just need better eyes ;-). (You didn't explain that the "B" power term comes from using a "B" battery used in the 20's with the A, B and C battery radios.)

[@shindvs1150]

Me too same

[@destination-nn1zq]

Absolutely brilliant demonstration with the analogue meter and the capacitor to show how a capacitor works to iron out the ripple of an ac signal, smoothing it out to create a nice dc supply for the output stage of a power supply........

[@adriannsk5702]

I was waiting for a video like this /for a teacher like Him/ for 20 years! Maybe more! Thank You, Sir!

[@allangumikiriza4952]

Keep it up for not being selfish with all this great knowledge in electronics

[@Fourty_7]

Now i understand why this channel was called " Electronic repair school " ❤

[@patrickmaritano3802]

Thank you so much Sorin for the time you spent for our knowledge !

[@saysles]

I love your explanations. I was taught to use open when switch doesn't pass and closed when it does pass.

[@hackersgaming1526]

When switch is close coil store megnitic field when open coil discharge +bat =more voltage out by s.diode

[@samchrome-g8v]

Thank you for the expiation , very clear now, and all those capacitors are connected in parallel. because they are connected to the power positive. They work hard.

[@hepburnwilsonsr.2025]

Thank you for teaching this old guy!

[@ClarkXDupont]

Sorin is Mister Logic. Great lesson!

[@maxgrove1661]

Excellent video Sorin. Makes it all clear now thanks.

[@donbox8073]

Excellent explanation Sorin

[@janparra9551]

Sorin you are the best and Thank you for simplifying for us a hard subject

[@hvala73]

Excellent video Sorin.

[@janosgajda5287]

Thank you for the video. One thing got into my mind: Sorin is the first bio-mechanical component in a switching power supply :)

[@banjoperator]

Sorin,, i had been having alot of difficulty understanding the process as to how mosfet, and capasitors worked in a powersupply , being a dyi person without any formal training in electronics.. however when you expllained there function as a swithch along with how current flows as like am frequency,,,well another door opened in my understanding, now having looked up the parts of a mosfet and capasitor , i now understand how when one fails it stops the flow of curent and thus the next circuit has no power and thus the funcrion of the ..ummm..devise..stops.. i wish i had watched this before.. thank you for another step in my understanding..cheers

[@photoguytom]

Another way of explaining the use of caps and coils is by looking at what is called impedance. In both AC and DC a resistor drops voltage. The equivalent function of caps and coils in AC is called impedance. With caps, the impedance decreases the higher you go in frequency, with coils it is the opposite the impedance increases with higher frequencies. Caps pass high frequencies - in this case to ground, and coils restrict high frequencies, in this case from going further through the circuit. Also what can be mentioned is what a square wave is comprised of. When you create a square wave, it is actually comprised of the fundamental switching frequency, plus odd harmonics in decreasing amplitude. So in your explanation where you are switching the mosfets at 300Khz (the fundamental frequency), also present are the third harmonic or 3x the fundamental = 900Khz, 5x = 1500Khz, 7x - 2100Khz, 9 times or 2700 Khz, etc. all in decreasing magnitude. These are all radio frequencies. So the caps are there to remove the fundamental, as well as those harmonics, which can cause radio interference. They effectively "purify" the DC voltage that goes to the digital circuitry.

[@allangumikiriza4952]

You are the greatest technician i ever seen some times i do wonder how you mastered all this electronics

[@LaptopDisassembly]

Hell, you're getting better and better in the explanations, after each video. Excellent Video as always. :)

[@jameswilson197]

Great teacher you are Sorin. However we still use AM modulation in Amateur radio and commercial radio here in the USA.

[@james.8985]

WOW you can draw with both hands 😲 now that's COOL !!🤙

[@karolrozycki6263]

Soon will be 50000 subscribers. Congratulations!

[@PerrynBecky]

Hi Sorin, doesn't the current change at the power supply from A/C to DC in the power pack before the input jack on the laptop? If so, why does the power supply need to have a capacitor on the 19v rail after the input jack? This video is so fascinating, I'm having to rewatch it several times to comprehend it as my understanding of electronics of this kind is very elementary. Thanks for these lessons. You have a big heart. I wish you lived nearby, I would definitely volunteer my time to do things for you even if it was just to be a gopher as long as I could learn from you too. Plus, I would donate some of my laptop parts to you as well for your repairs.

[@vlatkosurlan545]

Because the charger gives you a nice, pollished 19V at the input jack but after that, on the motherboard, there are many smaller buck converters which convert those 19V to 5V, 3.3V, 1V etc. The reason for the capacitors is that those small power supplies/buck converters located on the laptop motherboard itself reduce the voltage by generating a modulated pulse which also gives you a choppy signal at the output which looks like this: upload.wikimedia.org/wikipedia/commons/b/b8/Duty_Cycle_Examples.png. So to get a normal, smooth signal which can be consumed by the motherboard you need to polish that pulse to get a steady voltage and that is achieved by those caps.This is what the caps do to the pulse: pcbheaven.com/wikipages/images/pwmmodulation_1236520415.jpg After that, the voltage is steady and ready for consumption.

[@GPSOMG-]

I think what would help people out more who are learning, when your drawing schematics you could also have present capacitor , transistor etc (excetera) So people can relate to what you're talking about to the actual schematic and what the competitors MOSFET transistors look like just a thought? And I would like to say I also I'm learning from you thank you for your time.

[@electronicsrepairschool]

ok, i will

[@sijmengrunbauer7697]

Yes, I agree. Sorin, when you were talking about the dual MOSFET TV power supply, I first thought that the supply line was mains voltage, and was confused about where the isolation was. If you had mentioned things like input voltages, it might have been clearer to me that this was a secondary power supply (at least that is what I now understand). Also, as an Australian, I would like to say, what a great video it was. I look forward to watching more of them.

[@nikaldo7819]

best explanation on youtube......bravo

[@paulhancu3206]

Hello Sorin Nice video and next time maybe explain what happens with the coil and how it generates the higher or lower voltage depending on the configuration and the smoothing capacitor after the coil. Actually I think you should start explaining the conversion from ac to dc with a full bridge and show the sinus and what the capacitor does to smooth the sinus to dc because it't easy to explain the role of the capacitor in this case so they can easier understand it's role in the switching power supply. Thank you and keep up the good work!

[@johnoddvar1967]

Thank you for your good explanations. Yo give a very practical approach to electronic repair.

[@RafalPospieski]

Xd

[@loverboykimi]

It was very useful and clear. Thank you Sorin. What about coil/inductor ? Could you do a practical session for coils like capacitors?

[@JulioSantos-up2gz]

Very nice explanation Sr.! God bless you!

[@ThEwAvEsHaPa]

thanks Sorin, a great lesson. really good explanation of the capacitors it helped me understand it better.

[@davidlingaard860]

Hi sorin, how di, thank you for the videos on power supply, i learning a lot from you.

[@navinperera8699]

You are a great teacher.

[@ziggyironic]

Thankyou for sharing your knowledge, you are very good at explaining things.

[@808yorkie]

Thanks for the insights and the complex to simple info.

[@endribedini9608]

Great job, just the open and closed explanation of the mosfets is inverted. By open you mean current is passing = closed switch. By common meaning, when we say open, means no current can pass through and closed means current will pass through. Thanks for your job.

[@Dr.Leszek]

Thank you for great lessons, now i've got the point how it works

[@RepairsMX]

wow., it Really opens my mind about how it works. thank you very much.

[@bar2280]

Great tutorial best teacher! Do you have any tutorial about class D audio power amplifiers and clipping problems in amplified speakers? Keep the exelency and wish the best!

[@prakashsharma6186]

For the first time I can see your face. It was required since long. Thx 😄👍

[@ravindraadapa2952]

awesome explaining i understand a lot from you sir thank you sir

[@СрбићСрба]

thank you for a nice tutorial. Greetings from Serbia.

[@cambyelectronics2075]

Very informative, well explained Sorin, Thank you....

[@filmidla]

You are very good teacher I have a question. Why we use power supply in laptops? We cannot just plug 19v to the rest ? Why we use switching ?

[@tekmusti]

if an electronic teacher has watched that video,probably he would give up his job. basic , logic and simple all together.

[@frankyval1303]

Perfect lesson. Thanks Sorin!!

[@Waaasil]

Thank you very much Sorin, I'm really appreciating your videos.

[@Asynthetic]

Nice tutorial video. Very good explanation of things.

[@kenknoske1564]

Sorin you are the best! Thank You!

[@IsaacOLEG]

you did great ;) and now , pfc starting sequence explained similarly would be huge ;) t-hanks

[@MrRvdbeek]

Sorin you did great. When the cab is shortted because there was a problem. I remove the cab no shots. What can happen? When it looks fine.?

[@switzzzz1]

Another very good video.You should be teaching in a college.There every day is Friday.

[@teoginesviente5791]

Its a refreshing one for me, Thank you so much sir.

[@iconiatab5969]

This is perfect lector A+ its easy. Very thanks.

[@ЙорданТотков]

Thank You for the video, this was very helpful for me. Keep doing the lessons. Greetings!

[@blink4you4]

Great video, keep it on, you got very useful videos, thank you

[@laboratorioassembler]

Thank you Sorin

[@Digitaltiger123]

Basicly about the capacitor at the end another way of saying is that it keeps the voltage up instead of going straight to zero in the sinewave.

[@viswanadhambagati5556]

Thank you....... Lot of my My confusions were vanished...

[@Koick100]

Great Electronics Class!!!

[@ceejay_gaming9636]

Really appreciate this content

[@francismannion7075]

That was very interesting, thank you Sorin.

[@didierabder8455]

Hi Sorin. One of the best video ! Question: why do we modulate using mosfets if the output capacitor make stable like a straight line ? What component generates this modularity connected to base on the left hand side. Thanks

[@redserpent]

NIce job Sorin. I enjoyed it.

[@AtmaS]

Thank you Sorin. A great video.

[@ciprianvirjan]

Multumesc frumos!!! Felicitari!

[@RafalScrapper]

interesting thanks for info it was nice to listen 👍😀👍

[@Frank55]

Say you want 3.3 V. at the output. The power supply for this voltage is the 'push-pull' configuration with two MOS FETS. Now what happens if the 'top' MOSFET gets shorted? In this case the high voltage (maybe 19 v.) will appear on the output where 3.3 V. should be. Is there any protection to prevent this kind of disaster?

[@jm7296]

If I ever have a daughter, I'm gonna name her 'Dazmean'... lol... thanks for ur teachings.... accent and all. Cheers

[@Philippe-Philou]

Excellent Sorin, Thank You Sir

[@SanjayGupta-zm3zz]

Great lesson. Thank you very much.

[@seagorman]

Excellent Video as always Sorin, thank you

[@bobydz]

Thank you for the lesson. I want to know why is the capacitor capacity (µF) so important when replacing them?

[@wisher21uk]

Noureddine Babah it’s all about how long it takes to charge fully example 10uf cap will charge quicker then a 1000uf if you’re replacing a capacitor you can go up voltage but not down so if you need 750uf 35v you could safely use a 750uf 50v or maybe a 800uf 50v the idea of going higher on voltage is that it can help them last longer because sometimes they put 15v caps on a 12 v line and with spikes and ripple it can go over the 15v so going over on voltage can be a good thing

[@lpelectronics3747]

The answer is complicated. There is one more general term in electronic engineering. This term is electrical impedance. You have to have the same electrical impedance if you replace something with the impedance the designer calculated for the circuit. Impedance is directly related to capacity and the working frequency. Of course someone can take off of a power line a filtering capacitor without a lot of danger but only if there are more on this line not in any other case. So, generally speaking for repairs use same µF and same or higher voltage rating. Except if you are Sorin. :-)

[@wisher21uk]

TheWertyu2007 a cap is for either timing or smoothing when he takes out a cap it’s more then likely for a bit of smoothing, electrolytic caps are tested by an ESR METER peak make one they are the bees knees, there measure the Uf and the resistance a cap can look good nice and flat on the top but it can be dried out and be low on the esr meter example 1000uf cap may only be 300uf and have instead of .4ohm resistance it has a 4 ohm resistance,.......diode mode is really good for finding shorts put the positive probe on ground then probe around with the positive probe it works and is the best way some people use ohms instead of diode mode

[@krlenjuska]

Can you explain how feedback circuit works and how IC determines current limit?

[@TheBaregel]

sorin so what about the cases you short the I/O of mosfet together? that move will not abort all the mechanism of the frequency and the coil?

[@minoodeboo]

Those capacitors connected to +Vcc/+Vdd or +ve power rail are called "de-coupling capacitors"

[@mrOga]

Thank you Sorin, but you forgot to explain the source and nature of frequency that switches the mosfet through the gate

[@ЗлаткоЗлатев-э5к]

I Love You Sorin

[@TheMaGGiiiii]

Thank you very much Sorin. You realy help me to understand it! I Love your Videos.

[@Radek__]

17:21 Sorin i DO NOT understand this part. I was thinking that in TV the mosfet is there to control how much voltage is going to primary side of transformer. If you can change voltage on primary, then transformer will change automatically the output voltage on secondary side. This regulation helps to keep always the same voltage on output -no matter how big or low current TV will take later. So with this regulation we don't have the voltage drop. So that mosfet has maximum voltage on the source but it will allows the voltage to pass and go out only that much, how much the controller regulator chip will decide. So controller chip is using that mosfet and decide using his gate pin to control how much voltage should goes to primary side of transformer. And he knows how much must be, by rading output voltage which is coming back to from transformer secondary output to him by/trought optocoupler ic, which helps to keep secondary and primary side separated. If he see the voltage drop, then he will send "orders" to mosfet to rise up the voltage on primary side of transformer and if the secondary voltage will rise to much up, then he will send "orders" to mosfet to drop voltage on primary. SO i was thinking like that. I was wrong? I do not like and i'm affraid AC voltage so i know less about it that DC. So maybe I dindn't understand correctly what did you draw there at 17:21.

[@electronicsrepairschool]

Ok, u'r right, but hopefully you know the transformers are working on ac, not dc, right? Otherwise all what you wrote is correct.

[@Radek__]

from some time yes, but before I was thinking that there is two types of transformer - for AC and DC. now I start to laugh when I think about how stupid i was :-)

[@bomba6921]

Can i ask why this type of power supply is not preferred for finding a short?

[@fayrose3797]

Thank you.

[@Hindi61]

thanks you for these greate vidoe. I want to learn repair motherboard but i dont understand where to start any tips

[@seraloa8296]

im doing the same... best i can tell u just keep watching videos the more you watch the more u undrestand how stuff works

[@harounsahnoun]

Thank you mister sorin

[@amiramar2452]

man..you also spicked my understanding

[@joserodriguez-zp1zx]

very good, jose from Bolivia..

[@michaeldewawong977]

Great explaination

[@katoexotics6215]

What computer program you use in this video.

[@v1ncend]

I Will watch later but big thanks now !

[@asmvax]

Thank you. Good lesson.

[@ionix2000]

😊very usefull video. Thank you

[@n3o325]

yay, learning time!!! :). BTW I gain a lot from your video sir. Thank you

[@publicojornas1787]

And is AC/DC conversion, as well as generating voltages and multiple currents, not also the function of a power supply?

[@rizwanshaa]

as usual best vedio. if you can please mention the vedios with beginner course, then easy to differentiate.