Howto repair switch mode power supplies #1: basics, and block diagram of a PSU
Vložit
- čas přidán 1. 04. 2017
- The repair of switch mode power supplies (SMPS) is economically a good investment for electronics repair shops and for hobbyists. However, in contrast to the old low frequency transformers and linear power supply units (PSUs), SMPS are rather complex. Still, due to their low weight, high efficiency, and being able to provide stable voltage output, they have became an ubiquitous component in almost every electronic equipment.
I assume that the viewer has only a basic knowledge of electronics. In this video series we will cover SMPSs and ATX computer supplies starting from the basics and going into the details in the repair of such units. Here we look into the most important components and building blocks of an SMPS, and we cover the block diagram. Understanding the block diagram is highly important, since it provides an easy way for a technician to narrow down the potential components which are defective in an SMPS unit.
Due to high amounts of heat dissipated and high switching voltages, and frequencies, power supplies are the most frequent source of failure. Thus, although it takes more time and effort to understand the basics of SMPS, in the long turn it pays off to learn about their inner workings and also about their most frequent failure modes.
In this video we cover the power input, filtering stage and rectification portion of an SMPS. I explain the need for inrush current limiting. Next, the power distribution is explained on the high voltage DC side, where through the two different paths the stand-by and the high power chopping circuits will be fed, driving the transformers.
The main building blocks and how they are tied together in a modern switch mode power supply:
-power input plug or cable for mains voltage
-input protection (fuse, metal oxide varistor MOV)
-EMI/RFI filter (Xcaps, Ycaps, common mode chokes)
-rectifier diode bridge
-inrush current rimiting NTC Thermistor
-active or passive power factor correction (PFC) circuit
-bulk mains filter capacitor
-controller circuit for the FET of the stand-by power and main power
-switching FETs
-stand-by and main power transformers (high frequency ferrite)
-Schottky diodes for the secondary side rectification
-electrolytic filter caps
-voltage reference circuit
-optocoupler and feedback loop
-over-voltage and over-current protection circuit - Věda a technologie
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 😎👍
Finally someone explains what the parts do and in what order they do them , Thanks !
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.
Why are you watching electronics vids? I thought you were an architect...!
start from 5VSB check
Yes indeed
@@paulrichard4945 scammer
Understanding electronics in layman's terms ,I've learned more in this video than hundreds of other ones thank you 👍
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.
The best video I have ever watched about psu's. Thank you, appreciate it.
Absolutely brilliant. I love the diagrams and your abstractions are spot on for me.
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.
You mean that your teacher never taught you well?
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!!!
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!
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.
Came for basic info on switchmoded PSUs, got a whole series on design and parts. A++ thank you.
Sir, your series of videos about power supplies is absolutely perfect. Thank you very much for explaining everything. Give this man a cookie.
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
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!
Thanks mate. This was a great vid. I'm looking forward to the next one.
Best video I have seen for explaining how a PSU works. I'm looking forward to watching the next parts! Thank you!
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.
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.
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.
Finally found you again! The most comprehensive playlist on smps working. I am so thankful to you. :)
Thanks so much for taking the time to make such an informative video!
Great video. Just amazing. You made it so simple. Can’t wait to watch the part 2 of the video.
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.
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.
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!
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.
This is the best tutorial on switch mode power supplies. A++ Thank you
Nothing can be better explaining SMPS than this video. Core level and clear explanation.
Thanks for the positive comment. I am happy that you liked the video!
IMHO, very well done and well explained. You create a "real" learning experience. Keep up the good work!
Thanks, your videos are among the best on CZcams for the practical repair of electronics power supplies.
Well, so far I am presenting mostly theory, and many people are complaining about this. However, explaining practical repair without basic theory is impossible.
wow , best explanation i've seen on youtube so far .. good job!
Went through 20+ videos before finding yours -- by far the most helpful for a newbie like me. Thank you!!
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 CZcams. Making the same material looked kind of pointless, this is why I try to go through step-by-step.
Great video, and excellent approach to breaking the system down to explainable sub-components.
Are you serious? Where have you been my whole "electronics" life?
Definitely the best video on components ever made!! Very Much Appreciated!
Thank you, you are such a great teacher subscribing and notification is on. Thank you thank you.
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!
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.
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.
Thank you thank you. I'm watching from Zimbabwe Africa. This what I was looking for. I love your video.
Great explanation on SMPS. I really love it
Can't wait for the next video #7
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.
Great course, thanks for taking the time sharing this, much appreciated 👍🏻
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.
I am always happy to hear that my content has helped somebody understand electronics better! Glad you liked it.
Super great video! Can't wait to watch part 2. Awesome!
One of the best tutorial video ever on this topic.... thanks a lot for sharing
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!
Many thanks for the positive comment. I hope that by watching the other videos it gave you more insights as well.
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!
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...
LOL
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.
Thank you for your brilliantly clear lesson, well done!
Great video. Looking forward to next in series.
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 !
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.
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 ?
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.
It was about time to see such videos. This subject was never well explained before. Thanks for sharing!
Thanks for watching and commenting as well!
After all these years on CZcams, 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.
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.
So very true!!!!
@@DonkeyLearningIT you should try to activate the CZcams version of patron, I bet people would send you those CZcams super thanks. I tried but I can't. Thanks for the video
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!!!!
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.
Me too!
This is pure gold - thanks for the upload mate
Absolutely positively Superb! Very well done. Great teacher.
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!
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.
@@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
@@nosafetyswitch9378Many thanks for the feedback. I am glad that the video was somewhat informative even for an EE student.
You teached me so much! Your diagramm is really easy to undertand aswell!
Greetings from Germany.
Leon.
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!
Excellent video, thanks for the time you put into this! Explained very well.
This is exactly the video I've been looking for!
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.
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
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.
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
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.
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.
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*!
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!!!! 🇧🇷🇧🇷🙏🙏🙏😁😁😁
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.
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.
the best video about how switch mode power supplies work
Thanks for the positive comment!
This is a brilliant video. Thank you!
Really helpful and awesome lecture. Please keep on.
Thanks 1000x :)
Hello Sir, thanks for the explanation,I really enjoyed it and I wish to have more videos like this one from you. I love Electronic so much and I'll like to be an expert in this field
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 👏👏👏👍
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.
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
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.
Samsun lcd
Sounds like ITT to me. I went there 2 years. On the job training gives much more valuable experieince.
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!
Very informative comment.
Especially microwave oven capacitors ;-)
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.
great mate, simply great. also loved your comment about mathematics nonsense in university and any education about what you really need.
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.
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.
Information and explanation = Amazing
Accent = Priceless
Keep up the good work! I'm a huge fan!!!
I think he's Romanian.
@@milanhorvat6494 Austrian
Great video!!one of the best tutorial of SMPS on youtube
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.
thanks for this great work.keep it up please!!
Awesome video man. It so understandable thanks. We want more videos like this.
beautifully done am now going to watch your other vids thanks a million
Woowooh!!! Amazing step by step explanation. With diagrams and everything
Thanks for liking the video. I hope that if you go through the content you will learn something.
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.
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.
Great video, I hope to watch all your videos, thanks for sharing!
Great video! Very well explained which made it easy to understand. Thank you!
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?
wow! wonderful series!
i really appreciate your efforts for this videos.
I also appreciate it when people take their time and watch the series, since it shows me, that it was worth putting effort into making the videos. Keep on watching, more will come after I recover from this darn cold...
Thank you for the explanation ! very clear content and very useful i directly started to apply that in my work
Thank you so much. That was amazing! God bless you always!
Thanks for the comment! Wish you all the best to you as well.
Thanks, highly recommended to my colleague your videos. 👍🏼👍🏼👍🏼
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.
Nagyon jo video,koszonom szepen!!!
Great video. I can't wait to see next part.
Thanks for the feedback.
To make the upcoming vids more informative, I am wondering whether I should go into more details regarding the "block diagram" portion, or get over the blocks quick and instead concentrate on the individual components later...
Very well explained! Thanks!
Excellent introduction to SMPS. This first series really set the tone for a good learning experience. Coming from the old school (linear) and learning the new school is a positive and interesting way to learn. Looking forward to learn from you... Joe-K4JGA - JGA Electronics Repair Center - Fl.
I am glad that the videos can provide some info even for veteran repair guys! Originally I intended the series to be very basic. Still, slowly but surely we will go into more advanced stuff, which will be interesting.
The day we stop learning is the day we die! Electronics is a progressive field. We old repair guys need to keep up with the new technologies and apply then. Even in my late/mid 50's I still attend seminars and currently enrolled in another electronic field course! Thanks for sharing. Success my friend!! Joe-K4JGA - JGA Electronics Repair Center - Fl.
Great, really helpful video. Thank-you so much
Bravooo, estraordinaria explicacion del funcionamiento de una fuente conmutada, gracias.
Thanks for the feedback. Based on google translate it is positive, though for the username I got some weird results... ;)
Very helpful video,thank you!
Stick around for the new videos as well. It takes a while for me to produce a video, but sooner or later they will be uploaded.
Thank you for your service!
Thanks you sharing, very impactful knowledge
this is a helpful series. thanks.
Thank you really much, this guide helps me a lot.
everyone can understand ur teaching method....fabulous
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
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.
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
:)
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...
Just got more thumbs an subs comrade, our collective pursuit of, and access to knowledge(like this especially) benefits all society. =) thank you.
Subscribed before watching to the end!
Very nice and detail video,can't wait for the follow up videos
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.
Thanks boss now I know the basic step by step ..hope to see the next video soon...
Great Video Nice Explanition