Thanks a lot for the generous offer of knowledge.

@sambenyaakov

25 күн бұрын

Thnks. I appreciate it.

Thank you for the lesson professor! This was really good, I wish my power electronics professor was more like you.

@sambenyaakov

5 жыл бұрын

😊

Dear professor, I am a lab technician in IRGC’s college of electronics and the way I was taught the concept of magnetic induction in a fly back topology based on when S1 is closed and the S2 is open them the magnetic flux will be induced in the primary and when S1 open and S2 is closed the induced flux will be released via S2 into an energy storage like a capacitor. Your dot convention therefore should be opposite otherwise when the S2 closes there will be high voltage spark which will destroy the switch ,normally a diode or a FET. With love from Khorasan

@sambenyaakov

2 жыл бұрын

Please indicate the minute of video you are referring to.

@johnkyingilisi4395

2 жыл бұрын

@@sambenyaakov Dear professor Yaakov, I am sorry I couldn’t get back to you sooner and I feel a bit ashamed for questioning you on a small item in your fly back video especially with the epic job you have done so far. Any way using S1 and S2 is ok with me when explaining power supplies but on this occasion I would like to replace S2 ,as just a contact switch , with a diode instead in order to make it easier for me to explain. Let’s place a diode in the secondary coil circuit in such a way that the cathode faces the coil in the same direction of the current in your example. This way when primary is energised the magnetic field resulted in the secondary will induce a current flowing in the same direction which will result in a voltage in phase with input voltage, but the way I see it you are using 240v which produce peak voltage of 320v in order to produce 5 or 12 volts the other side (with higher current of course) which is not very efficient method .Where as if you change direction of diode and move the dot on the secondary to opposite side of that of primary , then when the primary is on the diode is reverse biased and energy builds up in the coils and when S1 is open magic happens and the magnetic field of B flips and reacts with secondary coil surface area of A which will cause change of flux per time which in tern causes an EMf of negative voltage. B.A= d(flux)/dt=- EMfv (Faradays law). That aside, may I say that your videos on Switch mode power supplies not only good but head and shoulder above the rest and I thank you for it and wish you long life and happiness. PS, I hope to god my boss wont see my comment admiring a lecturer working for a university which is named after a degenerate mass murderer.

As you said, An intuitive explanation. Thank you very much from Spain.

@sambenyaakov

4 жыл бұрын

Thanks😊

Thank you for this awesome video professor. This video has been in my watch list for more than an year now. This video clears all of my doubts on flyback converter. I've been hearing from my colleagues that flyback is the toughest topology for passing EMC certification tests. Now I got the main reason. Discontinuous currents at both input and output it is!

@sambenyaakov

3 жыл бұрын

Glad it was helpful!

Thank you professor for your efforts in making such clear presentations. Your channel is my “go to” when I need to understand electronics. All the best, Paul

@sambenyaakov

2 жыл бұрын

😊Thanks for comment

i was struggling with flyback transformer design, the video clear my doubt on the current flow direction on each stage. Awesome video!

@sambenyaakov

6 жыл бұрын

Thanks for comment

Thank you very much. I had a lot of doubts about this circuit until I found your video. It was really helpful.

@sambenyaakov

4 жыл бұрын

Thanks for comment.

This should help me in my interview tomorrow for a new job role as a power supply specialist, thank you for making this video! :)

@sambenyaakov

Жыл бұрын

Best of luck! Beat the machine: lnkd.in/efPuimEe

thank you so much for this video. It was well presented and gives me a better understanding of the operation of a flyback converter. This is exactly what I needed.

@sambenyaakov

3 жыл бұрын

👍

Best lesson on this topic I've seen.

@sambenyaakov

4 жыл бұрын

👍😊

Thank you so much, this really is an intuitive explanation!

@sambenyaakov

4 жыл бұрын

Thanks

I've been watching a few of your videos and they are excellent! Very well put together, explained, and at the end I understand not only how these circuits work but also their significance and importance. Thank you so much!

@sambenyaakov

7 жыл бұрын

Thank you for your comment and for the time to write it. Feedbacks like your keeps me going.

Just thank you, clear, concise, and accurate lecture!

@sambenyaakov

Жыл бұрын

👍🙏🙂

Thank you professor Ben-Yaakov for a very accurate explanation and an excellent lecture.

@sambenyaakov

2 жыл бұрын

Thanks

It is a very good video with lot of basic things uncovered. Thank you very very much.

@sambenyaakov

7 жыл бұрын

Thank you for comment and for taking the time to write it.

Bro you nailed it ! Respect from India

@sambenyaakov

4 жыл бұрын

😊🙏

Excellent Explanation ! Thank You very much !

@sambenyaakov

6 жыл бұрын

Thanks.

Great tutorial; clear and useful explanations. Thanks a lot for the lecture.

@sambenyaakov

3 жыл бұрын

Thanks

Thank you very much for your valuable lecture. Love from India!!!

@sambenyaakov

4 жыл бұрын

🙏😊

So nicely explained. Feel so blessed to be able to learn from your videos.

@sambenyaakov

2 жыл бұрын

Thanks. Glad to hear that.

Thank you for this professor

@sambenyaakov

3 ай бұрын

Thanks

It was perfectly explained. thanks for such a wonderful video.

@sambenyaakov

6 жыл бұрын

Thanks for comment

Simply Amazing thank you so much Mr.Professor.

@sambenyaakov

2 жыл бұрын

Thanks.

Absolutely, very nice!!! Thank you

@sambenyaakov

5 жыл бұрын

Thanks😊

thanks you so much for the lesson. i have been looking for a lesson that i can learn SMPS from and this is the best lesson i have found so far!

@sambenyaakov

2 жыл бұрын

You're very welcome!

أشكرك وأقدر مجهودك ، تحياتي لك من تركيا .

@sambenyaakov

Ай бұрын

شكرًا. من دواعي سروري

Very clear and helpful, thank you!

@sambenyaakov

4 жыл бұрын

Thanks.

This is such a beautifully explained lecture. Thank you so much Sir.

@sambenyaakov

3 жыл бұрын

Thanks

Excellent explanation your excellency!!!! Thanks a million!

@sambenyaakov

Жыл бұрын

😊🙏

Thank you so much for this presentation so useful

@sambenyaakov

Жыл бұрын

🙂🙏👍

There is so much useful information available on Prof. Ben-Yaakov’s channel! Thank you very much for posting all your videos.

@sambenyaakov

4 жыл бұрын

Thanks😊

Thank you from Ukraine, very helpfull. God bless you.

@sambenyaakov

4 жыл бұрын

Thanks and greetings to our prime minister now visiting Ukraine

Excellent lecture, I only wish you had them organized in playlists. So much information in a clear concise lecture, true hero for education.

@sambenyaakov

3 жыл бұрын

Good point. I am not sure how to that effectively. Any suggestion? Or help😊

@swalker157

3 жыл бұрын

@@sambenyaakov here is a video on how to create a KZread playlist. kzread.info/dash/bejne/p4t4yLCympSdh5M.html Thanks again for the great lectures.

@sambenyaakov

3 жыл бұрын

One playlist to all video? How will this help? One can just go to my channel

@sameqy

Жыл бұрын

@@sambenyaakov one playlist for power electronics or one playlist for flyback, DCM mode flyback and ccm mode flyback.

@sambenyaakov

Жыл бұрын

@@sameqy All that you need to do: go to KZread , in the search box type "sam ben yaakov flyback" Walla

thank u so much doctor for this amazing video and i wishe u all the best on ur life

@sambenyaakov

4 жыл бұрын

Thanks for comment 😊

Nice explaination. The basic principal of Electronic Device is Regulation on Current Flow.

@sambenyaakov

5 жыл бұрын

😊

Sir literally no one like you . I started watching your vedio with doubt that how current can be interrupted in a winding,and you clarified it at the very first moment.. Thank you so much sir❤❤

@sambenyaakov

10 ай бұрын

👍😊🙏

awesome lectures sir

@sambenyaakov

2 ай бұрын

👍🙏

Thank to you for the explaination

@sambenyaakov

5 жыл бұрын

😊

Thank you for a valuable lesson.

@sambenyaakov

4 жыл бұрын

Thanks

thank you sir from India.. excellent video.. I learned a lot It was really helpful.

@sambenyaakov

4 жыл бұрын

Thanks India from Israel😊

Hi Professor, On the slide at 7:28, the two lines you have at the bottom referring to the magnitudes of the peak currents: is the bottom line incorrect (because I believe that the top line is correct)? Do you mean that Ipk1/n = Ipk2?

@sambenyaakov

6 жыл бұрын

Yes, You are correct. The bottom line is in error. But then, I could have said that I did it on purpose to see who is really paying attention to the contents of the slides (-: Thank you for pointing this out.I hope people will see your comment.

Ty very well explained.

@sambenyaakov

3 жыл бұрын

Thanks,

Very helpful, thank you sir

@sambenyaakov

7 жыл бұрын

Thank you for comment and for taking the time to write it.

Thaks a lot for clear explanation.

@sambenyaakov

4 жыл бұрын

Thanks

If it might be useful: I often use a visual ( a not entirely accurate one ) that the inductor is like a spring that is attached to a reference voltage level ( 0v to ???v), then the switch pulls the other end to some other level, then releases it, the un-'fixed end of this' 'spring' will snap back and 'flyback' in the 'opposite direction. This excursion is then fed into a diode to charge the output cap, which can be at some other Vreference. The placement and polarity of the diodes and reference voltages give you the type of conversion you are looking for.

@sambenyaakov

11 ай бұрын

This is why the symbol of an inductor is a spring😊Yes, this is one intuitive way of visualization. Thanks for sharing.

Thank you for your valuable videos ! I saw many videos on SMPS design but all were just book concept. I was looking something about practical designing and my search ended here...

@sambenyaakov

5 жыл бұрын

Thanks for taking the time to comment. Keeps me going.

thank you sir. your lectures are very effective.

@sambenyaakov

2 жыл бұрын

Thanks

Thank you professor Sam Ben-Yaakov, sir

@sambenyaakov

2 жыл бұрын

😊

Thank you so much

@sambenyaakov

3 жыл бұрын

Thanks.

Nice video thanks for posting and you are right flyback it came from tvs circuit

@sambenyaakov

4 жыл бұрын

👍Thanks

Awesome Video, explaining principle, working as well as uses. What more can you ask for? Sir, if possible do a video on reverse recovery characteristic..

@sambenyaakov

7 жыл бұрын

Will try to prepare one. Thanks for comment.

Excellent

@sambenyaakov

Жыл бұрын

Thanks

At 8:00 I was initially confused as to why no current would flow in the secondary since I was thinking of the inductor as a passive component. If you see it as a voltage source instead until the switch on the primary side is opened, the current flow makes a lot more sense.

@sambenyaakov

5 жыл бұрын

👍

Thank you Professor. Does the core experience a net dc excitation? The flyback converters I've seen (and made!) had gapped cores.

@sambenyaakov

3 жыл бұрын

Yes it does but due to gap the H is lower . Search my KZread channel for Flyback and gap. e.g. in KZread window " sam ben-yaakov gap"

@jjmcrosbie

3 жыл бұрын

@@sambenyaakov Thank you Professor.

Far easier to understand the action of a Blocking oscillator IF pri current flows through the pri winding capacitance during Toff (see 14:08/20:15.)

@sambenyaakov

3 жыл бұрын

Blocking oscillator?

thanks a lot for the video .. can i ask you what is the value of secondary voltage when the switch is off and the Vs value too ?

@sambenyaakov

4 жыл бұрын

Which minute in video are you referring to?

Excuse me Professor, may I ask you about MOSFET's T-off state, I still confuse why the current of the secondary winding can flow through the diode (forward bias)? How the polarity can be reversed after MOSFET switching? Sorry for my bad English, thanks.

@sambenyaakov

5 жыл бұрын

When the switch turns off the current in the secondary flow same direction with respect to dot so the secondary diode is conducting. When the switch turns on again, the voltage of the secondary is same polarity as the primary with respect to dots so the voltage imposed on the secondary diode is in reverse polarity and it will turn off.

@gilang.cahyon

5 жыл бұрын

@@sambenyaakov thank you so much for the lesson Professor

Thank you sir.

@sambenyaakov

4 жыл бұрын

Thanks

at 5:38 minutes, the direction of current I 1 and I 2 must be different because different polarities are applied

@sambenyaakov

Жыл бұрын

Not so. Following the transition, the core is determining the direction of current . If before the switching the current was flowing into the dot so will be after the transition.

Thank you professor for this clear and indepth presentation. very helpful and informative. Liked your video.

@sambenyaakov

Жыл бұрын

🙏🙂

Great video. how does the turn ratio affects the resonant frequency of the coupled inductors? does a higher turn ratio increase the resonant frequency?

@sambenyaakov

2 жыл бұрын

What matters is the inductance. You can have different turne ratio with same inductance. But there is another issue: interwinding capacitance that can be reflected from secondary. In this case, high number of secondary turns will result in higher capacitance,

Hello Mr Ben-Yaakov, Thank you for the lecture. I noticed that on the art of electronics book by Paul Horowitz, the Buck-boost topology that you showed is called the inverting converter, the buck boost on the other have a positive polarity output. could you please clarify this subject?

@sambenyaakov

3 жыл бұрын

The circuit that I show(with a diode) is generally referred to as Buck-Boost, The non inverting version requires 4 transistors, also called Buck-Boost. Google buck-boost and see. This could be of interst? kzread.info/dash/bejne/rKysp6p6oJnQcsY.html

@thezodiace7399

3 жыл бұрын

@@sambenyaakov Thank you sir.

Thank you for this demonstration , i have a little question for you, do you know why we move towards a full bridge topology when we increase the power, (Voltage and current contraints on active components for both topologies are the same ? Is'nt it ? )

@sambenyaakov

2 жыл бұрын

The current IS smaller

in 17:38, the current flow in bottom circuit of secondary side should be in other direction, am i wrong?

@sambenyaakov

7 жыл бұрын

You are correct! Thanks for pointing this out. But, it could represent a negative current..Just kidding.

@we-are-electric1445

5 жыл бұрын

Only just watched the video. His solid arrows are correct. His handwritten arrow at the bottom is in the wrong direction so you are not wrong. After two years I am sure you will have figured it out but it may help someone else.

Great presentation. Do you have anyone where you talk about the difference feedback technique used in practical application for the flyback converter ?

@sambenyaakov

2 жыл бұрын

Thanks. Please search my KZread channel for 'control' or 'feedback' there are a number of videos on that.

Thank you professor. I thought that we dont need a clamp voltage circuit for flyback converters?

@sambenyaakov

3 жыл бұрын

WE do need, for the leakage inductance.

I think it would be better if the arrows are marked with the appropriate designations

@sambenyaakov

Жыл бұрын

Good point. Will try

Thank you for video but i have just question about Diode when switch is ON there is no current flow through diode could professor or someone else please explain why? thank you in advance

@sambenyaakov

6 жыл бұрын

This is because the voltage on diode is in the reverse polarity.

Hi sir, i have a question at 3:00 time stamp. If there is a delay between S1 going OFF and S2 turning ON, will there still be current flow in S2 ? (I am new to power electronics. i am thinking from magnetic induction point of view and assuming that 'change in magnetic field only can cause current in S2'. Once S1 is OFF, during delay period there are no changing current and hence no changing magnetic fields and hence no current in S2)

@sambenyaakov

6 жыл бұрын

In this ideal representation there should be no delay. With a delay there will be a voltage spike. In real circuits as shown later there is a diode that captures the current.

Dr. Ben-Yaakov. Thank you for your valuable lecture. I'd like to know the Fly-Buck converter (Texas Instruments Inc.) which is similar to Fly-back converter. From Japan more.

@sambenyaakov

6 жыл бұрын

Hi cxc# from Japan. Thank you for comment. Good topic. I will try to prepares a tutorial on that.

Thank you

@sambenyaakov

2 жыл бұрын

Thanks

Sir can you please tell us the Push-Pull Transformer design process ??

With two secondary windings, is the voltage reflected back to the input FET doubled vs one secondary winding? (Assuming both secondary windings same no of turns etc) So Vin' = Vin +2 (vsec/N)?

@sambenyaakov

2 жыл бұрын

The total reflected voltage is related to the flux (there only one core flux) and the voltage of each winding ( either forced or induced) is n*d(phi)/dt

What is the flyback advantages over forward. what type of application each one should be preferred?

@sambenyaakov

2 жыл бұрын

Forward is generally better at higher power levels, Flyback has the advantage of multiple outputs without inductors.

Hi Mr. Ben-Yaakov, would you plz give some light on the usage of a spark gap in the output.

@sambenyaakov

6 жыл бұрын

Spark gap at output? Please clarify.

Excellent Video. Have you any for explain Continuous mode and discontinuous mode? Best regards from Argentina

@sambenyaakov

7 жыл бұрын

Thank you for comment. DCM, may be in the future.

Professor Ben-Yaakov. I am interested to know the effects of reverse recovery characteristic of diode on both primary and secondary side of flyback transformer. can you recommend any reference or explanation? Thanks in advance.

@sambenyaakov

7 жыл бұрын

You got me there. I do not remember any document that treats the ill effects of reverse recovery per se. Perhaps it is a good subject to present in KZread video :-)

@siamak1246

7 жыл бұрын

I will appreciate if you also teach that on KZread ;-)

@Cyruus

6 жыл бұрын

Hello Siamak! Chapter 3 of Solid State Pulse Circuits by David Bell has lots of helpful explanations on this subjects.

Hi Prof, may I know what is difference symbol GND at your schematic diagram?

@sambenyaakov

2 жыл бұрын

This means that they are not galvanically connected

Dear Sir. I understand how to calculate a flyback power supply. I also understand how to analyze most of this type of power supply. However, a doubt still persists and I would be grateful if you could clarify it for me. How the equivalent circuit of the switched part of the transformer would look, considering the frequency. How to analyze the pulsating current waveform in the form of a straight line with negative slope in the secondary? Shall I regard it as a current source with a pole situated at 1/10 of the switching frequency? I would be grateful for your assistance. Thanks.

@sambenyaakov

10 ай бұрын

See kzread.info/dash/bejne/qZutsqynaNe0c8o.html

Excellent video (very clear) Have you any for explain flyback dc/ ac in discontinuous mode (birectionnal)? Best regards from France

@sambenyaakov

7 жыл бұрын

Thanks for comment. About "flyback dc/ ac in discontinuous mode " perhaps in the future.

@jonathanyanngordon

7 жыл бұрын

The futur could be next mouth ?

@sambenyaakov

7 жыл бұрын

I doubt but I may surprise myself:)

Hi, Do you have an explanation for the reason the flyback converter uses coupled inductors instead of a transformer? thank you!

@sambenyaakov

3 жыл бұрын

A transformer by definition conducts at input and output at the same time and does not store energy.

@bradleykitzul8073

3 жыл бұрын

@@sambenyaakov thank you!

Dear Sir A very nice video, although I would like to discuss one incident and I hope you can describe that. I have an old CRT TV, and it has this flyback Transformer and my TV outer case is made up of wood except side Speaker net is metallic, by mistake from repairing guy gave a connection from breakage of flyback transformer wire (connection between FBT to Picture tube) speaker net through a metal wire. it was making noise as well (may be because of leakage of such high voltage current), so I went near to TV to unplug it and this speaker net was near to plug. The moment I went near to somehow speaker net I felt a huge shock without even touching anything. can you please explain why that happened? TIA

@sambenyaakov

7 жыл бұрын

How close was your body or hand to speaker?

About 30kv, 45 miliamp, and yes its a handhold operated device.

@sambenyaakov

Жыл бұрын

30kV is a bit high for a flyback stage. You may need a second stage, spark or resonant base. Look up circuits for igniting Xenon lamps.

hi professor , i have designed a flyback converter in CCM mode, but at no load , output voltage is 60 volts instead of (designed)15 volts. at designed load it is giving 15 volts. I have used RCD snubbers. And converter is drawing 1 amper current from 30 volts input source at no load. will you suggest any solution?

@sambenyaakov

4 жыл бұрын

You apparently have high parasitic oscillation. Try to rewind the transformer for lower leakage add snubbers. Using a controller that goes into burst mode will help.

@AS-zs7jw

4 жыл бұрын

currently i am operating it in open loop with 555 timer to switch the mosfet, i have used RCD snubbers already, i think i have to use a controller IC with feedback mechanism.

@sambenyaakov

4 жыл бұрын

👍

can we use fly back converter to generat higer output voltage around 300v or 350v ?

@sambenyaakov

4 жыл бұрын

Yes. Very effectively

@yousefalmuzini7150

4 жыл бұрын

@@sambenyaakov thank you very much

It may be more intuitive to choose a step down transformer in the example. (n:1, instead of 1:n)

@sambenyaakov

2 ай бұрын

Just set n to be smaller than 1😏

@jpechacek80

2 ай бұрын

Lol thanks, Thank you for your transformer lectures, they helped me a lot. I translated your formulas using a N:1 instead of 1:N. Designing a step down offline switcher. Fractional turns ratio seemed unconventional to me. :) Trying it out with Spice

@sambenyaakov

Ай бұрын

@@jpechacek80 👍

I have a question professor. Let's say instead of a single diode we have a full-bridge rectifier at the output. How could you explain such a circuitry, I was surprised to see almost nothing change wen replacing the diode with a bridge-rectifier. In such a case is only thing happens that with the help of PWM signal DC voltage kinda turns into AC and then by the turns ratio of the transformer the voltage steps up(or down) at the output? This is how I explain that circuit. Is that true you think?

@sambenyaakov

3 жыл бұрын

The operatic will depend on the turn ration of coupled inductor which affects the output voltage when the transistor is ON.

Hello Mr Ben-Yaakov. There is something that confuses me. Let's say that our transformer's turn ratio is 2:1. At the moment when the switch turns off, primary side's current (let's say 1A) will disappear instantly in ideal conditions and secondary side's current will be 2A due to conservation of energy. 0.5*L1*1^2=0.5*(L1/4)*2^2 where L2=L1/4. That's ok but at that moment how does the magnetic flux remain the same? Flux1=L1*I1=L1*1=L1. Flux2=L2*I2=(L1/4)*2=L1/2 According to this, energy in the core remained the same but magnetic flux abruptly changed when the switch turned off. Please enlighten me.

@sambenyaakov

3 жыл бұрын

Flux=L*nI 😊

Hello sir. I am trying to design flyback transformer in CCM mode. But I don't know how to make initial guess for the duty cycle. V_in=390V, V_out=12V, P_out= 12W, f_sw=132kHz.

@sambenyaakov

10 ай бұрын

Duty cycle depends on turns ratio which sets the maximum voltage on the switch. Start with specifying the latter.

Thank you professor professor, I have one question How to model the Flyback ?

@sambenyaakov

3 жыл бұрын

See kzread.info/dash/bejne/qZutsqynaNe0c8o.html

At minute 5:04 you said that the curent rises in liniar fashion because V/L is constant. But the curent rises depending on V across the inductor, not V source. At a point in time, V across the inductor will be 0. What am I missing? Thanks!

@sambenyaakov

4 жыл бұрын

But the coupled inductors are connected across the voltage sources.

@gearstil

Жыл бұрын

@@sambenyaakov Even if the voltage sources are constant, the voltage across the inductor is not constant, as the current rises. I don`t understand why the current derivative is considered constant.

@sambenyaakov

Жыл бұрын

@@gearstil Even if the voltage sources are constant, the voltage across the inductor is not constant??? The voltage across the inductors are the input output voltages the tipples.

@gearstil

Жыл бұрын

@@sambenyaakov Yes, that is true, I had the impression that there is a resistor load in series. Thank you!

What if the load is removed and no current is flowing through the secondary while the primary switch is still switching. Will that cause the inductor to saturate since flux is increasing every cycle?

@sambenyaakov

2 жыл бұрын

Yes, and more over when the switch is off adangerous voltage may develop. This should be taken care of by the control. .

Thank you for this, Prof. Sam. I would like to point out, though, that I believe the dot notation for the transformers was misinterpreted. As far as I know the dot marks the positive reference of the voltage in the winding, by convention [1]. This means, that the current shall flow from the positive reference towards the negative one, as per convention, as well [2] [3]. Thus, I believe the diagram at minute 3:56 (kzread.info/dash/bejne/gYydxNWIqs3PoNo.html) used for the explanation may be confusing, because the real flow of the current will be on the contrary direction of i2. In the end the diagram is completely valid and the relations between voltage and current between primary and secondary are [2] [3]: V2/V1 = - N2/N1 = -1 and I2/I1 = - N1/N2 = -1 So, I just wanted to bring awareness that it may be misleading and one may think the current will flow in the direction of I2 when in fact flows in the opposite direction. References: [1] - circuitdigest.com/article/understanding-dot-convention-in-transformers [2] - slideplayer.com/slide/5922251/19/images/62/Voltage+Polarity+in+an+Ideal+Transformer.jpg [3] - slideplayer.com/slide/10877632/39/images/8/Dot+Convention+for+Ideal+Transformers.jpg Thank you!

@sambenyaakov

3 жыл бұрын

Hi Andre, thanks for sharing your doubts. At first, when seeing that you brought some references I thought you are bringing in Faraday or Maxwell (at least) , but then it turned out that these are internet postings😊. As it turns out, they are OK but I am afraid that you missed the point that my video is about COUPLED INDUCTORS and not a TRANSFORMERS. There is a major difference between them. In a transformer, at any given instance: Pin=Pout. Not so in a coupled inductors (in general, although it may function as a transformer too). Please watch again the video which explains the workings of a coupled inductor in connection with the Flyback converter. There are also other relevant videos in my KZread channel "sam ben yaakov".

where is the protection diode /snubber for the switch/transistor? ?

@sambenyaakov

5 жыл бұрын

Here they are😃😃 kzread.info/dash/bejne/npV8sJaRnpifnKw.html kzread.info/dash/bejne/q4d3j7Wvn7THY7g.html I recommend you scan my KZread channel for othe videos See kzread.info/dash/bejne/oHxpspl6ld2th5M.html

Professor Ben-Yaakov. thanks a lot for the easy explanation. I would like know more about the operation in DCM especially about design and differences with CCM, Do you have some info about it? Greetings from Colombia I hope come back soon to Israel. Tanks again

@sambenyaakov

6 жыл бұрын

Thanks for comment. Will try. Enjoy Israel (again?)

@camiloavila87

6 жыл бұрын

Yes, again. I've been twice and I love Israel. I going to come back, hope soon.

The energy is stored in an air gap or in distributed air gaps of the core.....

@sambenyaakov

4 жыл бұрын

Depends on construction: single or distributed air gap (s in powder core)

In my professor's notes, it says that the current in the magnetic inductance Lm of the primary winding, is increasing linearily during Ton (I agree), and it decreases during Toff (But during Toff it should be zero! The switch is open so how can a current still flow !?)

@sambenyaakov

5 жыл бұрын

Can you please point to the slide number (or minute in video ) you are referring to?

@f.a3202

5 жыл бұрын

it's the back EMF of the coil

Thank you sir, It is worth attending. What ever you have explained it ,i got it. I have a doubt, TV flyback osc frequency is 15625Hz (Tsw time is 64e-6) 52e-6 is duty(81%) so it is working as a boost converter. I have followed several schematic, i am not getting "where is the reflection voltage and which one part is the reflection voltage schematic and snubber capacitor? If you kindly inform me, I will be happy. So i hope you will response me. thanks.....

@sambenyaakov

3 жыл бұрын

To which minute in video are you referring to?

@RianWardana

3 жыл бұрын

@@sambenyaakov I think he/she is referring to minute 13:15 in which you said that there would be a voltage across the switch S due to the turn ratio between the primary and secondary coil

Why is the current travelling from negative to positive in the secondary? I thought if current travelled into the dot in the primary, then the current had to come out of the dot in the secondary. Or is I2 negative? Could someone please explain this to me.

@everythingaccount9619

5 жыл бұрын

Okay, I might have figured it. Is it because of magnetizing inductance across the primary winding?

@sambenyaakov

4 жыл бұрын

Yes, you can look at this way or, there is a continuity of magnetic field (not current as sometime assumed in error) so this result in secondary current also flowing to dot as in primary.