Flyback converter

[@pauludrea4082]

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]

😊Thanks for comment

[@rayachotybharathkumar268]

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]

Glad it was helpful!

[@johnkyingilisi4395]

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]

Please indicate the minute of video you are referring to.

[@johnkyingilisi4395]

@@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.

[@caiomar]

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

[@sambenyaakov]

😊

[@fromgermany271]

After starting with electronics at 9yo and then deciding against electronics over computer science after school in 1982, for the first time I understood how a flyback converter works. I might not use it practically, as my career time is over and the stuff is cheap to buy, but I always like the feeling that suddenly a door to a new room opens. Thanks very much for the lecture!!

[@sambenyaakov]

Thanks for sharing your thoughts. Trust me, there is no such thing as 'over'

[@hassaniftikhar8931]

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]

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

[@JHS168163]

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

[@sambenyaakov]

Thanks

[@my_home_interiors_hyderabad]

Bro you nailed it ! Respect from India

[@sambenyaakov]

😊🙏

[@abhishekmuppiri9457]

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

[@sambenyaakov]

Thanks. Glad to hear that.

[@CNLohr]

Best lesson on this topic I've seen.

[@sambenyaakov]

👍😊

[@swalker157]

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

[@sambenyaakov]

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

[@swalker157]

@@sambenyaakov here is a video on how to create a KZbin playlist. kzbin.info/www/bejne/q4inl4Gvn5ZqjZI Thanks again for the great lectures.

[@sambenyaakov]

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

[@sameqy]

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

[@sambenyaakov]

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

[@lammmpo]

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

[@sambenyaakov]

Thanks😊

[@조태호-c9h]

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]

You're very welcome!

[@ritikadas249]

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

[@sambenyaakov]

Thanks

[@libervolucion]

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

[@sambenyaakov]

Thanks for comment.

[@NatthapolVanasrivilai]

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

[@sambenyaakov]

Thanks for comment

[@dalenassar9152]

THANK YOU VERY MUCH!!! I am still studying your analysis VERY carefully. At the same timestamp 6:00 I see, in the bottom graph on the right side, that I2 actually goes BELOW the zero-current axis. I am assuming this is correct (but wanted to verify with you), that this actually can occur since -V2 can exceed +V1 (in magnitude) enough to fall below zero current (negative). THIS SERIES IS OF GREAT VALUE TO ME!!! I am studying it very carefully!

[@dalenassar9152]

At 6:00 at the bottom left, are these equations correct??? THANKS MUCH!

[@sambenyaakov]

Thanks for spotting the typo. The first equation is correct. The second one should have been I2=I1/n

[@billimew7496]

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

[@sambenyaakov]

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

[@raloed.363]

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]

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,

[@jwhammy75]

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]

👍

[@michaelcwu4466]

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]

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.

[@HamzaHajeir]

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

[@sambenyaakov]

👍🙏🙂

[@russelibrahim4045]

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

[@sambenyaakov]

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

[@1728lorenxo]

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]

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

[@shaileshchityala2787]

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

[@sambenyaakov]

Thanks India from Israel😊

[@sadunnakipoglu9471]

أشكرك وأقدر مجهودك ، تحياتي لك من تركيا .

[@sambenyaakov]

شكرًا. من دواعي سروري

[@kenc4104]

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]

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

[@alocin110]

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

[@sambenyaakov]

🙏🙂

[@wickedprotos1937]

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]

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

[@swathi9086]

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]

👍😊🙏

[@MORAL1952]

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]

See kzbin.info/www/bejne/rZjcgX2kbdmBeck

[@davebutler3905]

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

[@sambenyaakov]

😊🙏

[@TheKybliceek]

Simply Amazing thank you so much Mr.Professor.

[@sambenyaakov]

Thanks.

[@siamak1246]

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

[@sambenyaakov]

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

[@we-are-electric1445]

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.

[@777impresso]

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

[@sambenyaakov]

Thanks and greetings to our prime minister now visiting Ukraine

[@elboukharysidahmed3711]

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]

Which minute in video are you referring to?

[@mohd.shafiebakar7620]

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

[@sambenyaakov]

This means that they are not galvanically connected

[@shashankvarshney8487]

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]

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

[@bradleykitzul8073]

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

[@sambenyaakov]

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

[@bradleykitzul8073]

@@sambenyaakov thank you!

[@gearstil]

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]

But the coupled inductors are connected across the voltage sources.

[@gearstil]

@@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]

@@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]

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

[@enricopascucci4802]

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

[@sambenyaakov]

Thanks

[@wakeupsiddy6907]

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

[@jjmcrosbie]

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

[@sambenyaakov]

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

[@jjmcrosbie]

@@sambenyaakov Thank you Professor.

[@yousefalmuzini7150]

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

[@sambenyaakov]

Yes. Very effectively

[@yousefalmuzini7150]

@@sambenyaakov thank you very much

[@parametrikaarquitectos960]

my dear Professor, can I use this device for an electrostatic flocking machine?

[@sambenyaakov]

What is the required voltage and power? are you interested in a hand held machine?

[@parametrikaarquitectos960]

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

[@parametrikaarquitectos960]

kzbin.info/www/bejne/aaTHo2aOpZ6YqJY

[@sambenyaakov]

@@parametrikaarquitectos960 30kV is bit high for a flyback stage. You might need a second, perhaps spark or resonant based stage. Look up circuits that are used for igniting Xenon lamps.

[@ruixiong5237]

Thanks a lot for the generous offer of knowledge.

[@sambenyaakov]

Thnks. I appreciate it.

[@RDarrylR]

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

[@sambenyaakov]

Thanks😊

[@jamalhamdan5308]

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]

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

[@MSDnA420]

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

[@sambenyaakov]

Thanks

[@TSulemanW]

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

[@sambenyaakov]

😊

[@vitaliysutyk4476]

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

[@sambenyaakov]

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.

[@nabilkerbila6467]

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]

The current IS smaller

[@SaravananSelvamani121]

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

[@sambenyaakov]

🙏😊

[@subhojitdas108]

thank you sir. your lectures are very effective.

[@sambenyaakov]

Thanks

[@arunraj.k2418]

Sir what is about current mode control and voltage mode control in flyback converters?

[@sambenyaakov]

Have you seen: kzbin.info/www/bejne/nHeQm3l8hLyGj5Y There are other relevant videos in my KZbin channel.

[@arunraj.k2418]

Ok sir

[@resattr7425]

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]

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

[@amineoufella4953]

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

[@sambenyaakov]

WE do need, for the leakage inductance.

[@sanatghosh9278]

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]

To which minute in video are you referring to?

[@RianWardana]

@@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

[@burakapaydin9023]

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]

Flux=L*nI 😊

[@AS-zs7jw]

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]

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]

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]

👍

[@rj8528]

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

[@sambenyaakov]

See kzbin.info/www/bejne/rZjcgX2kbdmBeck

[@jpechacek80]

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

[@sambenyaakov]

Just set n to be smaller than 1😏

[@jpechacek80]

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]

@@jpechacek80 👍

[@harshvardhan8592]

awesome lectures sir

[@sambenyaakov]

👍🙏

[@sukhwantweber2260]

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

[@sambenyaakov]

Good point. Will try

[@alanx4121]

No energy is stored, but the fields (action & reaction fields according to Lenz'law) are there, oppose, and net zero?

[@sambenyaakov]

HI, not sure that I follow your question. Please clarify. (Is it part of an earlier exchange?)

[@alanx4121]

Hi thanks for your response. I was referring to the beginning of the video, forgot to mention it. There you said that there is no energy stored in the core of a transformer, but the field of the input remains the same as in the coupled inductor with the secondary not connected. Except that the primary field of the transformer is opposed by the field from the secondary according to lenz' law. I think there's still energy stored as 2 repelling fields, but not usable? Was also wondering this. Would it be possible to reroute the opposing field caused by the secondary to a third coil instead to the primary,,, which 3rd coil is wound opposite to the secondary, which has a diode to prohibit a current from the primary flux, but not from the lenz flux from the secondary? Using a small dutycycle current on the primary. I'm new to power electronic, am trying to learn some of it on my own. Many thanks for the video's!

[@sambenyaakov]

Regarding the first point, this video may clear thinks up to you. kzbin.info/www/bejne/kJezfWqKf5epidU If still in doubt, write to [e-mail] AS for the second, not sure what you mean.

[@thezodiace7399]

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]

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? kzbin.info/www/bejne/sKnbdnt3pZudeMU

[@thezodiace7399]

@@sambenyaakov Thank you sir.

[@kausalyabaissonale4804]

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

[@sambenyaakov]

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

[@raviteja218]

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]

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.

[@rosatouabi5543]

Thank you so much for this presentation so useful

[@sambenyaakov]

🙂🙏👍

[@nouiniaanass4136]

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

[@sambenyaakov]

Thanks for comment 😊

[@jamesjohnston9319]

Thank you for this professor

[@sambenyaakov]

Thanks

[@imshamail]

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]

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

[@martinmartinmartin2996]

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]

Blocking oscillator?

[@MCSGproject]

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]

👍

[@iblesbosuok]

Thank you professor Sam Ben-Yaakov, sir

[@sambenyaakov]

😊

[@everythingaccount9619]

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]

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

[@sambenyaakov]

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.

[@gilang.cahyon]

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]

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]

@@sambenyaakov thank you so much for the lesson Professor

[@mahmoudbenounissa8019]

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]

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

[@christiankandzia4884]

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

[@sambenyaakov]

Here they are😃😃 kzbin.info/www/bejne/opKrf2eOo5psoqs kzbin.info/www/bejne/r4SmXoaspLaUabc I recommend you scan my KZbin channel for othe videos See kzbin.info/www/bejne/pHmYgWp3mt96jZI

[@amritpattanaik203]

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

[@sambenyaakov]

Spark gap at output? Please clarify.

[@shreyatyagi3146]

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

[@sambenyaakov]

Thanks for comment

[@vikrantsharma9599]

why flyback requires some load at all times?

[@sambenyaakov]

Like in a Boost if the Ton does not shut down the voltage will keep rising

[@LHJARS]

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

[@sambenyaakov]

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

[@Celvin1000]

Excellent Explanation ! Thank You very much !

[@sambenyaakov]

Thanks.

[@MinhuChen]

Very clear and helpful, thank you!

[@sambenyaakov]

Thanks.

[@georgederleres8489]

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]

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

[@f.a3202]

it's the back EMF of the coil

[@jonathanyanngordon]

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

[@sambenyaakov]

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

[@jonathanyanngordon]

The futur could be next mouth ?

[@sambenyaakov]

I doubt but I may surprise myself:)

[@puneetrandar7456]

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]

Will try to prepare one. Thanks for comment.

[@raymondcisneros931]

Absolutely, very nice!!! Thank you

[@sambenyaakov]

Thanks😊

[@siamak1246]

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]

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 KZbin video :-)

[@siamak1246]

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

[@Cyruus]

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

[@melplishka5978]

Ty very well explained.

[@sambenyaakov]

Thanks,

[@naveensoni5150]

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]

How close was your body or hand to speaker?

[@camiloavila87]

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]

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

[@camiloavila87]

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

[@jeffryblackmon4846]

Thank you for a valuable lesson.

[@sambenyaakov]

Thanks

[@sergeybelov1682]

Thaks a lot for clear explanation.

[@sambenyaakov]

Thanks

[@ebrahimfathy4422]

Thanks can you please talk about modelling on Simulink ?

[@sambenyaakov]

Simulink is really not my cup of tea

[@ebrahimfathy4422]

@@sambenyaakov thanks for replying ☺️

[@cxc06033]

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]

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

[@picencasa]

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

[@sambenyaakov]

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

[@parametrikaarquitectos960]

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

[@sambenyaakov]

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.