Hello, I've been trying to understand what makes a flyback transformer generate so much higher voltage than a regular transformer. I've watched a bunch of videos about this and no one seems to explain why. All the videos just skip that part, which seems to be essential. Yours is the first that discusses the *air gap* and how it allows the higher magnetic flux. Great video. Thank you!
At about timestamp 2:40 where you show the B-H curves for different materials, I have two questions please: 1) WHAT WOULD THIS LOOK LIKE FOR AN AIR CORE?? 2) CAN AN AIR-CORE COIL SATURATE?? Thanks so much for the BEST videos and explanations on you-tube!!!!!
This answered just about everything I was going to ask. I can't believe I threw out hundreds of flybacks as a kid, and now I'm searching for one to no avail, locally!
You can still easily find something useful in power supply... They have ferrite core and air gaps and you can easily turn it into a very good flyback transformer all you need to do is unwind the coil and put on your own hundreds of windings with very thin 0.1mm wire
Thanks for the video. I am an electronics technician who cut his teeth on TV repair. I have been in telecom manufacturing for the last 23 years, and forgot how all the old crt tech worked. Thanks for the refresher.
The diode's role is a significant part of the high voltage that is generated by the flyback. You must not forget to include it, and you must know the polarity direction needed to prevent the Secondary winding from giving up its massive energy too soon. 1) during the time the primary winding's current is increasing, if the diode is *_FORWARD-BIASED_* for the secondary circuit, the energy is drained away into the secondary circuit, and you do not get the same high voltage spike 2) instead, while primary current is increasing, the installation of the diode, its polarity, is such that it is REVERSE-BIASED to eliminate any path for the energy in the secondary winding to couple into the secondary circuit, ie. the diode tells the magnetic field and particularly the gap magnetic field, where more energy is stored compared to a non-gapped core - "STOP, YOU BUILT-UP ENERGY IN THE SECONDARY - YOU CANNOT ESCAPE, I AM HOLDING YOU RESTRAINED" 3) when the primary winding's mosfet (or bjt or other) switch is opened, NOW the diode in the secondary circuit becomes forward biased and the 'canned-up' energy in the secondary now has a path to flow into the output circuit *ANALOGY* - a tall dam wall, called "The Diode", holds back a very deep body of water piped in from a deep lake - at a specific time, Mr. Primary says "Release the stored energy" and the diode dam wall opens and the stored energy flows suddenly - if the dam wall 'Diode' was missing, you could pump all the deep lake water you want, but you will not get a sudden, massive spike of water energy .
This is at least as good as the video!!! I am starting with such a circuit. Have you any information out there??? THANKS MUCH!! I should have read the comments sooner!
Hello can that flyback transformer being used to stabilise voltage in sensors or phase shift electricity? Is it posibel to re use those pins? My problem is an small AC generator inside distributor so I need kinde of phase shifter I have problems running engine in low rpm ranges so kinde of need help about pick up coils.
Fantastic video Suresh! I learned lots. I didn't know there was an air gap in a flyback. How curious are the flux lines expanding in the air gap. I do have a question. From 6.40 you cover two types of switching. But what are the effects of these on the output?
Thanks and happy that you found it useful. To answer your query, if the current is in DCM, then basically your circuit performance becomes load dependent. Load handling capacity decreases and ripples increases in the output. On the contrary in CCM, the load handling capacity increases and converter is less succeptible to load changes but losses and stress are greater on the inductor (more current). I guess different situations demand different modes of operation. Essentially the frequency and duty cycle selection plays the part here in determining DCM or CCM operation.
@@TheKnurdLab I think I understand now thank you! No such thing as a free lunch, we say! So in CCM the flyback is experiencing higher current flow for a larger part of the cycle. Of course this is more likely to keep the output capacitor charged with the demands of a higher load. Brilliant!
I would say that depends on your requirement. Ideally we design ferrite core transformers by calculating the current requirements (thickness of the winding) and voltage requirement (number of windings), its operating frequency (material used as the core) etc. If you are refering to any particular transformer, then ideally the manufacturer would only know the specs which they usually specify in its datasheet.
There is an excellent tutorial by Fuji electric on this topic. You may search Google with the keyword "fuji electric Fly-back transformer design instructions"
In CRT televisions, the picture is formed on the screen by continuously tracing an electron beam from side to side. The high voltage from this transformer is used to deflect the beam. The voltage signal is in the shape of a sawtooth and it helps the beam come back to its starting point from right to left and hence 'flyback' as per my understanding.
Flyback refers to the nature of this type of transformer, which is more of a coupled inductor than a transformer (the primary and secondary sort of take turns instead of the pri-sec current being 0-90 degrees out of phase), and the 'flyback' highlights the particular inductive behavior upon which this function relies. Inductive flyback or freewheeling refers to the most important electrical behavior of inductors, which is to resist the change of current. When an inductor is 'charged'/flowing current and the voltage supply is removed or the switch is opened, the current thru L continues flowing and builds voltage across the open circuit (voltage rapidly rises if there is only stray capacitance and no substantial capacitance to store the charge). Anyway, long response to answer your question, but I hope that helps illustrate why flyback transformers are called what they are, and why they're unique.
Basically Ferro magnetic materials like metals interact with the magnetic field and cause a change in inductance. If you can sense that change by some means like the frequency change in an oscillator, you essentially have a metal detector. I have explained how saturation and air gap and inductance are related in this video as well. I will try to make a video on your request in the near future.
I don't believe the high voltage is used to steer the electron beam. The high voltage is necessary to create the electron beam, and lower voltages are used to create the magnetic field that steers the beam.
Yes. But frequency of the magnetization cycle plays a big role as well. At high frequencies iron cores tend to have higher losses due to hysterisis and eddy currents.
@@THEMFORMATION Yes. That is why iron core are excellent material for electromagnets (DC current) and for low frequency AC like 50 to 60 Hz power transformers. At Kilo hertz frequencies they perform very poorly due to huge losses. Usually for high frequency AC magnetic circuits, Ferrite cores are preferred due to their excellent high frequency characteristic.
@@samueldavies646 @samueldavies646 No, even if you take the cores out they push snug together. Although I have seen one now with a definite gap (microwave inverter). The question remains as to where the "gap" exists if it actually microscopic gaps within the structure of the core? but thats not an "air gap".
i have taken apart gdt, smps transformer, crt tv flyback,and many others and most of them had a definite air gap. if it has an air gap it will be a definate gap.@@xONEWINGx
Hello, I've been trying to understand what makes a flyback transformer generate so much higher voltage than a regular transformer. I've watched a bunch of videos about this and no one seems to explain why. All the videos just skip that part, which seems to be essential. Yours is the first that discusses the *air gap* and how it allows the higher magnetic flux. Great video. Thank you!
Thank you for the kind words.
At about timestamp 2:40 where you show the B-H curves for different materials, I have two questions please:
1) WHAT WOULD THIS LOOK LIKE FOR AN AIR CORE??
2) CAN AN AIR-CORE COIL SATURATE??
Thanks so much for the BEST videos and explanations on you-tube!!!!!
Thank you for teaching us about electricity. You speak excellent English & you are highly intelligent.
This answered just about everything I was going to ask. I can't believe I threw out hundreds of flybacks as a kid, and now I'm searching for one to no avail, locally!
Thank you. Glad that you found it useful.
How dare you throw those valuable babies.. u could have given them to me instead 😭
You can still easily find something useful in power supply... They have ferrite core and air gaps and you can easily turn it into a very good flyback transformer all you need to do is unwind the coil and put on your own hundreds of windings with very thin 0.1mm wire
Thanks for the video. I am an electronics technician who cut his teeth on TV repair. I have been in telecom manufacturing for the last 23 years, and forgot how all the old crt tech worked. Thanks for the refresher.
The diode's role is a significant part of the high voltage that is generated by the flyback. You must not forget to include it, and you must know the polarity direction needed to prevent the Secondary winding from giving up its massive energy too soon.
1) during the time the primary winding's current is increasing, if the diode is *_FORWARD-BIASED_* for the secondary circuit, the energy is drained away into the secondary circuit, and you do not get the same high voltage spike
2) instead, while primary current is increasing, the installation of the diode, its polarity, is such that it is REVERSE-BIASED to eliminate any path for the energy in the secondary winding to couple into the secondary circuit, ie. the diode tells the magnetic field and particularly the gap magnetic field, where more energy is stored compared to a non-gapped core - "STOP, YOU BUILT-UP ENERGY IN THE SECONDARY - YOU CANNOT ESCAPE, I AM HOLDING YOU RESTRAINED"
3) when the primary winding's mosfet (or bjt or other) switch is opened, NOW the diode in the secondary circuit becomes forward biased and the 'canned-up' energy in the secondary now has a path to flow into the output circuit
*ANALOGY*
- a tall dam wall, called "The Diode", holds back a very deep body of water piped in from a deep lake
- at a specific time, Mr. Primary says "Release the stored energy" and the diode dam wall opens and the stored energy flows suddenly
- if the dam wall 'Diode' was missing, you could pump all the deep lake water you want, but you will not get a sudden, massive spike of water energy
.
This is at least as good as the video!!! I am starting with such a circuit. Have you any information out there???
THANKS MUCH!!
I should have read the comments sooner!
04:19 Don't you think the direction of the current in secondary coil (Is) should be marked in the opposite direction?
I am your 1000th subscriber. I have been searching how energy is stored in the air gap and you have wonderfully explained it.
Thank you!
Greetings to you and thank you, I appreciate your effort. Regards from Turkey.
Good video very informative 👍
That was very informative, and delivered in a way that I totally understood, awesome video bro
How does one create this clock signal for the BJT in practice?
Excellent explanation❤
Hello can that flyback transformer being used to stabilise voltage in sensors or phase shift electricity? Is it posibel to re use those pins? My problem is an small AC generator inside distributor so I need kinde of phase shifter I have problems running engine in low rpm ranges so kinde of need help about pick up coils.
Good explanation 👍
I enjoyed your explanation :)
Well done my dude. I like your diagrams. Well drawn.
Great video pal.
.
The high voltage in the crt is not for the deflecting coils , they only need like 200v , its for making the electron beem itself
Lot of stuff in simple video great
Excellent.😎
Amazing thank you sir.
Thank you :)
excellent
Good stuff!
Thank you.
Fantastic video Suresh! I learned lots. I didn't know there was an air gap in a flyback. How curious are the flux lines expanding in the air gap.
I do have a question. From 6.40 you cover two types of switching. But what are the effects of these on the output?
Thanks and happy that you found it useful. To answer your query, if the current is in DCM, then basically your circuit performance becomes load dependent. Load handling capacity decreases and ripples increases in the output. On the contrary in CCM, the load handling capacity increases and converter is less succeptible to load changes but losses and stress are greater on the inductor (more current). I guess different situations demand different modes of operation. Essentially the frequency and duty cycle selection plays the part here in determining DCM or CCM operation.
@@TheKnurdLab I think I understand now thank you! No such thing as a free lunch, we say! So in CCM the flyback is experiencing higher current flow for a larger part of the cycle. Of course this is more likely to keep the output capacitor charged with the demands of a higher load. Brilliant!
very well explanation
will you please inform maximum wattage drawn by flyback technology
I would say that depends on your requirement. Ideally we design ferrite core transformers by calculating the current requirements (thickness of the winding) and voltage requirement (number of windings), its operating frequency (material used as the core) etc. If you are refering to any particular transformer, then ideally the manufacturer would only know the specs which they usually specify in its datasheet.
Perfect
Hard to believe I made one of these from a broken tv using just this tv parts several years ago
Thank you
Make a video on How to calculate primary and secondary winding terns of AIR GAP FLYBACK TRANSFORMER for DISCONTINUOUS FLYBACK TOPOLOGY SMPS
There is an excellent tutorial by Fuji electric on this topic. You may search Google with the keyword "fuji electric Fly-back transformer design instructions"
@@TheKnurdLab Ok thanks.
Thanks! But why is it called "flyback"? What is flying? What is the 'back'?
In CRT televisions, the picture is formed on the screen by continuously tracing an electron beam from side to side. The high voltage from this transformer is used to deflect the beam. The voltage signal is in the shape of a sawtooth and it helps the beam come back to its starting point from right to left and hence 'flyback' as per my understanding.
Flyback refers to the nature of this type of transformer, which is more of a coupled inductor than a transformer (the primary and secondary sort of take turns instead of the pri-sec current being 0-90 degrees out of phase), and the 'flyback' highlights the particular inductive behavior upon which this function relies.
Inductive flyback or freewheeling refers to the most important electrical behavior of inductors, which is to resist the change of current. When an inductor is 'charged'/flowing current and the voltage supply is removed or the switch is opened, the current thru L continues flowing and builds voltage across the open circuit (voltage rapidly rises if there is only stray capacitance and no substantial capacitance to store the charge).
Anyway, long response to answer your question, but I hope that helps illustrate why flyback transformers are called what they are, and why they're unique.
How a flyback transformer work as metal detector
Basically Ferro magnetic materials like metals interact with the magnetic field and cause a change in inductance. If you can sense that change by some means like the frequency change in an oscillator, you essentially have a metal detector. I have explained how saturation and air gap and inductance are related in this video as well. I will try to make a video on your request in the near future.
I don't believe the high voltage is used to steer the electron beam. The high voltage is necessary to create the electron beam, and lower voltages are used to create the magnetic field that steers the beam.
Pure iron has much higher permeability
Yes. But frequency of the magnetization cycle plays a big role as well. At high frequencies iron cores tend to have higher losses due to hysterisis and eddy currents.
@@TheKnurdLab Hmm. I just know that pure iron has a permeability over 200k
Permeability METGLAS: 1,000,000 Iron 200,000 Ferrite: 3,500
@@THEMFORMATION Yes. That is why iron core are excellent material for electromagnets (DC current) and for low frequency AC like 50 to 60 Hz power transformers. At Kilo hertz frequencies they perform very poorly due to huge losses. Usually for high frequency AC magnetic circuits, Ferrite cores are preferred due to their excellent high frequency characteristic.
Iron has higher permeability but, still has a lower performance...
👍👍👍🌹🌹🌹
I don't understand why you are drawing an air gap? all ferrite cores on every HV flyback I've seen are a closed loop, there is no gap there.
In all TV's they have an air gap. I have a few of these transformers all have air gap.
Also it's not a flyback unless it has an air gap bruh
You won't see the air gap unless you take each halve of the core out
@@samueldavies646 @samueldavies646 No, even if you take the cores out they push snug together. Although I have seen one now with a definite gap (microwave inverter). The question remains as to where the "gap" exists if it actually microscopic gaps within the structure of the core? but thats not an "air gap".
i have taken apart gdt, smps transformer, crt tv flyback,and many others and most of them had a definite air gap. if it has an air gap it will be a definate gap.@@xONEWINGx
Nothing to do with conservation of energy LOL
Not "Woltage"...Voltage.