This is an excellent presentation. At least for someone already passingly familiar with the relevant concepts, it was extremely clear and easy to follow. F.Y.I., your audio levels are somewhat lower than other channels.
As we're talking about beginners theory class, I'd have also mentioned the damper diode, which would protect the driver from counter-EMF from when it swtiches off. More advanced, there were gate turn-off models in use, where gate voltage turned off the drive, otherwise the driver defaulted in conduction and a no-drive condition would result in overcurrent on the driver. Fortunately, such drivers were quite rare in actual production, as far as I recall, only present in one model Philco television and Sony televisions for a number of years, but not in any other form of flyback circuit in industrial usage.
I think that when the voltage is stepped up besides turns ratio being the effect of it, that the primary coil itself can have a high BEMF due to the ramp up time being larger than the ramp down time and that as well can effect the secondary BEMF.
GREAT VIDEO! at 6:38 iron cores are not used in flyback converters. Usually a ferrite core with a GAP. You used the word 'transformer' too much. It should be 'converter' or 'coupled inductor'. After the primary cycle, the energy is stored in the core...not the coil...before the energy goes into the secondary.
I had forgotten so much of this over 50 years. Actually if the MosFet stays on forever, the primary will saturate, and the current rise will stop (I think).
The current will actually increase faster after the core saturates (because the inductance becomes much lower) until it's limited by other parts of the primary circuit. In practice something will probably overheat and fail, likely the mosfet.
When speaking of transformer direction, dot, are you referring to current flow direction or electron flow? It’s important, and also confusing. I’ve seen designs where the 2 gets crossed up.
The dot refers to the polarity of the coil. If you push a positive going pulse into the dot side of a transformer, the positive pulse will appear on the dot side of the secondary. The philosophy of the current flow is irrelevant and is not intended to be denoted by the dots. It is strictly for the polarity of the coils, as the current is completely unaware of this mark on the schematic. This is why one shouldn't think of "current flowing through a transformer". It doesn't. It flows through the coils of the transformer. The *energy* flows through the transformer.
This is really a Beginner friendly class. Thank you.
I'm glad you found it helpful!
Thank you for the explanation; you made the Flyback circuit so much easier to understand.
Glad to hear that!
great breakdown.
thank you :)
This is an excellent presentation. At least for someone already passingly familiar with the relevant concepts, it was extremely clear and easy to follow.
F.Y.I., your audio levels are somewhat lower than other channels.
Thanks! I'll work on getting my audio levels better, I appreciate the feedback.
As we're talking about beginners theory class, I'd have also mentioned the damper diode, which would protect the driver from counter-EMF from when it swtiches off.
More advanced, there were gate turn-off models in use, where gate voltage turned off the drive, otherwise the driver defaulted in conduction and a no-drive condition would result in overcurrent on the driver. Fortunately, such drivers were quite rare in actual production, as far as I recall, only present in one model Philco television and Sony televisions for a number of years, but not in any other form of flyback circuit in industrial usage.
Interesting info, thanks for sharing!
I think that when the voltage is stepped up besides turns ratio being the effect of it, that the primary coil itself can have a high BEMF due to the ramp up time being larger than the ramp down time and that as well can effect the secondary BEMF.
thank you for your insight and knowledge :)
Thanks. Good info; especially the part about this type of converter being more or less failsafe if the MOSFET or similar were to fail short.
Glad it helped :)
GREAT VIDEO!
at 6:38 iron cores are not used in flyback converters. Usually a ferrite core with a GAP.
You used the word 'transformer' too much. It should be 'converter' or 'coupled inductor'.
After the primary cycle, the energy is stored in the core...not the coil...before the energy goes into the secondary.
Thanks for the info!
Great video. Very nice work. you are good at this.
Thank you very much!
Actually life changing info
you are actually a life changing human being
Thanks for the explanation!!
You are very welcome :)
Thanks for explanation!!!!!
You're welcome, glad you found it helpful!
Cool vid!
thank you :)
I had forgotten so much of this over 50 years. Actually if the MosFet stays on forever, the primary will saturate, and the current rise will stop (I think).
Yes, in real life, the ESR of the MOSFET and primary-side of the transformer will limit the current.
The current will actually increase faster after the core saturates (because the inductance becomes much lower) until it's limited by other parts of the primary circuit. In practice something will probably overheat and fail, likely the mosfet.
And what is switching the mosfet??. Key to the whole thing.
Usually a variable PWM
Check out this video on regulator ICs: ua-cam.com/video/B7wOFzCd6LA/v-deo.html
If the mosfet stays on, the inductor will saturate, the current will rise steeply, and the magic smoke will come out.
exactly :)
When speaking of transformer direction, dot, are you referring to current flow direction or electron flow? It’s important, and also confusing. I’ve seen designs where the 2 gets crossed up.
I am referring to conventional current flow.
The dot refers to the polarity of the coil. If you push a positive going pulse into the dot side of a transformer, the positive pulse will appear on the dot side of the secondary. The philosophy of the current flow is irrelevant and is not intended to be denoted by the dots. It is strictly for the polarity of the coils, as the current is completely unaware of this mark on the schematic. This is why one shouldn't think of "current flowing through a transformer". It doesn't. It flows through the coils of the transformer. The *energy* flows through the transformer.
It doesn't matter which current convention you use as long as you're consistent.