Once we get the switching pulse for the Ist switch. How is the Clamp switch pulse kept high from t1 to t2? And how is it again turned high at T4. How do we ensure that the switch turns on or off at the correct times?
Hi, really great video, I wonder why this channel doesn't have more susbsribers. you just earned one. I have a question at 8:16, at T4 how does the current INp build up if both Q1 and Q2 are open?
Thank you so much for the video. My name is Laith from Iraq. I watched all your videos and loved them all. I am excited to watch more new video on your channel. ✌✌ I have a question, is the Active Clamp Forward Converter the same Flyback Converter? Thank you, ✔✔
Hello. Is there any literature on the method of calculating elements? It is especially interesting to learn about the calculation of a transformer on square cores or on planar
You speak without some very distracting inflections other EE youtubers use, instead you sound much more natural. I appreciate that, makes it easier to pay attention to the content. Speaking of which, the graphics are good as others said. What software did you use to make this, if you're willing to divulge? EDIT: Also, I see it often stated such as in this video, a hard limit on a power supply type (500W) in this case. Seems that this would almost certainly depend on your component selection and availability, and of course we're ignoring paralleling and synchronizing supplies (obviously out of scope). But it would be interesting to delve into the limiting factors of the actual supply design.
@@FoolishEngineer I didn't understand a little, please clarify in the video you wanted to say that in this topology we need to use a capacitor over 500 volts, or this topology is not advisable to use in power supplies and converter over 500 watts?
Hi, which is better, Active Clamp Forward Converter or Double Ended Forward Converter? I think that Double Ended, because it has 2 transistors, which is why it, respectively, can give out more power compared to Active Clamp. Plus, the selection of components from Double Ended is easier. But I found an article on the Internet where it says that Active has such advantages as: "The transformer is magnetized by optimal voltage, i.e. there are no useless losses of the volt-second interval. Accordingly, we have minimal overloads of the components by voltage at the maximum possible transformation coefficient for this topology * The energy stored in the parasitic elements - the scattering inductance and the drain-source capacitance of the power key, not only does not dissipate, but also passes from one element to another, reducing the switching energy * Noise is significantly reduced when switching the power key, since its switching energy is significantly reduced * Due to the reduction of the switching energy of the key, dynamic losses are sharply reduced * The working stroke is limited only by permissible overloads of the elements by voltage * The pulse voltage on the power switch is connected non-linearly with the value of the input voltage, and can reach its minimum value in the middle of the range. · There are no voltage outliers on the power key due to the scattering inductance * It is possible to switch the power key at zero voltage * "Rectangular" voltage shapes make it easy and often without additional components to control synchronous keys on the secondary side " Which leads me to think that just because of this, Active Clamp will be much better than Double Ended, even though someone told me that this is a lie and that if I want normal demagnetization, I need to assemble a full bridge or a half bridge. What do you think about this in general?
Well. You observation is quite right. But selecting a topology is more of a designers choice. there are pros & cons based on your requirement & power you can select the converter.
The double ended is the equivalent of a normal forward without the third winding. It still has the same 50% top duty cycle limitation and requires a special top side gate driver, which adds up complexity. An advantage is that a standard single ended PWM controller can be used (so long as you can limit the duty cycle and provided you have some means to drive both gates) and that the maximun voltage stress is clamped to Vin. This is particularly important where using higher voltage FET's woulf result in higher gate charge and RDSon - which would drag down efficiency. Active clamp makes for a far simpler circuit with less duty cycle limitations, but you will need higher voltage switches. It's all a matter of compromises.
Liked your graphics and explanation, however the active clamp forward converter does need 2×vin rating for Q1, infact more than 2×vin is required as you are going beyond 50% duty cycle
Dear Sir, The same circuit, but we found the Q1 VDS still keep 2 times of Vin, seems there is some extra voltage added on the X'FMR. Would you please hit me whether any possible mistake will cause the boost Q1 VDS issue. Thank you. Paul Tseng
@@FoolishEngineer Yes sir, the Q1 is 60V, measured voltage on Vds is 30V, within application condition. But we found the Q1 will damage by linear mode operating, with big burn mark under the wire bonding of the source. We had use evb from adi (LT1952-1)to check the wave form, it's keep in 12V. That's what we found. Thank you. Paul
Very clear explanation with a great use of graphics. Well done!
Glad you liked it!
Excellent explanation ! Was looking for something similar since long time on this topic. Short, crisp and concise !
Great to hear!
Once we get the switching pulse for the Ist switch. How is the Clamp switch pulse kept high from t1 to t2? And how is it again turned high at T4. How do we ensure that the switch turns on or off at the correct times?
There are many pwm controllers we can use
@@abworld4370 Can you share some stuff regarding this.
Thank you for the video. What is the purpose of this converter?
Can we use active clamp in AC DC forward converter?
Hi Sir, In which tools you these video
Why can't a diode be connected across the primary winding to clamp the voltage at the mosfet to Vin + Vforward?
Hi, really great video, I wonder why this channel doesn't have more susbsribers. you just earned one.
I have a question at 8:16, at T4 how does the current INp build up if both Q1 and Q2 are open?
Thank you so much for the video. My name is Laith from Iraq. I watched all your videos and loved them all. I am excited to watch more new video on your channel. ✌✌
I have a question, is the Active Clamp Forward Converter the same Flyback Converter?
Thank you, ✔✔
no
@@FoolishEngineer Do you have video on the Fly back Converter then?
Hello. Is there any literature on the method of calculating elements? It is especially interesting to learn about the calculation of a transformer on square cores or on planar
You speak without some very distracting inflections other EE youtubers use, instead you sound much more natural. I appreciate that, makes it easier to pay attention to the content.
Speaking of which, the graphics are good as others said. What software did you use to make this, if you're willing to divulge?
EDIT: Also, I see it often stated such as in this video, a hard limit on a power supply type (500W) in this case. Seems that this would almost certainly depend on your component selection and availability, and of course we're ignoring paralleling and synchronizing supplies (obviously out of scope). But it would be interesting to delve into the limiting factors of the actual supply design.
Thank you so much!!
There are so many video creation software out there, I use After Effects
@@FoolishEngineer I didn't understand a little, please clarify in the video you wanted to say that in this topology we need to use a capacitor over 500 volts, or this topology is not advisable to use in power supplies and converter over 500 watts?
@@oblibox1 I think the author was talking about the inexpediency of using a converter with a power of more than 500 watts
Hi, which is better, Active Clamp Forward Converter or Double Ended Forward Converter? I think that Double Ended, because it has 2 transistors, which is why it, respectively, can give out more power compared to Active Clamp. Plus, the selection of components from Double Ended is easier. But I found an article on the Internet where it says that Active has such advantages as:
"The transformer is magnetized by optimal voltage, i.e. there are no useless losses of the
volt-second interval. Accordingly, we have minimal overloads of the components by voltage at
the maximum possible transformation coefficient for this topology
* The energy stored in the parasitic elements - the scattering inductance and the drain-source capacitance of the power key,
not only does not dissipate, but also passes from one element to another, reducing the switching energy
* Noise is significantly reduced when switching the power key, since its switching energy is
significantly reduced
* Due to the reduction of the switching energy of the key, dynamic losses are sharply reduced
* The working stroke is limited only by permissible overloads of the elements by voltage
* The pulse voltage on the power switch is connected non-linearly with the value of the input voltage, and can
reach its minimum value in the middle of the range.
· There are no voltage outliers on the power key due to the scattering inductance
* It is possible to switch the power key at zero voltage
* "Rectangular" voltage shapes make it easy and often without additional components
to control synchronous keys on the secondary side "
Which leads me to think that just because of this, Active Clamp will be much better than Double Ended, even though someone told me that this is a lie and that if I want normal demagnetization, I need to assemble a full bridge or a half bridge. What do you think about this in general?
Well. You observation is quite right. But selecting a topology is more of a designers choice. there are pros & cons based on your requirement & power you can select the converter.
The double ended is the equivalent of a normal forward without the third winding. It still has the same 50% top duty cycle limitation and requires a special top side gate driver, which adds up complexity. An advantage is that a standard single ended PWM controller can be used (so long as you can limit the duty cycle and provided you have some means to drive both gates) and that the maximun voltage stress is clamped to Vin. This is particularly important where using higher voltage FET's woulf result in higher gate charge and RDSon - which would drag down efficiency. Active clamp makes for a far simpler circuit with less duty cycle limitations, but you will need higher voltage switches. It's all a matter of compromises.
hi, is Active Clamp working with a mosfet and a Schottky diode the same as with a mosfet and a capacitor?
No, both turn on after one another
Liked your graphics and explanation, however the active clamp forward converter does need 2×vin rating for Q1, infact more than 2×vin is required as you are going beyond 50% duty cycle
Thank you for watching our Video!!!
The English is so beautiful)))
Thank you so much for watching!! Please don't forget to subscribe to our channel
Dear Sir, The same circuit, but we found the Q1 VDS still keep 2 times of Vin, seems there is some extra voltage added on the X'FMR. Would you please hit me whether any possible mistake will cause the boost Q1 VDS issue. Thank you.
Paul Tseng
Is Q1 Selected such that can sustain that increased Vds value?
@@FoolishEngineer Yes sir, the Q1 is 60V, measured voltage on Vds is 30V, within application condition. But we found the Q1 will damage by linear mode operating, with big burn mark under the wire bonding of the source.
We had use evb from adi (LT1952-1)to check the wave form, it's keep in 12V.
That's what we found. Thank you.
Paul
Great video. Just a minor correction, your body diode of pmos is wrong at 4:37. Otherwise fantastic video!
Thank you so much, Glad you liked it!! No, it is right.
Super..
Thank you so much, Glad you liked it!!
Please mention p channal mosfet voltage rating
Wattage required
It depends on specification of the converter?
@@FoolishEngineer t
Thanks But Any corelation with Input volt
Like equals v in
Or twice vin
Boss concept is wrong. You may have to correct your understanding on the role of transformer in the Flyback converter