1. We would be arranging many polls in the future to bring the exact topics that you guys require which will require access to the community tab. 2. But sadly it is only possible once the channel reaches at least 500 subs. 3. So it is absolutely important for you guys to subscribe so that we can bring tailor-made topics.
Very nice and compact explanation, thank you. However, when you move the RC snubber circuit from minus supply to positive supply, the anode side of the diode must remain connected to the drain of the MOSFET. It is not possible to connect the diode in between the primary transformer winding 1 and the leakage induction Llk, because that node is not a physically existing point. It is an internal node of the transformer model, so in practice you can’t connect anything to this point.
Waoo Many thanks for your guideline. The snubbing capacitor is electrolytic type or non electrolytic type. please guide . more over one calculated value may help as an example
Since snubber circuit is subjected to switching frequency, it charges and discharges rapidly. Electrolytic capacitors are not made for such rapid transitions. So, the capacitors should be of tantalum, ceramic or thin film types. And we will surely include a calculation but right now we are busy putting out a course on Embedded C development. Feel free to check it out - ua-cam.com/play/PLJGDxJZDiVu8JgYdVTxedAZhTJ5dyMkzO.html After the embedded C course we will surely give a calculation example for snubber circuit...
Can you suggest me best snubber design VALUES for Lleak = 180nH , Primary inductance with 0.9uH and secondary with 57uH in 1:8 turns ratio with Voltage spike of 242V at Vds whereas my Mosfet is can handle upto 200V my Vin_max is 9V and my Vout expected is 120V at Secondary Side with switching frequency of 1.5MHz and 12A Primary Peak current , Primary Current Mean =3A.I have designed it by 2nF and 40ohm snubber,my peak has been reduced but the power dissipation is too high than expected ..I need power dissipation less than 500mW at snubber.Can you help me with optimal Values? I prefer tuning the Rsnub and Csnub rather than adding new Components to Decrease the power dissipation!!
So in the second configuration where the snubber is between the primary coils, are we also allowing more voltage to stress the MOSFET since we aren't snubbing the leakage inductance? Which might be acceptable if the FET is rated for that, but just wanted to make sure I understood the tradeoffs of moving the snubber circuit.
Leakage inductance is not actually present in physical form. When we implement a transformer or inductor or any other source of magnetic field then a major portion of the magnetic field gets linked with the respective inductor or transformer. But a small amount of magnetic field does not flow through the intended magnetic element. This field gets lost and it does not contribute in energy transfer. So for simplicity we depict or display this field in the form of another small inductor or transformer in series (or may be parallel in some cases) with our main magnetic element. This is nothing but leakage inductance. So even if you do not show this leakage inductance in series, it is always present there. So in our tutirial the keakage inducatnce is already and always embedded in the primary of high frequency transformer. Now in our tutorial video it is shown that leakage inductance comes after the connection of snubber and primary of transformer. This was actually a mistake. From the above explaination we can say that the leakage inductance is embedded in the primary of transformer and it does not lie after the connction of primary of transformer amd snubber. Now the voltage withstanding capacity of FETs must be as low as possible because the cost of FET increases with increase in voltage withstqnding capacity. So snubber is designed in such a way that it must absorb as high energy as possible from the inductive kick such that energy diverted to FET is as low as possible and the voltage withstanding capacity of FET is again as low as possible to keep the cost to bay. I hope I made sense 😄😄
Thanks for the detailed reply! So if I understand correctly, the snubber in the 2nd configuration then also dissipates and attenuates the sum of the reflected voltage and the Leakage inductance kickback (0.3*Vin_max)
1. Any diode can take certain power or current for certain time which is generally in ms. You will have to look at graph of peak pulse power rating wrt pulse width. So for every power level you will get the maximum allowable pulse width in time beyond which the diode will get destroyed. You will have to know the power that will be dessipated through the TVS diode. 2. You can also refer the graph of peak pulse current Vs time. Follow same procedure as descibed for peak pulse power. 3. Or you can simulate it in LTSpice
Any component put in parallel of mosfet will not be able to stop voltage spikes from transformer. For that the component must be in parallel of transformer only
Excellent explained and also an interesting topic, but but Reading will not generate much interest in listening as explanation do, so try to explain in your own words. Sometimes reading shows that its not understood by your self. Anyways Keep up the good work
Thanks for the appreciation..... Unscripted explanations are coming soon.... Do share these tutorials on social media so that it can reach more people.....
In rcd snubber circuit,why energy only through diod and capacitor ??? I think it also through diode and resistor.you can explain ? I really don’t understand. Feedback to me.Thanks
1. Impedence of capacitor is 1/(2*pi*f*c). Which means it is inversely proportional to frequency and here the frequency of voltage is same as the switching frequency of PWM controller which is in kHz. Hence the impedence of capacitor is very less. So capacitor provides a low impedence path. 2. The capacitor is selected in such a way that the impedence of cap is lesser than resistor. Moreover, resistor is selected such that the R*C time constant is such that before the next cycle of PWM arrives the energy of cap is quickly dessipated in the resistor and it discahrges the cap totally..... PS- sorry to have replied so late 😇😇
1. We would be arranging many polls in the future to bring the exact topics that you guys require which will require access to the community tab.
2. But sadly it is only possible once the channel reaches at least 500 subs.
3. So it is absolutely important for you guys to subscribe so that we can bring tailor-made topics.
Thank you! I have read and watched other materials before. I think, finally I understood the principle of this circuit. :)
Thats really great bro...🤘
So dont forget to share with others and considsr supporting us on Patreon 😃
Very nice and compact explanation, thank you. However, when you move the RC snubber circuit from minus supply to positive supply, the anode side of the diode must remain connected to the drain of the MOSFET. It is not possible to connect the diode in between the primary transformer winding 1 and the leakage induction Llk, because that node is not a physically existing point. It is an internal node of the transformer model, so in practice you can’t connect anything to this point.
Waoo Many thanks for your guideline. The snubbing capacitor is electrolytic type or non electrolytic type. please guide . more over one calculated value may help as an example
Since snubber circuit is subjected to switching frequency, it charges and discharges rapidly. Electrolytic capacitors are not made for such rapid transitions.
So, the capacitors should be of tantalum, ceramic or thin film types.
And we will surely include a calculation but right now we are busy putting out a course on Embedded C development.
Feel free to check it out -
ua-cam.com/play/PLJGDxJZDiVu8JgYdVTxedAZhTJ5dyMkzO.html
After the embedded C course we will surely give a calculation example for snubber circuit...
Can you suggest me best snubber design VALUES for Lleak = 180nH , Primary inductance with 0.9uH and secondary with 57uH in 1:8 turns ratio with Voltage spike of 242V at Vds whereas my Mosfet is can handle upto 200V my Vin_max is 9V and my Vout expected is 120V at Secondary Side with switching frequency of 1.5MHz and 12A Primary Peak current , Primary Current Mean =3A.I have designed it by 2nF and 40ohm snubber,my peak has been reduced but the power dissipation is too high than expected ..I need power dissipation less than 500mW at snubber.Can you help me with optimal Values? I prefer tuning the Rsnub and Csnub rather than adding new Components to Decrease the power dissipation!!
Do I need a snubber circuit or a clamp diode for a push pull high frequency inverter? Or a push pull high frequency charger upto 50khz
A clamp diode will be required here because snubber circuits are slow and not suitable for high speed applications
Very well explained video thank you!
Thank you very much....
dont forget to mention areas where you are stuck...
So in the second configuration where the snubber is between the primary coils, are we also allowing more voltage to stress the MOSFET since we aren't snubbing the leakage inductance? Which might be acceptable if the FET is rated for that, but just wanted to make sure I understood the tradeoffs of moving the snubber circuit.
Leakage inductance is not actually present in physical form.
When we implement a transformer or inductor or any other source of magnetic field then a major portion of the magnetic field gets linked with the respective inductor or transformer. But a small amount of magnetic field does not flow through the intended magnetic element. This field gets lost and it does not contribute in energy transfer. So for simplicity we depict or display this field in the form of another small inductor or transformer in series (or may be parallel in some cases) with our main magnetic element. This is nothing but leakage inductance. So even if you do not show this leakage inductance in series, it is always present there.
So in our tutirial the keakage inducatnce is already and always embedded in the primary of high frequency transformer.
Now in our tutorial video it is shown that leakage inductance comes after the connection of snubber and primary of transformer. This was actually a mistake. From the above explaination we can say that the leakage inductance is embedded in the primary of transformer and it does not lie after the connction of primary of transformer amd snubber.
Now the voltage withstanding capacity of FETs must be as low as possible because the cost of FET increases with increase in voltage withstqnding capacity. So snubber is designed in such a way that it must absorb as high energy as possible from the inductive kick such that energy diverted to FET is as low as possible and the voltage withstanding capacity of FET is again as low as possible to keep the cost to bay.
I hope I made sense 😄😄
Thanks for the detailed reply! So if I understand correctly, the snubber in the 2nd configuration then also dissipates and attenuates the sum of the reflected voltage and the Leakage inductance kickback (0.3*Vin_max)
@@CannonballCircuit Yes exactly....😃
Thank you sir
Welcome sir 😀😀
Thanks sir.So useful!
Can we use p6ke or 1.5ke TVS diodes for high frequency switching for example 20khz or higher?
1. Any diode can take certain power or current for certain time which is generally in ms. You will have to look at graph of peak pulse power rating wrt pulse width. So for every power level you will get the maximum allowable pulse width in time beyond which the diode will get destroyed. You will have to know the power that will be dessipated through the TVS diode.
2. You can also refer the graph of peak pulse current Vs time. Follow same procedure as descibed for peak pulse power.
3. Or you can simulate it in LTSpice
Good explanation
Thank you....
Diagrams and visualization really helps in understanding topics intuitively...🙂🙂
How about having a "series RC circuit" in parallel to switching MOSFET.
Any component put in parallel of mosfet will not be able to stop voltage spikes from transformer. For that the component must be in parallel of transformer only
Excellent explained and also an interesting topic, but but
Reading will not generate much interest in listening as explanation do, so try to explain in your own words.
Sometimes reading shows that its not understood by your self.
Anyways
Keep up the good work
Thanks for the appreciation.....
Unscripted explanations are coming soon....
Do share these tutorials on social media so that it can reach more people.....
In rcd snubber circuit,why energy only through diod and capacitor ??? I think it also through diode and resistor.you can explain ? I really don’t understand. Feedback to me.Thanks
1. Impedence of capacitor is 1/(2*pi*f*c). Which means it is inversely proportional to frequency and here the frequency of voltage is same as the switching frequency of PWM controller which is in kHz. Hence the impedence of capacitor is very less.
So capacitor provides a low impedence path.
2. The capacitor is selected in such a way that the impedence of cap is lesser than resistor. Moreover, resistor is selected such that the R*C time constant is such that before the next cycle of PWM arrives the energy of cap is quickly dessipated in the resistor and it discahrges the cap totally.....
PS- sorry to have replied so late 😇😇
Very good
Electrolyte capacitor can we use as a snubber capacitor
Electrolytic capacitors cannot be used.
The capacitors should be of tantalum, ceramic or thin film types.
Sir your video is very useful pl. Hindi me video banaye thanks
Haan sir....
Abhi hum progrming videos pe focus kar rahe hai....
uske baad hindi channel ke bare me sochte hai
ترجمة للعربية رجاء
Do not understand this language...
sry bro....
@@SimplifyingElectronics Translit to Arabic. Please
Right now we do not have resources to translate....
Let me add arabic subtitles....
Thank you sir
Glad you got something out of it 🤟🤟