Thank you for great videos. Small correction, for the free wheel diode the inductor energy doesnt go back to the supply but dissipated in the diode itself.
Nothing new under the sun, cause the diode parallel, i.e. to the relay coil, is common since semiconductors was introduced, but very, very well explained. Good teacher.
@@FoolishEngineer i am going to create pure sin wave inverter using sine wave oscillator, class D amp. and low pass filter, i need your help. Could you help me?
That HUGE spike Of energy is the inductor wanting to oscillate You're preventing energy from doing what it Naturally WANTES to do instead of what you forced to do. That's why everything nowadays HEATS UP.
The voltage spike generated across the coil when the MOSFET goes OFF is the opposite polarity of the supply voltage. Therefore, the diode is conducting when this happens and dissipates this energy into itself and NOT as mentioned, into the supply.
Thanks for the nice video. It helps to explain about inductive spiking for switch FET applications but why does this then result in a ringing effect? Why not just a large spike and then the FET settles back to the supply voltage?
The ringing is because of the LC circuit that's formed with the output cap, now recall a series RLC circuit's step response. The R is summation of the dcr of the inductor, trace resistance, the source resistance in the path.. hope that clears your doubt
Sinceres thanks for your lettures. But, why most half bridge topologies converter use just a resitor and capacitor to reduce the spikes during off time?
I'm trying to make mosfet spot welder after blowing mosfets i searched alot about this failure and found voltage spike is killing mosfets this is my mistake to not knowing about mosfet properly after watching your video i found that my wires are inductive load which creates positive spike at drain so i need to place diode between mosfet's DRAIN (before wire bcz wire is inducing positive spike) to "+" Terminal Of My Battery. ANODE leg to DRAIN CATHODE leg to "+" terminal of battery. Correct me if I'm wrong?
thanks for this video but i have a doubt that ,i have a gate driver circuit and i have also used a diode as u taught and iam still getting high spike after some time my simulation runs? why
Great video! Any reason why I’d be getting a similar phenomenon when a solenoid is turned on. I see pretty significant spikes when I first turn on a solenoid and turn it off (with a button)
When the MOSFET is OFF, the back EMF from the inductor will cause a current to flow through the diode and back to the supply, but in addition to that it can also flow through the inductor itself. So there will be two paths for current to flow, right?
When MOSFET is off then diode act as close switch for flyback voltage so diode short circuit to the inductor during this time period so current flow only in inductor not to power supply because ground path of power supply is not complete . During this time inductor and freewheeling diode will heat so generally one snubber circuit i.e. parallel combination of a resistor and a small value ceremic capacitor add in series with freewheeling diode.
@@pushpendraaryan5551 Yup you're right about the diode part. The circuit is actually complete, since the MOSFET has a body diode, the only thing is that the body diode will be reverse biased.
At 5:00, the description is somewhat flawed I think. The protection diode just dissipates the flyback voltage as heat without diverting it back to the main power supply.
Im trying to use this aspect of inductors to create voltage spikes in a controlled fashion. How do I read the value of di/dt from the oscilloscope measurement
I was using inductors and high speed switching with a 27,000MHZ quartz crystal to create a swing for a Tesla coil and I was testing it with a dead 9v battery that had about 6v left in it and it went into a resonance cascade and it fried the whole ciruit also it wasn't hooked up to a coil yet .. but ya my goal was to creat a specific resonance only I got wayyyy more than I expected . If I can recreate it again it will be tricky to handle the continuing increase to find out far it can actually go without frying it again ,, not sure what to do next since it isn't ready for the coil or , maybe I need something else . I had originally thought I would create two circuits and apply them against each other with another crystal at 28,000MHZ to get the resonace started and then figure ways to adjust it provided it's close enough to correct parameters .. 🤔 I was able to run another circuit like it with an earlier SCR without it frying and it runs off of 5 v and of course the goal here is to keep it running after the 5 volts is gone if it can continue to remain regeneratively and if it can pull what it needs from the air and keep the LEDs lit up ....
The capacitor could get damaged because the potential difference between the + of the back EMF (i.e. Voltage between the Drain and the Voltage Source when the MOSFET turns OFF) and the positive terminal of the voltage source will be large. So, we might need a very high voltage capacitor.
@@electroquests Once the diode is added to the circuit, the back emf can never exceed the positive supply by more than one diode drop (not more than a volt or so, worst case). You only need a capacitor with a voltage rating a few volts more than the supply voltage. You really need a return path to ground via the supply in any scenario, so you're going to put a capacitor across the supply in any case.
Actually It can do it, because spike Voltages from inductor has more potential than the battery that makes a circuit acting like a charge battery with 2 sources.
Hello. I want to make a fake load circuit to test the battery that can adjust the current passing through, my idea is to use a mosfet. load directly from the mosfet. I hope you can help me calculate the tolerable capacity of the mosfet through its datasheet and how to dissipate heat for durable use. Thank you very much
Electronics seems like a game of chess mixed with magic the gathering. This has these basic moves. You pair this with that, and it has this unique move, but now it has a sudden weakness.
Thanks for the informative video. But there is correction in waveform, when vgs is high at that time vds won't be 0 it will be equal to the external supply as inductor will become short circuit (constant current). So full external supply will be shared to vds of mosfet
I want to replace the ignition system of my old car with a transistor (TCI) instead of a breaker point contact switch. is it necessary to also add a diode in this case on the ignition coil, to protect the transistor from damage. will it not affect the output of the spark plug flame
![Tee Grizzley - Blow for Blow (feat. J. Cole) [Official Video]](http://i.ytimg.com/vi/wNLN5xsx5dc/mqdefault.jpg)
Thank you for great videos. Small correction, for the free wheel diode the inductor energy doesnt go back to the supply but dissipated in the diode itself.
You are very good at explaining complex processes...to the last detail . You make them easy to understand....great work ...
Thank you so much for watching!! Please don't forget to subscribe to our channel
Nothing new under the sun, cause the diode parallel, i.e. to the relay coil, is common since semiconductors was introduced, but very, very well explained. Good teacher.
Thank you so much for watching!! Please don't forget to subscribe to our channel
Beautiful grafics and explanation.
greatings from Argentina.
Thank you! Cheers!
I did learn about dc to dc convertor through your vedios.Thank you very much.
Thank you so much! Please show support to my video with Super thanks.
@@FoolishEngineer i am from sri lanka. Thanks your helps.
@@FoolishEngineer i am going to create pure sin wave inverter using sine wave oscillator, class D amp. and low pass filter, i need your help. Could you help me?
That HUGE spike Of energy is the inductor wanting to oscillate You're preventing energy from doing what it Naturally WANTES to do instead of what you forced to do. That's why everything nowadays HEATS UP.
The voltage spike generated across the coil when the MOSFET goes OFF is the opposite polarity of the supply voltage. Therefore, the diode is conducting when this happens and dissipates this energy into itself and NOT as mentioned, into the supply.
Why there is ringing across DS voltage after putting the diode?
Thanks it is just great. I learned it like a charm. It is perfect.
your all videos are awesome, keep posting and best of luck for future
Thank you so much! Please show support to my video with Super thanks and don't forget to subscribe to our channel
Thanks for the nice video. It helps to explain about inductive spiking for switch FET applications but why does this then result in a ringing effect? Why not just a large spike and then the FET settles back to the supply voltage?
The ringing is because of the LC circuit that's formed with the output cap, now recall a series RLC circuit's step response. The R is summation of the dcr of the inductor, trace resistance, the source resistance in the path.. hope that clears your doubt
The ringing effects comes from the collapse of the voltage spike
Sinceres thanks for your lettures. But, why most half bridge topologies converter use just a resitor and capacitor to reduce the spikes during off time?
Why don't i see that diode on comercial inverters? does it bring additional problems?
I'm trying to make mosfet spot welder after blowing mosfets i searched alot about this failure and found voltage spike is killing mosfets this is my mistake to not knowing about mosfet properly after watching your video i found that my wires are inductive load which creates positive spike at drain so i need to place diode between mosfet's DRAIN (before wire bcz wire is inducing positive spike) to "+" Terminal Of My Battery.
ANODE leg to DRAIN
CATHODE leg to "+" terminal of battery.
Correct me if I'm wrong?
What about adding a capacitor of 47uf in parallel with the inductor instead of a fly wheel diode.
thanks for this video but i have a doubt that ,i have a gate driver circuit and i have also used a diode as u taught and iam still getting high spike after some time my simulation runs? why
Great video! Any reason why I’d be getting a similar phenomenon when a solenoid is turned on. I see pretty significant spikes when I first turn on a solenoid and turn it off (with a button)
solenoid is a type of inductive load
@@FoolishEngineer Thanks
so instead of hitting a MOSFET higher voltage hits diode and then power supply? what if power supply is not ready for it too?
When the MOSFET is OFF, the back EMF from the inductor will cause a current to flow through the diode and back to the supply, but in addition to that it can also flow through the inductor itself. So there will be two paths for current to flow, right?
I highly doubt that. I need to check on it.
When MOSFET is off then diode act as close switch for flyback voltage so diode short circuit to the inductor during this time period so current flow only in inductor not to power supply because ground path of power supply is not complete .
During this time inductor and freewheeling diode will heat so generally one snubber circuit i.e. parallel combination of a resistor and a small value ceremic capacitor add in series with freewheeling diode.
@@pushpendraaryan5551 Yup you're right about the diode part. The circuit is actually complete, since the MOSFET has a body diode, the only thing is that the body diode will be reverse biased.
@@electroquests stored inductor energy will be dumped into the diode
The inductance tend to keep the current in the same direction ( no change in the direction ). So it flows back to the source through the diode.
At 5:00, the description is somewhat flawed I think. The protection diode just dissipates the flyback voltage as heat without diverting it back to the main power supply.
can you also explain capacitive load with MOSFET? in Both side,,,capacitive load at the drain side and once in source side...thanks.
Im trying to use this aspect of inductors to create voltage spikes in a controlled fashion. How do I read the value of di/dt from the oscilloscope measurement
The ending "thanks watching " great style,I watch full video 👍, sir what software you used to make your video
Thank you so much!
I was using inductors and high speed switching with a 27,000MHZ quartz crystal to create a swing for a Tesla coil and I was testing it with a dead 9v battery that had about 6v left in it and it went into a resonance cascade and it fried the whole ciruit also it wasn't hooked up to a coil yet .. but ya my goal was to creat a specific resonance only I got wayyyy more than I expected . If I can recreate it again it will be tricky to handle the continuing increase to find out far it can actually go without frying it again ,, not sure what to do next since it isn't ready for the coil or , maybe I need something else . I had originally thought I would create two circuits and apply them against each other with another crystal at 28,000MHZ to get the resonace started and then figure ways to adjust it provided it's close enough to correct parameters .. 🤔 I was able to run another circuit like it with an earlier SCR without it frying and it runs off of 5 v and of course the goal here is to keep it running after the 5 volts is gone if it can continue to remain regeneratively and if it can pull what it needs from the air and keep the LEDs lit up ....
You likely created an uneven charge/discharge time in the ac cycle. Would be curious to see a circuit
Very good sir
For freewheeling theory.
Thanks
Always welcome, thanks for watching!!
Sir, very nice course, but what if I polluted the power source by using the diode, how can I solve this problem then?
Great video
Outstanding sir.. ❤
Hello, thank you very much. I have a question. Are the Spikes AC or DC inteferences?
DC
thank you very much
You are welcome
great video thanks
Bro, please explain Complete details about gate driver circuit for mosfets
Definitely, working on it!
@@FoolishEngineer thanks bro
One additional points all power supply are not sinking type so you can put large electrolytic capacitor to sink the current when MOSFET is off
The capacitor could get damaged because the potential difference between the + of the back EMF (i.e. Voltage between the Drain and the Voltage Source when the MOSFET turns OFF) and the positive terminal of the voltage source will be large. So, we might need a very high voltage capacitor.
@@electroquests no when freewheeling path is present at that time it will not damage the capacitor.. input voltage *2 rated capacitor is enough
@@electroquests Once the diode is added to the circuit, the back emf can never exceed the positive supply by more than one diode drop (not more than a volt or so, worst case). You only need a capacitor with a voltage rating a few volts more than the supply voltage.
You really need a return path to ground via the supply in any scenario, so you're going to put a capacitor across the supply in any case.
May i know which software are you using to make the animation
after effects
Please note a correction!..Energy can never flow to supply via freewheeling diode..
Very good!
Thank you so much! Please show support to my video with Super thanks and don't forget to subscribe to our channel
Good explain
Thank you so much for watching!! Please don't forget to subscribe to our channel
Thank you
Thank you so much for watching!! Please don't forget to subscribe to our channel
Good
Can I contact you via email for consultation about MOSFET Inductor Circuit?
Thank you.
How can I help you?
❤
niceee
Thank you so much for watching!! Please don't forget to subscribe to our channel
Kindly make a video of a capacitor instead of a free wheel diode
schottky diodes work pretty well in this application than fast recovery diodes.
The diode parallel to inductor will blow quickly 😂
This is not practical in real circuit
rubbish, the current does not flow trough diode back to the battery, it cuirculates inside of the inductor
Actually It can do it, because spike Voltages from inductor has more potential than the battery that makes a circuit acting like a charge battery with 2 sources.
At least that is what it supposed to be, if you know why it flows through the diode pls explain me 👍
@@thebread8918 if the mosfet is not damaged and fully closed there can be no current trough the battery. And if so, at least not in that direction
As a practicing design engineer, just want to say thanks for the refresher bro!!
Thank you so much for watching!! Please don't forget to subscribe to our channel
Hello. I want to make a fake load circuit to test the battery that can adjust the current passing through, my idea is to use a mosfet. load directly from the mosfet. I hope you can help me calculate the tolerable capacity of the mosfet through its datasheet and how to dissipate heat for durable use. Thank you very much
You can show the drain-source capacitance to show where the inductor pushes it's voltage when suddenly turned off.
Electronics seems like a game of chess mixed with magic the gathering. This has these basic moves. You pair this with that, and it has this unique move, but now it has a sudden weakness.
So true; mosfets, igbts, etc are not yet fully ready to be sold,still a kind of art... lol
Every new Solution brings new problems.
Pls make a video about how a rc snubber works 🙏
Thanks for the informative video.
But there is correction in waveform, when vgs is high at that time vds won't be 0 it will be equal to the external supply as inductor will become short circuit (constant current). So full external supply will be shared to vds of mosfet
How to protect power supply against the current which will returned after FET's off? If I have 150 uH inductivity and 4 V 200 A power supply?
I want to replace the ignition system of my old car with a transistor (TCI) instead of a breaker point contact switch.
is it necessary to also add a diode in this case on the ignition coil, to protect the transistor from damage. will it not affect the output of the spark plug flame
pChannelTransistor-Diode false! Intern Bypassdiode ( = Z-Diode) protects it most!
To me, that's a "damper diode", which probably dates me too well. You have an informative direct style I appreciate and recommend. 👍
I have been searching for two years, and I can only understand your course very well. its 11:20PM I was planning to sleep, but now am not going to
Good for you!!
Nice example
Thank you so much for watching!! Please don't forget to subscribe to our channel
your video is very usefully pl. hindi me banaye
Will try
Is it safe for flowing back to power source?
Yes, upto some extend
Explained well
Thank you so much for watching!! Please don't forget to subscribe to our channel