Inductive spiking, and how to fix it!

Well done.

Great

Could you use capacitors in parallel with the FET to help protect it? Ive been having some issues with a resonance circuit

but a freewheeling doide do not enough for this in an flyback.

How do I know if the diode that I am using is actually "fast enough"?

Best one soo far!!❤

Hi... I am facing the arcing issue with 48V DC motor, so it (Diode placing concept) will work for this arcing issue?

Excellent explanation, thanks for posting.

Such a good and well explained video

Perfection

this is interesting lesson. many thanks !

Great Explanation .

In layman's terms imagine trying to stop a freight train with a wall.
It's will not go well.

Basically inductive loads is like inertia. the bigger the coil the harder is it to stop.
It is also very similar to water hammer effect.

Hi! Good idea on this video. I've been struggling with my car heater speed circuit and I was actually suspecting this was the reason for the main transistor blowing up every time. Do you have any experience with these type of circuits? It's an old car so it uses one of those big round cap type of transistors to hold the 12v motor voltage back when turning at lower speeds. Thanks in advance.

Whenever circuit breaker opens up in transformer due to line to line fault in area(becoz crows sit and cause it there) ,this causes a complete damage to the pcb of my Refrigerator....is this the cause behind that.I have installed Stablizer as well as MCB but it couldn't save that from damaging.

..................good...................

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?

What about AC inductors?

500 comments already, maybe someone has written about it, but: we should keep in mind that, although parallel diode is "a must", adding it makes the current in the coil fade away quite slowly. U = -L(di/dt), so if U is like 0.7V on a silicon diode (or even less on a Schottky diode), the current remains significant for quite a while after the transistor gets switched off.
In many cases this might be not important, but if we need fast reaction, it is advisable to use a Zener diode in series with "normal" one (cathode to cathode or anode to anode), in order to increase U in the formula above. Alternatively an appropriately calculated resistor may be used. I personally learned that when I was designing solenoid driver for kind of a printing head, and the first version, where a regular silicon diode was used, dosed much more ink than was desirable and than would result from the duration of the driving pulse. (In turn, when a Zener diode is used, power dissipated on it must be taken into account, especially if pulse repetition rate is high).

will voltage built up at the same point if it high side switch?

Now say you want those spikes. Say for a muscle stimulator for example, where you need impulses of around 150V at around 70hz. What is the best way to achieve that with minimal components like transistors, inductor and capacitors. And what does the voltage of the spike depend on?

hello sir, i am trying to drive 48VDC motor through Microcontroller, its working fine but at some times arcing problem is occured. Connection- Relay contacts, NO- Phase, COMM- 10amp contactor(A1), GND- A2. when relay is on contactor will pass the 440V signal to a converter , then converter will convert 440v AC into 48VDC. And then this 48VDC is given to DC motor through DC contactor.

I have tried 0.1uf AC capacitor series with 100ohm resistor accross 10Amp contactor but not worked, what will be solution for this?

Brilliant explanation. Thank you!

sooo, if I use a relay to switch a dc motor, i have to put two diodes in parallel with 1) relays coil and 2) motor ? :)

This explanation is gold !!

How can barrier voltage be measured

I know this is an old video but talking about electrons flowing in some opposite direction is pointless, the only thing anyone needs to know is which way the electrons are actually travelling along with its voltage.

Great content ty

I love this explanation

What if I want to be able to reverse the motor?

I thought they were called "snubber" diodes...

I'm in the process of converting an automobile to full electric, and I have been building an open source DC Motor controller. This video was hugely helpful to me in understanding WHY I need to add capacitance across the bus bars of the IGBTs. I had already done so, but I was just a monkey imitating what a thinking person had done before me. Now I at least have an inkling of the theory underpinning it. Thank you.

Please can anyone explain this or correct me…..the way I see this is that, in this example , the diode doesn’t ‘correct’ the reverse voltage issue it just ‘deals ‘ with it. If this is correct then I get it. BUT, it still allows voltage to travel backwards albeit taking the easier path and ‘saving’ the motor/component etc…..wouldn’t it be simpler to add the diode in series - in this way allowing normal current flow in normal use but then COMPLETELY stopping any reverse movement at all? A lot of diodes have 50/60v reverse ‘protection’ and so would survive in the right situation. Where’s the advantage in using parallel over series. Please help/advise as my head hurts 😩

Once when I was playing with an old transformer I have had almost infinite inductive spike! How is that possible? Is it mayne an error of oscilloscope (my oscilloscope is fine and no problems at all) ? Mosfet transistor was a little bit hot and that's it...

This is nice

what if the mosfet is placed between the vcc and the solenoid????

👍

But what if the load is ac ??? Then how do you determine the direction of diode to be reversed if power goes off during negative halfcycle

Very well explained . The motor I am using is 3kv dc motor 24 volts it is a golf cart motor . and max current is almost 150 amps , please advise what kind of a freewheeling diode will be good to save the IGBT it blows up very now and then

Gold

appreciate the valuable information, i am 128hz pwm a 12v 18 amp dc motor, what is a suitable diode value? thank you

I have a 240v ac drill press which i want to add to the start circuit/button an LED light which is designed for 240v ac operation. The LED is a ring light module with an inbuilt voltage controller/regulator.
Will i need add any protection for the LED circuit ??

Is there any need for a flyback diode if the MOSFET features avalanche protection?

The best description I've seen on this topic. Thanks so much for sharing so clearly.

Best 5 min video ever <3