The amount of knowledge we can get from these videos is enormous . I am 72 and still learning things . I may never use this knowledge but for the young people out there this videos can open up job opportunities or prepare you in the field of electronics . Even if you were not good in math !
This is exactly what I needed to know, it really dumbs down the information about the function of a mosfet into digestable and useful information I can actually use thank you!!
So wel explained with the picture of water valve, it makes it so much easier to picture and understand. Hopefully your other teachings are of same quality
2:25 the electronic ignition in your car is highly likely to be using a BJT to fire the coil. In the GM HEI module it would be a MJ10012 or similar and would be conducting up to around 6 Amps. Almost every solid state audio amplifier from the 1960s to well into the 1980s was using bipolar transistors. High power mosfets became more popular later on. During the same period, bipolar power transistors were used in almost all mobile two-way radio equipment in the RF power transmitter stages, until power mosfet pricing and performance improved. There are plenty of high current bipolar transistors.
You forgot about the even less known Boron-Oxide Barium Field Effect Transistor, or BOBaFET. It seems that there is even a whole book about it. Jokes aside, nice video!
Some bipolar transistors can also transmit large currents at high voltages. Note that most inverter motor controllers use IGBT transistors which are a hybrid of MOSFET and BiPolar transistors.
Hello dear professor Your lessons are really interesting and crucial, thank you so much for your help and advice,i do appreciate your job,i wish you peace and happiness under the sky of prosperity,all the best. Take care and have a good time.
In an N-type MOSFET, electrons flow internally from the source to the drain, but conventional current flows opposite, from the drain to the source. So, if we choose to have water flowing in the direction of conventional current (as opposed to having it represent the flow of electrons) then that diagram would be correct, with water flowing from drain to source. It may be confusing, but that is the fault of 1980's electrical engineers, not the channel author.
@@prestonbecker8784 the channel author should have used an Pchannel then, or used a diagram that was different, this is absolutely the choice of the channel author. This choice made it confusing for their viewers. Not the "1980's electrical engineers" you are attempting to misdirect the problem at.
That's because there are two types of MOSFET, a P channel would go like you think from Source to Drain, a N channel (far more common) goes from Drain to Source. I agree not the best analogy.
Don't let the direction of current flow bother you. Think of one direction as electron-flow and the other as hole-flow. Hole-flow is aka conventional-flow and a hole can be thought of as where the electron flowing in the opposite direction used to be.
As a guitarist, the MOSFET distortion pedal is a very sought after tone. I have no clue why, but it gives the circuit a very unique flavor of clipping and is very popular in the blues/rock/classic metal genres. That's what brought me here.
From what I gather, it's the very fast switching rate that the MOSFET is capable of (which is one reason why it's commonly used in high-voltage power situations). Interesting that it's desirable for distortion since most tubes (12ax7, etc) are the opposite and have very sluggish responses. This is one of the reasons why the famed LM308 Opamp in Rats and Tube Screamers is supposedly so desirable.
I also started studying stuff like this because I play the guitar and wanted to build my own amps and pedals. I did build a distortion pedal with an LM386 and it sounded great. Sounded like a fuzz pedal. It was great.
I'm not an electrician or an engineer (that will probably become obvious in a moment) but it sounds to me like they got the drain and source mixed up. In the faucet analogy, why wouldn't the pipe leading into the spigot be the source? Is that not where the water flow is coming from?
People it's not right or wrong, you can connect a p channel MOSFET source to a positive voltage and have the drain on negative, so then which way is current flowing? Well, drain to source right? So without more context to the application you can't say whether it's wrong or right. It's just a rough visual of how the device generally works, don't try to hook your FET up to the water spigot.
Using the pot to variable polarize the gate is same to control the speed of your car with a valve from fuel tank to the carb or injection pump .Did you heard pulse with modulation sometimes?
6:00 That circuit would blow the MOSFET easily if it doesn't have protection against back EMF from the motors. Anytime the motor is shut off, the collapse of the magnetic fields generate a current in the reverse direction. Typically, you need to add a diode from drain to source wired in reverse to prevent the the MOSFET from blowing. The only time you don't need it is when the MOSFET has internal protection. Some MOSFET circuits that requires an external PWM signal to switch the MOSFET include optoisolators to prevent damage to the MOSFET. Who knows what type of signal people may use as an input. By putting in optoisolators, you decouple the two circuits and prevent external signals from damaging the FET. Its another layer of protection that is used in robust designs. Its common for MOSFETs to blow if its not designed properly. Its almost job security as soon as I look at some of the schematics.
All power MOSFETs have in inverse diode between drain and source. It is there because of the way FETs are fabricated. In the early days of FETs they were just sort of there. Now they are generally carefully characterized and can be used to advantage. The current in an inductor does not change direction when the field collapses. The polarity of the voltage changes but the direction of current flow stays the same. An inverse diode across the FET doesn't cope with that, however the internal body diode behaves similar to a zener and _may_ be able to handle the current.
In the last schematic of the DC MOTOR controller DRIVER module. If driving LEDS the schematic is correct. But if used as a motor controller there should be a Shottkey Diode over the motor to prevent spikes from the coil blowing up mosfet. ??
Yes, I agree that a diode (as substituted for the resistor) would be better at controlling the back-EMF as developed by the Motor - when the Motor is turned-off
What semiconductors are used for higher-power applications, e. g. electric vehicles and hybrids, locomotives, and DC power transmission between AC grids?
With a logic-level MOSFET, the circuit with the Arduino Uno would be just fine. however, with a power MOSFET (the kind that can control large currents), that would fry the microcontroller with the inrush current (gate forms a capacitor with the junction). In those cases, one needs to use a gate driver, which I think would be a good follow-up video subject. I've used MOSFETs to modify flywheel foam dart and ball blasters, since the motors I used have a 28 A stall current.
5:15 "If we talk about this circuit, since there's no damage to the potentiometer, this circuit will work smoothly even if there's no resistor." First the resistor is there to protect the MOSFET - Now it's ok to run w/o it since the potentiometer's still good.🤔
At 6:37 with the PWM you don't show any positive leads to micro controller. I don't know maybe it has a separate power source. You show 2 negative leads going to it.
The drawings have quite a few confusing bits in them. I mean of course if you know already it’s fine, but a newbie might get confused by the poor depictions. Such as both arrows pointing up on both sides of the battery, instead of continuing with one more arrow to show it going into the negative terminal. It makes it look like both sides are going in the same direction. And with the arrows appearing from bottom to top at 1:40 it makes it appear as though you’re showing electricity moving in the same direction for both, both upwards, which isn’t a deal unless the person doesn’t see the tiny arrow at the end that’s the same colour. It’s just presentation issues really. I’d avoid graphics unless you have a better understanding of how people perceive them when watching.
It sounds like a mosfet is a like a bypass valve. Access to full power ( source ) but if only a partial speed is wanted it sends the unwanted current to drain thereby bypassing the unwanted voltage / current to a different loop and circulating it not wasting in in heat like a potentiometer.
afters weeks of searching for a video that easily explains mosfets , I came across your video . Thanks a lot !! but can you make a video about mosfets with more than 3 pins , especially 8 pins mosfets ?
You don't need the resistor [in this example] because the potentiometer won't be damaged by back currents. It's good to use them most other times (like when hooked to an arduino or other complex controller) because the back current could damage those components.
As someone with a VERY basic knowledge of electronics, why is the MOSFET needed for the fan circuit? If the POT is used to change the voltage to the fan, won't it change the speed of the fan without the MOSFET anyway?
Without the MOSFET all the current would run through the POT which would probably burn it up. At leat that is how I understand it but my knowledge is also pretty basic.
@@audunskilbrei8279 This is true for most higher power circuits. POTs aren't meant to switch much current. The one shown here could probably handle the current for that motor but the purpose was to show the usage as a speed controller input to the MOSFET.
Yes, the fact that P & N mosfet actually have different directions makes the faucet analogy even more strange. Since in one of them, water would stream in reverse anyways.
The problem is that it's conventional to draw circuits with the 'ground' as a common rail connected to -ve, with the'electricity' entering from the +ve, going through the components, and 'back' to -ve. So N-channel FETs have the 'electricity' going from drain (+) to source (-). This is because, when electricity was first discovered, it was believed to flow from + to -, and the convention stuck. BUT, electricity is actually a flow of negatively charged electrons from -ve to +ve. So the tap analogy must be referring to the concept of 'electricity' rather than what actually happens.
Is it possible for me to control a higher voltage fan with the same setup? Of course, grounds of different voltages separate. I actually tried it and it wont accept anything but the operating voltage, which is useless to me. I really need to use lower voltage to open and close it, but i either dont get something or mosfets just cant do it
One thing that was drummed into me, working with them, was how fragile MOSFETs are in relation to high voltage. This why, when handling them, you should wear an earthing strap to short out static which may be many thousands of volts; no power or danger to humans but deadly to these devices and their packaging is conductive carbon foam.
They don't change it because they will not that to many people think about it. when you think deeper about the true direction of the flow, that will show that everything they teach about electron movement is false and in reality they know nothing about they have only theories! about how electricity works.
@@Toxxxic_ Just have a program change the literature. Going forward it doesn't make sense -- to me -- to keep the traditional concept of current flow when electron flow makes more sense.
I was going to mention this. Back when I was building power amplifiers in the late 1970s I had a large range of both NPN and PNP BJT transistors from which to choose with collector current ratings over 15 amps.
At 4:32 you show a mosfet being used in linear mode. Most mosfets on sale to hobbyists are not designed to work this way. They are intended to be used in switching circuits where they will be hard on or hard off.
In doing so they fail to answer "What is a MOSFET?" ;) So it's some kind of linear throttle something something? It's not a switch?!?! Thanks synth narrator, now I'm confused.
great question, i was also wondering how mosfet triggering mode really acts, was it the same as the potentiometer or just as simple as on/off switching device...
does it mean that the potentiometer was the actual control of current/voltage flow? so whats the mosfet for? it twisted my mind thinking about that circuit actualy
The potentiometer in that circuit triggers the MOSFET likely much earlier than when the motor starts to turn, it's in it's linear region (which is something one should avoid with MOSFETS). Since this is a motor, the momentum from the initial first turn of the motor made subsequent turns "less demanding" in terms of voltage needed to power the motor. MOSFET's work best (and as designed) when switched on and off, north of their linear region, not within.
I couldn't agree more, simple and practical knowledge. Add another sub for sure. Edit; It's really annoying me that I can't remember the term for power control using this method.....oh, hang on, the lazy little hamster that powers my brain just had a run on the wheel, Pulse Width Modulation, I feel so very much better now! Pax.
I might be wrong but I thought electron flow was from negative to positive, not the other way around as described here. Maybe it's different when talking about mosfets.
It is a thing called "conventional current". Conventional current does not exist but many people treat it like something that exists. Electron current exists, negative to positive. But when an electron moves, the spot it VACATED is then filled up the next electron and so on; this vacancy or HOLE appears to travel positive to negative. So it isn't actually a thing that moves but it appears to move. Considerable ambiguity can exist if people do not specify the kind of current they mean so I tend to ignore it. The arrow points in the direction of HOLE movement or conventional current, but I treat the diode symbol as you cannot go this way (arrow hitting a barrier) electrons move against the arrow.
@@thomasmaughan4798 not a bad explanation its the one I use myself maybe saying it doesnt exist might be going too far just say the holes `move` ? Ions and Ions the electron that gets detached is an ion and the atom missing the electron is also an ion.
Don't get confused .....what u are saying is " electronic current " which is from negative to positive. Conventially, current was thought to flow from positive to negative. And hence called conventional current . Mostly in tutorials and diagrams you have to keep in mind that they will depict conventional current. So, just be careful and dont confuse yourself. Even correct way of circuit diagrams still depict and follow the path of conventional current.
Thank you so much. The movement of electrons is normally from negative to positive. But in theory, the direction of the current is accepted as the opposite. Circuit analyzes are made according to the direction of the current.
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I'd like to see a simple bare-bones MOSFET configuration like this for audio. There are 10s of thousands of "audio amplifier" designs, but I'm curious about the absolute minimum to pass an audio signal by MOSFET. If there is already such a video, my apologies for not looking first. :-)
Your hose bib analogy is backwards. Such as in an "N" channel device the negative is applied to the source and electrons flow through the device to the drain looking for the positive. [or more positive] Electrons flow from the negative terminal of a battery towards the positive terminal.
By convention, because electrons are assigned negative charge, we diagram current as the flow of positive charge. So in electrical engineering this is correct, while not technically the case physics-wise (unless you want to talk about "holes" but that's another can of worms).
Can you tell me what does that Zener diode mean in the MOSFET symbol? I've seen MOSFET symbols with and without it. Does it represent some side effect of a MOSFET, or do they literally put a Zener diode in a a MOSFET for some purpose?
I haven't looked it up in a while, so maybe double check my info, but if I'm not mistaken the zener symbol is used to symbolize that this particular MOSFET is "Repetitive Avalanche Rated". The ones you see with just the diode symbol means it's NOT Repetitive Avalanche rated, so avalanches will result in a catastrophic failure, just like a typical diode. That's how it was described to me long ago... hopefully that helps.
I am pretty confused by this explanation! Especially the first circuit drawings. The electricity flow never gets to the pot, so how does the pot get to have to effect the speed? Plus, what purpose does the resistor serve if there is no electricity flowing through that either? Also, there comes a time when the electricity/plumbing analogies just simply dont work like when you have to say Water flows from a drain to the source, you know its time to find another analogy! I think I'll look for another tutorial series!
The explanation about the use of the fixed resistor in series with the potentiometer makes no sense whatever! Note that one end of the 10k pot is connected to the positive of the power supply, while the other end goes through the 10k fixed resistor to the negative of the supply. That means that the voltage at the wiper of the pot, connected to the FET gate, can range from half the supply voltage to the full supply voltage. Power MOSFETs are _transconductance_ devices. The current that flows in the drain-source path is proportional to the voltage between the gate and the source. There is no current flowing into the gate. There is a "threshold" voltage below which there will be no D-S current flow, but above that the D-S current versus G-S voltage relationship starts to come into play. By adjusting the voltage at the gate of the FET the current in the D-S path and hence though the motor can be controlled. It is a crude circuit but OK for experimental purposes. It should be noted that with this circuit the gate voltage of the FET might be sufficient to allow it to conduct tens of amperes even with the gate voltage set to minimum. That would likely be the case with the IRFZ44 which seems to be popular with hobbyists. I'd take the 10k fixed resistor out and make a direct connection between the "bottom" end of the pot and the negative of the power supply. Most power MOSFETs can be safely operated with a gate-source voltage between -20 and +20 volts, but its always best to check the datasheet.
The example of the foset is wrong… Drain and source should be turned around. Water is starting at the source and ends up (through the foset ) at the drain…
Hi. Shown with reference to conventional current in the faucet example. We didn't think in terms of the direction of electron flow. Because circuit analysis is done with reference to conventional current direction.
I'd say it's because the potentiometer is a 10KΩ. In effect this creates a total variable resistance of 20KΩ that has a physical limit set at 50%. Using the principles of a voltage divider, the voltage at the slider would vary between 4.5V to 9V when measured in reference to ground (which is the negative). And most likely to prevent a high current or short situation between the DRAIN and the GATE.
At 4:30 I really don't understand the reason for the 10k resistor in series with the low voltage end of the potentiometer. BUT if that resistor were located in direct series with the GATE, that would make some sense. As it is now, the *minimum* gate-to-source voltage would be 4.5 volt. Many power MOSFETs would be fully conductive at this voltage, so you couldn't turn the motor OFF. If conditions might exist where the the GATE-TO-SOURCE voltage became more negative than the maximum specified, then a simple diode between GATE-to-SOURCE would fix it.
Yes, the only 'backward flow' from the gate would be the gate discharging, since the gate is insulated from the drain and source. Even if it was not, a resistor between gate and source would not help. There would be some use in putting a resistor in series with the gate if the driver (such as an arduino) has a limited current output. Also, the circuit diagram of the switched mode power supply is wrong; as drawn, there is no way the MOSFET can turn of the current. The inductor should be where the diode is and the diode should be in series with the source.
The amount of knowledge we can get from these videos is enormous . I am 72 and still learning things . I may never use this knowledge but for the young people out there this videos can open up job opportunities or prepare you in the field of electronics . Even if you were not good in math !
Better tutorials than what I learned in school.
Thank you so much 🙏🏼
This is exactly what I needed to know, it really dumbs down the information about the function of a mosfet into digestable and useful information I can actually use thank you!!
Perfect explanation! And The example Mosfet Driver Circuit at the end of the video, made me understand it's use cases even better. Thank you!
So wel explained with the picture of water valve, it makes it so much easier to picture and understand. Hopefully your other teachings are of same quality
2:25 the electronic ignition in your car is highly likely to be using a BJT to fire the coil. In the GM HEI module it would be a MJ10012 or similar and would be conducting up to around 6 Amps. Almost every solid state audio amplifier from the 1960s to well into the 1980s was using bipolar transistors. High power mosfets became more popular later on. During the same period, bipolar power transistors were used in almost all mobile two-way radio equipment in the RF power transmitter stages, until power mosfet pricing and performance improved. There are plenty of high current bipolar transistors.
Good Definitions about MOSFET with Related Animations are Stands Apart , Thank for Sharing and God Bless You Too .
Thank you so much 😊
Great background on MOSFETs.
Thanks!
Thank you so much 🙏🏼
You forgot about the even less known Boron-Oxide Barium Field Effect Transistor, or BOBaFET.
It seems that there is even a whole book about it.
Jokes aside, nice video!
Thank you. Unfortunately, I didn't know much about this transistor.
Some bipolar transistors can also transmit large currents at high voltages. Note that most inverter motor controllers use IGBT transistors which are a hybrid of MOSFET and BiPolar transistors.
Your explanation got my novice level head aligned on the MOSFET. Thank you.
I just learned more about MOSFETs in 8 minutes then I did in two YEARS of AA degree classes.
Hello dear professor
Your lessons are really interesting and crucial, thank you so much for your help and advice,i do appreciate your job,i wish you peace and happiness under the sky of prosperity,all the best.
Take care and have a good time.
There is a mistake @5:44 . The electron charge is NEGATIVE so the current must flow the other way around as shown.
Well said.
Thank you God bless you, the more you help to give, the given wisdom you shall receive abundantly !!!
So when you turn on a tap, water flows from the drain to the source of the water?? That's where I switched off....
In an N-type MOSFET, electrons flow internally from the source to the drain, but conventional current flows opposite, from the drain to the source. So, if we choose to have water flowing in the direction of conventional current (as opposed to having it represent the flow of electrons) then that diagram would be correct, with water flowing from drain to source. It may be confusing, but that is the fault of 1980's electrical engineers, not the channel author.
@@prestonbecker8784 the channel author should have used an Pchannel then, or used a diagram that was different, this is absolutely the choice of the channel author. This choice made it confusing for their viewers. Not the "1980's electrical engineers" you are attempting to misdirect the problem at.
That's because there are two types of MOSFET, a P channel would go like you think from Source to Drain, a N channel (far more common) goes from Drain to Source. I agree not the best analogy.
Electricity works on draw from source. The source is the electric motor or whatever is drawing current.
Don't let the direction of current flow bother you. Think of one direction as electron-flow and the other as hole-flow. Hole-flow is aka conventional-flow and a hole can be thought of as where the electron flowing in the opposite direction used to be.
Ive been trying to tell my wife that for years, but she still won't try it.
As a guitarist, the MOSFET distortion pedal is a very sought after tone. I have no clue why, but it gives the circuit a very unique flavor of clipping and is very popular in the blues/rock/classic metal genres. That's what brought me here.
From what I gather, it's the very fast switching rate that the MOSFET is capable of (which is one reason why it's commonly used in high-voltage power situations). Interesting that it's desirable for distortion since most tubes (12ax7, etc) are the opposite and have very sluggish responses. This is one of the reasons why the famed LM308 Opamp in Rats and Tube Screamers is supposedly so desirable.
I also started studying stuff like this because I play the guitar and wanted to build my own amps and pedals. I did build a distortion pedal with an LM386 and it sounded great. Sounded like a fuzz pedal. It was great.
I like your video and the way of coaching easily understandable.. Thanks🙏..
I'm glad you like the videos. Thank you 😊
I LOVE THIS CHANNEL!! BY ORDER OF ME, GEORGE MILLER, DON'T EVER STOP MAKING VIDEOS 🙂
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No-one cares what your name is bro
This channel is indeed unique and different than others.. keep it up
I'm not an electrician or an engineer (that will probably become obvious in a moment) but it sounds to me like they got the drain and source mixed up. In the faucet analogy, why wouldn't the pipe leading into the spigot be the source? Is that not where the water flow is coming from?
You're right, they mixed up
@@laysleal13 It's not mixed up. This is called "conventional current". See the comment below about Ben Franklin.
People it's not right or wrong, you can connect a p channel MOSFET source to a positive voltage and have the drain on negative, so then which way is current flowing? Well, drain to source right? So without more context to the application you can't say whether it's wrong or right. It's just a rough visual of how the device generally works, don't try to hook your FET up to the water spigot.
You are right about the water tap.
Really nice explanation, kept it simple! Continue with the good work 👍
Thank you so much ☺️🙏🏼
Hello, what studies are required to master the operation of this electrical board with its components?
Very clear explanation i did enjoy it .i understand hiw they work thanks I'm your subscriber now
Nice Job! Thank you for posting it. This lesson is perfectly thought out and illustrated nicely. The AI voice is fine by me.
Thank you so much ☺️
Educational, clear and concise. Thank you. 👍
Subscribed!
Thank you so much ☺️🙏
Using the pot to variable polarize the gate is same to control the speed of your car with a valve from fuel tank to the carb or injection pump .Did you heard pulse with modulation sometimes?
6:00 That circuit would blow the MOSFET easily if it doesn't have protection against back EMF from the motors. Anytime the motor is shut off, the collapse of the magnetic fields generate a current in the reverse direction. Typically, you need to add a diode from drain to source wired in reverse to prevent the the MOSFET from blowing. The only time you don't need it is when the MOSFET has internal protection. Some MOSFET circuits that requires an external PWM signal to switch the MOSFET include optoisolators to prevent damage to the MOSFET. Who knows what type of signal people may use as an input. By putting in optoisolators, you decouple the two circuits and prevent external signals from damaging the FET. Its another layer of protection that is used in robust designs. Its common for MOSFETs to blow if its not designed properly. Its almost job security as soon as I look at some of the schematics.
Thank you for the additional information.
All power MOSFETs have in inverse diode between drain and source. It is there because of the way FETs are fabricated. In the early days of FETs they were just sort of there. Now they are generally carefully characterized and can be used to advantage.
The current in an inductor does not change direction when the field collapses. The polarity of the voltage changes but the direction of current flow stays the same. An inverse diode across the FET doesn't cope with that, however the internal body diode behaves similar to a zener and _may_ be able to handle the current.
Brilliant explanation! Thank you very much!
In the last schematic of the DC MOTOR controller DRIVER module. If driving LEDS the schematic is correct. But if used as a motor controller there should be a Shottkey Diode over the motor to prevent spikes from the coil blowing up mosfet. ??
Yes, I agree that a diode (as substituted for the resistor) would be better at controlling the back-EMF as developed by the Motor - when the Motor is turned-off
What semiconductors are used for higher-power applications, e. g. electric vehicles and hybrids, locomotives, and DC power transmission between AC grids?
now this is an interesting query 😁
hope someone answers
IGBT are used for higher power applications.
With a logic-level MOSFET, the circuit with the Arduino Uno would be just fine. however, with a power MOSFET (the kind that can control large currents), that would fry the microcontroller with the inrush current (gate forms a capacitor with the junction). In those cases, one needs to use a gate driver, which I think would be a good follow-up video subject. I've used MOSFETs to modify flywheel foam dart and ball blasters, since the motors I used have a 28 A stall current.
Thank you for explaning about MOSFET 👍🙏🇮🇩
Thank you so much ☺️
Superb, very Helpful for my quick review. Subscribed
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Excellent, well explained ,very knowledgeable session, all the best and keep it up..
Thank you so much ☺️
Wouldn't it be better to have a diode on the output of the uController to prevent reverse current?
5:15 "If we talk about this circuit, since there's no damage to the potentiometer, this circuit will work smoothly even if there's no resistor."
First the resistor is there to protect the MOSFET - Now it's ok to run w/o it since the potentiometer's still good.🤔
Yeah it seems teacher had no idea what he is talking about
I still don't understand why a resistor needs to be there.
At 6:37 with the PWM you don't show any positive leads to micro controller. I don't know maybe it has a separate power source. You show 2 negative leads going to it.
The drawings have quite a few confusing bits in them. I mean of course if you know already it’s fine, but a newbie might get confused by the poor depictions. Such as both arrows pointing up on both sides of the battery, instead of continuing with one more arrow to show it going into the negative terminal. It makes it look like both sides are going in the same direction. And with the arrows appearing from bottom to top at 1:40 it makes it appear as though you’re showing electricity moving in the same direction for both, both upwards, which isn’t a deal unless the person doesn’t see the tiny arrow at the end that’s the same colour. It’s just presentation issues really. I’d avoid graphics unless you have a better understanding of how people perceive them when watching.
It sounds like a mosfet is a like a bypass valve. Access to full power ( source ) but if only a partial speed is wanted it sends the unwanted current to drain thereby bypassing the unwanted voltage / current to a different loop and circulating it not wasting in in heat like a potentiometer.
What a good content! Thank you very much!
I'm so glad it was useful. Thank you 🙏
excellent tutorials! very informative and easy to follow and understand! thanks!
Thank you very much ☺️🙏
Nice video but I am wondering why you didn’t use a diode to protect the circuit instead of the resistor.
Thank you so much ☺️🙏 Unfortunately, when I was preparing the script of the video, I didn't think of it 😔
afters weeks of searching for a video that easily explains mosfets , I came across your video . Thanks a lot !! but can you make a video about mosfets with more than 3 pins , especially 8 pins mosfets ?
Hi. I am so glad you liked the video ☺️ I will try to do research and make a video.
5:24 - need the resistor to protect the circuit -> we don’t need the resistor because the circuit is protected - wth ?
You don't need the resistor [in this example] because the potentiometer won't be damaged by back currents.
It's good to use them most other times (like when hooked to an arduino or other complex controller) because the back current could damage those components.
If there's JFET and MOSFET, what about BOBAFET?
Kidding aside, I love your explanation between these two. Thank you.
As someone with a VERY basic knowledge of electronics, why is the MOSFET needed for the fan circuit? If the POT is used to change the voltage to the fan, won't it change the speed of the fan without the MOSFET anyway?
Without the MOSFET all the current would run through the POT which would probably burn it up. At leat that is how I understand it but my knowledge is also pretty basic.
@@audunskilbrei8279 This is true for most higher power circuits. POTs aren't meant to switch much current. The one shown here could probably handle the current for that motor but the purpose was to show the usage as a speed controller input to the MOSFET.
I think you flipped sourced and drain for the fauset explaination.... I could be wrong, but idk, it just confused me lmao
Yes, the fact that P & N mosfet actually have different directions makes the faucet analogy even more strange. Since in one of them, water would stream in reverse anyways.
The problem is that it's conventional to draw circuits with the 'ground' as a common rail connected to -ve, with the'electricity' entering from the +ve, going through the components, and 'back' to -ve. So N-channel FETs have the 'electricity' going from drain (+) to source (-). This is because, when electricity was first discovered, it was believed to flow from + to -, and the convention stuck. BUT, electricity is actually a flow of negatively charged electrons from -ve to +ve. So the tap analogy must be referring to the concept of 'electricity' rather than what actually happens.
@@paulrudman1349my compliments to your observation I’m an old man who uses electron flow hence electronics Cheers
Is it possible for me to control a higher voltage fan with the same setup? Of course, grounds of different voltages separate. I actually tried it and it wont accept anything but the operating voltage, which is useless to me. I really need to use lower voltage to open and close it, but i either dont get something or mosfets just cant do it
best video simple way explain 😉
Thank you so much ☺️
Excellent video, can you do a 2nd video by chance on how to measure a MOSFET to determ if it is BAD or OK ?
Good video, much appreciated
Thank you so much 😊
Thanks for the video.
One thing that was drummed into me, working with them, was how fragile MOSFETs are in relation to high voltage. This why, when handling them, you should wear an earthing strap to short out static which may be many thousands of volts; no power or danger to humans but deadly to these devices and their packaging is conductive carbon foam.
great video 👍
respect from Gilgit Baltistan❤😊
Thank you so much ☺️
Electrons flow from the negative to the positive round a DC circuit
Absolutely true, but to this day, diagrams are STILL made using "conventional flow"🤔. I don't know why this tradition persists. 🤷♂️
@@jamesslick4790 too much literture too change so easier and less confusing to keep using conventional
They don't change it because they will not that to many people think about it. when you think deeper about the true direction of the flow, that will show that everything they teach about electron movement is false and in reality they know nothing about they have only theories! about how electricity works.
@@Toxxxic_ Just have a program change the literature. Going forward it doesn't make sense -- to me -- to keep the traditional concept of current flow when electron flow makes more sense.
source make me confuse,,, source must change with output 1:31
wow bro u explained it so simple make more video make video on how to use it in circuit
Thank you so much 😊 I try to produce as much content as I can 🤙
2N3055s have 15A continuous and Vceo of 60 volts. First used well over 50 years ago
I was going to mention this. Back when I was building power amplifiers in the late 1970s I had a large range of both NPN and PNP BJT transistors from which to choose with collector current ratings over 15 amps.
@@bunkie2100 I was working on VHF and UHF mobile network transmitters in the 1980s, no mosfets there either.
At 4:32 you show a mosfet being used in linear mode. Most mosfets on sale to hobbyists are not designed to work this way. They are intended to be used in switching circuits where they will be hard on or hard off.
In doing so they fail to answer "What is a MOSFET?" ;) So it's some kind of linear throttle something something? It's not a switch?!?! Thanks synth narrator, now I'm confused.
great question,
i was also wondering how mosfet triggering mode really acts,
was it the same as the potentiometer or just as simple as on/off switching device...
does it mean that the potentiometer was the actual control of current/voltage flow?
so whats the mosfet for?
it twisted my mind thinking about that circuit actualy
The potentiometer in that circuit triggers the MOSFET likely much earlier than when the motor starts to turn, it's in it's linear region (which is something one should avoid with MOSFETS). Since this is a motor, the momentum from the initial first turn of the motor made subsequent turns "less demanding" in terms of voltage needed to power the motor. MOSFET's work best (and as designed) when switched on and off, north of their linear region, not within.
How about enhancement mode and depletion mode.
Nice video!! Subscribed!
Thank you so much ☺️
I couldn't agree more, simple and practical knowledge.
Add another sub for sure.
Edit; It's really annoying me that I can't remember the term for power control using this method.....oh, hang on, the lazy little hamster that powers my brain just had a run on the wheel, Pulse Width Modulation, I feel so very much better now!
Pax.
I might be wrong but I thought electron flow was from negative to positive, not the other way around as described here. Maybe it's different when talking about mosfets.
In electronics the direction of current is taken to be opposite to the direction of electron flow
It is a thing called "conventional current". Conventional current does not exist but many people treat it like something that exists. Electron current exists, negative to positive. But when an electron moves, the spot it VACATED is then filled up the next electron and so on; this vacancy or HOLE appears to travel positive to negative. So it isn't actually a thing that moves but it appears to move.
Considerable ambiguity can exist if people do not specify the kind of current they mean so I tend to ignore it.
The arrow points in the direction of HOLE movement or conventional current, but I treat the diode symbol as you cannot go this way (arrow hitting a barrier) electrons move against the arrow.
@@thomasmaughan4798 not a bad explanation its the one I use myself maybe saying it doesnt exist might be going too far just say the holes `move` ? Ions and Ions the electron that gets detached is an ion and the atom missing the electron is also an ion.
Don't get confused .....what u are saying is " electronic current " which is from negative to positive.
Conventially, current was thought to flow from positive to negative. And hence called conventional current .
Mostly in tutorials and diagrams you have to keep in mind that they will depict conventional current. So, just be careful and dont confuse yourself. Even correct way of circuit diagrams still depict and follow the path of conventional current.
Shown with reference to conventional current in the faucet example. We didn't think in terms of the direction of electron flow.
Thank you very much ....sir 😊
Great explanation
Thank you so much ☺️
Great explanation! Doesn't electricity actually flow negative to positive though? This is confusing me. Thanks.
Thank you so much. The movement of electrons is normally from negative to positive. But in theory, the direction of the current is accepted as the opposite. Circuit analyzes are made according to the direction of the current.
Conventional current
Super materiał bracie!
Thank you so much ☺️
Thanks a lot for your sharing Sir.
Thank you so much ☺️🙏🏼
Thank you I have learned a lot
P channel arrow going in n channel arrow going out. Thank you I have learned a lot.
Here's an easy way to memorize:
NPN = "Never Points iN" ( ⬅⭕)
PNP = "Points iN Proudly" ( ➡⭕)
Thanks for the teaching
What is the sense of first 1K resistor of driver module ? 7:52
my guess would be to draw current away from the LED ?
Excellent video. Not sure where many of these comments come from?
I'd like to see some vids on reverse polarity and short protection. Also latching.
This is how a MOSFET works, Not how to build a spce craft...
Don't just buy the book, read the words...
;)
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How do you size that series resistor?
This is we ll explained and understandable
Thank you so much 😊
Allsome work guys from cruzermans inventions 😁👍🎉🌟
You are super explainer. I hope you make more videos for us better understand. Thank you.
Thank you very much ☺️ I will always try to make new videos 🙏🏼
Great mosfet introduction
Thank you so much ☺️
I'd like to see a simple bare-bones MOSFET configuration like this for audio. There are 10s of thousands of "audio amplifier" designs, but I'm curious about the absolute minimum to pass an audio signal by MOSFET. If there is already such a video, my apologies for not looking first. :-)
Thanks. explained well.
Thank you so much ☺️🙏🏼
Your hose bib analogy is backwards. Such as in an "N" channel device the negative is applied to the source and electrons flow through the device to the drain looking for the positive. [or more positive] Electrons flow from the negative terminal of a battery towards the positive terminal.
By convention, because electrons are assigned negative charge, we diagram current as the flow of positive charge. So in electrical engineering this is correct, while not technically the case physics-wise (unless you want to talk about "holes" but that's another can of worms).
Yeah, lets talk "hole theory"...
;)
Good stuff....was better when EE were specialists back then.
Can you tell me what does that Zener diode mean in the MOSFET symbol? I've seen MOSFET symbols with and without it. Does it represent some side effect of a MOSFET, or do they literally put a Zener diode in a a MOSFET for some purpose?
I haven't looked it up in a while, so maybe double check my info, but if I'm not mistaken the zener symbol is used to symbolize that this particular MOSFET is "Repetitive Avalanche Rated". The ones you see with just the diode symbol means it's NOT Repetitive Avalanche rated, so avalanches will result in a catastrophic failure, just like a typical diode.
That's how it was described to me long ago... hopefully that helps.
@@Big74Mike2012 Sir ,i am stupid ! My q is that the diode = rds?
Zener 🤭
I am pretty confused by this explanation! Especially the first circuit drawings.
The electricity flow never gets to the pot, so how does the pot get to have to effect the speed? Plus, what purpose does the resistor serve if there is no electricity flowing through that either?
Also, there comes a time when the electricity/plumbing analogies just simply dont work like when you have to say Water flows from a drain to the source, you know its time to find another analogy!
I think I'll look for another tutorial series!
The explanation about the use of the fixed resistor in series with the potentiometer makes no sense whatever!
Note that one end of the 10k pot is connected to the positive of the power supply, while the other end goes through the 10k fixed resistor to the negative of the supply. That means that the voltage at the wiper of the pot, connected to the FET gate, can range from half the supply voltage to the full supply voltage.
Power MOSFETs are _transconductance_ devices. The current that flows in the drain-source path is proportional to the voltage between the gate and the source. There is no current flowing into the gate. There is a "threshold" voltage below which there will be no D-S current flow, but above that the D-S current versus G-S voltage relationship starts to come into play. By adjusting the voltage at the gate of the FET the current in the D-S path and hence though the motor can be controlled. It is a crude circuit but OK for experimental purposes. It should be noted that with this circuit the gate voltage of the FET might be sufficient to allow it to conduct tens of amperes even with the gate voltage set to minimum. That would likely be the case with the IRFZ44 which seems to be popular with hobbyists. I'd take the 10k fixed resistor out and make a direct connection between the "bottom" end of the pot and the negative of the power supply. Most power MOSFETs can be safely operated with a gate-source voltage between -20 and +20 volts, but its always best to check the datasheet.
The example of the foset is wrong…
Drain and source should be turned around.
Water is starting at the source and ends up (through the foset ) at the drain…
This uses conventional current. You would be correct using electron flow though. I remember this coming up at school haha
Hi. Shown with reference to conventional current in the faucet example. We didn't think in terms of the direction of electron flow. Because circuit analysis is done with reference to conventional current direction.
@@eeapplications Not according to many electronics instructors! They insist on electron flow. They might be a little stubborn though. 😃
@@nedcramdon1306 that should be the way it is done but most people just use conventional current.
I have often used the IRFzed44N.
What a great technology ❣️❣️❣️❣️ your so smart
Thank you so much.
You’re
The electron flow (electric current) is reversed here, electrons flows versus + in circuits, not vice versa!!
Bravo. Well said.
Any idea why a mosfet is used-WHILE the pentiometer can do do through its own resistance without the mosfet...
Thank you for this explication
I'm so glad it was useful. Thank you 🙏
@ 4:39, it will be interesting to see how that 10KΩ resistor was calculated.
I'd say it's because the potentiometer is a 10KΩ. In effect this creates a total variable resistance of 20KΩ that has a physical limit set at 50%. Using the principles of a voltage divider, the voltage at the slider would vary between 4.5V to 9V when measured in reference to ground (which is the negative). And most likely to prevent a high current or short situation between the DRAIN and the GATE.
Very well done.
Thank you so much ☺️🙏
At 4:30 I really don't understand the reason for the 10k resistor in series with the low voltage end of the potentiometer. BUT if that resistor were located in direct series with the GATE, that would make some sense. As it is now, the *minimum* gate-to-source voltage would be 4.5 volt. Many power MOSFETs would be fully conductive at this voltage, so you couldn't turn the motor OFF.
If conditions might exist where the the GATE-TO-SOURCE voltage became more negative than the maximum specified, then a simple diode between GATE-to-SOURCE would fix it.
Yes, the only 'backward flow' from the gate would be the gate discharging, since the gate is insulated from the drain and source. Even if it was not, a resistor between gate and source would not help. There would be some use in putting a resistor in series with the gate if the driver (such as an arduino) has a limited current output. Also, the circuit diagram of the switched mode power supply is wrong; as drawn, there is no way the MOSFET can turn of the current. The inductor should be where the diode is and the diode should be in series with the source.
Can you explain electric fence?
Hi. I will try to prepare a content about it 👍
@@eeapplications thank you
Sir. Think. for. a. nice. explaination
Thank you so much 😊🙏
What does field effect mean?
Copy & paste your comment to Google ... easier than explaining here ...
It is the flow of quasi-free electrons - through the graticules of the MOSFET Device, whether this is P-doped or N-doped. That is my understanding.
Hey teacher, you cannot hold mosfet transistor like showed on introducing picture. Electrostatic discharge may damage it.
Well explained 👏 👌 👍.
Thank you so much ☺️🙏🏼