Good video. Useful to see him tinker with the mosfets. It's so easy and simple that you feel you are doing it yourself. There is an enormous advantage to see technical man's hands doing it. My mind experience the whole video, as if I was doing it myself. That's the best way to learn/practice. This is much more then a tutorial, this is a mind coach! That's what makes youtube, a practical learning experience. Thank you for this video.
I have been struggling with how a MOSFET it connected up for a while. Your video has taught me things I surely didn't know. Thanks you for the time you took to put this together.
When I was in Electronics Engineering School, I was taught that current flows from negative to positive. Then when we got deeper into semiconductor theory they talked about the concept of "Hole Flow" a hole being the space between electrons, so the electrons flow from negative to positive, and the holes flow from positive to negative. So Current being a flow of electrons is always against the arrow in a semiconductor.
Thank you for all that you teach. Im working on a mosfet amplifier for my home stereo. The mosfet symbol in the schematic is a lil blury so how would a person tell the gate source and drain. Would the speaker output terminal be connected to the drain.
Thank you so much for this. I'm a person who is learning this stuff on my own and had no idea how to read what these kinds of old nmos circuit diagrams really meant.
Great video, thank you! You could have mentioned that since a mosfet is an inverter, with your NAND and NOR gates, and an additional inverter (mosfet), you get OR and AND (respectively) with 3 mosfets, via (IIRC) deMorgan's law.
The drain and source usually have different amounts of doping, so they are not symmetrical. so there is a justification to show the reverse diode across DS
At 17:20, the reason the diode is one direction is because the other side of the get opposite the gate is a metal pad that acts as a capacitor of sorts. It is connected to the drain (on an n channel fet). This causes the insulator to stop insulating, because it forces free electrons from the dopant to collect near the gate in the substrate, and they then carry the current from source to drain.
@17:00 ish - the difference between source and drain similar to the difference between the emitter and collector is the amount of doping in each one relative to the other. One carries slightly more current than the other.
Very nice. Where I apply MOSFET's is drone ESC 's (Electronic Speed Control) for RC cars, plane's, boats and whatever. So... Very nice video but the previous post under mine was correct. It is an NMOS logic circuit. You should have built a PLC (Programmable Logic Circuit) out of it. And controlled electric motors since people tend to find that more interesting. And then you could even include true stories of how the CIA created the STUXNET virus, or actually worm. That targets SCADA systems. And destroyed the Iranian centrifuges. Used to separate spent nuclear reactor fuel, into weapons grade plutonium. But, (sigh) this none the less, gives people a good understanding of how FET's operate. And how you can apply them. Especially when you inform us about the static sensitivity of MOSFET's. Which is important because drones tend to build static electricity and people wonder why the drone keeps burning up motors and ESC's. Also carbon fiber which is used in drone frames is also a good conductor of electric current. Altgough light and dourable if touched on the sides where carbon fibers are exposed, it can burn stuff up. Especially in naked racing drones. Anyhow.... Outstanding. Thumb up for you sir. Sorry bout the long post. If you find this annoying dont read it.
@@halonothing1 Bzzt no but thank you for playing! :D Both are accepted, just different ones in different English-speaking countries. If you really wanted to score a point you'd say "quickly" :P
@@RobertBaruch I did not know that. Thanks for sharing. I wasn't trying to score a point or come off as pedantic as most people do. I correct people, because I would want them to do the same for me if I was using some word incorrectly. I know a lot of people try to use it as a form of elitism. But not me.
It surprises me that components such as this can be rated at 60A-120A, etc. Because I know that physically, the "Leads/Terminals" going into the component cannot handle that much current. Take the size of one of those input leads and run 60A thru it. You'll be calling it a blown 25A fuse.
16:34 the parasitic diode is there between S and D because the bulk (= substrate, B, also called body) is connected to the source to prevent shifting of the characteristic curve (also known as Body-Effect).
One thing that should be mentioned is that 78 amps is for the absolute maximum. The chip will survive, but it's not meant to operate at that much current normally. There should be another section for the recommended operating conditions, which are more in line with what they can operate at in reality and still be expected to work properly during and after. On the subject of the MOSFET's gate not being a touch sensor, I've seen circuits meant for beginners which uses a JFET as a static sensor by building up a charge and touching it. Felt all sorts of wrong.
Incidentally, I came across a data sheet yesterday for a water cooled tetrode tube with an anode dissipation of 1500kw. That's not a typo, 1.5 megawatts. Hands down the beefiest non-industrial component I've seen.
so love to see a video on using a p mosfet as a charging light. red charging and green charged the fully charged battery would be 8.5 volts. the supply voltage would be 10 volts using a p channel enhancement mode power mosfet
Nice video Robert .. thanks for the hard work .. maybe try some more complex mosfet based circuits down the road .. multivibrator adder multiplexer .. I always keep mosfets in their original anti-static bag those plastic trays are really bad PVC creates massive static surface charges
@@RobertBaruch I have been pondering lining those plastic trays with anti-static foam. Has the advantage of allow multiple values in the same tray and never out of place.
Regarding the plastic case and static; I purchased so many different Fets I purchased some case's to sort them like you, it's like a milky clear nylon. How can I be sure I didn't ruin all those Fets?
THIS IS A GREAT VIDEO! A few tid-bits though: (1) @ 28:45 It is MUCH easier to insert these TO220 packages into a breadboard if you twist the leads 90 degrees with a pair of needle-nosed pliers. The mosfet will then go right into the breadboard like a resistor. (2) When you want to demo the switch by charging and discharging the gate charge with your hands: put the other hand on the '+' or '-' rails not recommended). 3) I cringed a bit every time I saw you slide the FET across the paper. THANKS AGAIN FOR THE GREAT VIDEO!!!
It's harder with new boards to insert TO-220 packages. I find it helps to stick a jumper in the hole and wiggle it around a bit to loosen up the copper fins inside. The downside to using a large gauge pin like on a TO-220 is the fins will always be loose after that, so anything you try putting in that's a smaller gauge doesn't make proper contact. It's a real bitch if it happens on your power rails. Took me forever to figure out why my circuits kept working intermittently when that happened. Also, metal sliding on paper isn't going to create much of a static charge, if that's what you're implying. ESD isn't really something that's a huge issue for hobbyists anyways. I'm not saying you shouldn't be aware of it, but the scare mongering surrounding ESD is blown way out of proportion.
Hey bro, I'm a relatively intellectual individual or should I say I "feel" that I am.. Lol. But anywho I believe you did a great job of explaining the ever more vast informations that keeps growing exponentially for me and I'm sure I others. Thank you for painfully explaining MOSFETs and transistors and some of their multi-use capabilities, all with a patients. I just wanted to rebuild a vintage set of full range speakers. And I'm sort of a nerd too, so I happened to playing with a18 volt Bluetooth radio upon which capacitors, resistors as passovers, transistors or MOSFETs as amplifiers, copper choke-coils for sub woofers...anyway all this in two weeks I learned. Big headache. I may not be a genius like everyone else on this page, but you did a great job doing what I've have seen others just skim over. I subscribed and click the bell icon.
Michael Smith Sorry to say your grammar, spelling and syntax is appalling for an intellectual. But, I must endorse your praise for the well delivered video.
Hi I'm still learning the basics but would like to ask you a question, in the n channel MOSFET why does the led turn off when the MOSFET is turned on, from a circuit point of view aren't the two connected in parallel ?
Great, now after I learned that arrow inward means PNP and arrow outward means NPN for BJT and looking at MOSFETs just settling down with "well ok here's the opposite" now you tell me, sometimes it can be displayed like BJT... XD Gotta love standards. Any way to know what convention they followed if seeing a circuit?
easy way to remember the difference between mosfets is npn = not pointing in. Gate needs to be higher than source to close switch. pnp = pointing in Gate needs to be lower than source to close
Thanks, this worked and I was able to get my mosfet to turn on! although it didnt when i had the resistor to ground, it did when I had the resistor to positive? maybe something was loose originally and was corrected it when i rewired it the other way, your way , but from what i remember reading it shouldnt matter the order of the resistor. Which i always thought strange but thats another subject. Also my mosfet didnt stay on when i took it off 5v, which was nice actually I didnt have to ground it to turn the led back on, instant on and off when i touch and released it, nice effect but not sure why i got a different result? I did salvage it , and mabybe heated it too much with the soldering iron? I also soldered exention legs onto it so i fit it into a breadboard easier and think i might have done some damage then, maybe that capacitor that holds onto its charge and keeps the mosfet on when you take it off the was damaged to account for this behaviour?Sort of like how you were saying a damaged one would still work but with wonky behaviour if you blew it, although i didnt blow it with excess voltage, but maybe too much heat? Or this is just normal behaviour for my particular mosfet? Anyway thanks for the tutorial, and i apologize for all these questions im sure ill find the answers too with a little more investigating. This video really helped in understanding how they work and what too look for in the datasheet so i can use one in a circuit, many thanks.
Apon further investigation it turns out the mosfet is indeed malfunctioning someway, as i tried another one of the same kind and it did stay on after voltage was take off the gate. Tried the suspected overheated one agin to make sure and sure enough it turns off as soon as you remove the voltage. Fascinating, I kind of like the way the broken one reacts, turning off right away. I wonder how it broke inside to make this behaviour? and if theres an application for it? hmmm
It is a parasitic component! There is a substrate with some conductivity (let's say P for N-MOS). Then you have a P channel between D and S on the substrate (yes, they are symetric). But you drive the ransistor by electric field between the gate and the substrate so it is connected to the S. But there's a PN junction between the substrate and the channel. On the S side it is short, on the D side it acts as a diode... For the switching supplies there are extra types that uses this diode and some of them has schottky diode inside ( FETKY ) When you have to eliminate that (e.g. if you have to switch off the battery without charge/discharge over the MOSFET) you have to use two FETs in series with connected gates and connected by sources together. It slower, it has biggest price, it has double lost but it works...
@@wmellick it won't help much for protecting from a switched relay. Vgs will be pretty high. An undamped automotive relay can easily spike 300V when turned off. Always clamp your load, don't rely on the body diode.
Yes, manufacturers always mandate the use of anti-static precautions just to cover their assess. No, accidentally killing a MOSFET just by touching it in practice almost never happens and so it's a non-issue. True even for tiny flimsy low-power SMD MOSFETs.
THANK YOU. It's nice to see somebody being reasonable about the risk of an ESD for once. I just replied to another comment about how cringey it was when he slid the FETs on a piece of paper. I rarely store my active components in proper ESD safe packaging. Most of them are in plain ziplock bags cuz ESD bags won't fit in my parts bin's drawers. In the 3 years I've been doing this, I've never once had an issue with an ESD. Even in the dead of Winter when the air's so dry it gives me nosebleeds. The scaremongering regarding ESD gets ridiculous. The most I do is make sure to discharge myself on a grounded piece of metal before I handle anything. Especially if, for example, I just took off my sweater and I can hear/feel the static on me. And more often than not, I do get a big spark when I discharge myself like that. But even then, unless I'm referencing a circuit to Earth, which I never do, it's not very likely I'll have an ESD into anything.
@@halonothing1 Many years ago had a chat with a disk drive installer on IBM mainframes. He was all earthed out and strapped up. I asked about the static risk and he said that while it was rare for a device to fail during handling they did experience damage which shortened their life or reduced their operating parameters. So I always adhere to static handling advice.
Been watching a ton of videos on electronics. No one except you has mention the way MOSFETs should be stored. Now I'm worried I may have destroyed my components. Should all transistors be stored in static safe containers? What other components should be store in static safe containers? Please consider a quick tutorial on how to safely store components. Cheers
Mosfets and any modern chip should be stored in a static-safe container -- most modern digital chips are made of mosfets. Generally, diodes, bipolar transistors, and passives don't need static-safe containment.
It's an arbitrary choice. At 5V, the max current is going to be approximately 15mA (5V/330R = .015A). Max power dissipation would be 5*.015 or 75mW. It's all about Ohms Law. You could easily select a 1K resistor and the LED would still be plenty bright enough. A lot of people go to silly lengths to get the LED current at a full 20mA (often the limit). This is a needless waste of electricity and the LED life will be greatly shortened. I find that most LEDs look fine with only 1mA of current. You should be able to find plenty of videos showing more details on how to select the "right" resistor. If your using battery power, you'd probably want to use as large a resistor you can, that gives suitable brightness. You'd also probably want to put the LED in seties with the resistor and drain so that power is dissipated only when the LED is switched on, not all the time.
25:11 you struggle with inserting the mosfet. I found the better bread boards are the transparent ones where the letter match from one end to another. A on the left will match A on the right. Your's is opposite. A matches J.
MOSFETs FTW !! The memory cell is the fundamental building block of computer memory. ... Modern random-access memory (RAM) uses MOS field-effect transistors (MOSFETs) as flip-flops, along with MOS capacitors for certain types of RAM. The SRAM (static RAM) memory cell is a type of flip-flop circuit, typically implemented using MOSFETs. - Wikipedia 🙂
Thanks for the great video. It's so annoying for a hobbyist to understand basic component specs when they're so far obfuscated with all these subscripts and "assumed" industry knowledge that no one teaches you in technical courses.
Should change the symbol of mosfet they way you show it less confusing and simpler symbol, actually the better symbol is like bipolar transistor only with two parallel lines at the gate to represent mosfet capacitance.
Seems I’m not getting this . I used transistor d45h8 as a voltage regulator to drop 40 v to 12 . Transistor has 40 v on the output without any trigger to ground . I’m using pnp according to spec
IRLB8743 is an all round EXCELLENT mosfet that I use when neede with great pleasure. It is supercheap from most Chinese sources, even if a little under spec, for the tiny price (about $0.20) it is great!!! :):):)
After my 77th mosfet video and 40+ data sheets, still confused a little. I am a retired auto tech, but have built a number of electronics. More information on what is safe to turn on a n channel mosfet....other than dinner and a bottle of sweet red wine, it would be shocking to get positive results. In a truck, an automatic w/over drive can overheat. I have a 28 amp fan pushing air across a new old stock A/C condenser that can handle 400 PSI. The automotive electrical system can vary from 12.8 Vdc to 14.6 Vdc. Using a tube or probe NTC thermistor inside the fins of this little radiator looking thing, hooked to a 10k pot, used as a voltage divider. Big words, my 60’s English teacher would be...passed away. But, place a 100 ohms resistor between the divider and gate to allow the mosfet to operated an external relay. Fluid gets hot, fan ramps up then maybe full fan speed then slows and off. I just want a robust circuit added to my service manual, but an external relay is in the group of many others. (Depending on your vehicle, it can have make it easy for diagnostics with out hunting to bend under a dash. No one likes that, if you can make it easy. Any thoughts? I am looking at your international rectifier that you spent time on the data sheet. Thank you for that. My grandad graduated from college in 1932, when the transistor was announced. He passed the year before I got married (40 yrs) but what was on his final term paper? All questions about tubes? Yes! Thanks for the clear explanation from a subscriber who has seen most of your videos. Info, input or suggestions very much welcome. Thanks again!
Keep it simple :) I think you want to compare your voltage to some other voltage you can set. A simple LM2903 comparator would work. Look for a circuit called "comparator with hysteresis" since you don't want the output clicking on and off rapidly when the voltage is approximately equal. Then keep it really simple by adding a heavy-duty relay that the comparator can drive. You would drive the coil in the relay with a mosfet! Search for "relay driver mosfet" and you'll get tons of ideas. Good luck!
@@tonyfremont Yes! and if you immerse the circuit board it in liquid nitrogen (I would prefer HFC refrigerants) You can really CRANK UP the amplifier! or run your CPU clock at ~ten GHz ;) Just don't try liquid Helium! Too cold! and too close to absolute zero, Quantum issues!
23:39 Re why it's called Drain and Source: thinking conventional current, in a circuit like yours the Drain actually drains current if the mosfet is on ("takes away" all the current). Likewise, if you put the resistor between Source and GND, then current comes out of the Source if the mosfet is on, it "sources" current.
I thought it was because the source is where the electrons come from, inside the device. (Probably it was named by people who were intimately familiar with semiconductor physics, and not so much with conventional circuit design)
Alex C As I said, thinking *conventional current* - ie. opposite the direction in which actual electrons go - the Source is where (conventional!) current comes out of and the Drain is where (conventional!) current goes into. So: actual electrons flow into the Source and out of the the Drain. Sure, it's a mishap that this "conventional current" vs actual electron flow came up in the first place, but we're stuck with it since, I think, Benjamin Franklin. But in fact, it doesn't really matter, and you'll get used to it eventually.
The source terminal is where the charge carriers for the current within the FET come from, during normal operation. It's the same for N- and P- channel devices. You're sort of talking about current "outside" of the MOSFET, and yeah, electrons will flow into the source and out of the drain on the outside, but change it to a P-channel device (and flip the resistor and transistor) and it'd be the other way around.
The "Load", which DRAIN the voltage in a useful manner, is (generally) toward the DRAIN pin of the MOSFET, while the SOURCE is connected toward the voltage SOURCE (and not toward the "load" which drains the supplied power). For a N-Chanel, the SOURCE pin is connected toward the N_egative side of that battery, as N is N; and for a P-Chanel, the Source pin of the MOSFET is connected toward the P_ositive side of the battery, as P is P. For a N-Chanel, the "Load" is thus (in general) at a higher voltage than the MOSFET (the load is said to be at the high side), while for P-Chanel, the "Load" is at a lower voltage than the transistor (the load is said to be at a low side). So, if you prefer to consider the conventional current, for any reason, for a N-Chanel MOSFET, the conventional current is generally from drain pin to source pin (against the arrow on the symbol) while, for a P-chanel, the conventional current is from source to drain (along the arrow on the symbol). Note, though, that for P-chanel, MOST datasheets consider that the current is still positive from drain pin to source pin, so the value given are ... negative... on the datasheet. MOST... but not all. And it is confusing MOST of the time :-) *About the arrow*, I am used to the symbol with the grid like pattern for an enhanced MOSFET. There are some symbols using the REVERSE direction for the arrow just to add to the confusion, as if it was needed. The author of this video uses these symbols while I was having in mind the grid like symbol (as at www.fairchildsemi.com/datasheets/2N/2N7000.pdf for example, for a N Chanel), so the arrow direction is all but confusing, without a specific drawing. If you assume that a N Chanel matches a NPN BJT, you have to admit that the arrows directions are ... reversed ! at least, if you take the symbol given in the datasheet, as given here up.
+Persona, +snnwstt So, are you saying that my little mnemonic ain't working for P-channel? To be honest, I have to think it over almost every time again, it is confusing. And right now, I am confused again.
Because transistors are current controlled, but mosfet are voltage controlled. So the emiter gets the current from base and collector, but the source only gets the current from the drain. Using the same words to different behaviours would be confusing.
What's with current flowing from drain to source? Why oh why did the early pioneers of physics have to make the electron the negative particle.... sigh.
Наука
You’re a terrific teacher, Robert! I wish that I had an instructor like you when I was in college…
Good video. Useful to see him tinker with the mosfets. It's so easy and simple that you feel you are doing it yourself. There is an enormous advantage to see technical man's hands doing it. My mind experience the whole video, as if I was doing it myself. That's the best way to learn/practice. This is much more then a tutorial, this is a mind coach!
That's what makes youtube, a practical learning experience.
Thank you for this video.
This is exactly what I hoped to find when I searched "playing with mosfets", funny how youtube has everything. Thanks for this
Honestly, its very informative video, which carries a crystal clear explanation on MOSFETS, thanks for teaching !
I have been struggling with how a MOSFET it connected up for a while. Your video has taught me things I surely didn't know. Thanks you for the time you took to put this together.
Love your video and the entire discussion. It is so fun and informative to watch. Thank you.
Well explained and demonstrated, this is the way it should be taught!!
Excellent tutorial. Easy to understand.
Very useful . Thank you.
Great video going from theoretical to actual breadboard builds.
Your channel is sooo amazing !!! I will start recommending your channel to people !!!!! Keep up the good work
How do come across gems like these at 4 am lol
This video is killer at 4am. It will help with my lab tomorrow.
4:45 for myself!
For myself, Thanksgiving
I started about 5 or 6 mins before 4am.
When I was in Electronics Engineering School, I was taught that current flows from negative to positive. Then when we got deeper into semiconductor theory they talked about the concept of "Hole Flow" a hole being the space between electrons, so the electrons flow from negative to positive, and the holes flow from positive to negative. So Current being a flow of electrons is always against the arrow in a semiconductor.
this is incredible! what a great teacher 👏🏻👍🏻👌🏻
so far the best mosfet video I have seen.
Very good explanation and demonstration. Thanks a million.
Very well explained ! Thank you.
Love your videos. Thanks
Great great! Please keep upload your videos! I feel bad because I’m watching this for free.
you explained mosfet very well
Wow! This guy sounds just like Mr. Rogers! Really! Cool!
Always wanted to know this in respect to logic circuits - thanks
Thank you for all that you teach. Im working on a mosfet amplifier for my home stereo. The mosfet symbol in the schematic is a lil blury so how would a person tell the gate source and drain. Would the speaker output terminal be connected to the drain.
Thank you so much for this. I'm a person who is learning this stuff on my own and had no idea how to read what these kinds of old nmos circuit diagrams really meant.
Great! Thank you! I just falling in love with MOSFETs:o)) - -- I wish finding your channel earlier ;o(
This video helped me a lot. Cheers!
I love it I am gonna watch again next week
Great video, thank you! You could have mentioned that since a mosfet is an inverter, with your NAND and NOR gates, and an additional inverter (mosfet), you get OR and AND (respectively) with 3 mosfets, via (IIRC) deMorgan's law.
Thank you. Excellent demonstration of gates and truth tables. Do you always use truth tables when constructing circuits?
Full of useful info, Thank You.
The drain and source usually have different amounts of doping, so they are not symmetrical. so there is a justification to show the reverse diode across DS
At 17:20, the reason the diode is one direction is because the other side of the get opposite the gate is a metal pad that acts as a capacitor of sorts. It is connected to the drain (on an n channel fet). This causes the insulator to stop insulating, because it forces free electrons from the dopant to collect near the gate in the substrate, and they then carry the current from source to drain.
Nice video, well done, thanks for sharing it with us :)
Man I loved watching your video 😍 ❤️ your a great teacher ❤️❤️😍👌
You're. =)
Super clean explanation
god damn thanks for the explanations..... it is comprehensive
Thank you please continue❤
@17:00 ish - the difference between source and drain similar to the difference between the emitter and collector is the amount of doping in each one relative to the other. One carries slightly more current than the other.
Alot of thanks for understanding mosfeet functions.
thank"s for teaching
Very nice. Where I apply MOSFET's is drone ESC 's (Electronic Speed Control) for RC cars, plane's, boats and whatever. So... Very nice video but the previous post under mine was correct. It is an NMOS logic circuit. You should have built a PLC (Programmable Logic Circuit) out of it. And controlled electric motors since people tend to find that more interesting. And then you could even include true stories of how the CIA created the STUXNET virus, or actually worm. That targets SCADA systems. And destroyed the Iranian centrifuges. Used to separate spent nuclear reactor fuel, into weapons grade plutonium. But, (sigh) this none the less, gives people a good understanding of how FET's operate. And how you can apply them. Especially when you inform us about the static sensitivity of MOSFET's. Which is important because drones tend to build static electricity and people wonder why the drone keeps burning up motors and ESC's. Also carbon fiber which is used in drone frames is also a good conductor of electric current. Altgough light and dourable if touched on the sides where carbon fibers are exposed, it can burn stuff up. Especially in naked racing drones. Anyhow.... Outstanding. Thumb up for you sir. Sorry bout the long post. If you find this annoying dont read it.
i learnt very quick from you. thankyou for your content.
Learned. =)
@@halonothing1 Bzzt no but thank you for playing! :D Both are accepted, just different ones in different English-speaking countries. If you really wanted to score a point you'd say "quickly" :P
@@RobertBaruch I did not know that. Thanks for sharing. I wasn't trying to score a point or come off as pedantic as most people do. I correct people, because I would want them to do the same for me if I was using some word incorrectly. I know a lot of people try to use it as a form of elitism. But not me.
@@halonothing1 :) No worries. I used to get annoyed at incorrect English. Then I just sort of lost the will to care.
It surprises me that components such as this can be rated at 60A-120A, etc. Because I know that physically, the "Leads/Terminals" going into the component cannot handle that much current. Take the size of one of those input leads and run 60A thru it. You'll be calling it a blown 25A fuse.
16:34 the parasitic diode is there between S and D because the bulk (= substrate, B, also called body) is connected to the source to prevent shifting of the characteristic curve (also known as Body-Effect).
well said and done .... Thank You
One thing that should be mentioned is that 78 amps is for the absolute maximum. The chip will survive, but it's not meant to operate at that much current normally. There should be another section for the recommended operating conditions, which are more in line with what they can operate at in reality and still be expected to work properly during and after.
On the subject of the MOSFET's gate not being a touch sensor, I've seen circuits meant for beginners which uses a JFET as a static sensor by building up a charge and touching it. Felt all sorts of wrong.
I don't think those small pins even can carry 74amps😂
Incidentally, I came across a data sheet yesterday for a water cooled tetrode tube with an anode dissipation of 1500kw. That's not a typo, 1.5 megawatts. Hands down the beefiest non-industrial component I've seen.
please make video about component. share with the world.
so love to see a video on using a p mosfet as a charging light.
red charging and green charged the fully charged battery would be 8.5 volts.
the supply voltage would be 10 volts
using a p channel enhancement mode power mosfet
Nice video Robert .. thanks for the hard work .. maybe try some more complex mosfet based circuits down the road .. multivibrator adder multiplexer .. I always keep mosfets in their original anti-static bag those plastic trays are really bad PVC creates massive static surface charges
I know, right? Those trays are the worst.
@@RobertBaruch I have been pondering lining those plastic trays with anti-static foam. Has the advantage of allow multiple values in the same tray and never out of place.
25:16 The defloration of a breadboard - so stirring...
Great video. I inserted an output of 3V at gate, from PIR motion sensor. It does not work. Any help will be appreciated. Thanks
Thank you for this, sometimes I need supplemental stuff.
Thanks a lot, easy to understand data sheet from you !
Could you please explain TRIAC data sheet too ! I recently used a triac and couldn't turn if off with my microcontroller although i could turn it on !
Regarding the plastic case and static; I purchased so many different Fets I purchased some case's to sort them like you, it's like a milky clear nylon.
How can I be sure I didn't ruin all those Fets?
THIS IS A GREAT VIDEO! A few tid-bits though: (1) @ 28:45 It is MUCH easier to insert these TO220 packages into a breadboard if you twist the leads 90 degrees with a pair of needle-nosed pliers. The mosfet will then go right into the breadboard like a resistor.
(2) When you want to demo the switch by charging and discharging the gate charge with your hands: put the other hand on the '+' or '-' rails not recommended). 3) I cringed a bit every time I saw you slide the FET across the paper. THANKS AGAIN FOR THE GREAT VIDEO!!!
It's harder with new boards to insert TO-220 packages. I find it helps to stick a jumper in the hole and wiggle it around a bit to loosen up the copper fins inside. The downside to using a large gauge pin like on a TO-220 is the fins will always be loose after that, so anything you try putting in that's a smaller gauge doesn't make proper contact. It's a real bitch if it happens on your power rails. Took me forever to figure out why my circuits kept working intermittently when that happened.
Also, metal sliding on paper isn't going to create much of a static charge, if that's what you're implying. ESD isn't really something that's a huge issue for hobbyists anyways. I'm not saying you shouldn't be aware of it, but the scare mongering surrounding ESD is blown way out of proportion.
Isn't the package-limit the limit for non-heat-sinked operation? And the silicon limit, the limit regardless how well heat-sinked?
Thanks
finaly i understand nand gates, thx
do you need to know a lot of traditional mathematics to get into electrical drafting?
Hey bro, I'm a relatively intellectual individual or should I say I "feel" that I am.. Lol. But anywho I believe you did a great job of explaining the ever more vast informations that keeps growing exponentially for me and I'm sure I others. Thank you for painfully explaining MOSFETs and transistors and some of their multi-use capabilities, all with a patients. I just wanted to rebuild a vintage set of full range speakers. And I'm sort of a nerd too, so I happened to playing with a18 volt Bluetooth radio upon which capacitors, resistors as passovers, transistors or MOSFETs as amplifiers, copper choke-coils for sub woofers...anyway all this in two weeks I learned. Big headache. I may not be a genius like everyone else on this page, but you did a great job doing what I've have seen others just skim over. I subscribed and click the bell icon.
Michael Smith Sorry to say your grammar, spelling and syntax is appalling for an intellectual. But, I must endorse your praise for the well delivered video.
Thanks.
Hi I'm still learning the basics but would like to ask you a question, in the n channel MOSFET why does the led turn off when the MOSFET is turned on, from a circuit point of view aren't the two connected in parallel ?
Think of the mosfet like a switch. When the mosfet is on, you've basically shorted the LED out so it cannot light up.
Great, now after I learned that arrow inward means PNP and arrow outward means NPN for BJT and looking at MOSFETs just settling down with "well ok here's the opposite" now you tell me, sometimes it can be displayed like BJT... XD
Gotta love standards. Any way to know what convention they followed if seeing a circuit?
Hey Robert..!! I am bit confused at 10:59 regarding naming of n channel and p channel MOSFETs. Wouldn't it be the other way around.?
For a p channel mosfet, shouldn't the arrow point away from the gate?
I think the P-channel Mosfet the arrow on the SOURCE pointing out and the N-channel is the reverse of that .
thanks
easy way to remember the difference between mosfets is npn = not pointing in. Gate needs to be higher than source to close switch. pnp = pointing in Gate needs to be lower than source to close
Thanks, this worked and I was able to get my mosfet to turn on! although it didnt when i had the resistor to ground, it did when I had the resistor to positive? maybe something was loose originally and was corrected it when i rewired it the other way, your way , but from what i remember reading it shouldnt matter the order of the resistor. Which i always thought strange but thats another subject. Also my mosfet didnt stay on when i took it off 5v, which was nice actually I didnt have to ground it to turn the led back on, instant on and off when i touch and released it, nice effect but not sure why i got a different result? I did salvage it , and mabybe heated it too much with the soldering iron? I also soldered exention legs onto it so i fit it into a breadboard easier and think i might have done some damage then, maybe that capacitor that holds onto its charge and keeps the mosfet on when you take it off the was damaged to account for this behaviour?Sort of like how you were saying a damaged one would still work but with wonky behaviour if you blew it, although i didnt blow it with excess voltage, but maybe too much heat? Or this is just normal behaviour for my particular mosfet? Anyway thanks for the tutorial, and i apologize for all these questions im sure ill find the answers too with a little more investigating. This video really helped in understanding how they work and what too look for in the datasheet so i can use one in a circuit, many thanks.
Apon further investigation it turns out the mosfet is indeed malfunctioning someway, as i tried another one of the same kind and it did stay on after voltage was take off the gate. Tried the suspected overheated one agin to make sure and sure enough it turns off as soon as you remove the voltage. Fascinating, I kind of like the way the broken one reacts, turning off right away. I wonder how it broke inside to make this behaviour? and if theres an application for it? hmmm
What are some applications for these components? What would I be building if I'm thinking 'I really need a MOSFET here'?
Probably for driving loads like DC motors from a microcontroller, or in protection circuits
Wow. I always that that the diode symbol from S to D was to prevent flyback voltage from destroying the junction when using with an inductive load.
You're correct. When the MOSFET is wired properly, that diode would protect the junction from flyback voltage.
It is a parasitic component! There is a substrate with some conductivity (let's say P for N-MOS). Then you have a P channel between D and S on the substrate (yes, they are symetric). But you drive the ransistor by electric field between the gate and the substrate so it is connected to the S. But there's a PN junction between the substrate and the channel. On the S side it is short, on the D side it acts as a diode...
For the switching supplies there are extra types that uses this diode and some of them has schottky diode inside ( FETKY )
When you have to eliminate that (e.g. if you have to switch off the battery without charge/discharge over the MOSFET) you have to use two FETs in series with connected gates and connected by sources together. It slower, it has biggest price, it has double lost but it works...
@@wmellick it won't help much for protecting from a switched relay. Vgs will be pretty high. An undamped automotive relay can easily spike 300V when turned off. Always clamp your load, don't rely on the body diode.
Awesome
Yes, manufacturers always mandate the use of anti-static precautions just to cover their assess.
No, accidentally killing a MOSFET just by touching it in practice almost never happens and so it's a non-issue. True even for tiny flimsy low-power SMD MOSFETs.
THANK YOU. It's nice to see somebody being reasonable about the risk of an ESD for once. I just replied to another comment about how cringey it was when he slid the FETs on a piece of paper. I rarely store my active components in proper ESD safe packaging. Most of them are in plain ziplock bags cuz ESD bags won't fit in my parts bin's drawers. In the 3 years I've been doing this, I've never once had an issue with an ESD. Even in the dead of Winter when the air's so dry it gives me nosebleeds. The scaremongering regarding ESD gets ridiculous. The most I do is make sure to discharge myself on a grounded piece of metal before I handle anything. Especially if, for example, I just took off my sweater and I can hear/feel the static on me. And more often than not, I do get a big spark when I discharge myself like that. But even then, unless I'm referencing a circuit to Earth, which I never do, it's not very likely I'll have an ESD into anything.
@@halonothing1 Many years ago had a chat with a disk drive installer on IBM mainframes. He was all earthed out and strapped up. I asked about the static risk and he said that while it was rare for a device to fail during handling they did experience damage which shortened their life or reduced their operating parameters. So I always adhere to static handling advice.
Been watching a ton of videos on electronics. No one except you has mention the way MOSFETs should be stored. Now I'm worried I may have destroyed my components. Should all transistors be stored in static safe containers? What other components should be store in static safe containers? Please consider a quick tutorial on how to safely store components. Cheers
Mosfets and any modern chip should be stored in a static-safe container -- most modern digital chips are made of mosfets. Generally, diodes, bipolar transistors, and passives don't need static-safe containment.
Thank you
How you selected 330ohm resistor between 5vdc & Drain pin? What is the formula for calculate this? For eg 12vdc
Please explain
It's an arbitrary choice. At 5V, the max current is going to be approximately 15mA (5V/330R = .015A). Max power dissipation would be 5*.015 or 75mW. It's all about Ohms Law. You could easily select a 1K resistor and the LED would still be plenty bright enough. A lot of people go to silly lengths to get the LED current at a full 20mA (often the limit). This is a needless waste of electricity and the LED life will be greatly shortened. I find that most LEDs look fine with only 1mA of current. You should be able to find plenty of videos showing more details on how to select the "right" resistor. If your using battery power, you'd probably want to use as large a resistor you can, that gives suitable brightness. You'd also probably want to put the LED in seties with the resistor and drain so that power is dissipated only when the LED is switched on, not all the time.
25:11 you struggle with inserting the mosfet. I found the better bread boards are the transparent ones where the letter match from one end to another. A on the left will match A on the right. Your's is opposite. A matches J.
MOSFETs FTW !!
The memory cell is the fundamental building block of computer memory. ... Modern random-access memory (RAM) uses MOS field-effect transistors (MOSFETs) as flip-flops, along with MOS capacitors for certain types of RAM. The SRAM (static RAM) memory cell is a type of flip-flop circuit, typically implemented using MOSFETs. - Wikipedia 🙂
looks like the parts made from allegro?
24:00 Are you saying electrons flow from ground?
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Try this, substituting the transistor. Maybe it will work. Maybe it won't! We learn by failing! users.skynet.be/BillsPage/TeslaPage.html
Thanks for the great video. It's so annoying for a hobbyist to understand basic component specs when they're so far obfuscated with all these subscripts and "assumed" industry knowledge that no one teaches you in technical courses.
Should change the symbol of mosfet they way you show it less confusing and simpler symbol, actually the better symbol is like bipolar transistor only with two parallel lines at the gate to represent mosfet capacitance.
CORRECTION: That timestamp should be 24:45
Seems I’m not getting this . I used transistor d45h8 as a voltage regulator to drop 40 v to 12 . Transistor has 40 v on the output without any trigger to ground . I’m using pnp according to spec
Lol I don’t know what I’m doing 11:52
Now I see I may have blow it out by using a heat gun to extract the part
23:40
, you went to school . They tech you electrons flow neg to positive. All my coworkers that learned on the street think I’m nuts
first time writing something on youtube video to say "thank you"
Could i maybe email you and send the diagram. I jist want to know for my own personal knowledge thats all. Nothing wrong with them.
"You can't use this on a breadboard. It's an SMD world. Get used to it."
Man, I still haven't gotten used to that.
IRLB8743 is an all round EXCELLENT mosfet that I use when neede with great pleasure. It is supercheap from most Chinese sources, even if a little under spec, for the tiny price (about $0.20) it is great!!! :):):)
After my 77th mosfet video and 40+ data sheets, still confused a little. I am a retired auto tech, but have built a number of electronics. More information on what is safe to turn on a n channel mosfet....other than dinner and a bottle of sweet red wine, it would be shocking to get positive results.
In a truck, an automatic w/over drive can overheat. I have a 28 amp fan pushing air across a new old stock A/C condenser that can handle 400 PSI.
The automotive electrical system can vary from 12.8 Vdc to 14.6 Vdc. Using a tube or probe NTC thermistor inside the fins of this little radiator looking thing, hooked to a 10k pot, used as a voltage divider. Big words, my 60’s English teacher would be...passed away. But, place a 100 ohms resistor between the divider and gate to allow the mosfet to operated an external relay. Fluid gets hot, fan ramps up then maybe full fan speed then slows and off. I just want a robust circuit added to my service manual, but an external relay is in the group of many others. (Depending on your vehicle, it can have make it easy for diagnostics with out hunting to bend under a dash. No one likes that, if you can make it easy. Any thoughts? I am looking at your international rectifier that you spent time on the data sheet. Thank you for that. My grandad graduated from college in 1932, when the transistor was announced. He passed the year before I got married (40 yrs) but what was on his final term paper? All questions about tubes? Yes!
Thanks for the clear explanation from a subscriber who has seen most of your videos. Info, input or suggestions very much welcome. Thanks again!
Keep it simple :) I think you want to compare your voltage to some other voltage you can set. A simple LM2903 comparator would work. Look for a circuit called "comparator with hysteresis" since you don't want the output clicking on and off rapidly when the voltage is approximately equal. Then keep it really simple by adding a heavy-duty relay that the comparator can drive. You would drive the coil in the relay with a mosfet! Search for "relay driver mosfet" and you'll get tons of ideas. Good luck!
get a white board sir. thank you for your time and information.
78 Amps? 150 Amps? through those tiny conductor leads? No Way!
Actually, yes way, but only for very short periods, as long as you keep Tj below 175C. It'll be fine.
@@tonyfremont Yes! and if you immerse the circuit board it in liquid nitrogen (I would prefer HFC refrigerants) You can really CRANK UP the amplifier! or run your CPU clock at ~ten GHz ;) Just don't try liquid Helium! Too cold! and too close to absolute zero, Quantum issues!
Wondering how far into any video on "MOSFET Basics" one can delve before the narrator pauses to define the acronym MOSFET... still waiting.
It's a Surface mount World Get Used To It...............
23:39 Re why it's called Drain and Source: thinking conventional current, in a circuit like yours the Drain actually drains current if the mosfet is on ("takes away" all the current). Likewise, if you put the resistor between Source and GND, then current comes out of the Source if the mosfet is on, it "sources" current.
I thought it was because the source is where the electrons come from, inside the device. (Probably it was named by people who were intimately familiar with semiconductor physics, and not so much with conventional circuit design)
Alex C As I said, thinking *conventional current* - ie. opposite the direction in which actual electrons go - the Source is where (conventional!) current comes out of and the Drain is where (conventional!) current goes into.
So: actual electrons flow into the Source and out of the the Drain.
Sure, it's a mishap that this "conventional current" vs actual electron flow came up in the first place, but we're stuck with it since, I think, Benjamin Franklin. But in fact, it doesn't really matter, and you'll get used to it eventually.
The source terminal is where the charge carriers for the current within the FET come from, during normal operation. It's the same for N- and P- channel devices. You're sort of talking about current "outside" of the MOSFET, and yeah, electrons will flow into the source and out of the drain on the outside, but change it to a P-channel device (and flip the resistor and transistor) and it'd be the other way around.
The "Load", which DRAIN the voltage in a useful manner, is (generally) toward the DRAIN pin of the MOSFET, while the SOURCE is connected toward the voltage SOURCE (and not toward the "load" which drains the supplied power).
For a N-Chanel, the SOURCE pin is connected toward the N_egative side of that battery, as N is N;
and for a P-Chanel, the Source pin of the MOSFET is connected toward the P_ositive side of the battery, as P is P.
For a N-Chanel, the "Load" is thus (in general) at a higher voltage than the MOSFET (the load is said to be at the high side),
while for P-Chanel, the "Load" is at a lower voltage than the transistor (the load is said to be at a low side).
So, if you prefer to consider the conventional current, for any reason, for a N-Chanel MOSFET, the conventional current is generally from drain pin to source pin (against the arrow on the symbol) while, for a P-chanel, the conventional current is from source to drain (along the arrow on the symbol). Note, though, that for P-chanel, MOST datasheets consider that the current is still positive from drain pin to source pin, so the value given are ... negative... on the datasheet. MOST... but not all. And it is confusing MOST of the time :-)
*About the arrow*, I am used to the symbol with the grid like pattern for an enhanced MOSFET. There are some symbols using the REVERSE direction for the arrow just to add to the confusion, as if it was needed. The author of this video uses these symbols while I was having in mind the grid like symbol (as at www.fairchildsemi.com/datasheets/2N/2N7000.pdf for example, for a N Chanel), so the arrow direction is all but confusing, without a specific drawing. If you assume that a N Chanel matches a NPN BJT, you have to admit that the arrows directions are ... reversed ! at least, if you take the symbol given in the datasheet, as given here up.
+Persona, +snnwstt So, are you saying that my little mnemonic ain't working for P-channel?
To be honest, I have to think it over almost every time again, it is confusing. And right now, I am confused again.
Ich schaue Mal nach,habe bestimmt nmosfet sind irfz46. noch was anderes tec1
Why is it Not base, collector & emitter?????????? Its the same thi g
Different technology, different words.
Because a MOSFET is not a bipolar transistor.
@@wmellick and the turn signal in my car is also a blinker and a lamp on intermittent cycle.....
Because transistors are current controlled, but mosfet are voltage controlled. So the emiter gets the current from base and collector, but the source only gets the current from the drain. Using the same words to different behaviours would be confusing.
irgendwer hier von der Vorlesung von Prof. Zipf?
Is it convenient to add subtitles? It is convenient for people from non-English-speaking countries to watch
dont use it as a touch sensor xD xD xD
What's with current flowing from drain to source? Why oh why did the early pioneers of physics have to make the electron the negative particle.... sigh.
The video Title sounds dirty 😂
They're small