Transistor / MOSFET tutorial

[@fzigunov]

When you realize this video is 8 years old and is still useful... Not many youtubers reach that level!

[@anonimuso]

But lol at "You can get a transistor from Radio Shack"...

[@Tumbleweed-vh4pt]

anonimuso if you can find a radio shack that is still open 🤔

[@lolbubs11111]

"your computer's parallel port" lol

[@chanakanirmal7298]

dame you comment brooo.. wow

[@mr.meticulous1241]

anonimuso dude that one hurt :’(

[@MyBigThing2010]

wow DUDE! ...this is like the 6th time I've watched this video and I just FINALLY had that "AHA Moment" where everything just aligned in my thick skull and I actually realized WTF is going on in circuits with transistors in them and how to go backwards through them in a LOGICAL way and KNOW what I'm looking at and looking for....I wish this channel had like 3 million subs and you were a full time KZbinr! your videos have spawned a few of those "oooh! that's how it works" moments for me while learning this stuff....I thought it was all alien tech that I'd never be able to learn/understand and your channel has been instrumental in helping me over hurdles...even if I don't know it while watching or feel stupid for not getting what the video was about...down the line I'll look at something and instantly revert back to the info in the video I inadvertently retained and I'll get a better grip of what I'm looking at because if that info...Afrotech University, electronics engineering school. hmmm, I wonder if that would fly if I put it on my resume? haha...nevertheless, I'll say it again. THANK YOU!

[@xXxkrispyXlolitaxXx]

i love those moments

[@jorgewashington2981]

Thanks Afrotech. You are one of the best Electronics instructors on KZbin.

[@loverboy-if3ox]

I agree the BEST! and I have a learning disability and that says a lot thx

[@idlando]

This is the most neurotransmitter efficient tutorial I've seen for a long time. Straight to the point, clear and precise. Thanks!

[@Afrotechmods]

Gah. Now I wish I had covered this in the video. The gate pin has a small capacitance, and will hold a voltage for many minutes with no power applied and pick up stray voltages very easily. So you should put a 100k resistor from gate to ground to discharge the gate and have the FET off by default.

[@za_ozero]

i figured it needs a pull down resistor. I wish you were posting more vids

[@MsMadLemon]

You've made FETs less intimidating for me, this will help me in a project i'm currently doing, thanks! :o)

[@dredrotten]

This is the simplest articulate and clear straightforward no BS tutorial Ive ever come across! Good on you Mate. Excellent job!

[@MrBelchfire8]

Thank you for a simple explanation without annoying music or "humor". Appreciate "just the facts".

[@deldarel]

To people thinking it's a relay. The general purpose is the same, but there are important differences 1. a relay is isolated from the circuit, but a mosfet is not. Drain and Gate share both the Source, meaning that the current of source is gate + drain. Usually this isn't too important, but be sure not to connect a fusion reactor to the gate. 2. Mosfets are much quicker. You really only want a relay at the very end of your circuit, and only use mosfets for this function within the circuit because it doesn't have a built in coil and the moving parts are much much smaller.

[@andriosz]

Can you use these to make a PWM control for a cooling fan for a car radiator ?

[@Afrotechmods]

Yes. Pulldown resistors are generally a good idea. See my PWM tutorial video.

[@StrsAmbrg]

This is the best teaching I found about N-channel MOSFET. So easy I understood. The voltage range you explained made everything complete. And the placement of silicon and zener diode made more complete.

[@TangodownNZ]

Thanks. I have watched many complex tutorials on transistors and none of them made sense to me. You explain it very well without over complicating things.

[@dagobb]

Excelent tutorial, now I can switch leds on my quadcopters and my airplanes for flying at dusk or night! THANK YOU !

[@Afrotechmods]

dagobb That sounds like a perfect application! Glad you liked it.

[@user-nd7rf3qi2i]

Afrotechmods )

[@PeperMintification]

Excellent video, it greatly helped sparking my interest in electronics a few years ago - I've built many toy systems with transistors since, namely my custom made power boat (that needs some maintenance)! Thanks for sharing your knowledge and spending time creating this really awesome electronics videos! Hope to see more tutorials :)

[@hardbuilder70]

Probably the best tutorial i have seen on electronics. Very well spoken and easily understood.

[@germas369]

FETs can be extremely complicated but im glad that videos like this exist. it simplifies the theory and its easy to put them in practice

[@Afrotechmods]

the capacitors usually go first, but once that happens all bets are off and pretty much everything is prone to failure.

[@Durgeshkr00]

4:05 made me to subscribe this channel. This is what i was searching. In a single video you had explained everything. Please provide direction of diode to be used with solenoid.

[@ristomatti]

I agree this is one of the best simplifications on how to use a MOSFET. Saying it explains everything you need to know would be exaggerating. For example it did not answer what do you need to do to switch loads of higher currents even though very high currents are often found in MOSFET data sheets. It's difficult to find a logic level MOSFET that can be used to switch for more than 1-2A of current. It becomes much more difficult if you want to do it with a controlling device using 3.3V logic levels such as an ESP8266 or a Raspberry Pi. When this video has been created 3.3V logic levels were not as widely used as today. In case you have not yet found the answer, Afrotechmods suggests watching this video of his in a reply to another comment made 4 years ago: kzbin.info/www/bejne/gomqpXhpjZeebbs

[@fritzj6803]

Omg I've watched a million videos, but you got straight to the point and made it understandable.

[@Aspins]

I am 62 years of age and have always wanted to undersand the fundimentals of electronics I have tried for years on and off to get my head around the why and how of it. Thanks to your tutorials the penny is slowly starting to drop. Thanks Keith

[@Flankymanga]

4:22 Can't believe my eyes... in America you had Tesla subcomponents?!?

[@diabloenergizer]

Best explanation i could ever find thnx

[@ten10ca]

KEEP LOOKING

[@IAMainvision]

Between Afrotechmods & RimStarOrg here on youtube there really isn't any reason to study electronics at university. Superb work! Clear, concise & accurate! Keep up the excellent posts. Cheers

[@haczyk84]

Short and straightforward. I've seen many student of technical schools who doesn't get it. Nice video.

[@Trielectify]

Great informative and interesting

[@technosasquatchfilms]

Who the hell is down-voting free information!?

[@pcproz3215]

I really love your teaching style. You eliminate the "mystery" from the circuits. Have you ever thought of doing a "full blown" electronics tutorial? I would definitely buy it if you did. Thank you for taking the time to do these vids.

[@jatinmali9310]

I never skip ads in your videos and that's the least I can do for you Thank you for making such videos

[@Afrotechmods]

Aw thanks!

[@hameedwafaAFG]

Hahah I like headache video

One of the best explanatory tutorial i came across. Thanks for making this video. Kind of weird i just now find it after 12 years. 😋

[@linkstatic12]

I am an Engineering and have alot of experience in transistors. I loved your tutorial on this. Keep up the exceptional work!!

[@Afrotechmods]

@Xearo167 Electrical engineers work with what is called "conventional current." It is backwards to what is correctly taught in physics, but all electrical engineering laws and formulas are based on it. So for the purposes of designing circuits in EE, current flows from positive to negative.

[@deanwesterburg]

All your tutorials are awesome! If you aren't a teacher, you should be! Your teaching style is very clear and easy to follow. You're KZbin channel has helped me a lot! Keep up the great work!

[@jerrychristensen6096]

Greatscott may be the buzz now but Afrotechmods will always be the OG

[@BackFlash2K]

I like the bits of humor in your videos. [Subscribed]

[@kieferonline]

Best tutorial of all time. Afrotechmods is a gifted teacher.

[@Afrotechmods]

@HHOhybridBuilder Sort of. Varying the gate voltage from 0 to 5 will vary the drain-source resistance, which will result in the drain-source voltage changing when the FET is operated in the linear region. This is usually done in amplifier circuits and it causes a lot of heat to be generated in the fet. For switching applications you want to avoid the linear region so the FET is either high resistance or very low resistance - nothing in between.

[@Mindthegap720]

This video explains quite a lot better than my professor at university. I thank you *Afrotechmods*

[@Apc204]

Thanks! I never really understood the N channel MOSFET in the few lessons we did about it in class. I watched this video just before my AS electronics exam and it helped me answer three questions about the MOSFET on the paper. :D

[@mikaelsantos316]

This is the most direct video ive seen so far.. very easy to understand!

[@ForViewingOnly]

Afrotech, you rule! These videos go at just the right pace for my aged brain... great work! I've watched 5 of your videos in the last 45 mins. Please make more to feed my new obsession.

[@computerchi]

5 minutes ago I did not know a MOSFET transistor from Adam. Now I think I can easily use them. Thanks. You rock.

[@TheMegajupiter09]

Excellent! Many who do such videos should learn from you. They miss the point of their tutorial. Your voice is also approved! Lol!

[@w3mq]

Great tutorial, I understood more about the transistor in the few minutes than i ever did in High school and College. I guess some people are better teachers than others, I'm going to watch this again and try to experiment.

[@jessesinclair4491]

finally, electronics signal flow/path etc.. has elluded me for so long. the videos by this guy are explained in the right manner for me to take in. subscribed, great videos thankyou.

[@chevytruckjerry]

Man I love these videos. Hearing him mention Radio Shack filled me with nostalgic sadness 😢

[@Afrotechmods]

The circuit in the video should work (you can use the version with a relay if you want) if you add a 100k resistor between the gate and ground. This allows charge on the gate to drain to ground which will turn the mosfet off.

[@warcog]

Hey Afro, I have to tell you: That was probably THE most helpful thing I have found on KZbin for a couple years. THANK YOU for making that. You're a saint. I have been struggling as a hobbyist building some MOSFET switches for airsoft gun application. Fiddling without understanding of much in the way of electricity - a big handicap. Now I think I just might get it - thanks to your tutorial!

[@creativejunior7060]

Nice, because of you i just repair my old and rusty angle grinder with brown armature. And now it really works good. Thanks

[@ahonda55]

Man, you are great, and what time you had trying to teach someone something will not go to waste, the world will apreciate that. THANK YOU

[@DavidFowlerEngineer]

Just a note: MOSFETs more often then not, need more the 5V on the gate to turn on. Study the specifications for your FET and watch out on the dissipation. An important parameter is RDSon.. This is the resistance when the gate threshold is met (Vgs). FETs can have very small RDSon values, like 0.05Ohms.. With very low RDSon values you can switch large currents without a lot of dissipation.

[@thomastrout1075]

David Fowler thanks

[@Afrotechmods]

@HHOhybridBuilder yes. It turns the fet off by default by discharging the gate.

[@LoganEdwards]

Wonderful video! Simple explanation, solid narration with a hint of humor. We need more of this in the technical world.

[@Maham899]

I am impressed by the narration and graphical description.

[@wilfredmulenga5558]

best tutorial on mosfet transistors that I could possibly find

[@mikemetallia]

Thank god for one normal tutorial on mosfets. And thank you.

[@Afrotechmods]

You would need an optocoupler with a totem pole or logic output. A logic level mosfet would also be a good idea. The project should be doable.

[@Afrotechmods]

@rainbowsalads Use a diode to convert the AC into DC then use an NPN transistor to toggle a relay which switches on the bulb. Or find a small relay with a 3VAC coil voltage.

[@slvrserfr]

I was wondering why the MOSFETS and even zener diodes I've replaced often only have what seem to be ground connections and some without even a source connection. This tutorial helped out alot.

[@Afrotechmods]

3VDC is generally quite low for mosfets. It might work, but there will be noticeable resistance between drain and source (perhaps 1 ohm or more). You can get 'logic level mosfets' that switch on with very low voltages, but they are usually only good for switching 10-30V. If efficiency is not a huge concern and you just want something easy, get a TIP110 from Radio shack or any NPN power transistor. They will switch on fully with 3V no problem.

[@cecilomar]

Getting a refresher on mosfets... Went to like the video... Already liked it at some point... I wish I could like it again.

[@Target008]

Excellent tutorial, it is nice to see that some people don't assume that everyone already knows everything, Thank You

[@davidjereb]

You are awesome! Everything you explain is so easy to understand, you speak clear, proper english, so there are no problems to understand you and you have a gift for teaching. Keep these tutorials coming! Thanks! : )

[@clintonraubenheimer5879]

very cool. I often look for tutorials like this and as mentioned in the end of the video, some of them are enough to give one a head ache.

[@Afrotechmods]

@Bizorke For an N channel MOSFET Vgate has to be typically 3-10V higher than Vsource to turn on. The drain voltage does not factor into this, although it indirectly does when the FET is being driven high side. But for example, if Vdrain is 20V and you tried to make Vgate higher than that you might kill your FET.

[@seethaljayasankar459]

I love Electronics again!! Thanks to you!

[@CharlieTechie]

Great tutorial! Simple, Clean, to the point with a little humor.

[@Afrotechmods]

On a datasheet, the relevant graph is Rds(on) versus Id for different Vgs

[@BadDL282]

Excellent tutorial !!! The source-drain terminology seems backwards but that's the way it is. Clear and easy to understand. Thanks

[@NetPwn]

Transistors have officially just become my new love, thanks for the vid.

[@michaelangel6201]

Nice simple and to the point, great tip on looking on old boards for parts before buying.

[@FranktheDachshund]

I lost this channel for at least a decade, glad I refound it.

[@Afrotechmods]

@jackwhitesguitar Yes, there is a small linear region, but that goes beyond the scope of the tutorial and most people will never apply it anyway.

[@Afrotechmods]

@lowsideswitch Transistors can be switched faster infinitely - most relays can only be switched a few times per second and have a life of 100k cycles. Switching an N MOSFET high side will require some extra gate drive circuitry.

[@betergigech]

i been looking for a clear explanation in spanish about this gadgets but i didnt find it until found this in english thank you very much is very clear and understanding

[@philbx1]

Wow, never saw your channel until you recently commented on eevblog's channel. Fantastic stuff, and I don't know how you do the 'voice' thing, but the combination of great dialog and straightforward tutorials I think amazing. Surely you are (or will be) a fine teacher! Thanks much.

[@Afrotechmods]

It should be written on the transistor's casing. You may have to remove the heatsink to see it. You may also have to use some acetone to rub off any dirt that might be covering up the part number.

[@Afrotechmods]

@sjh7132 Good comment. When driving MOSFETS in switching applications, you want to drive them hard on, or hard off. Putting a wussy 1.5V signal at the gate won't be enough to fully turn the FET on, so there will be more resistance, so there will be more heat. A good gate driver circuit will switch hard between 0V and 10V, but 5V is often enough to get the job done if you aren't switching high currents. It all depends on the specific Rds(on) versus Vgs characteristics of the FET.

[@sbreheny]

@Afrotechmods Awesome tutorial! Regarding the voltage between gate and drain - once the FET is in the ON state, the voltage on the gate does indeed need to be at least one threshold voltage higher than the DRAIN in order to make the FET FULLY ON. This is only really important when passing very large currents through the FET, where the current times the RdsON is more than 1 volt. This is the reason why it is important to drive the gate with a few volts more than the Vthreshold.

[@fc3sbob]

out of all the video's explaining transistors think this one is the best! I just got my arduino +5v to switch 24v DC Relay's.. let the fun begin!

[@mkayeka]

You are making electronics way easier and much fun. Thank you very much Sir.

[@artype9550]

the most amzing electronic guru i ever known

[@Afrotechmods]

Meow

[@Afrotechmods]

@herctrap The LED will also need a current limiting resistor as usual. But the main problem here is that the voltage between Gate and Source has to be at least 5V for the FET to turn on, which won't happen because Vsource will now be ~12v when the FET is on, so you'd need a gate voltage of 17v, which is impractically high. In other words, you need a high side gate driver circuit.

[@Afrotechmods]

That's a more complicated question to answer but i'll simplify it... the IRFZ44 will start to turn on somewhere between 2-4V but there will still be some resistance around 1k-100k ohm. With Vgate at 5V the resistance is low enough to be useful, roughly 1 ohm. It will be 'fully' turned on with 10V and the resistance will be around 20 milliohms.

[@Afrotechmods]

@WINANDMACNERD Sort of. There is a small linear region (around 1-2V) on many fets that will act like a voltage controlled resistance. However you will need to DC bias your sine wave very precisely and make sure the amplitude of the wave stays within the linear region. Read up on the datasheet for RDSon versus Vgs to find the region. This will also cause the fet to heat up. You could also look into digitally controlled potentiometers.

[@jestork1]

Nice tutorial for beginners just what I needed to get a bit of reassurance and a confident start. Thanks and keep it up.

[@spaideman7850]

if all teachers were as efficient as afrotech, our kids don't have to stay all day in school.

[@Afrotechmods]

Yup.

[@jarekz90]

Im from Poland, this video help me to understand how to work the transistors. thank you!!

[@fgdfhtrhg]

Your tutorials are SO much better than the others! cheers dude

[@animelvr99]

Thank you for such a great tutorial. I love how you went from the mosfet to other things you can switch on and off. Really helpful

[@jayurban4313]

Love your high tech professional looking labeling machine!

[@MidnightMechanic]

Most fun to be had out of these is when building a 12~14.6VDC car amplifier or radio head unit, coupled with a few high power capacitors to really crank out the sound. What I'm confused about is when a radio head unit is supposedly rated at 50 watts MOSFET for 4 channels each, yet expects to pull all that power (at least 200 watts) through the little tiny gauge ACC power wire. The memory wire has to be attached to for the radio to work correctly, but there is no way in hell that radio is pulling anywhere near 200 watts RMS without frying wires! The Pioneer amp I'm using outputs 300 watts max, and it uses pretty fat power input and ground wires!

[@Afrotechmods]

@floydiangreen That's connected to the symbol marked ground.

[@Paul67558]

afroman i think you have the only channel where can i can learn electronics

[@kevinrhug]

I really appreciate your videos. I have been a technology teacher for 25 years and this past year I was placed in an electronics class (something I had never taught and hadn't studied since college). I had to do a lot of studying to relearn some things. I had an absolute blast and these videos have given me tons of ideas for next year! Have you ever worked with microcontrollers?

[@101Osprey101]

Great vid. I have been attempting to understand the transistor for some time and while I had the basic idea, your video helped put at least the part I am concerned with, into context.

[@feralbigdog]

this video answered a question i had perfectly about which way power flows through transistors, and explained how they work better than trying to understand them on ehow and wikipedia articles

[@Afrotechmods]

@BadDL282 Well, the reason is sounds backwards is because if you look at it within the context of semiconductor physics, the electron flow is from source to drain, which is the opposite of the conventional current terminology that electrical engineers use.

[@RJSoftware2000]

Ground switching. gate=switch (0=ff, 5v=on). drain=conductor from load intended to be grounded. source=the actual connection to ground.

[@saksi_mata]

10 years later.... I am keep watching this guide. And i can confirm that i am a changed man now.