Added: 3 years ago
From: Afrotechmods
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  • What is a good way to control the gate signal? For example if I want to build my own ESC for a RC car.

  • thanks for knowledge

  • To clarify for beginners, I would show the complete power circuit. For example, show that the 12 volt battery has its negative terminal connected to ground so you see a complete circuit. Makes it easier for someone wanting to play with flashlight battery powered circuits, etc.

  • I should specify that this is the gate voltage. Source/drain voltage doesn't really matter.

  • Not all MOSFETs will turn on completely at 5V and may overheat. Sometimes you need 9-12V. A logic level MOSFET will turn on at 5V for sure.

  • Can you turn an IRF510 fully ON with only 5V? I thought that you need to use a "logic level" MOSFET (like an IRL540) to do that.

  • Share the knowledge with other people Great job man!

  • turn inspector gadget on, lol

  • BJT Power Trannys come in the same shape ... just google the part number .

  • Really helpful tutorial ............Good......

  • muy bien explicado, excelente jeje

  • I have to tell you, this is a great video.  I've been sort of playing with transistors, and you pared it down to the basics and gave me a lot of ideas. Thank you.

  • I am very happy to see the vidoe Also, remember to put a 100k resistor between gate and ground if you want your FET to stay off by default! from you, hopefully the others also are happy for You

  • Steady I Really Like This Video N channel MOSFET to turn anything on and off.

    Also, remember to put a 100k resistor between gate and ground if you want your FET to stay off by default

  • Good, I like that you share this video How to use an N channel MOSFET to turn anything on and off.Also, remember to put a 100k resistor between gate and ground if you want your FET, I wish success always

  • nice man go on you are doing a great job GREAT JOB MAN THANKS

  • is a p60nf a transistor

  • instead of 5v to switch on at the GATE, i have only a 1.5 to 3V of

    LED current to use. Any idea of cheap mosfet to use to swtch on a 3 or 4 volts at D, S ?

  • how to read SMD Code of a Transistor AND GET DATASHEET FOR A Transistor ?

  • I'm having problems when using multiple transistors. I'm using an Arduino. When I press a button it makes a high output, other wise is low. When I only use a transistor, it works as expected. But the I use the signal to control another two transistors at the same time, both of them appear to turn on with half power, regardless of the output signal. What am I doing wrong?

  • So it flows drain to source?

    Maybe you need another plumber mate.

  • U shouldve mentioned current limitation on a transistor

  • I lole this tutorial! Awesome!

  • thank you mann !!! :)

  • Hi Afrotechmods, excellent tutorial, I have a question, I have conected drain to the possitive side of the 12V battery and source of FET to the positive side of a 12 V light bulb, and the negative side of the bulb is grounded; in this way the bulb goes on when a voltage appear in the gate, but I feel the light bulb iluminate less than if I connect it as you explain in the tutorial (FET between bulb and ground) is this true? would it damage the FET or make it hotter when working? thanks

  • i had to put the positive side of my external source to the drain insted of the negative for the transistor to work. Will this cause problems or is this ok?

  • no entiendo tu idioma

  • very basic and good tutorial. thanks!

  • PLease clarify for me why u need a diode to use the transistor with a motor?

  • @xXxRadicalDesignsxXx Look at my video on inductive spiking

  • because when motor will stop after running that time motor will continue slowly slowly stop so that time motor will make volt back to transister so can damage.so diod will work as break.

  • is this not just a relay switch?

  • Hey, doesn't the gate have to have a higher voltage than the drain? I thought that's what I was told (although I don't have experience actually building circuits with mosfets).

  • @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.

  • What can I use to make the gadget stay on for minutes if the voltage to the transistor is 5V for only a few seconds and then drops back to 0V? Would a latching relay work?

  • @FailsAreEpicToo Look at my peak detector circuit video and my comparator circuit video.

  • @FailsAreEpicToo Connect a high value capacitor to the gate and ground. The capacitor will discharge through the resistor connected to the ground. And use a high value resistor.

  • much better than the book

  • What is the difference between drain, gate, and source, and collector, base, and emitter?

  • Excellent, brief and clear explanation. Thanks

  • Sooo, what's the difference between a bipolar transistor and a MOSFET? Because they both seem to do the same thing.

  • @hbar45 The bipolar transistor doesn't have as much in-take impedance, so it takes more current to turn on.

    A bipolar may take 10-20 microAmps to turn on, while a MOSFET in the same situation may only take 0.3 microAmps to turn on.

  • @Saxappealed So basically they do /do/ the same thing, but the MOSFET does it without needing as much power, but at a higher price. K, tnx!

  • you can turn ur low power amp into crazy subwoofer destroyer by useing transistors lol... i had 100w amp, bought 30A ultra powerful transistors and got output power- 1800w rms at 30A 12v

    sould really fucking g00d!

  • would 0 to 6v work?

  • I really like this; It is good, clear and well done. It explains things easily. Although MOSFETs were not the easiest thing to build. It took a lot of effort.

  • for what is the diode used? doesn't it work without the diode?

  • @varer Check out my video on inductive spiking

  • it may be a stupid question ... but your gate needs power to 'open' (close the circuit)

    so power can go from the drain to the source ... but why would you use a transistor then instead of a normal button or switch? :s in the end you mostly just going to connect the gate to the power supply so ... :s

  • @kcinkcinkcinnick

    Transistors are used usually to "amplify" weak signal.

    Let's say thay you need to light up a huge light bulp with weak wireless signal. You cannot just hook the bulb to the receiver, because there isn't enough current. You also cannot push too much current through the receiver either.

    So you can use transistor to _control_ higher current with lower one. Then you can push 100V through the transistor for the bulb with the 3V signal.

    See MAKE Presents: The Transistor.

  • @RealationGames thanks!! that's a good example! now i get it ;-)

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

  • simply fantastic hope to watch more of this kind of video

  • You are a life savor. I've been trying to figure out this exact application for over a week now. I've been posting on forums but no luck. I tried simulating this circuit in multisim but I'm not having much luck the only MOSFET in their database that looks like the one you are using is an IRF530 and it's not giving me anything close to 12V across the bulb. :/ please helppp!

  • any simple and clever way to make an inverter? like when it got power it stay OFF, and when the power's gone it turn ON...

  • what are the benefits of a transistor over a relay, it looks as though ,in this case you are using them in the same manner? and it looks like your switching low side, any specific reason??

  • @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.

  • Beautiful. I see YouTube University in the making...

  • switch youtube on or off

  • Great tute, cheers mate

  • very well explained 5*!

  • On 'n' off!

  • So where does the 'source' of my mosfet go? to the ground on my arduino or the ground of my 12V battery?

  • @TunioMir Both. They should be connected together in most cases.

  • @Afrotechmods so a current of 1A flowing through my arduino is ok??

    no, i think must be that the large battery somehow draws the curent to its ground

  • congratulations for the tutorial i like

  • สุดยอดเลยครับ อาจารย์เข้าใจดีจังเลย !!!!!!!!!!!!!!

  • THAAANK YOOOU!!!

  • Hell yes, very helpfull!!! I haven't checked yet but I hope you made videos for all different types. You explain it perfectly.

  • nice

  • what idiot decided to call the input "drain" and the output "source"...

  • @aplacefaraway I agree. I guess it comes back to the whether you regard current as flowing from positive to negative or negative to positive. I always think positive to negative, so the labels look back to front to me.

  • Perfect... just... just perfect... :'-)

  • Those professors should take a cue from you and actually teach.

  • Hey Afroman,

    I have a N channel MOSFET, the IRF510. For some reason, if I apply 5v to my gate, my LED is very dim. But if I touch it, it lights up like a Christmas tree. Is my Mosfet broken?

  • and why to use a transistor and not a simple switch ?

  • you really got me with that gadget joke :D

  • It wasn't enough to give me a headache...

  • Why not just use low voltage relays.....

  • Comment removed

  • i just want to know all about of mosfet transistor..

  • And by the way I am now the worlds blinky light  KING

  • 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

  • Where am I gonna connect the DRAIN and the SOURCE If I would use a P-Cnannel

    mostfet in order to control the speed of that electric motor ?Is the GATE voltage should be negative 5 volts ? Can you suggest any particular P-Channel mosfet  with a higher amperage around 20 amps @ 60 volts?. THANKS

  • redstone torches (minecraft)

  • Do you have a video on how to make a "NOT" gate? If not, how would you go about making one?

  • you could also control inspector gadget with this not just any gadget!

  • why would you need a diode between a motor?

  • amazing ....it's really amazing

    

  • Would transistors be used in Tv's too, to regulate the flyback transformers?

  • Could you make a tutorial about P channel mosfets?

    This tut was very helpful!

  • Awesome tutorial, and thanks for straightening out my DC motor driver circuit I was prototyping... which mostly felt like banging my head against a wall. Had the motor on the wrong side of the mosfet... duh.

  • thanks, how will the transistor know the delay of flash?

    peace

  • How to control mosfet from isolated circuit.For example I want to switch 400V capacitor , is that safe to connect mosfet gate to source in that case ?

  • @bodziobran ..nah.... a nice good quality isolated switch is best. I you must have electric control then use a high voltage relay (<$5) if you want to control that relay from a small current source like a micro-controller use a transistor to control the relay.

  • @CmdrTobs

    Thanks.Main problem is I'd like to switch capacitor at high rate (khz)

  • @bodziobran ah.... i thought you meant by hand for some sort of coil gun type thing....

    Sure it will do, you will have to find a thus rated device. Could be quite expensive. Also is that a high F capacitor? because at Khz speed it would probably need a crazy current that would blow it to charge it to 400V in time. Basically what are you doing?

  • I'm trying to figure out how to use MOSFETs with a Arduino, and I don't quite understand the grounding. It's confusing because it only has one ground pin (Source) unlike a relay. If I'm using a 5V signal from the Arduino to switch on 40V do the Arduino and the 40V circuit have a common ground (FET source pin)? What if I'm passing large amounts of current through the FET? the Arduino can't handle that, but it's still safe because it's not actually passing through the Arduino?

  • @gizmoguyar You got it. Make sure you connect the grounds (a thin wire will do). The high current should be flowing through the FET. That will of course depend on where exactly you have the power wires connected. The -ve wire of your external power source should be connected directly to the FET's source pin. If you were to connect it to a ground pin on your Arduino, you can imagine the current would flow from Source-> Arduino PCB -> -ve wire which would be bad.

  • @Afrotechmods SO Mosfets can be used only for switching on and off OR can they amplify the signal like OPAMP ? Trying to use it for the electric fan.

  • @gizmoguyar

    You can use an optocoupler between the arduino board and the MOSFET, with common ground

  • @gizmoguyar MOSFETS are so simple to use, because they only require a change in voltage and almost no current to switch. Your digital outputs from the arduino should work fine.

  • @gizmoguyar The 120 volts in your house shares a ground with the cold water pipes and the metal duct work. But you don't get a shock when you touch them, do you? Of course not. Think about it like that, too.

  • very informative!!! thank you!!

  • lol innuendo

  • Man very nice video!!

  • GREEEEEEEEEAT!!!!!!! VERY GREAT VIDEO!!!

    WELL WELL!! GOOD!!!

    I am from Italy =D

  • dude your videos are so helpful, thanks dude.

  • This MOSFET's are just ON &OFF ?

    

  • So, I'm trying to control 12 Volt DC motors with transistors (and arduino controlling the transistors). I'm going to wire an h-bridge to get forward and reverse. my question is since the direction of current changes to change the motor's direction, I can't have the diode on the motor. Can I put 4 diodes on each of the transistors in the h-bridge?

  • im new to electronics, whats grnd mean?(ground)

  • so could I safely turn on something using 112v with an arduino that can put out 5v withought frying my board

  • I liked it very much!

  • Hi, can i just ask. does it matter if you place the load/lightbulb on the source instead of placing it in the DRAIN side? Thanks!

  • @nadre25 Shouldn't matter in this case. The placement of the drain side tends to be more of a conventional thing than anything.

  • Your Videos are really great!!

    I could understand realy good what youre explaining. Also im German, i understand nearly everything you thought

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

  • i have to make switching for very low voltage whose value varies in between 0.1 to 0.7v and its frequency is in between 50 to 200Hz how can i make siwtching for this signal

  • Can i switch my girlfriend on and off ?

  • I don't understand. I read that scientists can now fit hundreds of billions of transistors on a square centimeter. But why is the transistor you use so big? is the the same type taht is used in industrial components? Plz answer!

  • @RTRVII : Anything that handles electricity will transform a portion of electrical energy into heat, no exceptions, because of resistance (ohms). A computer chip indeed has a large number of microscopic transistors but they are designed to handle relatively small electrical currents compared to a current running through a light bulb. Still, a computer chip requires some decent cooling in order not to melt or burn out. The transistor in this example is big because it has to handle high currents.

  • @dongpedroyi thanks for the answer man. +rep.

  • THIS VIDEO IS WHAT I'M LOOKING FOR!!!!

  • @AMIELrenaissance ikr lol

    

  • Thanks to the 25 people who made the dislike bar look like a joint :D

  • I have the exact setup in here with a 12v light bulb being illuminated via a transistor. when 5v is applied the light turns on. What i want to do is make it dim to off rather than switch off. i know i need to use a capacitor on the gate but what mosfet should i use? they all seem to just turn straight off.

  • @Sethjxl You don't want a cap on the gate. What you want to do is PWM - check out my tutorial for that.

  • @Sethjxl Due to the exponential source drain resistance to the gate voltage relationships, MOSFETS are practically only on/off switches and it is close to impossible to control the load voltage via controlling the gate voltage. PWM is an option however you would be limited by the switching speed of the FET and so your "dimming off" may not be seamless. I would recommend adding a capacitor in parallel to the source-drain of your FET. The time constant of the Cap would be your dimming time.

  • @daniel1c MOSFETs can switch quite quickly, in fact in the 100's of kilohertz and up. The key is charging the gate capacitance quickly enough to get the gate voltage up to and past the MOSFET turn on voltage.

    If you're just dimming a light then you don't need a fast switching speed, not even a capacitor. Also, someone correct me if I'm wrong but putting a cap across drain-source is not a wise decision

  • By varying the DC gate voltage from 0 to 5 volts, will it control the DRAIN SOURCE voltage?

  • @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.

  • @Afrotechmods So therefore I can use then this circuitry to use a 12 volt lead acid battery to charge a 6volt lead acid battery by varying the gate voltage? ( Just mount the mosfet on a very good heat sink to avoid overheating? )

  • @HHOhybridBuilder Do I still need to install a 100k reristor between the gate and the ground?

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

  • 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

  • YEA BABY 3:36 !!!!

  • Thanks Bro. I am trying to learn this thing from 12 years. you really explain so nice.

  • as always, the tutorial on youtube is so much better than the professor at school.

  • @TaeChanvit Same #(=

  • @TaeChanvit agreed, you can learn everything via the internet and experimenting on your own

  • Super teacher. Thanks very much.

  • i love to laugh while i learn. especially dig the inspector gadget cameo. thank you for all your great videos!

  • fucking brilliant tutorial

  • I've been thinking of making a vacuum-tube based synth with computerized functions, but I'm not sure how to interface the two without frying the DAC. I was thinking of using high-power transistors, but I'm not too sure if a DAC can supply enough voltage.

  • Ok, say if i inputted a sine wave into the gate, will it act if a were turning a potentiometer back and forth, like if it was a voltage controlled potentiometer?

  • @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.

  • will ac or backwards voltage kill a mosfet?

  • @ubuntupokemoninc Yes. Don't do that.

  • ******

    Great video.

    Check out my water detector universal switch.

    /watch?v=S_vU4X4Mz0I

  • What is the relay you mention at 4:07? Can't you use directly a transistor to switch on and off a fridge or a light bulb?

  • really good tutorial

  • Wow another great Tutorial. Now I'm gonna subscribe. Your videos are clear and directly to the point. PERFECT

  • Ok i have a 360 with no power, hlaf the transistor is charger and half isnt? It seems to not let the power pass all the way through.. any thoughts? could it be a capasitor?

  • Very helpful, thanks!

  • Question, why would you need a diode on the circuit 4:02?

  • @mikey0186

    I think it's because all of those parts (motor, solenoids, and relays) have coils which generate noise that can disturb any other IC near them. Putting a diode ( i forget in which direction, but i think its positive side to the negative side, and vice versa) as close as possible to the motor or solenoid, eliminates the noise. I'm not sure why, but I've seen it being done before.

  • @Jamlx Coils (Basically, any inductive device) generates back EMF and so the diode clamps this otherwise this back EMF can rise to well beyond the max rated drain-source voltage and destroy your MOSFET.

  • How do mosfet's work in an amplifier?

  • Hey i´m looking for a circuit where i can use a mosfet to build a light dimmer. I have seen it before, and i think it was here on youtube, but i cant find it ;-(

    Can someone help me out?

  • how to switch when im on dark the light to go on and to work?? i try it but idk it didn't work can you tell me or show me??

  • thanks

    I will try to test a trasistor like that on my Hobart 125. It only click and click, but the feed motor is not advancing.

  • Very nice tutorial!

  • Comment removed

  • 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!

  • 5V at the gate will be a bit low for many MOSFETs. The transistor won't be fully opened. This could be a problem when switching a high current load. There are logic level MOSFETs that are open at 5V. So check the datasheet of the device for the right gate voltage and don't assume 5V is enough!

  • Excellent. Best tutorial video I've ever seen. 5 * Pronunciation clear and accurate. THANKS FOR POSTING.

  • gostei muito deste video..........vejam  tambem meus videos são legais.

  • wow, where were you when I was taking my electronics class in the Millitary. I was having problems understanding transistors. My instructor had to use a beer bong reference before I could figure it out.

  • So is a Bilateral Switch mostly the same thing? and What type of Transistors are the type used for amplification?

  • The last part with Arnold made to laugh XD

  • WHY DOES MY PHYSICS COURSE MAKE THIS LOOK SO DIFFICULT!?!?!

    that was an excellent explanation, it's too bad I need to learn all of the crazy details and formulas that don't really seem to have any relevance to any sort of application of the mosfet....

  • @SoundSpaceOdyssey Well, this was a basic explanation and while good at explaining how a MOSFET works, it is not the whole picture

    MOSFETs have gate capacitance which you will probably remember from school and this can be thousands of picofards which may not seem like much but when you have to switch these devices at hundreds of kilohertz then you need the formulas to make sure your switching losses are kept to a minimum.

  • good job

  • can you put the n-chanel mosfet like this? +12v -> drain -> source -> device -> ground??