DIY Buck converter - TUTORIAL

[@americanrebel413]

This is the best tutorial I've heard on buck converters, I actually understand now. Thank you, I subscribed.

[@roseelectronics4582]

It's also very nicely explained by Adamant IT.

[@PyccoloSantos]

Its 2023 and this circuit will help me on my thesis, ty Electronoobs, I will credit you in the references.

[@Fiskelord]

Why you only have 50k subs is a mystery to me. I randomly found your website while searching for info on buck converters, and you gained me as a sub with just one video. Keep up the good work, buddy!

[@ELECTRONOOBS]

oh. Thank you very much!

[@pietervheerden]

I love the way in which you break things down. Imparts knowledge in stead of just information... and extremely helpful for someone like myself who's trying to learn electronics.

[@nostalgistl0058]

Okay,for N-MOS in Buck converter,i didn;t see any bootstrap circuit for High side switching

[@dushyantchaudharymathura]

What ic should be used for upto 15 amp of current like lm2576 for 3 amp.

[@hardikyadav5277]

hey bro can we make a buck converter for convert 220-240v ac 50hz into 35v dc 8a without using transister or mosfet

[@donaldhenke2750]

how do i get a 15amp from this buck conveter? please reply.

[@CoolDudeClem]

This is a good video and I don't want to have to critisise here buuuuuuuuuuut ... I don't see how the circuit at 8:28 could work, or at least work well. I know how a buck converter works, but it's the way the mosfet gate is being driven here that is getting at me. Surely like this the gate won't get a good square wave and instead will be more of a ramp wave because of the mosfet gate capacitance, right? And wouldn't that get even worse with more load due to the miller effect? And also, having an n-channel mosfet connected like this, surely the gate voltage could never get high enough to turn the gate fully on so the mosfet will be in it's linear region? Also it's drawn here as a p-channel mosfet where as an IRFZ44N is n-channel.

[@wdujsub7902]

Yes there is a N- channel mosfet and there should have been a P channel just like you said. If you put a N channel like that it will be mostly closed or just very slightly opened. Well the miller effect is really a problem only in case of transistors used as amplifiers, since it changes the input and output impedances slightly and can limit the frequency range of the amplifier, but in case of switching transistors it shouldn´t be a problem. The gate doesn´t get the same square wave as it comes out from arduino, but it is a lot sharper that you might think, to make it ever sharper I would decrease the value of the 10k resistor to maybe 2-3k depending on the datasheet of the bipolar transistor. But because of the approx. 33kHz frequency the mosfet operates on it is low enough to make sharpness of the edges more than sufficient to fully open and close the transistor (at least my oscilloscope says that :) ) hope that helped. if you want to correct me on something please go on :)

[@musabbirsakib6439]

I have some questions, shouldn't be the gorund of arduino connect to the circuit? And why Vin is connected to input voltage? Can arduino stand 12V ?

[@WaltonPete]

Interesting and well thought out video, as usual, with very informative and useful content.

[@ELECTRONOOBS]

Thank you!

[@tacca2747]

I never understood how buck converters work until now. Thank you for a great and simply presented tutorial

[@maotradok3790]

@Electronoobs can you make a tutorial of calculating the parameter of the component of each of the converter? that should help me a lot

[@johnaweiss]

5:47 Unclear. How can an open switch be damaged? 5:59 Unclear. How is current going from supply negative to load positive?

[@d614gakadoug9]

A very fundamental property of an inductor is that you cannot instantaneously change the current through one. When the switch is ON, current flows from the input supply through the inductor. When you turn the switch OFF, the inductor "tries" to make the same current that was flowing just before that continue to flow. The voltage across the inductor will rise to whatever magnitude is required to make that current flow. That voltage could be a few millivolts if there were a low-resistance path or it could be thousands of volts if the only path available were very high resistance. (with practical, real inductors you usually don't get extremely high voltage because there is enough capacitance between the turns of the windings). The very high voltage can easily destroy a semiconductor switch. With a mechanical switch the high voltage would cause an arc across the opening contacts. In order for the current to continue to flow in the same direction in the inductor itself, the voltage across the inductor changes polarity. One way to understand this is to draw a simple circuit with a battery, an inductor and a resistor in series. If you "instantly" replace the battery with a short circuit and keep in mind that the same current continues to flow at that instant, you'll see that the voltage across the inductor must now be the opposite of what it was with the battery in the circuit. In the circuit as it is shown in the video, the diode makes the path that allows the current to continue to flow, transferring the energy stored in the inductor to the capacitor and the load. One thing that helps in understanding how these circuits work is to consider the output capacitor voltage to be constant during any single switch cycle. In reality the capacitor voltage does rise a little bit, but normally the circuit is designed so the rise is very, very small relative to the average voltage on the capacitor when the circuit is operating normally. Of course when you first start the circuit the capacitor voltage is slowly raised over many switching cycles.

[@joprieur7718]

does the voltage and the specs of the MosFet are important or can you choose a random MosFet ? Thank you

[@arunajain4218]

please make a tutorial for DC motor drone! waiting it for a long time ! please make it

[@sporkeh90]

you added another transistor between the pwm and the gate without explaining it. your tutorial is the only one which has it, kinda confusing more than anything else.

[@grahameskate3741]

definately confusing

[@chronny21]

He added the extra transistor as a driver so the supply could operate at higher than 5 volts, as the atmega chips on arduinos can't handle more than that.

[@chandradasabulathsinhala6038]

P-Channel MOSFET DRAIN PIN WITH POSITIVE ? HOW IT WORK ? Please correct .. THANKS...

[@miguelcolon4690]

Excellent!!!!! Liked to know how to change a 40vdc battery trimmer to a wired one. 110vac. A boost switch? How it works?

[@chaddd41]

Great video editing. You're very good at explaining things in a clear, concise manner that isn't too technical, yet still informative.

[@RoyAndrews82]

Couldn't you use a OpAmp for the gate of the MOSFET..? To Regulate the output or charging of the capacitor based on the resistance or discharging of the capacitor?

[@BennyJacksonbj121]

How to increase the current of buck converter

[@John_Smile]

You use the LM2576 circuit. People in China use the LM2596 circuit for the same construction.

[@screen-protector]

I want to build a buck converter with minimum 200W constant power, up to 500W even. I need 24V input and 12-13V output. I'm considering to use a 50Hz +90% efficient toroidal transformer for it. I'm ordering a transformer just now and will post a video about it as well. The goal is to use my 2 x 12V 130Ah deep cycle batteries, to power my workshop. They are in series so 24V, but I need 12V here as I use an old car battery before the inverter which is 12V as well. For now I use one from China to convert, but the power is too small for what I need. If anyone have done such thing, what drivers did you use and which Mosfets, please :). I'll be able to use my 24V PWM 50Hz signal if I'd want for an inverter even ;) later on, and repurpose this buck converter to use in some other room. So, won't be wasted anyway. Before I'll build my 24V inverter, will be a long time though. Now I'm building Electronoobs 12V to 230V pure sine inverter on EGS002. Thank you :).

[@bertbronson8395]

Where the heck am I supposed to get a 100 milihenry (mH) inductor? I HOPE you mean 100uH. I dont think the one in your video is 100mH with that few of turns - but clearly it is high Q given the wire size - I mean trying to buy one from like Mouser is $46 for a 1A and it looks like a small transformer. Also on some of your schematics on your website, you have some of your FETs the wrong way (forward biasing the body diode). That would suck if you hooked it up that way LOL.

[@kreynolds1123]

Consider an electrolisys aplication. The plates and electrolyte form a capacitor. In the begining, the electrolyte is cold and conducts less requiring higher voltage to push current through. Then as the electrolyte warms it becomes less resistive and conducts more current. Annunregulated buck converter dops in voltage with a higher current draw. And with electrolisys, lower voltage end up drawing less current and produces hydrogen more efficently. The current voltage responce us more like a zener diode and resistor than a simple resistor. This loosely uses current to warm up the electrolyte making it more conductive so that it can pull more a little more current at a lower more efficent HHO generating voltage. It loosly self regulates the current without feedback circuitry. An adjusable pwm circuit can may be more interested in lowing the duty cycle with feedback from a temperature sensor to further regulate how much current goes through the cell by lowering the outut voltage further, thus controlling the watts consumed by the HHO cell and further improve efficency.

[@easyki84]

Why is the diode in parallel? Shouldn't it be in series to the coil?

[@SaliyaRuchiranga]

how to choose or wind the inductor ? , waiting for boost and buck-boost converter videos !

[@jugalmistry1726]

Saliya Ruchiranga Use a ferrite core to wound a simple wire on it and then measure it using LCR meter.

[@familyjiang6997]

Hello, maybe I still make something wrong. There is a schematic at 8:28. You use IRFZ44N. It's an N-Channel, but you use a P-Channel symbol. Another is the value of L and C. The value of L can not be compatible with 100UF E-Cap.

[@MathewPanicker1010]

You're correct, it should be a ptype mosfet. An ntype wouldn't work here.

[@rfly-fpv]

11:10 Can we add supercapacitor "tank" (like 500 F) at the end terminals to smooth the ripples?

[@jamest.5001]

So it's the mosfet, inductor, and voltage divider feedback, that seta the current potential. I need a buck boost that can take 14-36v and output a cc cv, 29v adjustable, from 27-29.4v, but here is the kicker, I need about 150amps, the LTC4000, or LTC4020 will help do what I need, but I'm self taught, and z bad teacher, this is a bit beyond me, I could possibly build what I need some day, but it's the time!! I do not have the time, I am looking for some help, someone who could help get the PCB made, and figure the components, and basically give me instructions, I can solder, and been playing around with components, trying to learn. I should have gotten into this when i was younger. It's difficult teaching old dogs, I need a affordable lithium charger, I can power with a alternator, it can do about 28v if you are interested I could compensate, for your time, and it could be a video, thanks either way!!

[@justdoingodswork]

12:12 I didn't get where does the pwm signal i.e. GATE for LM2576 goes? How we control the output voltage, is it the ON/OFF pin, cause it seems like going to ground and I'm confused Please help...

[@barbasbandas6665]

Great videos as always. But I would suggest changing the background music. It sounds like baby music... Thanks!

[@ahmedhisham5034]

hello, i tried to use the mentioned P-most but the voltage at the input was almost the voltage at the output, when i tried connecting a nmosfet the 20n06 the voltage was ranging rougly from 1->5 volts when the input was about 10-11 volts any idea why?

[@musabbirsakib6439]

Hi, did you find any solution of your problem? I am trying to make a buck converter , your suggestion could be helpful for me.

[@next8226]

hi I love your video can you please tell me how you make that cartoon animation and which software do you use for that

[@thomastrautenberger3826]

Will the in4001 diode not explode because it has a too large recovery time in front of 31kHz signal ?? See schematic 9:45 in the video.

[@ibrahimabubakr2227]

great video, for me you explain it basically better than all those academic videos, if only you can explain more related to the higher power systems, liek inverters for EV it will be great

[@DrScanlon]

This is one of the best explanations of a buck converter that I've seen. Simple and to the point.

[@AliG.G]

why do you have bjt and mosfet? why not connect mosfets gate directly to pwm pin?

[@ELECTRONOOBS]

The bjt is for the Arduino circuit only. Arduino works at 5V. I wnat max current for the mosfet. To drive the mosfet at 12V I use a bjt. Keep up!

[@artbyrobot1]

yeah some mosfets gates have a minimum voltage required to turn them on that is higher than the 5 volts an arduino pwm pin can manage to put out. For this you need a separate power source that is high enough to match that gate threshhold voltage - a lot of power n-channel mosfets have a gate threshhold voltage of 20 volts. You need the arduino to control another mosfet that turns on from only 5v and that mosfet will turn on the power supply to the big power mosfet which will turn the big power mosfet on. So you need that middle man mosfet to make things work.

[@musabbirsakib6439]

At 8:28 In the arduino circuit, Shouldn't be the ground of arduino connect to the circuit? And the value of inductor is 100 mili henry. Should not it be 100 micro henry?

[@torresyoreparo]

ENG: Fake or true? In the diagram circuit to video, I see irfz44 symbol mosfet CH P... Its'n Chanel P.. It is Chanel N 🤔 Sorry for my English 😂 ESP: Verdadero o chamuyo? En el diagrama de circuito del vídeo, veo que el irfz44N figura con la simbología de un canal P... Este mosfet es canal N

[@sssserya1]

IRFZ44N is an N channel transistor you need P channel

[@ELECTRONOOBS]

True!

[@wdujsub7902]

i think it would work just fine if you would put an N channel close to ground

[@amanprasad6221]

P channel have 10 times higher resistance w.r.t. n channel So n channel is efficient (S-D resistance)

[@jakenbaked87]

When is the best time to use an optocoupler for feedback? How do you get around frequency limitations for high frequency optocouplers?

[@robertmckelvey3091]

What would I use if I wanted to lower 40v to 36v or 12v

[@tchubang]

Ummm sir what if we want to make this for higher current like 12 Amps output at 5 volt... How can we make that ?

[@powapumas38FTW]

Hi! This video has been very usefull for me but i've got one question. How can i control an lm 2577 (or a xl4016 in my case) with Arduino? I'm trying to control it with Arduino by sending an PWM signal directly to the feedback pin but it won't work... Can you help me? Edit: At the moment i've removed the potentiometer and inserted the Arduino pin in series with an 360Ohm resistance connected to the ground the feedback pin is connected between the arduino pin and resistance.

[@artbyrobot1]

the feedback is supposed to come from the voltage divider, not an arduino. The point of feedback is for the IC to know what the varying output voltage is at any given moment. The arduino doesn't know that info.

[@toniljones_Graphite]

I've watched a bunch of videos to get a grasp of this concept. Yours did the trick Thank you sir!

[@aydnknal2049]

Do you help me , ı can't this in proteus , how can ı make dc dc buck converter in proteus with feedback

[@zahidfaheem3233]

I just noticed in the diagram that the emitter of the bjt is not connected to the ground of arduino (since arduino gnd is not connected to input gnd) so how does any current flow to turn the bjt on?

[@protonspeed]

Can anyone explain how pwm is set without changing TCCR2A register ?

[@siddhat7802]

How did you calculate the inductor and capacitor values. Also, what factors did you take into consideration while calculating those values? Finally, how did you select the switching frequency to turn on and off the Mosfet?

[@abdohajar908]

+Electronoobs bro why didn't you ground the arduino together with the negative terminal of the circuit

[@musabbirsakib6439]

I think he forgot it in the schematic. In the main breadboard circuit he connected the ground

[@RoyAndrews82]

The inductor has a current charge rate.. The capacitor has voltage charge rate.. Together, if you know how to sense voltage discharging edge triggering, you can choose when to charge the cap n inductor.

[@steinlfromthebronx7372]

Can you make a video about mmpt in this converter using arduino uno, please🙏

[@Yash_Verma5]

Hi i want to make 48 volts to 12 volts 10amps buck converter please me

[@zenithedianel6250]

just like GREAT SCOTT, intro. and Channel name quite similar to ELECTROBOOM 💥💥💥

[@pedroramirez5905]

F* off

[@swedensy]

I checked your homepage too. If you really understand this why not make 50A current buck?

[@ELECTRONOOBS]

That would be easy. But you would need a huge heat dissipator on he MOSFETs to keep it cool. Maybe even a cooling fan!

[@bassome3000ify]

i used to say to others, their videos are the best in explaining, now i found new best explain-er videos :P really cool, helps all beginners, even pros new to the application topic. thanks!!!

[@John_Smile]

I watched your video. Thanks for the lesson of making a voltage source by conversion. If you have the necessary knowledge, please help me to build a voltage source with adjustable voltage and current. I would like the sura to operate with a voltage higher than 40 V and a current higher than 5 A. I opened a topic here on a forum, where I also asked for help. forum.softpedia.com/topic/1180747-tensiune-variabila-cu-curent-variabil-0-50-v%3B-0-10-a/page__st__72#entry27381050 I will also post your video on this forum, because I find it useful. I still have to find the possibility to adjust the output current. With adjustable tension, I found the answer in your clip. I tried to make the source with LM 317. But at this integrated I am limited to the voltage of 32 V.

[@DavideBaccolini]

Good. But why the disturbing background music?

[@EXMattix]

Its sensing the voltage not the ampere on feedback

[@Mateo-vl3zv]

Well 3 hours later and i burned my arduino Not even mad Fffffffffuuuuucccccckkkkkk!!!!!!

[@hansdegroot652]

Hi. very nice video. But how can i make a 15 amp buck converter that can handle 60 volts. It seems when the voltage gets too hight the gate / source voltage gets too big this way? And how can I supply the arduino with power from same source we try to buck down? Als these tutorails make it look so simple but somehow it never fit my needs. For my solar shed and e-moped batteries I need 40 and 54 volt projects.

[@AndrewTuboro]

i wonder what is the purpose of using a BJT transistor as as Driver of another transistor (mosfet)

[@d614gakadoug9]

In that circuit he's using the input power source to drive the gate through a pull-up resistor (which is a very poor way to do it in a real converter but it's OK for demonstration purposes). The input supply can go up to 12 volts. The BJT is actually used to turn the FET off. It is necessary because an Adruino output can't handle 12 volts.

[@hengliu7498]

Hi, your Arduino in the circuit diagram at 8:28 is not powered (GND not connected). Could you please explain how did you do that other than connect the USB? Thank you. Nice video overall.

[@Berghiker]

Do you have a simple buck converter circuit that steps up 1.5V to about 152V at 1A max? It must function just like a power supply.

[@TheJavaSync]

Great, but it is pretty hard to find LM2576 - please make it with UC3842 cheap & easy to find it - thank You :)

[@md.razonchowdhury3256]

Dear, In buck converter the capacitor current is both positive and negative. So should we use a polar or non polar capacitor?

[@d614gakadoug9]

The capacitor _current_ is both positive and negative, but the voltage across the capacitor is always positive. You would only need a non-polar cap if the voltage across it changed polarity.

[@garethronaldo8692]

Yes Yes yes videos like this we need take a hug like from your old friend "(me)"

[@andreapiccini23]

Capacitors in LDO are not for reject noise, they're for stability of the circuit!!!!!!!!!!!

[@d614gakadoug9]

Yup. Some LDO linear regulators are quite sensitive to the characteristics of the output capacitor. The ESR of the capacitor can be neither too low nor too high or the circuit will be unstable Newer LDO ICs generally will tolerate very low ESR so you can safely use monolitic ceramic capacitors.

[@omsingharjit]

Arduino for Bug con PWM isn't Pocket Efficient , But i Know is only for Education .

[@abdullahalrazi3491]

Brother please make a full circuit of desire constant voltage and constant current output at the same time.. in a same circuit.. without Arduino.. just like SMPS.. please it will be helpful for my electronic project.

[@thomassorensen7907]

Hi I the video where you explain the feedback a P-channel mosfet is shown. But should the source not be connected to the input? Otherwise the body diode of the FET will make it conduct always.

[@pault6533]

I did! I did learn something! - Another Mechanical Engineer stopping by!

[@psikodelriot6754]

Very great expainations about circuits and high understanable.Especially, that you explain, why is every part where it is an what does it do there. Glad to learn from you. Thx and greatings from Germany!!

[@Tommybotham]

I really appreciate your video. So many idiots on the internet explaining buck converters and feedbacks in such a confusing way. Yes you can just buy the LMxxxx, but I love the way you explain the DIY version, so that using an LMxxxx is just another step up. Very nice.

[@usmanriaz94]

Can anybody explain what is the effect of changing the output LOAD on voltage divider feedback value ?

[@azenarnoriv403]

Frnd tnx for the informative video, i understand it well but i have a few questions. I made one of the buck converters using potentiometer. I can adjust the voltage up and down but i observed that the current output of the circuit is low. I used it to charge a mobile phone but its difficult for it to charge because the amps is low. What do i have to do my frnd to increase it? Thnx my frnd again.

[@artbyrobot1]

I think you need to increase the pwm frequency in your code with shorter off times to maximize amp flow

[@azenarnoriv403]

@@artbyrobot1 ok tnx my frnd, so do i have to increase also the windings of the inductor?

[@azenarnoriv403]

I observed that the voltage is also increasing as i ncrease the pwm. What happens my frnd if i try to increase the switching frequency? Tnx my frnd

[@musabbirsakib6439]

@@azenarnoriv403 what inductor value you use?

[@azenarnoriv403]

@@musabbirsakib6439 i don't know because its hard to find 100mh inductor in electronic shops here. So i just use a choke filter with 50 or 30 maybe windings on it. But the numbers indicated on the choke is 1R1A852A 0BK.

[@gregorykafanelis5093]

I wish the best to you. This was beyond helpful

[@marcus_w0]

Very nice explaination. Imho your best Video so far - you're getting better and better.

[@Dc_tech386]

Can the Ic drive mosfet for bigger load

[@MrZiolelle]

Hi great compliments!!! Great tutorials !!! Only one question... in the schematics you list in the comments: www.electronoobs.com/images/Circuitos/tut_10/Schematic_NO_feedback.png www.electronoobs.com/images/Circuitos/tut_10/Schematic_feedback.png I think you put the P-Mosfet in the wrong way, shouldn't the P-Mosfet have the Source Pin connected to the Input Voltage? also because in that way the body diode would always conduct... Am I wrong ?

[@remeshk6275]

Please share 110 v DC to 48v DC Circuit

[@TechnoEveryday]

Awesome tutorial

[@zahidkopu9220]

Did you use a 100 uH inductor or 100mH ? In your parts list it was 150uH. I tried the ckt using IRF9540 mosfet, BC547 NPN transistor and I used 10uH inductor .. but it didn't work. What should I do now?

[@ELECTRONOOBS]

Hi. You have 4 schematics in the description of the video each with different values. Check those out!

[@zahidkopu9220]

I added map function in the code.Now the ckt works

[@musabbirsakib6439]

@@zahidkopu9220 What inductor value you use?

[@musabbirsakib6439]

@@ELECTRONOOBS could you please assure me that at 8:29 you used 100 mili henry or 100 micro henry inductor

[@tiagorocha4]

Can you please tell me what was the inductor you have specifically used in that project?

[@wdujsub7902]

Your video quality is outstanding! Great videos, keep up the good work :)

[@TrentSterling]

Whoa, top notch video editing on this! Your channel is really picking up. I was already subbed, but this video made me turn on that bell!

[@ELECTRONOOBS]

Thank you very much!

[@doaaesam9656]

why are you use this function " constrain() " in the program for Buck converter - FEEDBACK?

[@omarmajdalawi6966]

Thank you for this explanation , but i wonder if the input voltage 20 volt what is the value of inductor and capacitor will be ? could you help me

[@sonyolcu23]

He says check out the web site.

[@tomgeorge3726]

Hi, a schottky diode is used because it is a high speed switching diode, compared with a 1N4001 series diode. High speed because of the switching speed of the converter output.

[@ronaldleon6952]

what sort of current are we dealing with here?

[@shreyaskumar5366]

Sir but you are having the ADJ version of the LM2576 IC and not the HV-ADJ version So how can you apply 55 volts according to the schematic??

[@steinlfromthebronx7372]

Hii please check out your email❤️

[@Saimoun82]

You're a great teacher!! Very clear :D Thank you!

[@anonymous39400]

There is no common Ground between Arduino and the circuit. Is it weird??? Could you explain how to choose a value for inductor and capacitor?

[@anukeshambatkar6255]

Sir can you please make a tutorial on how to make toroid from basics

[@superproxy3782]

What is the current of the input voltage to power on a buck converter? Is +32V, 720mA DC or +16V, 610mA DC will work as my input voltage to power on a buck converter?

[@2020SENn]

Best explanation👌🏻👌🏻

[@RohanKumar-iz3cr]

Can we use inductor of like 100 uH ? What about the allowed current?

[@erikderuiter7475]

Wow... Your explanation is so good! Exceptional... I'm learning about power supplies for Nixie tubes and your information is invaluable. I only wonder about safety of for example a NE555 based PS. Dedicated IC's have protection circuitry but I read that the often used Maxim 1771 has a poor design because the gate of the Mosfet is pulled to ground by a resistor: quote "a substantiol amount of power is wasted in the FET" But I need to look into that much more... I want a safe PS so I can leave a home made HV PS safely on 24/7.

[@BICIeCOMPUTERconGabriele]

Thank you very much, your video is super well taught and finally I understood how these circuit work!