DC-DC Boost converter tutorial

How boost converters work and how to build a 50W adjustable boost converter circuit.
Want more videos like this? Visit www.afrotechmod...
Parts list:
LT1370HV:
octopart.com/lt...
Electrolytic capacitors:
octopart.com/ee...
Input and output ceramic caps:
octopart.com/pa...
Schottky diode:
octopart.com/st...
10uH inductor:
octopart.com/ai...
Potentiometer:
octopart.com/p0...
Heatsink:
octopart.com/57...
Schematic:
i.imgur.com/RU...
Control loop compensation information:
goo.gl/zxJ9MT
goo.gl/aD8mqF
goo.gl/Z9Oho8

[@Afrotechmods]

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[@jimschiltz5343]

I purchased (and watched) your Wireless course on Udemy (I have been using them for years!). Thanks, its a nice little explanation and demonstration of Wireless Charging - 5 Stars!

[@carmichaelmoritz8662]

i'm trying to figure out a simple inline way to make a 48 volt automatic battery charger kick out at 50 volts instead of 59 volts . i dont want to have to take the unit apart and change a resistor and in the process maybe burn something out.

[@iDahl]

You sir have the best tutorial voice I've ever come across.

[@Afrotechmods]

***** Why thank you sir

[@Flankymanga]

+Afrotechmods I could watch your videos all day and i would never get bored! You should become a college professor...

[@xgenesys]

English isn't my mother tongue, but you are speaking so clearly that I can understand everything really easily. Great job mate !

[@HA7DN]

Magyar vagy?

[@fb5601]

And this is a great way to learn English

[@iListRealEstate]

"Don't do dat." wise words from a wise man.

[@Fedetk]

You'd better take the advice when it comes from a cyborg from the future.

[@laharl2k]

i built a 12 to 375V boost converter with a MC34006 and a few components from a few dead compact fluorescent lamp. Best thing ever. got 2,2W out of it. Electrocutes a cockroach easily (empirical data). I added a type A amp made with the same shitty high voltage transistors and got about 175vrms sinusoidal using my siggen. got myself an electro massager. AC feels good :P

[@Mavish11]

Plz build me one :)

[@laharl2k]

Sergio Perez nah, now i'm looking at making a 20KV+ one. Got a few flyback transformers around and was wondering what i could use them for :D If i can get the resin and the HV caps, resistors and diodes then maybe 50KV max is a good start.

[@akkudakkupl]

MC34006 is that a dual op amp? Can't find it's datasheet... So what are you running it as, a comparator? Comparing the reference to the feedback output?

[@laharl2k]

akkudakkupl it's a dc-dc controller, with current sensing. 8pin dip, internal reference. a pretty generic and universal solution. Its design is a bit convoluted but after you do the math it works relatively close to what it said. here's the datasheet www.alldatasheet.com/datasheet-pdf/pdf/12065/ONSEMI/MC34063A.html

[@akkudakkupl]

Laharl Krichevskoy Thanks mate. Probably just what I needed ;-)

[@NNNILabs]

You inspired me to become an electronics hobbyist, and a year later I have 130+ subscribers! Thank You!

[@wilsonfranciscobrito2817]

I'm learning More from your videos that my University Teachers! Thanks a lot!!!

[@daemoncan2364]

Great tutorials. Good pacing. Concise & clear explanations, with occasional humor thrown in for good measure. Well done.

[@deathdragon6660]

I always watch these videos but I never really understand it XD but it make me feel smart i guess :D.

[@TBL_stevennelson]

Feeling smart is part of the Learning process. Once you decide on a project, You'll start to remember stuff from videos that you might want to try. Its also fun to practice.

[@grassulo]

I like how you pointed out the shock hazard of these things, they really can give you a nasty bite if you aren't careful, same with any switch-mode power supply. At least it's not a CRT flyback or HID light ballast, those hurt when they bite...a lot.

[@power-max]

Once time I found a small 8 pin DIP package boost converter and I wired it up according to a schematic on the original datasheet for the part, but accidentally used a 4.7k ohm resistor instead of a 470 ohm one for the feedback, and I ended up with nearly 80V on the output; my electrolytic popped and then the chip let out the magic smoke! LOL, Oops! (BTW the absolute maximum rating was 40V output)

[@ChargedPulsar]

This video ended for me when it started using a professional IC for boost converter.

[@revealingfacts4all]

Excellent videos. If love how your videos get right to the point and dispense with the bla bla bla I see in other, similar, videos. Your material is current and the coverage is very thorough in an easy to follow format. Keep 'em coming.

[@Vsor]

I'm not understanding one part of this video. Why does the current from the inductor cause the voltage to rise? I understand the part about inductors not wanting to change current quickly, but I thought current couldnt induce voltage.

[@RC_Engineering]

It causes voltage by forcing current into the capacitor. Charge entering the capacitor causes an increase in voltage.

[@Vsor]

Ryan C. Engineering So without a cap, the voltage would not increase?

[@RC_Engineering]

Prometheus It is hard for me to visualize exactly what would happen. But I will give it a shot. When the switch is closed, current will build up, and when it opens, it will be forced through whatever load was connected (this will produce whatever voltage is necessary to maintain that current). This means indeed the voltage will increase, but it will also decay with time. The capacitor smooths that voltage ripple by absorbing the ripply current and due to it maintaining a nearly constant voltage, will output a nearly constant current to the load. What you should understand though is that voltage is electrical pressure, so any time an inductor tries to force current through a resistance, it causes a "pressure" or voltage. The capacitor in this analogy would be like a holding tank, whichis large enough that its pressure stays relatively steady.

[@santiagopicco1397]

If you dont have the capacitor, the voltate would but hundreds of volts. Inductors are used to create sparks. In cars, a current flows throw a coil, and suddenly opens. The inductor oposes the change in current generating hundreds or thousands of volts and finally release the energy through a spark.

[@LucasHartmann]

The textbook equation for voltage gain is valid for continuous conduction mode, or HIGH CURRENTS, as long as they respect the circuit's limits. Low currents will cause the output voltage to rise above that equation.

[@Arhentir]

Congratz! You earn 80 plus silver(%85) efficiency certification :D

[@viralinyoutube4727]

// connect motor controller pins to Arduino digital pins // motor one int enA = 10; int in1 = 9; int in2 = 8; // motor two int enB = 5; int in3 = 7; int in4 = 6; void setup() { // set all the motor control pins to outputs pinMode(enA, OUTPUT); pinMode(enB, OUTPUT); pinMode(in1, OUTPUT); pinMode(in2, OUTPUT); pinMode(in3, OUTPUT); pinMode(in4, OUTPUT); } void demoOne() { // this function will run the motors in both directions at a fixed speed // turn on motor A digitalWrite(in1, HIGH); digitalWrite(in2, LOW); // set speed to 200 out of possible range 0~255 analogWrite(enA, 200); // turn on motor B digitalWrite(in3, HIGH); digitalWrite(in4, LOW); // set speed to 200 out of possible range 0~255 analogWrite(enB, 200); delay(2000); // now change motor directions digitalWrite(in1, LOW); digitalWrite(in2, HIGH); digitalWrite(in3, LOW); digitalWrite(in4, HIGH); delay(2000); // now turn off motors digitalWrite(in1, LOW); digitalWrite(in2, LOW); digitalWrite(in3, LOW); digitalWrite(in4, LOW); } void demoTwo() { // this function will run the motors across the range of possible speeds // note that maximum speed is determined by the motor itself and the operating voltage // the PWM values sent by analogWrite() are fractions of the maximum speed possible // by your hardware // turn on motors digitalWrite(in1, LOW); digitalWrite(in2, HIGH); digitalWrite(in3, LOW); digitalWrite(in4, HIGH); // accelerate from zero to maximum speed for (int i = 0; i < 256; i++) { analogWrite(enA, i); analogWrite(enB, i); delay(20); } // decelerate from maximum speed to zero for (int i = 255; i >= 0; --i) { analogWrite(enA, i); analogWrite(enB, i); delay(20); } // now turn off motors digitalWrite(in1, LOW); digitalWrite(in2, LOW); digitalWrite(in3, LOW); digitalWrite(in4, LOW); } void loop() { demoOne(); delay(1000); demoTwo(); delay(1000);

[@JustinAlexanderBell]

What's with the safety warning for 30V DC. I'd be more concerned about burns from the heatsink.

[@power-max]

I think he said (or meant) that he limited the output to 30V, and that these can go a lot higher. I have seen designs that can boost up to tens of kilovolts!!!

[@JustinAlexanderBell]

This chip can only go up to 37V

[@Vsor]

Justin Bell obviously if you wanted to go into kilovolts, you wwouldn't use that chip. There are many options and the chip isn't even really necessary.

[@power-max]

the data you see on the datasheet is for a certain configuration. If you use a different configuration with say, a external IRFP450 MOSFET and the feedback though a large resistor divider, the chip would only see 1.25V at the feedback, and it has no way to 'see' the output voltage. It is the feedback resistor divisor network that determines the output voltage. I know from experience it is very easy to confuse say, a 470 ohm resistor with a 4.7K, and that could be the difference between 24V output and a 240V output. Especally if the components used can handle those voltages! I often use 100uF photoflash capacitors for filtering due to there large physical size and consequentially low(ish) ESR, But usually only because I cant find a similar capacitance. You can see how things can get ugly fast!

[@power-max]

I would know because I made this mistake once, and had 80V output using a simple configuration with the internal switching element. The Absolute maximum rating was 40V.

[@molozakos4084]

nice nice .......... well done and thankou my frend . give us knolege xexe.. sorry for my bud english

[@VictorRivarola007]

The way you explain how this works is extremely good. You can make a SMPS DC->DC fixed voltage converter like you showed us here. However, you should also be able to use one of those to build a constant current SMPS? Can you show us how to do this for all SMPS types (step up, step down, step up/down, flyback, etc)? Thank you!

[@Coolgiy67]

I bought 3 boost converters from China for 10$ and it says it steps up voltage to 400kV which I believe it cause I made a taser out of it. Sparks through air from so far away

[@igrewold]

guys please help me. Can someone supply me with generic dc-dc boost IC numbers? I cant find these in my area. Thanx in advance.

[@imbored7779]

2:41 "We need a controller chip" This is where the project instantly gets too complicated for me :(

[@hansdietrich83]

Clorox Bleach closed minded much? You wont get anywhere in electronics like that

[@mc-ec3bu]

And expensive £20. odd.

[@kalyngriffin1771]

Start taking broken electronics apart and desolder all the components. Build up a good collection of random circuit boards (power supplies have good stuff in them). The key to learning electrical circuits is having the right parts at hand. You would be surprised what you can put together when you have all the parts right in front of you

[@yfs9035]

Most chips are easy to work with. Give it a go!

[@adnanahmadknowledgevideo]

*With Great Power Electronics Comes Great Responsibility* 💪

[@power-max]

If you want to use a water analogy, you could use the concept of a RAM pump!

[@chanakyasinha8046]

When you need to beat bmw 1000rr with your moped to impress your crush ,you feed clutch sytem with pwm signal 😂

[@j5892000]

Because of this video I spotted a fake lol. Guy is boosting 12 volts up 24 volts with a 12 volt laptop battery chargers. Claims the current output of the battery charger is 5 amps... hes also running a large motor. I think the voltage is either dropping alot on the output and current is rising... alot.. lol but 5 amps is going to cut it with what he has on the load lol

[@mrsemifixit]

Isn’t current flowing through the inductor even with the switch open? Does it just build a stronger field when it’s the only thing flowing current to ground?

[@surgingcircuits6955]

I bought a Raspberry Pi 3 pi-topCEED that requires a power input of 18V@1A - (actual measured load was around ~800mV, but it could call for a bit more at times, e.g. if something is plugged into a Pi USB port). Want the option to power it out in the wild from a 20k mAh battery pack (USB) that can supply 5V@2A from up to 2 ports (4.2A max pack total). 1A x 18V = 18W ~~~ 18W / 5V = 3.6A So now the crazy idea part… (keeping in mind that this/your design was for boosting to 14Vout max) Q1) Would this project build be stable enough to support and drive something as sensitive as a Raspberry Pi board? -- If yes, … -- Q2) If I built 2 boosters, set both at 5Vin-->9Vout, and connected the outputs in series (now 18Vout, with more than enough current), would it work? Or, would I just end up with Pi on my face? (sorry) Feel free to embarrass me with a better solution. Cheers.

[@dh66]

Would these switching boost converters at 500 kHz (or 72 kHz) cause a lot of noise that would affect nearby analog audio circuits? What about the inductor? How would I design a circuit to match LT1111CN8-PBF? Would a 120 kHz IC be better than a lower frequency IC like I mentioned?

[@Landotter1]

I am looking to build a boost converter to boost 12/24V to 300V to power 12ax7 preamp tubes with a small transformer i can get at radio trash. Using a 555 or 556 timer is fine. Output current is unknown but .5 amps is probably right. would like switching freq to be 40Khz and above, well out of the human ear range and also gentle on animals. Any ideas or links you could point me to, would be highly appreciated. Thanks in advance! otter

[@ady0187]

Just love your channel man its the best!I built a boost conv. 12v-15v 3A for laptop backup power based on mc34063 with output mosfet,and i don't know which inductor to use,i tried some but either the components heats up(shotky diode/coil/mosfet) here is the crkt 320volt.com/en/mc34063-12v-15v-dc-dc-konvertor/ tnks,keep it up

[@j5892000]

I've seen videos were people make a boost converter and use an inductors with a secondary coil to oscillate which I guess open and closeses the gate boosting the voltage . Is that something that can be done?

[@gweliver]

The link for the input and output ceramic caps says page can not be found? I'm a newbie so I am not yet at a place to be able to figure out from the schematic what size I actually, (10uF)? I ordered everything thru the links you provided, and do not want to stray from what you recommend in order to have the best chance for a project that works, this will lessen all the variables I have control over? I have some ceramic caps from other projects but want to make sure I'm using the correct size. Question: Can I use a 470 uF 200V cap in place of a 50V?

[@AliMirjamali]

So we could adjust output to whatever we want (00:19). Let's create a Tesla coil. Oh no better, Thunder and lightning :-P Just kidding. Excellent series. We are really happy you are back.

[@divern]

Hi, hope someone here can answer my question. My analog audio processing device has dc-dc step up converter with output of 18v. It can except anything from 9 to 18v. Does converting still happens If I feed the unit with max 18v or it only pass dc current to output? Thanks

[@DanielSmedegaardBuus]

Has anyone tried those step up modules you can buy on a certain Chinese website for less than a dollar? I'd like to get more 12V pixies from a 22A 5V rail on a PSU. I need to feed 4x 2A 12V to power up four HDDs for a few seconds, after that the current draw drops significantly. Instead of having one, beefy converter that can handle a lot of watts, can you just put several smaller ones like the Chinese ones in parallel on a single power source or will they interfere with each other?

[@DanielSmedegaardBuus]

Has anyone tried those step up modules you can buy on a certain Chinese website for less than a dollar? I'd like to get more 12V pixies from a 22A 5V rail on a PSU. I need to feed 4x 2A 12V to power up four HDDs for a few seconds, after that the current draw drops significantly. Instead of having one, beefy converter that can handle a lot of watts, can you just put several smaller ones like the Chinese ones in parallel on a single power source or will they interfere with each other?

a guy has made an induction coil winding to the primary and is using it like that

[@cameraman1234567890]

Is it true for buck converters to increase the output current by dropping the voltage? Are they opposite of each other? I have a solar panel that outputs 19.4 volts that outputs 3.1 amps, I wish to drop that voltage to roughly 13 volts, but I wish for it to be able to supply more current on the output just like a MPPT Controller, would this be possible?

[@zetnakatel]

What will happen when your power requirement will be higher than input ? For ex I want to power LED, which need 30V and 1A, from a powerbank, 5V and 1A.. So power bank can give 15W, and we need 30W. It will not work. It can only give 30V on 0.5A. But what will happen to power bank when you get over 15W, it will burn ?

[@SianaGearz]

You are correct, it will not work very well. It's hard to say what will happen. A well designed, safe voltage source should contain over-current/under-voltage protection, which can be combined. I.e. as the current limit is reached, the voltage starts buckling; however then, if the consumer is a boost or buck converter, it will keep drawing more current, creating a dangerous situation where all elements and wires are emitting even more heat. Then the safety circuit should detect voltage being below the limit (e.g. 4.5V at the output, although really it will be measuring a different voltage at the battery) and disconnect the battery, and wait for recovery conditions to be met. Power banks, and actually all kinds of cheap electronics, are not usually designed with sufficient protection. If they are based on Lithium-Ion Polymer Pouch battery, there may be a fire. If they are based on a cylindrical Lithium Ion cell, the cell itself should usually contain two security devices which will disable the battery permanently by detaching its positive terminal if there's a heat buildup or gas expulsion. Of course with cheap cells that don't come from major manufacturers, you can't rely on those security devices either.

[@shriharimadhav]

Afrotechmods please can u make a explanatory video on all sorts of current and voltage sources..(dependent independent practical ideal)??.....they are kind of a mess to understand...can u pls???

[@TheIlook1]

Can this type of circuit make a small electric brush-less motor spin faster? I'm trying to make a hovercraft thrust propeller spin faster but I'm limited to either 9 or 18v (two 9v batteries). I think I'm correct that when I boost the voltage, the current decreases? Is there a way to do what I want with light weight electronics?

[@Unknown-mn1ui]

Hi Sir, can I ask a question, why you add a resistor to your dc dc boost converter? What is the use of it? And I am your new Subscriber. Thank you, and pls answer.

[@lucheeket5431]

Higher efficiency, better phase perhaps and more elegant concept as compared to transformer-transistor-diodes, particularly for wanted D.C. output.

[@sdarquea2]

This tutorial is good as a supplement but for a more comprehensive understanding read/scour this article from TI. You will most likely never understand the operation of an SMPS without also busting out a pencil and paper to draw the circuit in its different states, write out (and better yet derive) the equations and practice some different values. www.ti.com/lit/an/slva061/slva061.pdf

[@diy-speaker]

Great video. Does anyone know appropriate solution for guitar preamp? I'm searching for boost converter from 12-18v@1.2A DC to 400V@20ma DC.

[@billmanhillman]

Thumb in butt, plus finger in socket equals about 400V@20ma. Am I right? 🤣

[@kristensalve1462]

I was looking for dc to dc boost converter but couldnt find powerful enough converter to boost 24v to 36v with 60A output, is there a way to build power converter powerful enough to do so? or is it possible to connect multiple power converters in parallel? to achive high enough power output?

[@jukkapekkaylitalo]

So i have 20V Input and same input should also be 30V output from battery. I need to step up 20 V to 30V so that i can charge my battery to full. Same time i don't want to blow up my step up converter. So can i connect step up converters output to it's input or do i need to make somekind of circuit.

[@jeffbeck6501]

I learned how to calculate efficiency. Input watts/Output watts. duh. Kind of obvious, but it helps make it clear.

[@dylanbutler4449]

I would like to convert a 4.5V 1.5W solar panel to a 5v output with 500ma output to charge a phone? I want to use a 555 ic to accomplish this can anyone help?

[@alexjordan3174]

is this ok if i have an unstable power source like pedaling a bicycle connected to an alternator? since my rpm value for the alternator is not high enough, due to the limitation of my bike, because it gives me at most 10volts(not constant due to the speed of the pedaling of the bike...)...should i use this booster circuit in the video?

[@itube612]

May I ask how exactly is the power knob called? Btw, awesome video and channel, I personally find it very helpful and educational.

[@Afrotechmods]

It is called a potentiometer

[@itube612]

Afrotechmods Thank you. And again, thank you for your amazing work.

[@Berghiker]

If I use 6V, 7amp battery, will I be able to draw more current on the output at 30V? And is the variable resistor on the output to adjust the voltage output?

[@mehdi76302]

Hi sir, i cant find the LT1370 in my country, can you please tell me different one that would work with this schematic?

[@anwarigroup]

I like when "ARNOLD" speaks like " Don't do that"

[@testface1828]

Im trying to make a 1.5 to 3v booster. Any changes i would need to make to the components. obviously the values depending on my maths but can i still do it with same mofset

[@piuselectronics5707]

your tutorial is very good. I tried mine it boosted 3v to 12v using a 100uH inductors but I got lower ampere than that of my input current. My input current was 0.6amps and I got 0.01 at the output. Pls help

[@cenexes12]

what if you wanted to take say 14 volt and step it up to 348 volts like the dc current coming from a 370 amp Mechman alternator ? I ask cause I would like to be able to use the dc current from the alternator to run an ac motor from a rinehart ac motor controller

[@crossbones911]

I want to build all this cool stuff but I also don't want to die. Guess I'll just keep reading and taking notes until I'm positive I won't do something stupid that'll get me hurt.

[@bp968]

Do you have some suggestions on a (cheap) design for producing VFD and/or nixie level voltages? Actually the one I really want to make is something that can produce the 600ish volts needed for an old argon dekatron I have! Great video btw, love the channel!

[@killzonemaster77]

if i used a 9 volt battery connected to an inverter so that the current becomes AC, then connected that to a boost converter, how many volts, amps and wattage would i be getting on the output? how would the inverter affect the current ( what voltage would i get between the inverter and the booster) then with that, what would my final output be?

[@BibendiYT]

I know this sounds like a really stupid question but I don't understand what the trade off for inputting a low voltage and getting a higher voltage in return?

[@seaham3d695]

Subbed! Great video just what I need, Ill be watching this 100 times until it sinks in :)

[@pappupappu7342]

Can i use 3.7 v battery for it i well convert the output hie voltage i convert it my lm 7805 to 5 v for i can use as a power bank

[@candrasniper3404]

Is there a way to reduce current on input, but the current output is not being reduced too? Or maybe input current as same as output current. I just need the raising voltage, not the raising current consumption.

[@brighterpressltd5049]

Please l have a mini generator that generates up to 50v and I want to use this circuit on it so it can power my refrigerator, can this circuit work for the purpose ?

[@guidir0.1]

I have a UPS that works with 72V batteries, I would use it for my solar installation with a 12V battery, how to do??

[@edwardfletcher7790]

AliExpress sells a lot of these modules very cheap, they're incredibly handy !

[@lucheeket5431]

In term of actual application, this is a better circuit. The thing is we need another pulse rather than automatically attached.

[@tonypachino4535]

i'm new in those stuff, can you explain me why is boost converter so much better than joule thief?

[@shanejawahir9430]

how would i get 85-90vdc frm 12vdc an wat would b the amperege on it

[@heinzi56464654654]

haha its exactly the same design than an hydraulic ram pump..only for electronics :D

[@Bylga]

I love Afrotechmods videos. In the beginning i couldn't understand a single thing, but now i start to get it. Thank you.

[@glyndaleablen7203]

sorry for my name.. hahhahaha... its so weird like my dog I will just change it

[@arklanbk]

i want to make a boost converter that can go from 1v 8a to 8v 1a but i cant find anything that can take that low input voltage :(

[@glyndaleablen7203]

afrotechmods, your my idol!!!.. your the best electrical video tutorials i ever encountered in youtube. today, I was creating a mobile charger using a solar and steam powered generator.. can you suggest a nice type of boost converter which have an input of max 2v 100mah to output 5v 2.1ah (max)????? plssssssss

[@liney118]

30v dc isn't killing anyone :(

[@jewelmahmud5967]

but heat can damage

[@markschmitt5550]

Now for the fun part... I repair and build tube amps. This begins my journey to build a switching mode / boost converter power supply that can give me the high voltage that I require for the B+. Most tube amps run around the 100 to 200 ma, with a B+ voltage between 199 to 500. I've searched the net and I've found very little information. I am also aware of the risk involved with voltages this high. I have safe work practices. I just need some material and data to steer me in the right direction...

[@alihassoun10]

I simulated your simple boost circuit on Proteus but without the LM2678T IC, instead I used a 555 timer IC to give me the signal to control on/off transistor(simple switching technique), but the output voltage kept increasing and didn't stop! so I put a zener diode to limit it to 20 volts (I want a 20V output), Question Is: Is it safe for the zener diode ? and for the circuit? thanks in advance.

[@MrOpenGL]

Mane laston If the current through the zener and the power dissipated through it is below the maximum ratings of the diode, everything is safe. If you exceed the ratings of the diode you will notice it immediately because. A: the diode will get hot, very hot B: smoke might come out of it C: it may go bang

[@chethanraju6647]

Hello, I want an SMPS with 5v USB input and dual output of 12v and 5V for Battery and Ardunio respectively. I would request you to suggest a PCB board or an IC. Thanks and Regards

[@chauhandhananjay5881]

why it not get short circuit of voltage source through inductor after switch is closen ??

[@Afrotechmods]

That is a good question. It takes a certain amount of time for current to increase in the inductor. (The steady state short condition is not instant.) So as long as you only close the switch for an extremely short period of time, there is no sustained short.

[@chauhandhananjay5881]

thank you sir..

[@chauhandhananjay5881]

one more question ..... when we connect primary coil of transformer to ac supply why it not get short circuited?? it is simply a coil. so why it doesnt sc??

[@Afrotechmods]

Chauhan Dhananjay Because the primary coil of a transformer has significant inductance, meaning it impedes (resists) alternating current. I recommend researching inductance and impedance.

[@MN_Puck]

If you increased the inductor to something larger, like 56uH, and a larger 50V cap, would that be the proper way to increase the output voltage, to something capable of 50 V? I would imagine that you'd need active cooling, as the heatsink on the controller wouldn't quite be enough. Would you need to cool the cap as well? Also, since my experience with boost converters is very limited, if you increase the values of the inductor and cap, would the duty cycle on the controller need to be as high to boost the voltage higher? Would the lower switching frequency require less cooling?

[@bodziobran]

Can you give me answer to this question : what would be the voltage in your example after just a single step of shorting coil and releasing switch ? In other words, if capacitor is initially at 9,5V due to diode voltage drop and you run one cycle on/off how to compute the voltage in capacitor ? is this doable ? How that voltage depends on parameters like inductance ,capacitance, input voltage ?

[@ManojPatil-gy8lv]

Thanks for video..But can you please give the standard design procedure to select components for dc dc boost converter..for low voltage solar application..if possible please share useful link..

[@keineahnung4227]

Very nice video. However, I always miss a nice explanation of which parts exactly can kill you. Yes, I know it's touching + and - of the capacitors. But still, it would be nice to have someone explain where exactly you can and where you can not touch a capacitor in such a circuit.

[@kaelthassunstrider4559]

great videos ^_^ what can you do if you want to step down like 10A?!! I mean you can't use them in parallel :( and the step downs with that Current are expensive :O

[@XxLogo]

How did you do the feedback calculation with the 10K pot? I know in the datasheet it gives formulas to calculate if only using 2 fixed feedback resistors, but nothing about calculations with a pot. I am doing a thesis project on this and would be helpful if I knew how these were calculated. Thanks!

[@musthaqahamed8370]

What is the Linear Tech. IC which can be used to handle a 9A input current?

[@4everFitnessBlog]

Looking at the data sheet, it recommends one tantalum capactitor for the output capacitor, and says that ceramic capacitors alone have an ESR (effective series resistance) that is too low. Is the electrolytic and ceramic capacitor combo an alternative to the tantalum capacitors? (which are very expensive - about $10 a piece on Digikey. ouch) Also, what about the frequency compensation capacitors? Can they be ceramic capacitors? What is their required voltage rating?

[@robogangbsmrstu1926]

Nice tutorial. But I have question.. For how long can I keep the "switch closed"?? suppose I am using an inductor with 560uH Inductance and the applied voltage across it is 12v....

[@wgj427]

E-mania Ideally you would want a pulse width modulator at the switch to keep the switch alternating on and off. The reason for this is that inductors can only take so much of a sudden change in current that you would end up burning out your inductor. Anything in the kHz range would be sufficient, but your design would have to account for a lot of factors such as switching frequency and voltage and current ripple.

[@wgj427]

E-mania So in response to you, I'd say keep the switch closed and open for a few microseconds. Which would mean your switching frequency may be upwards of 20-50 kHz depending on your design.

[@crazy1be]

Why do you use both ceramic and electrolytic capacitors in series? Naively, it seems like the circuit should behave the same regardless of the *type* of capacitor. Is it something to do with distance from the feedback pins? (i.e. ceramic -> small but close, electrolytic -> bigger but further). Btw, thanks so much for your videos. Very clear and well explained!

[@Afrotechmods]

I am in the process of producing a detailed video answer to this, but it will be a while before it gets released

[@neoweixiang3302]

How do I re-modify this boost converter such that I can input a voltage as low as 1.5V yet keeping the the output voltage at about 30V?

[@hichamtassi1753]

Hello, can we use the UC3843 circuit instead ? thanks

[@m.berrada3696]

How can I calculate the values of the components I'm gonna be using ? I want to build a portable charger and I'm using 3 Li-Ion batteries from a computer in parrallele(to easily charge them and have a longer efficiency. Which means that I have to step up the voltage to 5V so I can charge portable devices(such as phones). But I wasn't able to find anything that could help me on the internet. I appreciate your help.

[@MrOpenGL]

+Mohamed Berrada It depends on your output current For a simple controllre that can supply high power, and good design tips, check the MAX641 datasheet.

[@imwatching2901]

This is a great video

[@girishkarthik9972]

Nice video! My question is that when the switch is open, the capacitor is getting charged( and hence voltage is boosted). However, this happens during every cycle, so the capacitor keeps on charging ( and hence the output voltage keeps on increasing). How is this prevented?

[@pyroslavx7922]

Damn, just the chip costs (in my country) way more then the old laptpop AND tablet AND homemade "sound system" used mostly to annoy neighbours and bragging rights ;-) which i planned to use it to power them from one "slightly" smashed (ENORMOUS, and tested, has bout 95% nominal cap.) single Li-ion cell from a crashed beyond repair hybrid/electric car ;-) Now if that thing, slightly smashed battery, bursts in flames/smoulders in crowded public transport.... DOUBLE BONUS for me ;-)

[@darel90820]

Can you make Input: 3V (2x AA) Output: 5V 0.8A or 0.5 ? Is it possible Sir?,. Your video is very helpful,.but it will be more helpful when you made one of this. Circuit. Thank you.

[@lepayen]

Yes you can get 5v out of 2xAA. The dollar store in Halifax has them, they're emergency cellphone chargers.

[@darel90820]

But I want a Circuit for it. I don't want to buy one, I want to build one.

[@leestons]

Darel Ocampo and he was saying it's possible to make one.

[@bloggervista]

Darel Ocampo Yes just use joules thief circuit . But AA battery cannot supply so much amperage for charging ipods etc if you are planning one :)

[@ThangNguyen-ss7dq]

Do you have any reference about boost converter? for example how can I build a DC-DC boost converter with whatever Vout I want? How can I calcular all component including in the circuit. thanksPS: I can use microcontrollẻ instead of IC to PWM