How Boost Converters Work (DC-DC Step-Up) - Electronics Intermediate 1 

It is SO hard to find videos that clearly explain the step by step function of a circuit. Thank you!

Thanks a lot, I'm studying mechanical engineering and whenever I come across electronics I tend to understand very little, but I've fully understood this circuit thanks to your video. Will definitely subscribe and try to learn more about electronics :)

Simple way to make one of these - 4093 Schmitt NAND gate. Make the first gate into a Schmitt RC oscillator. Use other 3 NAND gates as inverters connected in parallel, to buffer the oscillator into the MOSFET. Use an NPN transisor to pull one input of the NAND oscillator low, stopping the oscillator when the transistor is on. (Because of the inverters between the oscillator and the MOSFET, the MOSFET will stop OFF - very important). Tap off a small proportion of the output voltage using a resistive divider and use this to turn the NPN on when the output reaches the desired voltage. Use high value resistors to avoid loading the output. I first saw that circuit as a TENS machine. Since used it very successfully as an LCD backlight driver. Make sure the diode is a fast switching diode or schottky rectifier. Ordinary rectifiers line 1N4001 are too slow to turn off, and drain the output capacitor when the MOSFET turns on. Even when just breadboarding, I found a slow rectifier is rubbish.

your channel should have more subs.

This intermediate series is really useful, thanks and I hope you continue to make them.

Holy shit! A boost converter is the same as a ram pump!

Very clearly explained - which is a real skill when dealing with complex topics such as these - thanks!

One of the best explications I have ever seen. Period.

awesome buddy! I am preparing an exam and had a lot of trouble understanding this, now it is easy! well done!

I am loving the tool you used to show the circuit graphically. What software or service did you use?

Well explained. One thing to help remember inductor behaviour is they attempt to keep the current going in the same direction, when they "collapse".

A boost converter is a DC-DC step-up converter. It takes in a low voltage and outputs a higher voltage. The boost converter is a popular choice for powering microcontrollers, sensors, and other electronics. There are many different types of boost converters on the market. Some are simple, while others have more features. When choosing a boost converter, you'll need to consider the voltage requirements of your project, as well as the size and weight of the converter. Boost converters can be used to power projects that require 5 volts or more. They're also a good choice for systems that need higher voltages, such as 12 volts or 24 volts.

Thank you having clear voice and reasonable speeds of explanation. I would think some call this a "Buck to Buck" convertor. I understand automotive electrical systems and a few components plus using a lab scope. As a dealer tech since the mid 70's, I am trying hard to make a simple HVAC actuator control circuit. It is a low current dc motor, plastic gear reduction to drive a door to direct air into or around the heater core. The dash controls are mechanical but I am handy in fabrication. It could be "Heat" but with a linear potentiometer. Since actuators can be simple, this on is as it drives a pot for feed back. Move the dash lever, the motor turns on and moves to new location and stops. Yet, it has to change directions. I was thinking of an OP Amp, the 2 pots as voltage dividers for input. To make it easy, use mosfets in "H" bridge. Just working out on paper, then test and build. Actuator are $10 and I can make a 5 Vdc circuit for mosfet control. Like you, I am into motorcycles but started on lawnmowers to make the $1 it paid in 67 and better than mower with wheel driven blades. Self taught as Yamahas where metric and metric tools fit standards, but not the other way. In the county, word of mouth found Datsuns, Opels and everything else coming to me to fix. It didn't hurt growing 7" to 6'3" at 11 and had tools w/unused machine shed on the farm. I just want to built this as I am updating a 67 C10 PU and auto trans where manual is. Plus updating the engine on the cheap. This way I can have my vehicle to drive to Dr. or store. My wife has a 96 Corolla w/160k so need backup vehicle she can drive and operate. Just simple but reliable. Sad to say she had medical issues and I will have my 4th fusion at L3-L2 and hopes it the last. I don't have a Facebook or cell phone, but get by. If you have an idea for a new video using two op amps to drive H bridge, I will be watching your channel. Thanks again for very good just job on the videos. Subscribed! Omaha.

For the first time I actually understand this. Great explanation.

This channel deserves million subs.

This is cool. I knew what a boost converter is but I never realized how easy it is to build one

This is a great channel, you should really have more subs. Will recommend to my fellow ET students.

the explaination is so smooth & simple, really worth it watching

Thanks for your channel. Im really stupid, but I love electronics. Your videos help me a lot to learn. Thanks.

Very nice explanation. Author should be proud of himself, wish i had doctor like this in my EE study. Ps-how out voltage control implemented practicly in this circuit? As well as clock for MOS (bet it isnt opAmps and crystals)

This is such an easy to follow explanation. Thanks!

good of you to make this video showing how an L works. esp. the part about the V across the L reversing and the current flowing in the same direction.

This is the one of the best video ever that explains about this in very short video.

Can you explain me why When the switch if off, the polarity of the inductor changes, and the circuit uses inductor as a source instead of the 9v voltage source ?

You are always just showing us how they work we also need to know how to design them

Great great great channel. I have been looking for you for centuries.

Great video. The only thing that's missing is the loss of amperage mechanics. As voltage goes up, the amps go down dramatically.

just learning this stuff so 2 questions if u have time? 1) if the switching is so fast that the inductor never fully discharges and discharging is faster?, then it would be the same on the charge side? it would never fully charge on the 9 V. 2) what is doing that crazy amount of switching on the transistor? what is firing it? 3) what is the determining factor of that output voltage? the size of the capacitor? 4) the on duration and off duration are not the same correct? inductor and capacitor both discharge quicker than charge

Thanks.... you have just made it easier to understand the working principle clearly.

This reminds me of the old fashioned coil/points system used on cars and motor bikes to produce the high voltage spark to the spark plugs, way back when long time ago.

Excellent excellent excellent! I have been building these things for quite a while now, and you are spot on!

Thanks a lot, this movie is very useful! It describes the operation of the boost converter in a really clear way.

Use two of these circuits paralleling the inputs and outputs. Have the mosfet hi speed switches alternate so that one o0f the inductor coils is always collapsing generating current, thus a more stable and higher current output potential.

What will make the output voltage settle at 100V?? As far as I know, here the output voltage will keep on increasing till the capacitor bursts. Someone..... Please correct me if wrong. Thank You.

Brilliant! Do you plan on providing actual components/values for something common like Input 5-9V 6A, Output 6-30V? Thanks for this vid!

Thank you for your explanation of the boost converter. Unfortunately, I still have a question on their working. When the mosfet is off, the capacitor is charged by the circuitry. However, when the mosfet is on, there is a direct path from the input power source to the ground. That means that power is still being used, unlike the boost converter. It also means that the boost converter should short circuit. But it doesn't, so there has to be something I cannot figure out... Do you know what is It?

sir you are doing really good job using every circuit....please do more videos on power electronic converters thank you

Hi your video was amazing, may I know what simulator you've used? :)

Boost converters are more efficient now than they used to be but it's worth bearing in mind that a considerable amount of current gets ditched to ground when you're charging the coil and that can be an issue if you're looking to source much current from your boosted voltage., Buck (stepdown) converters are a LOT more efficient. Back in the day when phones actually had real bells in them I built a simulator box that needed to supply the base tip-ring on-hook voltage of -48VDC which wasn't that hard, but the ringer voltage to make a princess desktop phone's bell ring was more like 80-100VAC at about 20Hz and that part required some serious attention to the breakdown voltages on everything in that part of the circuit. It was fun and I learned a lot but I never got shocked as much by any other construction project as I did by that thing. I think I still have it in the basement somewhere.

At DC voltage, inductor gets short(V=L(dI/dt) or ()Reactance offered by L, XL=JWL, W=0, XL=0)....so how does it boost the voltage

This is great, thank you. But what happens when we put a load on it? How do V and A relate to each other? 9V1A becomes 100V0.0001A?

Hello, nice explanation! What is the software you are using for simulation?

If you had included the current change (draws) over the circuit ... Doesn't the inductor voltage spike to around 3+400? Is the current divided by the voltage when it spikes. You had not included the series of the inductor to the cap as a voltage . Using batteries as a analogue would have helped support what was occurring.

really helpful! if you ever do continue the series can you post a video on buck converters?

If the magnetic field is going to accumulate each time the switch closes , then that means the voltage will increase into infinity!!!,actually what limits the voltage to stabilize at 100 volt??

Very good clear audio.

i havent seen a such clear video ever ! thank you so much

I have such an appreciation for this video. Thank you

Great video with an excellent simplified explanation.

What a great video. That was very interesting. It's the same principal as an ignition coil works in a point type ignition system in a car. Thanks for posting. I get a simple yet great education. Barry, KU3X

To make this even more helpful please explain how to control the output voltage. E.g. how to get from a 9V battery up to 48V output to drive a phantom power audio circuit with a current of no more than 20-25 mA. Thank you!

plz don't forget to explaine about curcuit amperage and voltage changes, at the same time . it is more easy to understand. And thnks about the video

Thank you for the video but I have question Why the current doesn't flow through the diode when the switch is on? Normally the diode is reversed to ensure that the current will not flow through it

So what i think ive learned is that your better off connecting capacitors in parallel with a booster to get better capacitance and desired voltage...??? Correct me if im wrong anybody... Good explanation on boosters very use full information for my next project thanks

Good explanation. Where’s the mosfet gate connected to pls? Thanks

Just a quick question. Why doesn't current constantly flow through the diode even when the switch is open, as the power supply is connected in such a way that you would expect it to.

simply brilliant. easy to understand. explicit .

The subscribe circult won't work, which means that you are NOT allowed to subscribe

Amazing, really useful for students man. Thanks ;)

Excellent, can I convert a battery TRIMMER to a wired one with this circuitry?It's 40v 2ah. Thanks for your answer, Shubham.

I went to the link provided to "play" with the circuit, but the page said that there was no circuit? Please help....

The fact the voltage across the capacitor got increased every time is due to the increasing incoming voltage of the inductor , does that mean the spike's voltage is infinite when the mosfet is off? If so, why will it settle eventually at about 100v instead of even higher than that over time?

Very impressive, ?How much power output can I get out of a boost converter? For example could I get enough power out to run most DC appliances?

What is the voltage source controlling the base of the transistor. I tried building the circuit from scratch on every circuit but I can’t find it the parts bar and it doesn’t function without it

Very good explanation and the animation is on point. Thank you very much!!

Very Very Good Undarstanding Way for beginner

You explain things very well, thank you

At 100 v out, what would the current capability be? Could you get 10 amps at 100 v from a DC low votage?

Hello. Very good video. I realized that I am looking for a similar boost converter, maybe you could recommend me a chip?

I want to use a 9 VDC source to produce exactly 90 VDC output. Also, I want to use this to power an AM tube radio without creating RF interference. Can you provide the circuit design and a Mouser parts list? Thanks so much.

Good understandable video, thanks, can I ask I ask, if and where within the circuit board would you have an earth connected, if at all, this might. Seem a daft question, but not so coming from me... Lol ... Thanks, Thom in Scotland

I loved it, thank you !!!! Very insightful

At 5:15 you say that when the switch is opened polarity of the inductor switches so that negative is on the left and positive is on the right. Then you go on to say that current flows from left to right. But current flows from a higher potential to a lower potential, so why isn't it flowing from right to left?

Basically, you charge a capacitor that has a high output voltage (high capacitance) and cause it to rapidly charge and discharge, the discharging is the output voltage.

by having the meter on the end of the circuit wouldnt it discharge the capacitor?????, nice vid

How did you figure out the values for the resisters, capacitors, transistor?

This is intriguing. Normally in a purely inductive circuit with a sinusoidal wave the voltage and current are always 90 degrees out of phase. In this type of pulsed circuit the inductor voltage and current are 180 degrees out of phase when the switch is open and the field is collapsing. That really confused me at first.

when does the voltage stop raising and why?

Excellent explanation!!

It could be nice to hace a resistor in the output so that we could play with the load. P.D greate video!

if you stopped opening and closing would it stay on that voltage or would it just stop? also does the speed of switching on and of influence the output voltage? I've heard on another video that the output is almost entirely a function of the duty cycle for a given circuit.

So nice description, so hard to find. Great fellow regards.

Fantastic explanation

What type of transistor can we use(N, P, NPN, PNP)? Great video

How do you configure or set the parameter of the MOSFET to work correctly simulate? Can you explain. I'm using same app.

Superb basic knowledge of converters

WoW. This i such a clear explanation. Thanks man. Awsome.

Hello! I'm doing a project on a solar bike with boost converter. I like your idea and very simple. I could apply it in my project with minor modifications. But, I wonder what kind of software did you use?

So whats gonna happen if V out is set eg to 30V, and the input voltage will be 40V? Is it gonna step the 40V down to 30V?

I'm a bit confused as to why when the switch is closed, there is no current flowing across the diode to the capacitor? Surely there would be some without a resistor there?

Hello, could you tell me please, what timer 100µs you put at the bottom of the circuit--- and the way you have connected it ?Thank's !

Great video!! Clear and concise!

Question : so the Henri value of the inductor is what decides how large is the magnetic field built around it, and by the same occasion decides the maximum voltage output ! am i right ?

If I got 15 amps and only one volt supply, how can that be used for the circuit you got?

Would the batteries still last the same time as normal?

Please explain switching of the mosfet

Can i know what's name of this software?. Good teaching. Thanks buddy

really good explanation

Great teaching. What's the difference between a boost converter and a voltage multiplier (doubler/quadrupler)?

Nice video. Great demonstration. Thanks!!!