How NOT to make a Modified Square Wave Inverter 

-Can you make an inverter? -No -...

"Invest into a proper one with a lot of safety features" Yeah... without any kind of proper reverse polarity protection :D #ElectroBOOM

You can use this circuit to make a sine wave inverter. Instead of driving the fet's with the low frequency square waves , use a higher frequency(say 20khz) pwm signal. Apply a half cycle sine modulated PWM signal to each side of the bridge. One side at a time obviously :0) A small LC filter on the output of the transformer will give you a nice clean sine wave at 220V . I've used same setup to build a 2KVA sine wave inverter. works great. Mine works at 48VDC and uses more parallel fets , but the basic circuit. Not sure if the Arduino can do a fast enough pwm , but an STM32 board will handle it no problem!! FYI , the diodes in the circuit are not really needed. The fets have inverse parallel diodes in them anyway. Unless you are using schottky's , they won't be doing anything. Keep up the great videos!! Cheers Rob

Perfect circuit to power up light bulbs.

- "Can you pleeeease make an inverter? It would be the best thing in the world! Thank you!!!" - *NO.*

10:48 "I calculated an efficiency of 84%" proceeds to write 83

Great video as always! You mentioned the pure sin inverter. Can you make a tutorial on how to create a low voltage sinwave from 12V?

I have a 300W Sine wave inverter and its great. We get sporadic power outages here and with that thing i can power my fridge, charge my phone, power a light all from a old ebike battery (that i connected together for a massive ~12V 40 Ah. It gets charged by a 50W solar panel and is completely off grid. I used it 2 times and each time it was just brilliant to be the only person who had electricity. That smug feeling is worth it.

One of the problems with square waves is that they bring a ton of additional harmonic frequencies. Since harmonics are usually higher frequency, is it possible to round out the output using low-pass filters, or are the capacitor and inductor values to filter a cheap inverter too extreme? It’s my understanding that the good inverters use VERY high freq PWM with duty cycles corresponding to the sine function. The higher frequency of the PWM allows them to be cleanly filtered out. You might be able to achieve this kind of inverter with this same circuit but a new program.

Excellent tutorial! I remember watching AfroTechMods video a while back and it's good to hear you shout out to it!

I would like to suggest that you include the shorting function, where you turn on both of the bottom fets during the dead-time of the inverter. This will greatly reduce transformer noise, make the transformer's output waveform look totally textbook - and improve the inverter's overall efficiency when driving purely inductive loads. Anyway, great video, as always :) .

aw don´t use P-Channel... Use a charge pump and N-Channel only! Much better :D RDSOn of P-Channel isn´t that great most of the time... And use a port of the uC instead of setting each pin line by line.. So you can just set the bimask and have all pins flip at the same time.. Otherwise you might produce a short for some us while both low- and highside FETs are on.. Better circuit b.t.w.: Step up form 12V -> 400V DC and then do the H-Bridge on the 400V DC, the 12V -> 400V DC Step up is much easier to build with a feedback and you can have storage capacitors for the 400V.. If you have really fast FETs you can even do a sine wave via PWM on the 400V H-Bridge.

Why not adding a capacitor to the output (to smooth it down)

Your common pcb soldering is amazing.Your soldering is better than a printed circuit board😍😍😍😍

The pull up resistors for the P-channel MOSFETs have to be between *gate and source* and not *gate and drain* , am I right? 🤔

Do a video about a pure sinewave inverter

Great scott fans like here... 👍👍👍👍👍

Hey great Scott, you should build a diy air conditioner. It would be a fun project and be helpful in the summer. Thanks!

I love you Great Scott and appreciate all the videos it's incredibly inspiring. But it's a crime not to go over SPWM and RC/LC filters in this video. You gave us the H bridge beginner course when you know we can handle intermediate or advanced.

Lol for EDUCATIONAL PURPOSES ONLY. Well to properly learn you gotta DIY

My brain: OOF

Make a tube amplifier !!!!

how to make all the lights in your neighbourhood flicker.

Can your create a pulse transformer?

Interesting, I was planning to do a similar job using an old transformer and an IGBT module given to me. Probably the biggest challenge (as shown) being to tame the switching spikes.I'll start by examining a few commercial designs & those presented in electronics magazines (Electronics Australia etc) for some ideas that worked for them.

I don’t know why you have less views :{

could you recommend a good 500 watt pure sine wave schematic on google that's good for small electronics?

I love how you tell us the disadvantages of the circuits you build

Sent by ElectroBoom. I'm an old EE and hobbyist/troubleshooter. This is a great site. Wish this was around in the 70's and 80's! Subbed.

What about adding capacitor to perform low pass filter and make its resonate at 50 Hz?

As you mentioned, turning on the bottom FETs during dead time will solve your spike problem. i have built exactly this type of inverter using a discrete transistor high/low side driver and NMOS FETs only. The efficiency is very good and the dead time conduction in the bottom transistors does not seem to impact eff. significantly. It powers all my home's lights plus TV and most small loads and never runs hot and has been super reliable.

And why not make a pure sine wave inverter with proper safety features? You always give up too early! I know you're trying to protect people from mains voltage, but remember that when somebody is told not to do something, they will do it. So they will build this circuit (or worse, another one they find on the Internet), at their own risk, no matter what you tell them to do, especially if they don't want to buy an inverter. The best way to impede that is making and publishing a better circuit!

Hey... can you make a high voltage capacitor charger circuit ( 450 V electrolytic) for coil gun.

Going to hit 1 Million sub...great going😜👍

I wish one day i could get entire knowledge on electronics just like you sir... as i am an electronics engineering student i have some hope on my wish...

FULL BRIDGE RECTIFIER

Great videos.... Love from india...❤❤❤❤

1:43, Dang what a savage rejection!!

Pretty darn good work, dude! Fantastic! 😃 But for the next one: good and expensive inverters, DIY or buy? 😂

Give me the circuit without microcontroler...Because the microcontroler is not easy for all..

I'm looking for a pure sine wave inverter circuit

using a -1+1:1 transformer and some caps you can turn the modified square into a more sinusoidal waveform also using a different driver that is

I have several MSW inverters with dead H bridges and I don't even bother fixing them. I just wire the DC out from the inverter directly to the plug. Most electronics these days have switching power supplies and they don't care. And it is a little more efficient.

wanna project mixer 4 input one out put using jrc4558d also how to make one output like amplifier HA400 audio behringer

It would be cool to see that H bridge PWM and filtered to get way closer to a sinewave

Please make Plc programmer and runner board using arduino make this video and also provide circuit diagram

You mentioned Afrotechmods in this video, that man does not exist on youtube anymore. he did not upload anything for period of 5 years , and I am still interested in what happen with him , any info that you know ?

Fun fact: apart of producing the pure sine wave is not an easy task, most of the electrica appliances would perfecty operate on DC current. What are they: - Ohmic resistor, like heating elements, incandescent light bulbs, etc. - Machines with universal motors like drills, grinders, they operates much more smoothly on DC. - All appliances with switching power supply, from mobile chargers to modern computer's power supply. - Machines with BLDC motors like central heating water pump. They also have switching power supply. The last two appliances' power supply's first task is make DC from AC. Thus they will work on DC just as well as on AC. What will not work: - Induction motors. - AC transformers. These lists are far from complete but most of the electrical appliances around the house will fall to the first group. One major disadvantage of the DC current is the stubborn electrical arc in the switches what makes serious damage in it.

i am only 10 years old and you teach me a lot Greatscott thank you for your effort have a nice day

you can significantly improve the shape of the voltage on the output of the inverter by doing the software properly. Use dead times, PWM and soft switching. Driving the mosfets at 50 Hz will give a ton of harmonics. Use >1 kHz and PWM within the 20 ms period to generate the RMS voltage of the sinusoidal 50 Hz wave. Look at my inverter, in the scope you see a period of my three phase inverter. www.ingdemurtas.it/wp-content/uploads/realizzazioni/6pulse_converter_controller.png

I thought a reasonably simple pure sine inverter would have a pure sine 50Hz signal generator amplified by a Class D amplifier. Both components are quite simple and definitely efficient. Where is the problem(s) with such a design?

make a class D amplifier with a 50hz oscillator then step up the output to mains voltage.....? you get a pure sine wave inverter with a 85+% efficiency? class D amplifiers can be designed to handle down to 1 ohm load on the output

what if you made one using the same principals as the class d amp you made? then you could use a 555 timer in triangle mode to make a "sine-ish" wave

A pure sinewave inverter modulates the PWM using a 50 or 60Hz sinewave. Sort of like a class d amp, but with the load being a transformer.

How about resonance inverter. It's produce perfect sinus. Using a half bridge plus resonance circuit with mains transformer. And add in this circuit some sort of feedback.

2:40 reminds me of electrobooms clone: haha viberator original one: What electrobooms clone: just call it an Astable Oscillator original one: grow up you little child. 😂

The a-holes that sells inverters here calls them "Modified Sine Wave" so searching for Pure Sinewave inverters just shows a bunch of modified sine/square wave inverters and only a couple real sinewave inverters

I always look forward to your videos thank you so much !!!!

Make an automatic Solar panel cleaner , like a rubber thingy attached to the sides that moves with a bit of water over the solar panel cleaning it in 2 goes like a cars windshield wiper, but this one moves like a 3d printer in 2 direction (2 for coming back) instead of rotating, thus covering the maximum area possible

Very informative Video. Hey, I was wondering if we could also use H-Bridges like L293d or l298 instead of using 4 mosfets?

Love the video Great scott.

square wave inverters are terrible, and will damage your electrons, samlex makes decent pure sinewave inverters for a good price, never bother with modified sinewave inverters...

im using victron phoenix pure sine wave inventer for around 500euro for my solar system

Couldn't you make a controlled current side that urilizes a transformer and capacitor to generate an analog sine wave, and use that to give a voltage reference to an op amp which drives mosfets, which gets stepped up by a second transformer, to deliver the load?

Yeah, considering how incredibly cheap they can be if you're looking at low wattage ones, building seems like way too much of a hassle... unless it's just for small AC fun, like you said.

So like, basically, it's a bad idea to make one if you want an inverter for practical use, but not a terrible idea as much if you want to learn how they work?

Why not use a zebra diode snubber?

Pls make an video or send me an reply for how to make electricity from noise

Afrotechmods also doesn't think diy inverter is a good idea, it seem like all electrical engineering youtubers agree on this one.

JUST THINKING ...... how about making a CNC soldering machine ????? (maybe NOT for SMD (TOO HARD) ..... just for THT) PLEASSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSE (I would like to add some emojis BUT i CAN'T)

very ilustrative, i have the same problem with this shit, why not do you prove with sne wave generated with pwm with your arduino and filters in the output of the mosfests. don´t give try again please !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Use all N Channel mofset and biffilar transformer winding with 2 Channels or conventional transformers with 4 (2 High+2Low) Channel with Battery Postive wire connected on( Hi Side )2 Channels drain and Battery Negative Connected on (Low Side) 2Channels source And High side Source and low side Drain connected to transformer for switching

Ist der Volttroinc 600W Spannungswandler gut?

Which is your favourite pure sine wave inverter brands???

nice video sir..I am your big fan...I recently try to make a project (automatic changeover switch by relay like ups system) For my Desktop motherboard...normal relay working fine but my PC Crushed...please solved This problem...& make a video about It( automatic changeover switch by relay like ups system)...please please please.

How to make an MSW: Don’t. Honestly, I’d pony up the few extra bucks and pay for the pure sine wave. You won’t get as much power, but take into the equation the fact that MSWs tend to draw a bit more power in my experience, and also they run switchmode power supplies *much* harder, and could lead them to premature failure. If you are running only switch modes, use H DC instead. They will run perfectly fine, even a bit *more* efficiently than walk AC, off DC. My Omnicharge (which I love) runs at 150VDC for 110VAC nominal or 300VDC for 240VAC nominal, so maybe start here! That said, I bought my inverters from an Australian store called Jaycar. If you’re not in Australia, google a company called “sondar” or “son dar” - it’s one of the two. Absolute top notch. Completely bulletproof. They’re not the cheapest, but they are the best.

From my experience, it's probably better to not use Modified Square-Wave Inverters at all; they generate a lot of acoustic/electrical noise, and are rather insensitive to the load... Pure sine is the way to go, if you like inverters. It's also 'easy' to build as a DIY; half the circuit is in this video! I see that transformers will couple the high-frequencies and may hum/buzz, motors will work less efficiently than they should, and SMPS such as computer PSU or laptop chargers will experience high peak-currents in their primary-side rectifier bridge. Also the X capacitors will be passing a lot of current during the switching - this makes acoustic noise (from a capacitor!) and the constant high peak currents may cause them damage... [OKAY for short durations like power outage, but no-good for permanent installs!] Another one is the CAPACITIVE DROPPER, which as my all-capsing portrays, causes most problems. The capacitive dropper limits current on a sine wave only, it will still "work" on modified square, but like the X-caps in your SMPS, they pass huge current spikes on the switching cycles... ... Which can lead to sad capacitors, or as i found in a mains power-meter; a sad inrush-limiting resistor, which overheated from constantly damping the current spikes from the square-wave switching. Did i mention the noise? Plugging you laptop into the inverter, then using a small portable amplifier; the same 50Hz buzz will come out the speakers, making music extra high-fidelity! For this reason and others, i'd say NEVER connect a power amplifier to one of these. Resitive-droppers, or other resistive loads (basically anything with a unity power factor) are the only things that can be run "safely" from modified square wave... SMPS can be used, just make sure it's not a cheapy-chinese explodey-device, or you'll have a sad inverter too!

What about upgrading this inverter? It would be a nice video

Pure sine wave inverters really aren't that expensive these days. There's a number of ASICs available which do all the relatively difficult PWM generation for you (EG: www.egmicro.com/download/EGS002_manual_en.pdf), so the Shenzhen sellers are able to make them easily. They also use high frequency (25-50kHz) push pull converters to generate high voltage DC first, so a large (and expensive) output transformer is not needed.

Please make a vedio... ...How to make a variable... power supply... 24volt 10amp...

Fucking great Job and Video 👌👌 Maybe you can make a tutorial about a transformer from a Smps ??? About the windings and feedback coil ..that would be great and how we can check them🙏🙏🙏🙏🙏 Greets from Austria

PWM + IGBT H-bridge + LC Filter + transformer with feedbck !!!!! not so complicated XD

Dammit i thought you wouldnt use a microcontroller.

Can you make a popcorn machine with the heating element from a rice cooker?

Solution: use a class D amplifier design rather than the worst possible inverter design. You only need to switch at around 2-10 khz to get a roughly sinusoidal 60hz in PWM to make a decent design. This may be somewhat more difficult code, but totally worth the higher power quality.

Hi sir, I'm working as electronics professor. Your effort for each project is great and awesome 👍 I have two doubts always preset in my mind when thinking about sinewave inverters 1: Why RC phase shift oscillator or any other sinewave oscillator is not commonly used as oscillator source in pure sinewave inverter? Is any problem with that?? 2: MOSFET have Giga ohms resistance in its gate , is it necessary to add 10 Ohm resistor in its gate ? Kindly reply 🤗🤗

What if you used the DC output of solar panels to power DC motor spinning at 3000 or 3600 RPM instead? And then connect DC motor to electric generator which will spin the electric generator and output AC voltage, which you can then regulate with transformer, capacitor and voltage regulator to 120 volts or 230 volts. Can this be a viable cheap way to output pure sine wave AC?

GreatScott: Great video and advice. Now take your conclusion and watch the youtube video called How to convert a Modified /Square wave inverter to Pure Sine . A perfect solution and work around with few modifications. Also google Texas Instruments inverter circuit that uses similar features of your design. They too are impressive.

I'm thinking about making a simple square wave inverter to directly power resistive loads like a crock pot. I want something that will not shut itself down completely if the input voltage drops (because there is no battery.)

Step 1 find a washing machine pump Step 2 connect pump to a small 12vdc motor and power the dc motor Step 3. That's it ! your inverter is done. 🙅🤷💁🤷🙅💁🙅

Plz fix the zip file as it does not work

hey there !!!.Excellent Video,i have a question ,if i want to change frequency at 60 hz ? i thought changing 20.000 to 16.666 but the another value (6.000)...

JohnAudioTech channel featured an inverter using audio amplifier using a specially wound transformer (8 ohms on the primary, I guess). Interesting to test his idea. ru-vid.com

Jirrr

I am a BEGINER in electronic and can you please make a tutorial with BASIC information and tools for hobby. PLS! I don'd build any circuit made by me or even pre-made one

Now I think about it, isn't class D amp also use sinusoidal pulse width modulation? A class D amp, a transformer and an old smartphone for sine wave audio generator. Simple 100 watts inverter with adjustable voltage to test smps..since I only have 10 watts isolation transformer which is not enough power

Very cool. As the negative DC potential remains the same all the time I guess there's no need to apply any PWM to the low side mosfets but only the high side ones (in unipolar inverter)? This way a return path for currents always exist, also doing what you did in your workaround. It sounds reasonable?

Now do it in triplicate, program that arduino to offset the phases 120° to each other, make the voltage output and frequency variable, and run some brushless DC motors. Go! Lol

Making an inverter DIY from what I've seen is actually more expensive for low power, and for higher power it's only a *little* cheaper but it's much more work

Couldnt you just use a cap to remove the noise and get a cleaner wave?