Does it suck? Chinese DIY Pure Sine Wave Inverter || Sinusoidal PWM (SPWM) Tutorial

Previously I showed you how to create this little circuit, which after powering it, creates a modified square wave at its outputs. We should not, but can step this voltage up to mains voltage through a transformer, and thus use the setup as a crude mains voltage inverter. Only problem is that the stepped-up voltage at the transformer outputs still looks nothing, like the sinusoidal mains AC voltage, we are familiar with. That is why many viewers asked me whether I could showcase a technique called SPWM, to create a pure sine wave inverter, that like the name implies, outputs a pure sine wave. Now of course such modification is definitely possible, but it does not change, that my circuits features no feedback system as well as a couple of other important safety features. Luckily though, another viewer asked whether I could have a look at the EGS002, which is a cheap pure sine wave inverter module, which comes with a voltage current and temperature protection and apparently even a feedback system. So in this video, let's find out how SPWM is used to synthesize a pure sine wave And afterwards, let's try to build an inverter based on the EGS002 to find out whether it is a decent DIY alternative for commercial inverter Let's Get Started! [Intro] This video is sponsored by JLCPCB, upload your Gerber files today to order high-quality PCBs for ridiculously low prices and make your projects look more professional First off what does s pwm stand for well the S stands for sinusoidal and PWM for ports with modulation through pulse width modulation We create a port with whose frequency we can change as well as the on time of the bolts Also known as a duty cycle So by varying the duty cycle, we alter the average voltage of the poles For example with 100 percent duty cycle we would have around four point nine five volts Were 50 percent the half of that and with 25% 1/4 of the maximum voltage Now assigned voltage is basically an analog waveform whose different voltage levels We can reconstruct with different duty cycles For example, let's use the 16-bit timer one of the Arduino for this task with a pre scalar of one and a counter limit of 1600 we would get a Poots wave with a time period of 0.1 milliseconds Which coincidentally fits 100 times in one wave of the main sine voltage? so next we have to divide our half sine wave into 100 pieces and Calculate their voltage values in correlation to the amplitudes for which we can easily use a graphical calculator Last but not least we convert the 100 percentage values into time account values by multiplying with the counter limits and Subsequently store those values in a lookup table in the code of the microcontroller During the microcontroller operation the timer will then increase Decrease the duty cycle of the pulse wave after every periods according to the lookup table But since setting up the timer properly year is not that simple Let's rather use this well-written Arduino ad Mel s PWM codes from github After uploading the codes to not we know and talking up its PWM p9 to an oscilloscope We can observe a practical as PWM signal with a slowly increasing Decreasing duty cycle and a fundamental PWM frequency or carrier frequency of 10. Kilo Hertz This s PWM signal along with its 10 milliseconds shifted counter as PWM signal on pin 10 Can now be applied to the H bridge but make sure that the diagonal opposing MOSFETs get the same signal this way our attached loads gets powered by an ACS PWM signal Which obviously is not a pure sine wave yet? For that we have to attach an inductor and capacitor in this configuration to form a low-pass filter which like the name implies filters out the high carrier frequency of the PWM signal and thus turns it into a more or less pure sine wave and with that you are now familiar with as PWM and should understand that a practical hardware implementation of such a technique can be a bit daunting but Thankfully we got our Chinese as PWM driver boards, which will hopefully help us to achieve good results Honestly speaking though I was quite happy with the PCB quality of the module itself as well as the quality of all the solder joints which is a good start and While the datasheet of the module is only six pages long it gave me all mandatory information even without broken English The board consists of an e GE a t10 which is an ASI C so application-specific integrated circuits that manages the feedback system for the voltage current and temperature and most importantly spits out 4's PWM signals rather high frequency of 23.5 kilo Hertz Additionally d-bots features and LM 393 op-amp for the current feedback functionality and two IR2113 MOSFET drivers to drive 4 N-channel MOSFETs Just according to those facts anti schematic the ports did sound promising The only thing we have to do is to add a couple of complementary components Which brings me to a PCB year that was advertised alongside the module? It is called the e GPU 1000 watts. And as you can see here forms the circuits for the complementary components So I went ahead and ordered it, which is where all the problems started The first thing I noticed about the boards where it's big traces Which is not a bad thing though because it needs to be able to handle 1000 watts But what I didn't like was the fact that even though the board is big and has tons of space on it They still utilized the smallest of SMD components while a complete tht mounting would have been possible But nevertheless the next problem. Was that the only datasheet Manual I found for the PCB year was in Chinese and even worse It seems like a couple of component calculations where explained in its But coincidentally, I found another eBay seller which at the time promised an English manual for the PCB But the translated manual I received was such a joke that they apparently do not offer it anymore After I complained about it So what I did as a result was utilizing all the data sheets I found and a bit of my gathered electronics knowledge to determine what complementary components the PCB requires Afterwards, I sourced all the components and successfully order them and As soon as I received them, I started soldering all the SMD ones to the board which would have been much easier if there were a bit bigger or just simply th Anyway after I sold it on the *in booming voice* FULL BRIDGE RECTIFIER Which was a bit too small since I got the wrong one because there was no information about it I moved on to the THD components which were quicker and easier to solder and Once I added a solder bridge to a jumper so that everything is powered by only one 12 volt supply I edit the filter capacitor and inductor and was basically done with the circuits So I inserted the module and connected the power which to my surprise did not lead to an explosion but instead the LED on the module simply lit up and By having a look at the outputs We can see the filters pure sine-wave with an RMS voltage of around eight point five volts That means we also require a transformer for the circuits which I hooked up in the same way as I did it with my modified square wave inverter and After also adding a small loads we can see here that everything seems to work But if we look at the voltage form we can see that the shape is not that pleasant to look at The reason is that we only have done since the outputs keeps shutting down after certain time while the module LED flashes four times According to the data sheets. That means there's an under voltage problem Which is obvious since there exists no feedback from the high voltage side of the transformer yet So according to the Chinese data sheets I removed the capacitor an adductor edit a wire bridge for the inductor soldered the capacitor to the Transformers high voltage sites and connected the feedback circuits and With crossed fingers. I powered up the system which to my own surprise did not blow up But still featured the shutdown problem But after adjusting the potentiometer these circuits finally worked correctly and the waveform on the high voltage side did also look acceptable and Actually pretty perfect without any loaded attached but then again the achieved voltage wasn't about 230 volts like mains voltage For that I would have to increase the input voltage or use a different transformer I Have no interest in doing that though because even without a load these circuits draws around 20 watts while doing nothing Which is pretty terrible There also exists an LCD for the system, but that also only delivers wrong values at least for me So all in all the module and PCB year seem to do the job except ibly well And I believe that there's a lot of room to tweak the circuits but then again due to the non existent English manual that is very hard to do and With that being said, I hope you learned a bit about s PWM pure sine wave inverter 's and most importantly about effects that you should never trust Chinese products without a proper manual in English as Always don't forget to Like share subscribe Stay creative and I will see you next time

Channel: GreatScott!

Views: 910,495

Keywords: pure, sine, wave, inverter, DIY, how, to, make, project, tutorial, guide, beginner, beginners, SPWM, sinusoidal, pulse, width, modulation, explain, theory, filter, low, pass, capacitor, inductor, calculation, frequency, carrier, timer, arduino, library, calculate, look, up, table, µC, uC, h bridge, MOSFET, transistor, load, EGS002, EGS001, EGP1000W, china, chinese, does, it, suck, datasheet, test, comparison, kit, efficiency, electronic, electronics, greatscott, greatscott!

Id: Dn2PFebi2ww

Length: 11min 46sec (706 seconds)

Published: Sun Nov 18 2018