The following concept I have explained a simple yet viable solar grid tie inverter circuit which can be modified appropriately for generating wattage from 100 to 1000 VA and above.
What's a grid tie inverter
It's an inverter system designed to work just like an ordinary inverter using a DC input power with an exception that the output is fed back to the utility grid.
This added power to the grid may be intended for contributing to the ever increasing power demands and also for generating a passive income from the utility company in accordance with their terms (applicable in limited countries only).
For implementing the above process, it's ensured that the output from the inverter is perfectly synchronized with grid power in terms of RMS, waveform, frequency and polarity, for preventing unnatural behavior and issues.
The proposed concept designed by me, is yet another grid tie inverter circuit (not verified) which is even simpler and reasonable than the previous design.
The circuit may be understood with the help of the following points:
How the GTI Circuit Works
AC mains from the grid system is applied to TR1 which is a stepped down transformer.
TR1 drops the mains input to 12V and rectifies it with the help of the bridge network formed by the four 1N4148 diodes.
The rectified voltage is used for powering the ICs via the individual 1N4148 diodes connected across the relevant pinouts of the ICs, while the associated 100uF capacitors make sure that the voltage is appropriately filtered.
The rectified voltage acquired just after the bridge is also used as the processing inputs for the two ICs.
Since the above signal (see the waveform image #1) is unfiltered it consists of a frequency of 100Hz and becomes the sample signal for processing and enabling the required synchronization.
First it's fed to pin#2 of IC555 where it's frequency is used for comparing with the sawtooth waves (see waveform #2) across pin#6/7 obtained from the collector of the transistor BC557.
The above comparison enables the IC to create the intended PWM output in sync with the frequency of the grid mains.
The signal from the bridge is also fed to pin#5 which fixes the RMS value of the output PWM precisely matching with the grid waveform (see waveform #3).
However at this point the output from the 555 is a low in power and needs to be boosted and also processed such that it replicates and generates both the halves of the AC signal.
For executing the above, the 4017 and the mosfet stage is incorporated.
The 100Hz/120Hz from the bridge is also received by the 4017 at its pin#14 which means now it's output would sequence and repeat from pin#3 back to pin#3 such that the mosfets are switched in tandem and exactly at the frequency of 50Hz, meaning each mosfet would conduct 50 times per second, alternately.
The mosfets respond to the above actions from the IC4017 and generate the corresponding push pull effect over the connected transformer which in turn produces the required AC mains voltage at its secondary winding.
This may be implemented by supplying a DC input to the mosftes from a renewable source or a battery.
However the above voltage would be an ordinary square wave, not corresponding to the grid waveform, until and unless we include the network comprising the two 1N4148 diodes connected across the gates of the mosfets and pin#3 of IC555.
The above network chops the square waves at the gates of the mosftes accurately with respect to the PWM pattern or in other words it carves the square waves exactly matching the grid AC waveform, albeit in PWM form (see waveform #4).
The above output now is fed back to the grid conforming the grid specs and patterns accurately.
The power output can be altered right from 100 watts to 1000 watts or even more by appropriately dimensioning the input DC, the mosfets and the transformer ratings.
The discussed solar grid tie inverter circuit remains operative only so long as the grid power is present, the moment utility mains fails, TR1 switches OFF the input signals and the entire circuit comes to a halt, a situation that's strictly imperative for grid-tie inverter circuit systems.
Warning: The author cannot be held responsible for the results of the experiment. Please do it at your own risk!! The projects explained here are recommended only for the experts in the field of electronics.
Circuit Diagram
Assumed Waveform Images
Something's not right in the above design
According to Mr. Selim Yavuz the above design had a few things which looked doubtful and needed correction, let's hear what he had to say:
Hi Swag,
hope you're well.
I tried your circuit on a bread board. It seems to work except pwm part. For some reason, I get a double hump but no real pwm. Could you please help me understand how 555 does pwm? I noticed that 2.2k and 1u create a ramp of 10ms. I believe the ramp should be much faster than that as the half wave is 10ms. May be I missed a few things.
Also, 4017 does a clean job switching happily back and forth. When you power up, the 100 hz clock makes the counter always start from 0. How can we assure that it always in phase with the grid?
Appreciate your help and ideas.
Regards,
Selim
Solving the Circuit Issue
Hi Selim,
Thanks for the update.
You are absolutely correct, the triangle waves should be much higher in frequency compared to the modulation input at pin#5.
For this we could go for a separate 300Hz (approximately) 555 IC astable for feeding pin2 of the pwm IC 555.
This will solve all the issues according to me.
The 4017 should be clocked via 100Hz received from bridge rectifier and its pin3, pin2 should be used for driving the gates and pin4 connected to pin15. This will ensure perfect synchronization with the mains frequency.
Regards.
Finalized Design as per the above conversation
The above diagram has been redrawn below with distinct part numbers and jumper notations
WARNING: THE IDEA IS BASED SOLELY ON IMAGINATIVE SIMULATION, VIEWER DISCRETION IS STRICTLY ADVISED.
A major issue with the above design faced by many of the constructors was the heating up of one of the mosfets during the GTI operations. A possible cause and remedy as suggested by Mr. Hsen is presented below.
The proposed correction in the mosfet stage as recommended by Mr. Hsen is also enclosed here under, hopefully the said modifications will help control the issue permanently:
Hello mr. Swagatam:
I watched again your diagram and I am firmly convinced that the gates of the MOSFETs will reach a modulating signal (HF PWM) and not a simple signal 50 cs. Therefore I insist, a more powerful driver the CD4017 must be incorporated, and the series resistance should be of a much lower value.
Another thing to consider is that at the junction of the resistor and the gate should not be another added element, and in this case I see going to the diodes 555.
Because this may be the reason why one of the heats MOFETs because it can self oscillate. So I think that the mosfet heats because it is oscillating and not because of the output transformer.
Excuse me, but my concern is that your project succeed because I feel very good and it is not my intention to criticize.
Yours affectionately, hsen
Improved Mosfet Driver
As per the suggestions from Mr Hsen, the following BJT buffer could be employed for ensuring that the mosfets are able to work with better safety and control.
any update on this design? please post the final layout with parts and any comment if already tested?
the inverter is for solar would it work for a wind turbine
no it won't work for wind turbines
Thank you, have only recently become interested in the GTI, for me it was very interesting and timely
you are welcome!
Possible person benefit me how what kind of plug which is based
I am very interested in your article, I place a lot of problems like this. I want to learn a lot from your article.
I've seen articles that you provide. I want to ask, the battery was connected to the mosfet leg or TR? and, in the synchronizing voltage must be the same system, the inverter output will be the same whether the system? if not then there will be the potential difference and the GTI will be load system.
thanks Agung, the inverter is perfectly synchronized with the grid, I have tried to take care of this issue as far as possible.
The voltage may be tweaked at the start before the integration with the grid by adjusting the preset at pin5 of the first 555 IC.
Once this is adjusted to the level of the grid, the output could be joined with the grid and rest will be automatically monitored and adjusted by the circuit itself, hopefully.
Hi,
may i know witch circuit is working?
Thanks,
Oliver
Hello mr. Swagatam: According to my understanding the 4017 cd is not enough to drive the MOSFETs gates models
While by no current GATE, however this has a very high capacity parallel, and when working in this capacity derives high frequency excitation energy to gnd.
Therefore it should employ a driver to excite said MOSFETs, and also the series resistance should be no more than 10 or 20 ohms.
So I think that may be the reason why heat the MOSFETs
Hello Hsen, thanks you may be correct, but according to me the problem could be due to incorrect loading at the output of the trafo due to the absence of a neutral terminal.
mosfets are voltage dependent devices and can be driven by any CMOS IC output so I guess 4017 output would have no problems driving these devices.
a lower resistance at mosfet gate becomes crucial at higher frequencies, but here since we are dealing in Hz, the gate 1K resistance value wouldn't make much of a difference, but surely a lower value around 100 ohms could be tried.
Moreover only one of the mosfets gets hot and only when the inverter is connected with the grid, so I am suspecting the problem to be with the secondary section of the trfao.
Hi Swagatam majumdar
i have a idea . source dc solar depends on sun . it not connect on grid network . you can do a boost circult in dc source(solar input in boost ) . output alway is dc source fixed . so circuilt always on grid network.
thank's
Hi Khang,
you mean a DC to AC Gritie inverter using a ferrite cored trafo right?
it's exactly what we have discussed so far but by using a ferite core.
If possible I'll try to post it.
HI Swagatam Majumdar
I have one idea about the problem on grid .It makes circuit at any time also works on grid
m.youtube.com/watch?v=9z2WjbC8yaE
Hi mate i attached the much clearer video just. Skip to 1.43min..and sorry for the background voice just dont mind it..you will see the moving backward of the meter.
Thanks mate,now it's crystal clear, by the way how did you connect the watt meter? is it in series with the inverter output?
Hi mate i attached the video of my meter moving backward…its too slow as my battry is little damaged not enough voltage also…
http://www.youtube.com/watch?v=x-XuFsHW0sk&feature=youtu.be
good effort mate,thanks…but couldn't make out much from the video, the rotation was hardly visible.
Same here, my killowatt meter running backward only 1 round then stopped.
Hi rto make sure your wattmeter is in enough hieght and 90degrees angle…its wierd but kilowattmeter…using at home seem afected by earth magnetism…for me i put it atleast more than one meter and 90degreess anggles…all become wow..!!! And when for example brown out or no electricity your grid tie will not provide voltage or light from your home but when you see your wattmeter it spin double…in speed..oh mate…this gti is fun…actually..im like a kid playing on this thing…
Hi mate..no worry i will upload much clearer view..im using phone thats why..i will try to use my cam..and upload it 🙂
For the readers..take note this is dangerous..you'll get in prison if this is not allow in your place and get fine…from the electric company…what we are doing here with swag is purely..expiremental purpose only to prove the law of inductive and capacitve reaction in circuit…but were not actually building this thing…to used..
hi RTO
can you connected GTI output on a wattmeter(solar meter) and connect it for grid meter.you can saw solar meter run
Hello mr. Swagatam: I watched again your diagram and I am firmly convinced that the gates of the MOSFETs will reach a modulating signal (HF PWM) and not a simple signal 50 cs, therefore I insist, must be incorporated a more powerful driver the CD4017, and the series resistance should be of a much lower value.
Another thing to consider is that at the junction of the resistor and the gate should not be another added element, and in this case I see going to the diodes 555. Because this may be the reason why one of the heats MOFETs because it can self oscillate.
So I think that the mosfet heats because it is oscillating and not because of the output transformer.
Excuse me, but my concern is that your project succeed because I feel very good and it is not my intention to criticize.
Yours affectionately, hsen
OK, thank you very much Mr. Hsen, I'll update the information soon in the above article with the suggested corrections
HI Barbe I've been checking the conversation can you send me the finalized design of the circuit so I can try , I Only have a Multimeter so I Cant Improvise that's why I'm asking the finalized diagram and parts list .
Thank you.
.1 mate, no…this is actually a optocoupler mate…so no short circuit…is actually working…im running a while ago thats why no part number i will make goodone in computer…i! I just copy the concept from ur design and look for the work of 4017 and 555… So insted of using relay as its noisy and soon be burn better optocuopler on and off light only….you can make it more complex to make much more good square wave…but actually..is 80 to 100hz the output of that one u just need to adjust the caps defend…me i put 2uf…but sometime 5uf
But the tempting here mate is that is actually the kilowatt meter moving backward even digital…the only problem i have is that my kilowatt meter using for testing is hve some kind of lock after one round it just not moving but the main kilowatt meter is doing backward…can u please help me on this to remove that one..im trying to figure out but..i cant see anything…
optocoupler?? mate I'm confused,which circuit are you referring to?
I have no idea about wattmeters, let me research more, will update you once I get well versed.
Hi barbe, I made the second design which is two 555. What value you are using on C3?
a neutral is crucial at the output of the inverter
if both the terminals are "hot", one half cycle will short circuit with the neutral of the grid.
Hi swag, the caused of unbalanced voltage from pin 2 and 3 is one of my diode from PWM got leaked. Now, the voltage is equal.
I have another problem is when I test the voltage (using analog tester) of pin 2 and 3 of IC 4017, i see the pulses. When 1 diode from disconnect either from pin 2 or 3 the pulse is not visible.
Is that normal pulses from pin 2 and 3 are visible on analog tester?
Hi RTO,
pluses will not be visible under any condition.
You'll be able to measure only the average voltage levels at these points.
pulses won't be visible because the frequencies are very high and cannot be detected by voltmeters.
there could be something not right with your circuit.
Hi RTO, the same of what i get…if you have scope u will see to much interfernce…im not sure but need some filter some wher
s63.photobucket.com/user/barbe10/media/imagejpg1_zpsc1919185.jpg.html?filters[user]=139832643&filters[recent]=1&sort=1&o=0
I attached the gti without tr1 base on swg design,,,is working..i used igbt much better than mosfet
Barbe, you can also try using BJTs as shown in the following article.
BJTs are much easier to handle than mosfets and are much cheaper.
https://www.homemade-circuits.com/2012/02/how-to-make-mini-homemade.html
Hi sir
I recommend using IGBT inverter circuit for the best. igbt working at high voltage and high currents
if you use TR3 transformer to driver for Q1 and Q2 . I see it was dangerous because of Gate connecting directly to an AC source.
you can connect 2 diodes in the TR1 output transformer and a resistor at pin G, add 1 zener diode to ensure they are safe.
Hi sir
I was student of electronics, that is my opinion
thank's
Khang, Q1, Q2 are rated to work at 500V, so it's fine to use them in that way.
There's no portion in the circuit which is unsafe, I have taken care of everything,
you can specify the points which you feel are doubtful… I'll explain it to you with reasons..
I consider mate the suggestion of khang…igbt is much safer in inverter…!!! Base on my reserch to…he have alot of advantage…specially on inverter…!!!
Actually this design is already working just need some touch up i would suggest try khang the second design of swag with 2 555 ic…!!! That one is working…i try that one already..the issue on that one is not smooth squarewave output 323vac..and when u connect to the grid to much interference…on sine wave…the output frequency is to high as well like 1 to 10 khz….we need atleast an output of 90hz as we can adjust it….
Be caution if you want to try the third design…on the spot..i burnt my 2 mosfet with no idea wat wrong…!!i try to check for any mistake on my soldering nothing found..better try the second one and work with that.
Hi khang…i think you are correct and eliminate the tr1 then used 741 ic as a switch then single 555 for the pwm then 4017 or never mind the 742 is optional work with single 555 only that will work for changing input voltage…i seen that one in scope…i will try that one base with the design of swag… Im just busy at the moment with my solar panel… I need to install my gti…200watts i buy from online…hahah…though the design that im working at the moment is perfect already but im not yet finish with the relay incase there is some no power some engineer working outside they can probubly get hurt…so try the QC one already…but your suggestion is actually working i seen that with my friend similar with swag design…may be he actually copy it from him but that guy..dont want to share his thing…anyway swag is there..we can figure it out…
Hi Swag,
I made your circuit using pwm and the results are..
One of mosfet that connected on pin 3 is hotter than the other.
I just check the voltage from pin 2 and 3, the pin 2 voltage is 7v and the pin 3 is 4v.
My output transformer voltage is half of grid voltage.
Hi RTO,
the pins of 4017 should have same voltage outputs, because there's no reason for it to produce different voltages.
the PWM will need to be tweaked by adjusting the preset at pin5 of IC1 until the output voltage matches the grid voltage, before integrating
the transformer must be rated lower than the battery voltage for the above voltage matching
Hi Swagatam Majumdar
a good idea
I have a question . why not use TR1 to activate Q1 and Q2.
Solar power has always changed, the solar voltage from 0-17 . low voltage , circuit always connect grid or the power network not connect
Hi Khang, yes that's exactly what we have tried to do in RTO's circuit, you can check it out here:
https://www.homemade-circuits.com/2014/04/simplest-grid-tie-inverter-gti-circuit.html
Swag, I would like to try your circuit.
Can I use this mosfet?ph.mouser.com/ProductDetail/Fairchild-Semiconductor/RFP50N06/?qs=sGAEpiMZZMsX0CFs5rpLHrnMqvVNUDbo
sure RTO!
the mosfets is rated at 60V, 50amps, just perfect for the project, no issues.
I thnk rto is correct..that simple one is working i just try that one mate…its working also..the issue of that one has no protection…yet…on the one that i build im starting to put a scr protection switch and a line frequency monitor to maintain the tie
yes that's right
Hi Swag, i attached a link before a design work perfect with zero neutral aswell i only used normal caps as filter to the output.
s63.photobucket.com/user/barbe10/media/imagejpg1_zps88f2ccdb.jpg.html?filters[user]=139832643&filters[recent]=1&sort=1&o=0
Hi Barbe, that's great, by the way how did to check the results whether it's adding the required amps to the grid?
I used wattmeter mate…public will read this but..the meter is actually reversing..note that wat we are doing here with swag is only xperinment…we follow the law…thats it or if the mter is no reverse polarity its actually stop..the more you increase your watts the more it spin backward or otherwise even youre using airxon is the meter is too slow..:)
thanks mate, I am sure folks would be learning a lot from the discussions.
Hi Swag, the design is :(, busted first try burnt the mosfet instantly also the second and thrd design..i try the old is fine but unstable.
That's sad mate, but somehow I feel that the mosfets could be burning due to some unknown reason, not because of the grid integration, because with the neutral now added, things should become much safer.
mosfets are too sensitive devices and many factors need to be taken care of while configuring them.
Hi Swag,
I'm also follower on this project. I had read your conversation with barbe, seems the circuit is still not stable. I tried some circuit (GTI) using my old UPS parts and it's worked fine without using PMW circuit. Please see the schematic diagram and the actual project.
Yellow Tester is the Amp usage from input.
Black Tester is the voltage input.
and White is the Wattmeter from the output.
postimg.org/gallery/5l89n1by/
Thanks RTO,
I can't believe it. Can it be so simple?? It looks great, though.
I post these diagrams soon in the above article or may be I'll create a new article out of this.
I would require more feedbacks from you regarding the design.
Thanks:)
however I think the design strictly needs to have a "neutral" at the output without which things could get nasty.
A center tap at the secondary would solve the problem.
The only problem is the efficiency. I hooked up 200 watts solar panel on it and I only got 92 watts peak output.
I have discussed the design elaborately in a new article, please find it here:
https://www.homemade-circuits.com/2014/04/simplest-grid-tie-inverter-gti-circuit.html
Thanks Swag, I will try the SCR version.
BTW, I'm still waiting your GTI circuit using bridge mosfet output.
I'll try to update the full bridge version soon, but it could be a bit complicated,
after seeing your design I have lost interest in the other complex designs and want to see how it can be improved further.
The only one feature that may be lacking in your design is the voltage control features, there's no arrangement that would tie the grid voltage level with the inverter voltage level…presently the inverter voltage is solely dependent on the transformer rating….it needs to be tied in sync with the grid so that it adjusts automatically corresponding to the grid voltage.
Ah ok mate thanks…i made the primary bigger as well…im working with the board now…let see…i but one cheap wattmeter aswell…to verify xsactly the work…! I keep u posted what ever i found…
that's great mate, we'll wait for the updates.
Hi mate…i dont know actually if it is crucial or its fine..i actually calculate six O six but i think i mis one volt mate it become seven O seven mate do you think is fine?…
Hi mate, it doesn't matter much, we just need some decent margin so that the voltage can be tweaked and synchronized using this margin, that's why we need a trafo having voltage lower than the battery voltage which will facilitate setting of the output voltage right from 200V to 400V, ofcourse this whole margin won't be used……so may be even a 9-0-9V trafo will work, but 6-0-6 would provide a better and bigger margin for the adjustments.
Yeah mate into the grid and not in the grid….its become to hot any way…im rewinding at the moment my 12 0 12 to get 6 0 6…let see….how its going….you have any sugestion to make wattmeter..as i read…if thr grid tie is feeding without load watt meter should reverse if its working…if its not happening is not working…?
Is the one i show u before…the IGBT and four control transfo mate
OK mate thanks, if you can show me the new schematic, I can probably suggest something.
as for the 44n mosfet, you said it became hot only after integrating with the grid…it may be because previously we did not consider the "neutral" point at the inverter output which could be shorting the TR2 during the wrong cycles from the grid.
Let's hope the new mod in the last two diagrams above solves the issue.
Its another design i found in the net…im curious as its only transformer…like basic…but is actually work mate perfect frequency also not bad..just minor filtering will be good i evn connected to the gird and no issue i see it feeding…but i need atleastn18volt input on 0 12 to get 220volts…
In your desgn im goin to used 6 0 6….as i read that 0n 12 0 12 the primary actually rich 48pp..will that is the reason why may be my 44n get very hot and burnt….in 6 0 6 it will up to 24 volts only…which will keep my 44n in safe…but hence the frequency its high the reading on voltmeter will be defferent as u used the oscilloscope…
Let see mate what will happen im starting to make layout on the board..as my breadboard is already crack burn and not in shape…becAuse of those very high temp mosfet….
Hope we get it perfect this time…:)
Im goin to try the first one… And let you know…
all the best to you!
Sure mate…the potentionmeter im gonna na used 10k no prob? Or i need lower than that or higher i have 100k and 10k with me? What u think mate
yep, could be a 10k no probs.
For the 10k i will put in 50% yeah??? Or what should be the reading or any specific resistance into it mate??
mate, keep the slider position somewhere on the center and then by simultaneously measuring the output of TR2 adjust the preset until it's almost equal to the grid voltage, once this is done it should automatically correct itself according to the grid fluctuations.
Barbe, I would recommend that you first try the second last deign and confirm the results by tweaking the preset etc, after that you can proceed with the last design which is rather a risky one.
…for both the cases, synchronizing (by verifying) the grid phase/neutral with inverter phase/neutral is crucial.
i can only see a transformer with lots of wires and an oscilloscope trace image on the right………. i did not understand your question mate
Ah sorry mate…not this one…i mean this one….
s63.photobucket.com/user/barbe10/media/imagejpg1_zps5655eada.jpg.html?sort=3&o=0
Sorry for that one i didnt notice it.
Sure mate, the scope looks great to me, you can buy it and use it for all frequency related jobs…
Hi mate, i have delay in making your design..as spare parts here is out of stock so im ordering it online hopefully i can recieve the items by next week from hongkong….:)
OK mate no problem, we can wait!
Also im having issue in finding the p channel mosfet….!!! You have any suggestion
Ok then mate..i need to wait for this item they dont have currently in stock so hopefully by next week we can start cracking…!!! 🙂
Sure mate i will do that…im preparing the parts…and let see again…
I have list of mosfet …..could you pleas check if we can use this,
Irf710(400v/2amps N-ch)
Fqi2p40(-400v/-2amps P-ch)
Thanks Mate
yes mate, they look perfect to me for the purpose, you can try them out
Hi mate..im preparing d parts again once its ready im goin to have a blow this one again..thanks mate
mate I would recommend the single diode version first before going for the mosfet version.
also please see the inclusion of the preset at IC2 pin5, this could be used for fine tuning and matching the TR2 output with the grid voltage before integration
…also pin2 of IC1 is NOT connected to the anode of its pin5 diode
Hi Mate what is the value of the TR3, and the other Mosfet? Thanks Mate
mate, TR3 is 0-9V/220V, mosfets should be rated to handle 500V at 2amps
I would want an expert to verify the design before implementing.
Hi Mate, i have little confusion on my project regarding phase…polarity. I attached the link to find more easy to explain to you what i mean..coz on the diagram the dot of primary and secondary are both on top…while on my transformer what ever i do the polarity was different the primary dot is on top the secondary is at the bottom. Is it ok even like this right,.. correct me if im wrong i think as long as you find the +/- is no problem right. For long years i already forgot the banking and polarity of transformer. To be honest mate my job is different from what i really love to do and my hobby i work in fitness company…while at home im doing this hobby..:) anyway here is the link below;
s63.photobucket.com/user/barbe10/media/imagejpg1_zps3e737c8c.jpg.html?filters[user]=139832643&filters[recent]=1&sort=1&o=0
Thanks..Mate
Hi Mate, i think we have missed a crucial point in the whole issue.
In the GTI explained above, both the outputs will ofcourse show a LIVE response since the terminals are changing polarity 50 times per second, so your line-tester will show a glow on these terminals.
However in our home we don't face this issue, rather find one of the terminals to be in a non-active state which we call the neutral point.
In the above design there's no neutral and that's exactly why we are reeling with the problem and were unable to find the solution so far.
THe remedy is simple, use a center tapped winding at the secondary side of the trafo.
That's it, once we do this the problem will be solved once for all.
I'll update the diagram soon.
As for the diagram that you have shown, for AC the polarity or the dot becomes immaterial since the polarity would be changing in an up/down manner constantly.
ah ok mate..thanks for that…..
in update diagram..im waiting for it mate..hopefully we get it smooth.
Thanks Mate
Sure mate i will do that…thanks
Hi Mate,
Please check attched link for further analysis…what you think of this design…? At this moment im trying to figure out still whats going but still stable then not…the waveform is not continues sometimes is just cut off..maybe the 555 or the transformer..!!!
s63.photobucket.com/user/barbe10/media/imagejpg1_zpsba130c50.jpg.html?filters[user]=139832643&filters[recent]=1&sort=1&o=0
thanks mate, it's the same design that you showed me previously and it looks feasible.
the instructions written on the page are all correct and may be followed as given.
as for the inverter design shown in the above article, for te waveform info you can refer to the following link which includes an identical design but not a GTI
https://www.homemade-circuits.com/2013/10/modified-sine-wave-inverter-circuit.html
Thanks mate…this is AC caps right…..anyways on your design the 1k resistor can we make it like 100ohms? On 4017 Thnks
yes mate it's AC cap, 1k could be replaced with 100 ohms in the 4017 circuit, it's not a critical value
Thanks mate i will check that one still not hundred percent success…sometimes ok sometimes not..!! So also im going back to the book and read a little to understand much bout the circuit…!
Hi Mate, i need your help on this one they said its actually working GTI the issue is they remove the capacitor value..do you have any idea if you dont min to calculate this one or what is the value.
Im actually wanna try dis one while waiting for your next design…also xcited with that one..as that is a transformerless.
Thanks in advance for your help.
s63.photobucket.com/user/barbe10/media/imagejpg1_zps5d36adf4.jpg.html?filters[user]=139832643&filters[recent]=1&sort=1&o=0
mate, it's not too crucial, it's just for preventing peak transients from entering the devices.
as far as i know such networks are used across triacs also, and I have seen 0.1uF/400V being used for such applications.
so you can use 0.1uF/400V caps for these.
Hi Swag i found some diagram in the net but not sure about this…i will attached below the link for your analysis may be this could give an idea?
s63.photobucket.com/user/barbe10/media/imagejpg2_zps6d2ce45a.jpg.html?filters[user]=139832643&filters[recent]=1&sort=1&o=0
s63.photobucket.com/user/barbe10/media/imagejpg1_zps6078a863.jpg.html?filters[user]=139832643&filters[recent]=1&sort=1&o=1
By the way i will continue on this one and try to find something..maybe i juz miss something on this…let you know for any update…
Thanks mate for the help and support….
Thanks mate! The diagrams make sense doubt…but can't really confirm until checked practically, it also incorporates a trafo although it's synchronized and guarded by triacs so definitely looks a better one.
you can give it a try and let me know about the results.
the triacs in series with the trao output terminals makes lot of sense, so you should give this a try.
I think im going back to the breadboard…it much more easy to check….
Im just tired yesterday mate…i will start again today…
Quick question i will eliminate for the moment the big transfo and power up the circuit using the the small 12vdc supply i think thats is the safest wAy..and check how is going to work…mAy be i miss something…i will not give up on this..im just tired yesterday and blow up too manu component hahah…let start again with this mate…
Anyway if you have updated design let see aswell that one…electronics sometimes need a cup of coffee coz of the headache but cant give up…coz of the challenge…
Thanks mate…let you know of any progress….on this design
surely mate…I appreciate your interest….be assured I'll post the other concept soon using full bridge topology and without an output trafo.
On the main output mate….
barbe how it's only 32V, you said the inverter was working perfectly when not integrated to grid?
Its 323vac mate….
Hi Mate…i think im going to stop this…i think need more studies need no make…output is pure sinewave connected to grid..50hz…but i dont understand that after a minute my transformer and the mosfet, and 4017 got damaged…
I dont know where to troubleshoot because the frequecy sometimes is cut off and work again…i cant get a picture as all is so quick…i try to do it again but the same issue happens..i think you need to modify something from the circuit…yesterday was stable…and today i check with scope seems perfect to me,.,,but i dont get…those things happen when connected to grid…even frequecy are the same..maybe you mis something in the design…i dont know mate…!!!
Total damaged
10nos. 555
12nos.4017
4nos. Transformer
And also the diode is very hot too…
Hi mate, the output of the above design is perfectly in tune with the grid AC and is a sinewave, although it's PWM based.
I think here the culprit could be the transformer, which I thing should be completely eliminated, because different sets of winding could interpret the input differently no matter how much the 555s try to synchronize the grid data
However with no transformer the output stage will need to be a full bridge network using four mosfets.
soon I'll update a new design where the transformer will not be used
anyway, hard luck mate
hope you succeed finally sometime later.
in my life so far i have burnt thousands of bucks while learning the practical stuffs in electronics….that's a part and parcel of the whole thing:)
Hi Barbe,
by the way I thought you would first confirm the various stages using the oscilloscope and only after verifying them all you would go for a grid-tie??
that's exactly why we waited for the scope, right?
Hi Swag,… Any idea why im getting this reading i attached the link below,
s63.photobucket.com/user/barbe10/media/imagejpg1_zps6e6ab845.jpg.html
Hi Barbe, where are you getting this voltage, across which points?