The following article explains a pure sine wave inverter circuit using the IC 556 which forms the main sine wave processor device in the circuit.
How it Works
The presented design actually produces a modified sine wave output, but the waveform is highly processed and constitutes an exact equivalent of a sinusoidal waveform.
A single IC 556 forms the heart of the circuit and is responsible for manufacturing the required PWM controlled modified sine output waveform.
One half of the IC on the left is configured as a 200Hz frequency generator, this frequency is used for providing the required square wave clocks to the preceding monostable which is formed by wiring up the other half of the 556 IC.
The clocks are received from pin#5 and applied to pin#8 of the IC. The right hand side section of the IC does the actual processing of the above square wave by comparing it to the triangular waves applied at its pin#11.
The result is an output at pin#9 which is a PWM, varying in accordance with the amplitude of the triangular waveform.
Ideally the triangular waves can be replaced with a sine waveform, however since triangular waves are easier to generate, and also appropriately replaces the sine counterpart, its been employed here.
R1, R2, C1 should be appropriately selected so that pin#5 produces a 50% duty cycle, 200 Hz frequency.
The 200 Hz is not critical here, however it becomes critical for the IC 4017 stage and that's why it's been selected to that value.
The modified sine wave PWM generated by the IC556 is next applied to the switching stage comprising the IC 4017 and the relevant output mosfet devices. Let's see how it's done.
Parts List
IC1 = 556
R1,R2,C1 = select to generate 50% duty cycle
R3 = 1K
C2 = 10pF.
The output stage
The diagram given below shows the output stage configuration where the IC 4017 takes the center stage. Basically its function is to switch the driver transistors alternately so that the connected mosfets also conduct in tandem for inducing the required mains AC output into the transformer.
The IC receives the clock pulses from the above explained 556 circuit (pin#5/8) and its outputs sequence across the connected transistors alternately as discussed above.
Until here the circuit behaves like an ordinary square wave inverter, however the introduction of D1/D2 with the pin#9 of the 556 transforms the circuit into a full fledged pure sine wave inverter.
As can be seen, the common cathodes of D1/D2 are integrated with the processed PWM pulses from the above 556 stage, this forces D/D2 to conduct only during the negative pulses from the generated PWM blocks.
It simply means that when D1/D2 are forward biased, T1 and T2 are inhibited from conducting since their gates become grounded through D1/D2 into pin#9 of the IC 556, which make the mosfets respond exactly to the PWM pattern.
The above process generates an output across the transformer secondary that's perfectly chopped and processed and equivalent to a sine waveform.
Parts List
IC2 = 4017
all resistors are 1K
D1,D2 = 1N4148
T1,T2 = IRF540n
Transformer should be also appropriately rated as per the requirement.
The Triangular Wave Generator Circuit
The entire modified sine PWM waveform construction and implementation is dependent on the fed triangular waves at pin#11 of the IC556, therefore a triangle wave generator circuit becomes crucial and imperative.
However there are many types circuits that will provide you with the required waveform inputs, the following is one of them which incorporates yet another IC555 and is pretty simple to configure.
The output from the below given circuit must be fed to pin#11 of the IC556 for enabling the proposed sine wave inverter functioning.
DESIGNED BY "SWAGATAM"
A simpler alternative to the above design is shown below, the configuration would produce same results as explained above:
For the final verified design of the above circuit please refer to the following post:
https://homemade-circuits.com/2013/10/modified-sine-wave-inverter-circuit.html
Solomon says
Hello sir, i asked some questions in one of ur post and i see no reply, let me ask u the same questions here:
1. In choosing or selecting MOSFETs, what must i consider, is it the volt or the amp of the MOSFETs?
2. Can i use stabilizer transformer to connect with my inverter circuit?, or does a stabilizer and inverter has different pattern of winding
iyiola semiu says
Gud job boss
Shadmehr Aria says
Hi,I want to convert 310 VDC to pure sine wave 220 VAC using 4 N-channel mosfet IRF740 or IRF830,I already made it with AVR and IR2110,but now I want to use no microcontroller,Would you please help me doing this job?Regards.
Swagatam says
you can try the following circuit:
https://homemade-circuits.com/2014/01/simplest-full-bridge-inverter-circuit.html
Sudhee Krishnan B says
THANKU SIR FOR YOUR REPLY… HERE I USED A 12-0-12/ 230V, 5A TRANSFORMER.. AND I AM GETTING ONLY 120V OUTPUT. FROM THE ABOVE COMMENTS I HAD UNDERSTOOD THAT I SHOULD USE 6-0-6/ 230V 5A TRANSFORMER. I WILL REPLACE THE TRANSFORMER SOON.. THANKU…. I WILL BE BACT IF THEIR ANY DOUTS ARISES….. THANKU
Sudhee Krishnan B says
am getting an outputvoltage of 120v. i had used irfp55 as mosfet.i need 220 volt out put. in the circuit diagram u had given in the output that it will give 120 v or 220v.what change to be done to get 220v output
Swagatam says
remove the PWM diode connection from the mosfet gate and check the voltage, if you see it to be 220V … connect back the PWM and adjust the pin5 preset of IC2 until the voltage settles to 220V,
if you are using a 12V battery then make sure the transformer is either 6-0-6V or 9-0-9V
Sudhee Krishnan B says
i had wired up the circuit.. i had used irfp55 as the mosfet,.. am getting only 120v output…….
daniel adusei says
sir please i build this circuit and got 6.8v at output of ne555 and i got 5.8v at ne556 output cd 4017 i got 2.3v at pin2 and pin7 how can do to raise up pin2 and pin7 lik 4v to maybe 5v cos the circuit don't start i think it the out put of 4017 is too small to open the gat of the mosfet, sir i found 4017 circuit its the same as this one but the different is you added transistors at pin2 and pin7 but you did not put value of the component thank you.
Swagatam says
you are seeing the average voltage in your meter…the peak voltage should be well close to the supply voltage…so it's perfectly OK for triggering the mosfets
Dinesh says
Hello sir,
I want to make a circuit for 8kHz sine wave. Can you plz post a suitable circuit with correct component values?
thanks!
Swagatam says
Hello Dinesh,
you can make the first circuit shown in the following link:
https://homemade-circuits.com/2012/02/making-pure-sine-wave-inverter-concept.html
alter the timing component R1 value by some experimentation until you get the required 8khz output
khang ly says
hi sir
you received my picture
Swagatam says
No, did not receive any new pictures??
khang ly says
hi sir
i will sending you any my picture. this is results
It output not pure sin. I'm wrong in area ?
specifiction tranfo 12-0-12 =>220v ,i'm supply 24vdc,output 20vac – 30vac,
i'm supply 21.9vdc, output 204vac
output tranfo i connect a 0.33uf/400 but it not pure sin
Swagatam says
hi khang, did you put a load at the output? please put a load and then check.
anyway you won't get a pure sine wave rather only as shown in this article:
https://homemade-circuits.com/2013/10/modified-sine-wave-inverter-circuit.html
you can also try connecting an inductor after the capacitor as shown in the above article….
Peter Anongo says
After using the link "http://www.royalrife.com/555_calculator.html" I've come up with the following values: R1=100 OHMS, R2=10K, C1=330nF which gives a frequency of 217Hz and a duty cycle of 50.2%. Will this work? Am trying as much as possible to work with parts i already have. Thanks.
Swagatam says
At IC1 pin3 it should be around 500Hz, at 4017 pin 14, it should be 200Hz
khang ly says
hi sir
you received my picture.can you help me
thanks
Swagatam says
hi khang, yes i saw them, please check it after connecting a load and also connect a 0.22uF/400V capacitor across the output terminals of the transformer.
please check the response with the above.
khang ly says
hi sir
i'm check again and let you know the results.
thanks
khang ly says
hi sir
yes .i will sending to you
thanks very much
khang ly says
hi sir
im tweak them perfect. i use 12-0-12 out 220vac tranfo.
DC input 12v .but output tranfo give me 120vac 50hz it's not pure sine, it's give me spikes pulse
can i connect RC filter for output tranfo sine pulse . it's is value
thanks
Swagatam says
Hi khang,
you must use a 6-0-6 trafo for a 12V battery.
anyway how did you check the spikes, I guess you checked them on a scope, can you please send the images for verification??
yes filters can be used but that will make the fets hot.
khang ly says
hi sir
thanks .im check again . i try tweak them
khang ly says
hi sir
i have a question
pins rest not use (IC 4017) is open or connected to each other
Swagatam says
the remaining outputs are all unused and open.
khang ly says
hi sir
I have followed the guide but circuit operation not good. output 80Vac and 200hz, i can't control accurate frequency in circuit . i adjust frequency IC1, IC2 frequency change too,
can you help me
Swagatam says
Hi Khang,
the above circuits are perfect, may be you are not able to tweak them rightly.
you can try the following design instead:
https://homemade-circuits.com/2013/10/pure-sine-wave-inverter-circuit-using.html
khang ly says
hi sir
i have a idea
can you use wien or pubda bridge circuit to generator true sine . sine pulse input pin 14 ic 4017
thanks
Swagatam says
hi khang, it's not pubda, it's bubba oscillator.
pwm sine is more efficient than bubba sine concept
my previous simple sine wave inverter was based on the same principle (bubba)
https://homemade-circuits.com/2013/04/simple-pure-sine-wave-inverter-circuit.html
khang ly says
hi sir
thanks for relay.im check again.
frequency in ic 1 and ic 2 (7555) not stabilize.
pulse in ic1 and ic 2(7555) is spike pulse and very noise
output 2-7 ic 4017 is square pulse not sine pulse
ic ne555 Specifications not good i think so
Swagatam says
Hi Khang,
everything is perfect in the circuit, it's done as per the datasheet info of the IC 555, for the waveform images you can refer to the following article:
https://homemade-circuits.com/2013/10/modified-sine-wave-inverter-circuit.html
Khang Ly says
hi sir
can you tell me out put pin 3 ic 7555(1) what is pulse? spuare or triangle…
out put Ic7555(2)is pulse ?
help me. thanks
Swagatam says
it will be a square or a rectangle pulse
khang ly says
hi Swagatam majumdar
im construction your design (three ic 555) but i can't control frequency 200hz and 500hz . your design in generator frequency have problem , can you update for me ?. can you help me ?
Swagatam says
Hi khang, I don't think so, the 555 section was published in elektor electronics magazine so it can't be wrong moreover i have tested it for a motor control design, it worked perfectly…the same has been applied here.
try using a lower value for the 50nF, make it 22nF or lower and check the response.
Swagatam says
yes definitely
khang ly says
can i use three ic 555
khang ly says
hi Swagatam Majumdar
image not risk
c3 in ic2 7555 is val?
is 1mF?
Swagatam says
Hi khang, yes it's 1uF
Peter Anongo says
Hi Swagatam. Have you tested this circuit and confirmed it to be working? Is this circuit suitable for digital electronics (PC, Led TV)?
Swagatam says
Not yet Peter, but I am sure about its results, it will work if done correctly. It's suitable for all sophisticated equipment.
khang ly says
Hi Swagatam Majumdar
sorry i have a question stupid
output is true sine or square pulse
Swagatam says
Hi khang, it's a true sine.
Anurag says
your circuits are really innovative
Swagatam says
thank you!
franco rossi says
dear Swagatam Majumdar,
in the explanation of the circuit comes to T3 but I can not find it on the diagram.
you can tell me where it is?
thanks
greetings andrea
Swagatam says
Dear Andrea, goo observation, thanks.
Actually T3 has been removed in the above updated diagram.
In the previous design T3 was connected with the common cathodes of D1, D2, however later I realized that T3 was in-fact inverting the PWMs which would cause incorrect results at the output of TR2.
Therefore I did the necessary corrections and removed it from the diagram.
……..I'll remove it from the article too, shortly.
Swagatam says
…by TR2 I mean the transformer shown in the diagram:)
biannz says
sir please in the last circuit ca i use 4n35 opto?
sir please it this a pure sine and ca it be use for long period i mean always without switching off?
sir can ne555 replace this ic (7)555? if i use ne555 can it produce same as (7)555?
please sir .
biannz says
sir please the link you gave don't work please resend again thank you
Swagatam says
the links is perfect and works, copy it correctly.
biannz says
sir thank you sir please this circuit, from ic556,ic4017 and NE555 it work but the problem is the two fets got hot,sir im asking you that i use (1k for R1) i use (10k for R2) and (104 for C1) in NE555 i did not get 62k so replace it with 68k so sir it becos of that im experiences all the problem? sir my question is it 20k preset use for 220v output or for frequency? please i need your assistance sir its this pure sine wave?
Swagatam says
biannz, the parets used are approximately correct.
I will recommed you to use te following circuit for the triangle wave generation:
http://www.next.gr/uploads/544-18813c9c29.gif
C = 0.1uF
the mosfets should not become hot without any load at the trafo output
biannz says
ok sir but please in the ic 556 where is pin3 of 556 connect to?
Swagatam says
it's unused
biannz says
sir please i want to ask you that in this circuit Make this IC 556 Pure Sine Wave Inverter circuit from firs circuit to third circuit should be connect together?
Swagatam says
yes, these three stages will integrate with each other as per the given instructions.
biannz says
sir please im going for the 556 and 555 sir you said pin 11 of 556 should connect to 555 out put in the 555 it need to be power so im asking 555 can be power by 12v BATT or it need 6v supply? sir please im talking about this circuit The triangular Wave Generator Circuit
Swagatam says
biannz, you can use 12V for the triangular wave generator circuit.
biannz says
sir please im going for the 556 and 555 sir you said pin 11 of 556 should connect to 555 out put in the 555 it need to be power so im asking 555 can be power by 12v BATT or it need 6v supply?
Swagatam says
I did not understand your question….which circuit are you referring to?
555 wii work with 12V
biannz says
sir why me i did it exactly as you said but still heating and blowing the transistors i chick every pats of the circuit nothing seem to be wrong sir i even build it Sevres times and it have cost me a lots cos our electronic pats are not chip at all sir have you ever build this circuit before do you have it pcb? sir i use 250k preset in place of 180k cos i did not get 220k preset,in my country we only have 10k pot,2kpot,2.2k pot 4.7k pot 50k pot 100k pot 500k pot we don't sell 180kpot or 220kpot no.sir please i dont care how much it going to cost me i still want to survive help me sir cos im going mad sir thank you looking forward to hear from you.
Swagatam says
bianzz, don't depend on me, i advised this to you once before…ask the questions to yourself why you are not succeeding. If you are not able to troubleshoot the problems yourself means you have not understood the circuit, or may be this circuit is not for you.
If you are having difficulty in making this design, there are many simper circuits in this blog you can try those and learn from the scratch..
All components indicated in the diagram will need to be as given, the parts values cannot be compromised.
biannz says
ok thank you im very appreciate of it the way you responds my quotations but sir in the last circuit i finally build but the transistor got hots without plugin any load sir i need your help thank you looking forward to hear from you son.
Swagatam says
Biannz, that can never happen as long as your 4017 IC is sequencing correctly in response to the clocks at it's pin14. Or alternatively you can try connecting TIP122 transistors and a smaller trafo initially for confirming all the circuit functioning as per the explained specs. If the TIP122 also becomes hot would indicate some other issue with your circuit design
you can also try using 3V zener diodes in between the mosfet gate resistors and IC4017 pinouts, this will ensure complete switch OFF of the mosfets when the pinouts are at zero potential.
biannz says
sir please i want to ask you that is it compulsory to use opto i mean to put there the ldr and led? its the circuit going to work if i did not ues LDR AND LED? thank you.
Swagatam says
You can use it only if you want to get an automatic voltage regulation.
biannz says
sir please the last circuit what is the per pose of the opto? can i use opto 4n35 or LDR and LED combination? thank you sir hope to hear from you son.
Swagatam says
only led/ldr combination will work, 4n35 will not work
biannz says
sir the lats circuit that use 3 ics (555) can i replace 47nf in place of 50nf? and also the two preset 180k can be remove and use 180 resister? sir is not that i am not follow your circuit but some of the pats lists or component are very difficult to find it that's why so forgive me for bordering you thank you sir im looking forward to hear from you son.
Swagatam says
I think we have already discussed this question earlier, 47nF can be used for 50nF and 180k can be replaced with 220K preset.
how can you use 180k fixed resistor when it's clearly shown as a preset and is crucial for setting the frequencies??
Pat Selim says
Hi, could I expand this circuit to include as many transistors as necessary, in parallel, to get a higher wattage?
Swagatam says
yes surely you can do it.
biannz says
hi sir please sorry for the question ok cos i really like your skills of creating circuits especially the inverters circuit,my question is in this circuit Make this IC 556 Pure Sine Wave Inverter circuit can i replace NE555 in place of 556? its this a real pure sine wave as its named? thank you sir.
Swagatam says
Hi bianzz,
please see the last diagram, you can do it in that way. It's a modified sine wave, equivalent to a pure sine wave.
Pat Selim says
Great circuit, however I read somewhere that it's always good practice to put a rather large capacitor on the primary transformer stage so as to avoid "dirty" AC. But you didn't include it ? Also, you don't explain, really, how a PWM waveform is somehow coverted into sine wave at the secundary stage
Swagatam says
Thanks! I have included only the crucial things in the designs, ofcourse it can be enhanced in many different ways, I leave it upto the readers to do them as per their own preferences and knowledge levels.
The PWM is manufactured inside the opamp of the 555 IC by comparing the external square waves and the triangle waves across the 555 capacitor.
ibitoye isaac says
swagatam you are great i love every page of your articles
Swagatam says
thank you ibitoye!
Siddhant Shrivastava says
thank u very much i was tooo much confused that how to design inverter bt nw i got idea
bt which transformer to be use ???
Swagatam says
transformer should be ideally a 9-0-9V and wattage as per load requirements.
Arnab Dasgupta says
Hi Swagatam,
I have gone through several inverter circuits in this blog and i wish to make one of my own. I have tried to make inverter in the past but i faced one major problem of the output transformer. I have confusion regarding this matter. Is there anything called "Inverter Transformer" of particular rating? I asked many but none of them gave me a suitable answer. Can i get it readymade ? Do i have to manufacture of my own? It will be extremely helpful for me if you kindly clear my confusion.
Swagatam says
Hi Arnab,
There's nothing called "inverter transformer" you can use any ordinary transformer having one side winding matching the battery voltage while the other side winding corresponding to 220V, that's all is required….current rating of the transformer will correspond to the load that needs to be operated, higher rating would allow higher loads and vice versa.
Sudhee Krishnan B says
sir,u are saying that one side of the transformer should match with the battery voltage.then how can one use 6 0 6 /230v or 9 0 9/230v for a 12v battery supply…?
Swagatam says
6-0-6 is a matching transformer when a PWM is used, otherwise 9-0-9 is a matching spec,
here matching does not mean that it should be exactly the same.
Anonymous says
Hi Swagatam
I'm still following your inverter posts and build your circuits then try understand them before i ask all the questions.
What is the purpose of the (2v7 zener,BC557,470 ohm resistor) and why is it necesary to have them,my my 10k output sine RMS adjust does not work without them.
Regards Robin
Swagatam says
Hi Robin,
It just a constant current configuration so that the IC2 does not get affected with supply voltage variations and current up-downs.
It is not necessary, you can remove the zener, the 470 resistor, and the transistor and just connect the positive resistor to the IC pins directly
Swagatam says
…it is not necessary if the supply is constant.
Anonymous says
dear swagatam
is this circuit able to bear a load of 2kw?if yes please tel me what will be the extra things need to add.
thanks
Swagatam says
yes it can be done by using input voltages upto 60/100v and by using transformer/mosfets capable of handling 2000 watts of power
SHIV-FOUNTAIN says
hi dear swagatam can you please tell us which type of capacitiors used in all digram whether they are porcelain or ceramic.since while buying componenet they ask me which type capacitior you want.is there major change in result if i buy wrong type capacitior.
Swagatam says
I answered this in G+
Michael M. says
Hi Sir,
first I want to express my respect to you, answering all the questions here.
My Name is Michael. I only want to ask a Special question……is it possible to immitate a tapped tranformer, with 2 equal resistors connected in series, which to connect both parallel to trafo to get a middle Point ? Only a thought….might be a weired one 🙂
Swagatam says
Hi Michael,
no that will not work, because the voltage has to pass through the winding in a push pull manner in order to generate the output voltage.
Anonymous says
Good work!
Can I parallel 2xIRF3205 total 4pcs. and use a 0-12V 1000W transformer to get more outputpower, and if, how to connect the transformer?
Swagatam says
thanks! this circuit will work only with center tapped trafos.
Anonymous says
Hi, great job, sir!
If I parallel 2pcs IRF3205, and want to use a 0-12V 1000W trafo not centertapped, is that possible? And how to connect the trafo?
Swagatam says
Thanks,
for the above circuit you will need a center tap transformer, two tap cannot be used.
vishwas poojary k says
sir i think output becommes pulse type at heavy load ??
Swagatam says
did you test it?
vishwas poojary k says
i stimulated in multisim softeware , after putting a output filter capacitor , output will be a pure sine wave but as soon as load is applied output pulses.. i have already made 4017 modified sine wave , 300watts output , its working perfect , i am thinking to upgrade it to sinewave , so i stimulated above ciruit bt output result put me in dilemma,
Swagatam says
you will have to try it practically for confirming!
vishwas poojary k says
ok.. sir can u try the above circuit practically in small scale(in your free time) ??
Swagatam says
I have simplified the circuit to a great extent in the last diagram, you can try it.
avijeet agrawal says
Hello sir,
circuit u had provided at the end of above article consisting two 555ic and a 4017ic is pure sine wave producing circuit or closer to sine wave?which Circuit is good for lcd tv and computers. the above one or one u had discussed using ic3525?
Thanks
Swagatam says
Hello Avijeet,
It's close to pure sine wave, not pure sine wave.
The above circuit better than SG3525.
avijeet agrawal says
Thanks for ur reply sir,
At the last in above article u had posted a circuit having two (7)555ic and one 4017ic.
Is 555ic and (7)555ic has some difference in their working.
I had read some where that 7555ic has a diffrent packaging (cmos) type.can i use normal ne555 ic for above circuit
Thanks
avijeet agrawal says
Thanks for ur reply sir,
At the last in above article u had posted a circuit having two (7)555ic and one 4017ic.
Is 555ic and (7)555ic has some difference in their working.
I had read some where that 7555ic has a diffrent packaging (cmos) type.can i use normal ne555 ic for above circuit
Thanks
Swagatam says
7555 consumes less current and its output is more accurate than the analogue IC555, but IC555 is able to output 200mA current which the cmos counterpart cannot….so according to me IC555 is much better than (7)555, however it largely depends on the specific application, which one suits it better.
avijeet agrawal says
Thanks for ur reply sir
So will u suggest me to use ic555 instead of ic7555 for above circuit u had discussed at end of above article.
Some more doubt i want to clear it with u
#can i use 473 instead of 50 nf capacitor.
#can 2.7v zenner will replaced with 3 v zenner
Swagatam says
both types will work, you can use 555 or 7(555) doesn't make any difference.
473 = 47000pF = 47nF, so that's fine, you can use it.
3V zener will be ok!
avijeet agrawal says
Thanks for ur reply sir
At last ,there is no any Preset used in above circuit so this circuit is fixed to produce 50hz 220v at output(approx).
which mosfet i had to use and how much on each channel for 750watt trafo
(I had couple of irfp250, urfz44,irf540,irf54n06)
Thanks
Swagatam says
You have made a good point, the last circuit is actually not set for producing 50Hz, IC1 parts will need to be changed for setting up this frequency. I'll do it soon.
Also I have added a RMS correction preset to the last circuit, I hope you have seen it.
Swagatam says
you can use single mosfets IRf540 for each channel as shown
naresh says
hai sir
This circuit 500va transformer support
naresh says
hai sir
i am using 100w invater circuit digram i use this circuit ic 4017 and irf540 and 500v transfomer but i am power supply 12v battery but why burnig trnsistor what is prablam sir please help me
Swagatam says
Hi Naresh,
The previous diagram had a mistake, I have corrected it now, please check out the new diagram and make the required modifications as per this new diagram.
naresh says
hai sir
500w invater how much rating use mosf transistor and transistor value
thank you.
Swagatam says
Hi Naresh,
use irf540n mosfet and 500 watt trafo..
naresh says
hai sir
frist circuit ic 556 circuit digrams R1,R2,C1, what is value
and total circuit connection digrams web address
thank you
Swagatam says
Hi Naresh,
I have answered in your previous comment.
for getting 200Hz adjust the capacitor value appropriately.
naresh says
hai sir
how many wattes using this circuit 500w or 1000w
what is transformer using 500va or 800v and abov reaply
thanks you.
Swagatam says
it will depend on the transformer and the mosfet rating.
naresh says
hai sir
R1, R2, C1 should be appropriately selected so that pin#5 produces a 50% duty cycle, 200 Hz but what is R1,R2,C1 val
thanks
Swagatam says
Hi Naresh,
refer to this article, the diagram is given at the end of the article:
http://www.ti.com/lit/ds/symlink/lm555.pdf
Anonymous says
I really appreciate this but I need to know something. How can we vary the voltage and is it possible to use this circuit to drive ir2110 full h bridge
Swagatam says
you will need a separate circuit for controlling the output of the inverter, the above circuit cannot be modified for that.
you can show me the h bridge circuit, I will try to figure it out.
prabath says
can't we use sine signal instead of triangular signal to generate PWM
Swagatam says
that would be even better…
Gayathri sankar says
sir, i am getting the following output from cd4047 10th pin (scale voltage/div 0.1v and time/div 20 ms) http://postimg.org/image/8vtytj0f1/
Initially i got a square pulse but now i am getting this one.I have checked my circuit a number of times,but the problem persists,I dont know what is wrong in my circuit,can this pulse be used to drive a mosfet?
my ciruit diagram
http://postimg.org/image/c7ojzxh8b/
(I used c=0.22micro farad and r=10k)
Thank you!!!!!
Swagatam says
Gayathri, the waveform looks weird, they should be like square waves, I think there's definitely something's wrong with the settings or one of the parts is faulty..
Jonathan Depusoy says
In the triangle wave generator IC555, VCC pin8 is supplied with a +6VDC. What is the reason behind the selected +6V? Looking at the 555 data sheet it can accept 4.5V min.to 18V max. Why not use the same supply power of the inverter which is the battery at 12V? Any logical explanation sir Swagatam behind the +6V?
Swagatam says
the circuit drawing was lifted from a different applications, so it's given as 6v there, it's not necessary, the supply can be provided from the existing supply also…no issues.
Anonymous says
hello sir,
i need to design a full bridge inverter. i have attached the image of the circuit (http://postimage.org/image/73swwalx5/)using cd4047.can you tell me whether it is feasible? or if any changes do help me.
Thank you!
Swagatam says
It is not that simple, though it looks correct, practically the mosfets would blow off within seconds….
see the last diagram here,this might work…
https://homemade-circuits.com/2013/03/how-to-design-inverter-basic-circuit.html
Anonymous says
Thank you sir
vishwas poojary k says
NO two or more gates of mosfets can be directly connected , if we do so mosfet gets blow off, we must connect each through 47ohm resistor..
Anonymous says
hello sir,, what should be the frequency of the 556 pin5 if i want a 60hz outpu? would it still be 200hz
Swagatam says
yes as mentioned in the article it should be 200 Hz.
Swagatam says
actually it should be 240 Hz….
Jonathan Depusoy says
What's the reason why should it be 240hz not the 200hz as mentioned before? So which freq. is better then?
Swagatam says
it's for acquiring 50 cycles across the 4017 pin outs, each input pulse at its pin14 allows one step across the outputs of the 4017, there are 5 pins to be crossed which should be covered 50 times per second……….. providing 240 pulses per second at pin 14 would result these 50 cycles at the output of 4017
Anonymous says
HELLO SIR..
HOW MANY MOSFET IRFB260N SHOULD I USE IF I WANT TO PRODUCE 500W OUTPUT POWER AND WHAT SHOULD BE THE RATING OF THE TRANSFORMER?
THANK YOU
Swagatam says
Just a couple of them would do, transformer should be 9-0-9V/70 ampere rated, and the battery 12V/100 AH minimum.
Make sure you understand the circuit first, and then commence….
Anonymous says
hi sir. can i use IRF540 for the mosfet.. battery is 12v 7.2Ah and transformer is 12-0-12 rated 12A
thank you
Swagatam says
yes you can use them
Rokai Salami says
Thanks Mr Swagatam. I have been able to build the circuit and will be testing it soon. On the power section that drives the transformer, there is no protection for the mosfets against back e.m.f. Why is that so? Rokai Salami.
Swagatam says
Yes it's a good practice to include protection diodes even though all modern mosfets carry them internally….you may put 1N5402 diodes across the drain/source of the respective mosfets.
Rokai Salami says
Thanks Mr Swagatam. But if the deadtime on the sg3525 was removed and pin 13 and 11 are tired together (correct me if am wrong) will produce a perfect squar wave. That would work right? Am looking to see if it will be possible to get the sine wave using both the 555 timer and the sg3525.
Rokai
Swagatam says
yes it can be done, but it won't be a great idea to get a sophisticated IC like 3525 for functioning like a square wave generator….because it can be done by a simple 555 circuit also.
rokai salami says
Hello Mr. Swagamatam.
Will it be possible to generate the PWM with a sg3525 and feed it to the 555 along with the triangla wave? Will the same sine wave front be achived? If possible how can it be done?
Swagatam says
hello rokai,
the 555 will require square waves and not PWM, so it won't be correct.
Anonymous says
Hi sir,
I require a full bridge inverter with spwm control,please can you design the circuit,its very urgent.
thank you!!!
Swagatam says
you may try the following circuit:
https://homemade-circuits.com/2012/10/simplest-full-bridge-h-bridge-modified.html
Anonymous says
Dear swagatam.
Is there any possibility to change dc 48 v inverter to dc 220v inverter.
Dose a mosfet support such a hi dc 220v.
thanks
Hassan.
Swagatam says
ear Hassan,
yes it's possible, there are mosfets which can handle much higher voltages than 220V.
Anonymous says
Dear swagatam,
Thanks for your support. I will check my 48 inverter mosfet number.
If the mosfet support the dc 220v. Can i disconnect the transformer and where i must connect new dc 220v suply.
As you know this inverter frequency isolator is working with dc 48v.
Could you just hilight in this.
Thanks.
Hassan.
Swagatam says
Dear Hassan,
If your transformer is a center tap type then you would require a push pull mosfet configuration for acquring AC without the transformer (n-channel/p-channel)
the circuit should be fed with 48V only.
Anonymous says
My 48 inverter mosfet number is B442N20D
IxR 414H
DB E9
These are the letters can see.
Can you please tel me weather it support dc 220v.
suply.
thanks.
Hassan.
Swagatam says
I couldn't find them on the net, not sure what they are.
Anonymous says
Hello Mr. Swagatam,
is the output waveform a pure sine wave?
Swagatam says
equivalent to a pure sine wave..
Anonymous says
hi sir, just want to ask about the signal output coming out from the drain part of the mosfet Q1 and Q2.
are they exactly in-phase?
Swagatam says
they will conduct alternately at the rate of 50 Hz.
reg says
hi sir,, what would be the output power if i use 12-0-12 12Ampere transformer
Swagatam says
Around 120 watts
reg says
hi sir, is it okay if i add 1 mosfet each parallel to each other.. would the circuit still operate well
Swagatam says
Yes you can do it, the circuit will produce more power….
Anonymous says
Hello sir,
i just simulated the triangle wave generator circuit given above and im getting a small voltage output which is around 50mV.
is that the real output?
thanks a lot
Swagatam says
Actually it should be around 1V, not sure about the actual results, try reducing the value of R4, may be that will help to increase the voltage.
Anonymous says
hello sir,
just want to ask what is the purpose of C5..
if its 1V output, is it sufficient enough to drive T3..
thanks again
Swagatam says
yes 1V would drive T3 easily.
Swagatam says
C5 is for shaping up the triangle waves along with the other associated parts….
Anonymous says
thank you for the help sir..
can i replace the mosfet with a bjt transistor like TIP35
Swagatam says
yes it can be done….for that you would also need to replace T1, T2 with 8050 transistors, and the power BJTs should have their appropriately calculated base resistors.
Anonymous says
thanks for the help sir.. appreciate it.
would it still be the same for the values of R6 and R7 if I replace T1, T2 to 8050
Swagatam says
you may have to reduce the values of R6/7 if you find the output devices not generating enough power.
reg says
Hello Mr. Swagatam,
I,m using CD4047 to produce square wave. My question is how can it be converted to sine wave.
thanx for the help
Swagatam says
Hello Reg,
You may try using a 555IC PWM circuit for tailoring the base or the gate voltage of your inverter output devices…..refer this article for help:
https://homemade-circuits.com/2012/09/make-400-watt-mosfet-sine-wave-inverter.html
Anonymous says
Hello Mr. Swagatam,
I put the image schema "Pure Sine 555" on the site here:
http://img29.imageshack.us/img29/7833/puresinus555.jpg
Or here:
http://img580.imageshack.us/img580/7833/puresinus555.jpg
Please, before sending it, can you verify that it is correct?
An error is possible because I'm not a big electronics.
Your suggestions and comments are welcome.
In particular on the part of the diagram marked a, b, c, d, which is a summary of safety voltage.
Regards
Marcelin.
Swagatam says
Hello Marcelin,
That's great, you have done a lot of hard work in configuring the whole design, and everything looks correct to me…..
I'll publish it as a new article with detailed explanation in this site very soon.
I'll be associating your name in it with full credit.
Kindly wait until it gets published.
Thanks very much!
Anonymous says
Hello again Mr. of France,
I drew the pure sine with 556 on one page.
But with 3 x SA 555 (- 40 ° C to + 85 ° C). Two SA 555 replaces the 556, I did not.
I added a safety summary.
Is it possible to pass you a picture?
Cordially.
Marcelin.
Swagatam says
Hello Marcelin,
surely you may send it……. I'll publish it here for the benefit of other readers.
Upload it on imageshack.us, and give me the link, I'll do the rest.
Regards.
Anonymous says
hi sir,thanx for the recomendation.Can i used 250 to 5000 watts pwm dc/ac 220v power inverter author by nickk?or whats the difference betwen your design compare to him?Because we have 20 units of computer in our internet cafe and i need high wattage of inverter.I wish that you could design 5kva inverter,using sg3525.Hoping for your help thanx a lot.
Swagatam says
Yes you can build it, there's not much difference, the only difference is the use of mosfets in my circuit and a low voltage cut-off included in my circuit.
just by adding more mosfets and by using an appropriately rated transformer, you can easily upgrade the circuit to produce 5kva
Anonymous says
Hi sir i give my time and efforts to study the diagram im planning to build pure sine inverter in our internet cafe.Is this iverter is applicable? or can you make pure sine wave with sg3525 use? thanx for the help
Swagatam says
Hi,
Pure sine wave may not be strictly required, you may go for modified sine wave inverter, I have already posted one SG3525 circuit, you may try it:
https://homemade-circuits.com/2013/01/modified-sine-wave-inverter-circuit.html
Anonymous says
IC 4017, Why pin 16 Vss, but pin 8 Vdd??
Anonymous says
Hello Sir Swagatam from France
My English is very difficult.
I intend to make this arrangement with amplifier and transformer 3000 VA
Just a doubt: The pin 14 of IC 2 is connected to pin 5 of IC 1 and 8?
Thank you for confirming.
Best regards
Swagatam says
Hello,
Yes pin14 of IC2 is connected to pin5/pin8 of IC1
Your English is good.
Regards.
Anonymous says
Hi Swagatam,
can i use this circuit to a inverter using CD4047?
Regards,
Swagatam says
Yes, there's no harm in trying it.
Anonymous says
Hello sir. This circuit I like … but you proved this circuit? I want to know if it really works well to connect a desktop PC and a notebook, laptop, LCD TV thank you very much
ATTE: Joseph.
Swagatam says
Hello Joseph,
No I haven't checked the circuit practically, but to me it looks a feasible idea….yes hopefully this will be perfectly suitable for all types of sophisticated equipment.
Syed Aquib says
hi sir,
i am planning to build a inverter for normal home use and this is my 1st time but i am good at this electronics stuff so sir plz recommend me good circuit and it be able to handle 4 60watts lights and atleast 2 fans please help me out…
Swagatam says
Hi Syed,
You can try the following circuit:
https://homemade-circuits.com/2012/09/mini-50-watt-mosfet-inverter-circuit.html
Just increase the transformer rating to 200 watts(12-0-12V/20amps) and use a 12V 40 ah battery with it.
Anonymous says
I have an idea to generate pure sine wave invertor without PWM because its not perfactly sine wave but nearer to sine wave.
Use IC8038 for frequency and Sine wave generator.( From pin 2 it generates Sine wave and from pin 8 we can adjust frequency)
Amplify output of sine wave with desire frequency by Power Transistors.
Connect transistor output with Xmer.
Swagatam says
That's appreciable! Thanks!
However first of all the suggested IC is obsolete now.
secondly, pwm pulses are made up of chopped square waves which become more suitable for transistors and help to keep them cooler compared to exponential sine waveform inputs.
By the way I have discussed quite a few pure sine wave inverters in this blog using sine wave generators withou incorporating PWMs
foma says
hello sir Swagatam, i will be gratefull if you can help me on Pure Sine Wave Inverter circuit using ic sg3525 with mosfet and a center tap transformer.
Swagatam says
Hello foma,
I will try to update it soon in this site.
Anonymous says
Hello sir on the triangular wave generating circuit, how I can calibrate? Because I have no oscilloscope … And do not get there alone potentiometer 20k 22k and 25k … Many thanks. ATTE: Miguel.
Swagatam says
Hello Miguel,
I am sorry there isn't any way of confirming the waveforms without an oscilloscope….cannot think of any other alternative presently.
vishwas poojary k says
we can istall visual analyser softeware in pc , den we can use pc as oscillocsope (20hz to 20khz) .. input is mic input in sound card , appropriate strobe must prepared , use o.1u capacitor , 1M ohm resistor in serias with phase for 220 v ..
Anonymous says
sir,
Whats the wattage of the inverter and how can it be increased…
And have you tested it functionality..
Thanks
Swagatam says
wattage always depends on the transformer, battery and the output device ratings….select it appropriately according to your needs.
The circuit has not been tested practically.
Anonymous says
hello sir Swagatam. a question, I like this circuit. but I need to know the values of R1, R2 and C1 to 220vac / 50hz in the inverter output.
also pin 3 of IC556 where it connects? … thank you very much
ATTE: Miguel, from Buenos Aires Argentina
Swagatam says
Hello Miguel,
You may use the calculator given in this link for finding out the right values:
http://www.royalrife.com/555_calculator.html
pin3 may be connected to ground via a 0.01uF cap.
Anonymous says
thanks so much for the circuit, but how do we vary frequency?
Swagatam says
welcome! frequency can be varied by varying C1.
Swagatam says
Hi Roger,
Triangle frequency should be 50 or 60 Hz as per country specs.
C1 is a filter capacitor, can be removed…
Anonymous says
hi sir
my name's YAO
i made this circuit but it doesn't works
i don't anderstand the rule of D1 and D2 in the schematic
Swagatam says
hi yao,
make the stages separately and test…then integrate them together….read the following article to know how IC555 works to produce modified PWM pulses for the inverter:
https://homemade-circuits.com/2012/12/how-to-use-ic-555-for-generating-pwm.html
D1 and D2 is for chopping the square waves to the applied PWM form…