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Make This 1KVA (1000 watts) Pure Sine Wave Inverter Circuit

A relatively simple 1000 watt pure sine wave inverter circuit is explained here.


As can be seen in the first diagram below, the configuration is a simple mosfet based designed for amplifying current at +/-60 volts such that the connected transformer corresponds to generate the required 1kva output.

Q1, Q2 forms the initial differential amplifier stage which appropriately raises the 1vpp sine signal at its input to a level which becomes suitable for initiating the driver stage made up of Q3, Q4, Q5.

This stage further raises the voltage such that it becomes sufficient for driving the mosfets.

The mosfets are also formed in the push pull format, which effectively shuffles the entire 60 volts across the transformer windings 50 times per second such that the output of the transformer generates the intended 1000 watts AC at the mains level.

Each pair is responsible for handling 100 watts of output, together all the 10 pairs dump 1000 watts into the transformer.
For acquiring the intended pure sine wave output, a suitable sine input is required which is fulfilled with the help of a simple sine wave generator circuit.

It is made up of a couple of opamps and a few other passive parts. It must be operated with voltages between 5 and 12. This voltage should be suitably derived from one of the batteries which are being incorporated for driving the inverter circuit.

The inverter is driven with voltages of +/-60 volts that amounts to 120 V DC.

This huge voltage level is obtained by putting 10 nos. of 12 volt batteries in series.


The below given diagram shows a simple sine wave generator circuit which may be used for driving the above inverter circuit, however since the output from this generator is exponential by nature, might cause a lot of heating of the mosfets.
A better option would be to incorporate a PWM based circuit which would supply the above circuit with appropriately optimized PWM pulses equivalent to a standard sine signal.
The PWM circuit utilizing the IC555 has also been referred in the next diagram, which may be used for triggering the above 1000 watt inverter circuit.






Parts List for the sine generator circuit


All resistors are 1/8 watts, 1%, MFR
R1 = 14K3 (12K1 for 60Hz),
R2, R3, R4, R7, R8 = 1K,
R5, R6 = 2K2 (1K9 for 60Hz),
R9 = 20K
C1, C2 = 1µF, TANT.
C3 = 2µF, TANT (TWO 1µF IN PARALLEL)
C4, C6, C7 = 2µ2/25V,
C5 = 100µ/50v,
C8 = 22µF/25V
A1, A2 = TL 072

Part List for Inverter

Q1, Q2 = BC556

Q3 = BD140

Q4, Q5 = BD139

All N-channel mosfet are = K1058

All P-channel mosfets are = J162

Transformer = 0-60V/1000 watts/output 110/220volts 50Hz/60Hz


The proposed 1 kva inverter discussed in the above sections can be much streamlined and reduced in size as given in the following design:

The diagram also shows the method of connecting the battery, and the supply connections for the sine wave or the PWM oscillator stages.

Here just four mosfets have been used which could be IRF4905 for the p-channel, and IRF2907 for n-channel.



Complete 1 kva inverter circuit design with 50 Hz sine oscillator




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  • 204 comments:

    1. hi mr swagatam about the transformer how is it wired to the inverter? im confuse! Regards

      ReplyDelete
      Replies
      1. Hi Roger,

        The circuit operates at +/-60 volts which are derived from 10 nos of 12 batteries. All the 10 batteries are arranged in series, the joint at the 5th/6th battery +/- points becomes the ground, while the end terminals of the series become the positive and the negative of the supply.

        The transformer is connected across the mosfets and the ground derived from the 5th/6th connection battery.

        Regards.

        Delete
      2. ok so the transformer must be a center tapped for this configuration im just concern because on the circuit it doesn't show a center tapped transformer, what is the need for a 60-0-60v primary or both ends meet together? Regards.

        Delete
      3. No, the transformer does not have a center tap, rather the supply has a center tap.

        The center tap of the supply is derived from the 5th/6th battery connection and connected to one of the transformer ends, indicated as earth.

        This earth also becomes the negative point of the sine generator or the PWM circuit.

        Delete
      4. hi sir about charging the batteries how will it be possible?
        Regards.

        Delete
      5. You will have to build a special battery charger unit using a made-to-order 120V sec. transformer, rated at 1/10th of the involved battery AH.

        Delete
    2. ok thanks......great job man...your work is well appreciated D-tech

      ReplyDelete
    3. hey Mr. Swagatam

      Please give me the detail making of pure sine wave inverter for 12v dc to 230v ac for home use

      which i could make myself
      regards

      ReplyDelete
      Replies
      1. Hi Rajan,
        you may try the one shown in this article, use just 4 mosfets initially and see the results.

        Regards.

        Delete
    4. i like to make a pure sine wave inverter for dc 220 volt to ac 220 volt. can u send a circuit to me.
      regards,
      m.siva subramanian

      ReplyDelete
      Replies
      1. You can try this circuit:

        http://homemadecircuitsandschematics.blogspot.in/2012/05/how-to-make-transformerless-inverter.html

        just feed the input from a sine generator circuit...........

        Delete
      2. Hi veniyan, where do you get your 220V DC from? remember DC in high voltage is lethal and can kill you instantly with AC you still have a chance to get away but not with DC.

        Delete
    5. Mr. Swagatam

      can this circuit run a PA system with 8 10' speakers? ty

      ReplyDelete
      Replies
      1. According to m, it should be OK to run a PA with this inverter.

        Delete
    6. Hi sir, i am navanithan im studying BE EEE Dept so i have large interest for to make a no of project. First i have a 1000watts inveter and 2000watts sound amplifier using power ic. So i have need to some help from you. So please give the above circuit with description and range then i will start the project. Thanking you sir

      ReplyDelete
      Replies
      1. Hi Navneetha,

        You can try the 1000 watt inverter circuit shown in the above article.

        I provided the necessary explanation in the article.

        Regards.

        Delete
    7. sir i want to exchange panel to other materials what can we use

      ReplyDelete
    8. what is the efficiency of this circuit

      ReplyDelete
    9. Swagatam,

      could this inverter be powered by 24 volt battey (2 12 volt battery) and get 120v a/c out from the transformer. what would i have to change?

      thank you, DEREK

      ReplyDelete
      Replies
      1. Hello Derek,

        You won't have to change anything, just upgrade the transformer rating as per the required output.

        voltage to A1/A2 circuit should be supplied from one of the batteries (12V).

        Delete
    10. haii sirr...i'm very much interested nd fascinated with ur wrks....
      is dis inverter is economical dat using 10 batteries...those many mosfets etc...
      i wanna make this in my home sir...so plss kindly help in dis regard...
      thank u sir..
      and using ic555 u hadd given a circuit on pwm technique...wat is d purpose of dat nd hw cn dat relates to the inverter..i,m unable to understand plss gve me some xplanation sir....nd even the above information...
      thank u sir...awaitng for ur reply sir...

      ReplyDelete
      Replies
      1. using higher voltage makes the design less complicated, compact and allows smaller transformer to be used.

        you can reduce the mosfets numbers by using modern higher rated mosfets.

        555 PWM input will enable to tailor the output RMS as per the standard AC RMS value.

        Delete
    11. Hello sir,

      I am Naresh from Hosur, presently i am working in Ashok leyland ( Dept - Product Development).

      Can u pls advise me how to make a 1KVA inverter using a 12 V car alternator? It's possible to make inverter using alternator?

      Thanks,

      Naresh

      ReplyDelete
      Replies
      1. Hello Naresh,

        A 1 kva inverter would require a 100 to 200 ah current at 12V for satisfactory operations, an alternator won't provide that much of current so the idea isn't feasible.

        Delete
      2. OK sir...

        I have a 12V 75 AH alternator. how much of power can produce using this?

        Thanks
        Naresh

        Delete
      3. Do you mean 75 Amps? because alternators are not rated at AH rather only in amps.

        even at 75ah, you would get 12 x 75 = 900 VA max.

        This would be its extreme limit, and would damage the alternator very soon.

        Delete
      4. Yes sir it is 75 Amps Alt. Thanks for your valuable informatio and swift reply.

        Sir i have a doubt. I want to convert 16 V 75 A AC to 12 V 75A DC. What type of Diode bridge (for rectifying) (eg. 1N4007 or) and resistor (for limiting voltage) should i use?

        Thanks
        Naresh

        Delete
      5. You will have make the circuit which is shown in this article, don't use the diodes which are placed at the ground of the IC.

        http://homemadecircuitsandschematics.blogspot.in/2012/11/high-current-transistor-tip36-datasheet.html

        You'll have to put 4 transistors in parallel including the emitter resistor.

        Delete
    12. HI swagatam sir, this mic. i want to made 500watts inverter from 12v source. what type of transformer i need to be use.how may amps transformer is the best one.i want to learn more about the trsnsformers which is the best one.

      ReplyDelete
      Replies
      1. Hi Mic, please refer to the following links, it has many detailed inverer circuit designs, you can choose any suitable one from them:

        http://homemadecircuitsandschematics.blogspot.in/p/sine-wave-inverters.html

        Delete
    13. Can this inverter run on 12 volts

      ReplyDelete
    14. What would i need to do to make this circuit work off 12 volt with a output of 120 volt

      ReplyDelete
      Replies
      1. with 12v supply the circuit would require a HUGE transformer, rated at around 100amps....so it's not recommended.

        Delete
    15. hello sir,,,
      i want to make 1000watt ups for home to run load of ceiling fans do u have any article or help related to it?

      ReplyDelete
      Replies
      1. To make an UPS you will need to make a inverter first, so you can begin with the above circuit, once you finish this I'll help you to proceed with the further things.

        Delete
    16. yes,i m trying to do,,but the problem is i have 12v 100amp battery and 1000watt transformer and want to use it for inverter,,but above circuit works on more than one 12 v battery which is very costly to me,,,if there is any solution? thnx

      ReplyDelete
      Replies
      1. The above circuit will work with 12V supply also, but with 12V supply a 1000 watt inverter will become too heavy with thick wires and huge heatsinks, that's why higher voltage is recommended.

        Delete
    17. Hi swagatam sir, tis is kabir, i have an enquiry, im doin a project and trying to power up an AC load of 230V from a solar panel rated at 50W 12V DC, can i do so using a power inverter with PWM as input as shown above? if not my mistaken,the circuit above has an output of 120V rite so defnitely my project cant support it as my country AC is 230V and the voltage input is how much DC (is it 12V DC)? any recommendations circuit to solve my problem? tq

      ReplyDelete
      Replies
      1. Hi Kabir,

        50 watt panel is too low to power an inverter directly, you will need at least a 100 watt solar panel for this.

        You can try a simple inverter circuit that's explained in the following article:

        http://homemadecircuitsandschematics.blogspot.in/2012/09/mini-50-watt-mosfet-inverter-circuit.html

        Delete
    18. hi,im kabir here again,jus wanna add on for my previous question is that the load is a 1000W 230V and im using a 50W 12V solar panel as a source and a bank of probably rated at 200Ah, possible?

      ReplyDelete
      Replies
      1. That won't be enough, you will need a minimum 200 watt panel for charging a 200 AH battery within 6 hours, please confirm it further with your panel dealer

        Delete
    19. hey, i would like to build an inverter for 3-phase (380V) submersible pumps. The pump is rated 5.5kW and is used in a borehole...Can u help

      ReplyDelete
      Replies
      1. If possible I'll try to design it and post it for you soon

        Delete
    20. hey, please i would like to know the function of the function of c2 in the 555 pwm circuit. I need to connect a comparator to the 555 timer circuit for my switching supply

      ReplyDelete
      Replies
      1. C2 is for keeping pin#5 unresponsive to stray noise and disturbance that may be present in the supply and atmosphere

        Delete
    21. Hi, I'm building a hydro, as a generator I'm using truck alternator 24V 100A, could I use the above design inclusive PWM, and also what would I have to change in order to double its output to 2kV ?
      Thank you for your reply. Ladia

      ReplyDelete
      Replies
      1. Yes you can use it.

        You can increasing the input voltage and the trafo primary voltage appropriately for increasing the output wattage to the desired levels, without increasing mosfets nos.

        Delete
    22. Mr swagatam thank you for the good job sir i want to build this circuit named Make This 1KVA (1000 watts) Pure Sine Wave Inverter Circuit to power my house so please help me build it my 1th question im going for the LM555 where is that point show 3 to 15v dc from pin 4 of the ic lm555 going to connect second question in the TL072 A1,A2 where is the point show plus symbol from pin8 of the A1 connect and A2 pin7.can i use one of this mosfets IRFP250 IRFP260 AND 2N3205 OR 2N3055 please sir kindly help me cos we having a lots of problem in our electricity thank you i am looking forward to hear from you son.

      ReplyDelete
      Replies
      1. Hi Stev,

        you will need two 12V bats connected in series for operating the above inverter. Meaning together the battery will generate 24V

        The series connection will become the ground (earth symbol) of the system.

        For the IC 555, the positive of the battery which generates 24V will become its positive supply while the series link of the batts will become the ground of the circuit, same can be done for the A1/A2 circuit if it's being used in place of the 555.
        This also means that the earth or the ground of all the circuits can be made into a common line.
        pin7 of A2 will connect with the inverter input.

        Delete
    23. than you sir for the respond but sir there is one thing i don't understand in the mosfet you named some of the mosfet Q6,Q7,and Q9,Q9,please which of them are the N-channel mosfet K1058) and P-channel mosfets J162) in the Make This 1KVA (1000 watts) Pure Sine Wave Inverter Circuit,thank you stay bless looking forward to hear from you.

      ReplyDelete
      Replies
      1. I just cut/pasted the first mosfet section across for indicating the following identical moset stages, that's why it's showing a repetition of the same mosfet, please ignore it, and simply repeat all the section identically with 0.22 resistors on each and every mosfet source

        Delete
    24. thank you for the replied but sir i still don't get you right can you please come again or you mean all the 20 mosfets should be the same mosfets? and also the diode (1s207) i never head that kind of that diode before any diode can be use or what is the value of it? thank you looking forward to hear from you stay bless.

      ReplyDelete
      Replies
      1. all the upper n-mosfets are same and all the lower p-mosfets are same.
        you can use 1N4148 diode in place of the shown unknown diode.

        Delete
    25. ok sir thank you very much for the respond sir i build it but it dont work why sir is there anything i did not connected? ok let me tell you how i connect the circuit, in the 555 there is line that from it 7pin show (PWM pulses) i connected it with A1 pin8 that show positive symbol to the Btr positive im i right? and also i connected pin7 of A2 to the sine input sir in the 555 you connect pin4 and 8 together and you show 3 to 15v DC where is that going to? thank you sir for your time on me.i am waiting for you reply before i will continue the circuit Make This 1KVA (1000 watts) Pure Sine Wave Inverter Circuit.

      ReplyDelete
      Replies
      1. There are many things that must be taken care of here. The circuit will require a dual battery supply, example 2nos 24V batts in series. the series connection will become the ground.
        the preset will need to be adjusted correctly or alternatively it can be simply replaced with two series connected 1N4148 diodes, anode up, cathode down.
        try with the 555 circuit first and using just two mosfets

        Delete
    26. sir im very confused why becos in the parts list there is C4,C6,C7,C5,and C8 while its not in the circuit i can only see C1, C2, and C3 in the op am TL072 sir im talking about this circuit Make This 1KVA (1000 watts) Pure Sine Wave Inverter Circuit here are the parts list

      All resistors are 1/8 watts, 1%, MFR
      R1 = 14K3 (12K1 for 60Hz),
      R2, R3, R4, R7, R8 = 1K,
      R5, R6 = 2K2 (1K9 for 60Hz),
      R9 = 20K
      C1, C2 = 1µF, TANT.
      C3 = 2µF, TANT (TWO 1µF IN PARALLEL)
      C4, C6, C7 = 2µ2/25V,
      C5 = 100µ/50v,
      C8 = 22µF/25V
      A1, A2 = TL 072

      Part List for Inverter

      Q1, Q2 = BC556

      Q3 = BD140

      Q4, Q5 = BD139

      All N-channel mosfet are = K1058

      All P-channel mosfets are = J162

      Transformer = 60-0-60V/1000 watts/output 110/220volts 50Hz/60Hz

      ReplyDelete
      Replies
      1. zinnaboy, please follow the diagram only, I might have put the parts list of "simple sine wave inverter" which is quite similar to the above design.

        So please follow the diagram only.

        Delete
    27. thank you sir for the humble replied cos some time we asked questions that almost make you upset but becos of the sacrificed you ignore and answer thank. so if i understand well the out put of 555 and out put of A1/A2 should connect to the inverter in put right?

      ReplyDelete
      Replies
      1. yes that's correct, but make sure you do the connections as instructed in the previous comment.

        Delete
    28. hi sir i build this circuit Make This 1KVA (1000 watts) Pure Sine Wave Inverter Circuit but the fets got hots without load please help me solve the problem thank you sir

      ReplyDelete
      Replies
      1. Hi Bianz, connect small flashlight lamps in series with positive and the negative lines of the circuit...these lamps should be rated at the battery voltage level.
        now without connecting any load switch ON power to the circuit.
        The flashlights will light up brightly, now carefully adjust the preset until the lights just shut off. This setting will ensure that your mosfets stay cool when there's no load.

        Delete
    29. thank sir but one thing is that when i switch on the power to the circuit the 0.22 ohms resister blow i used only 2 fets (K1058),(J162) for trying before i go ahead and build bigger one please i need your help sir.

      ReplyDelete
      Replies
      1. biannz, keep the trafo wire disconnected initially, and connect it after power switch ON, if still it the 0.22 blows off means there's something seriously wrong with your circuit.

        Delete
    30. hi Sawagatam, I am new here but you seem to be in the know. I have some 250volt 250watt solar pannels and some 30 12 volt 240ah batteries, I want to make a transformerless inverter, do you have any sugestions for me? like battery pack voltage. I was thinking of about 216vdc before switching as I know that this will affect the ac voltage.

      ReplyDelete
      Replies
      1. Hi Simon, you will need a full-bridge inverter (without transformer) circuit for implementing the application.

        I'll be publishing one such circuit soon in this blog, in the meantime you can search it online to get a idea about the design.

        The batteries can be connected in series for getting the required 216V.

        Delete
      2. sir thank you sir i did it a exactly as you said but still blowing the fest and the resistor it happening to one side i used 2 most fest N-channel mosfet K1058
        channel mosfets J162 , sir in the inverter i use 18pf in place of 15pf,and the resistors i used 5.6 in place of 5.1 cos it not aveable here im asking sir is it the cost of problem? sir i will be very glad if will be able to build this circuit so please sir help me sir thank you i hope to hear from you son.

        Delete
      3. biannz, the preset needs to set correctly first....alternatively you can replace the shown preset with two 1N4148 diodes back to back in series. anodes will be upwards and cathodes will be downwards.....

        Delete
      4. hi sir i understand but want to ask you a little question where is the 1k resistor which indicate ground connect to is it connect to the positive and negative center of th batt or directly to the negative of the batt which generate 24v? thank you your assistant.

        Delete
      5. hi biannz, pls see the last diagram, i have shown how to connect the batteries and the supply connections for the oscillator circuit

        Delete
      6. ok thank you sir but one thing is how can i post or upload so that you can see pics can you give me your email address if you don't mind? i prefer to chart with you live but i don't think that would be possible thank you sir.

        Delete
      7. you can use Google drive and create a image link through it and provide me with the link.

        Delete
      8. sir please can i use two 12v batt in series for test?

        Delete
      9. yes can be used but it will give 50% less power

        Delete
      10. ok sir please i sent you some pics to this email homemadecircuits@gmail.com please check and correct it if any wrong connection.

        March 24, 2014 at 3:41 PM

        Delete
      11. bianzz, i cannot check your circuit due to lack of time...you will have to do it yourself.
        You should first make it on a general purpose board going for a PCB

        Delete
    31. .....than compared to two 24V batteries

      ReplyDelete
    32. sir please i have sent you a pic of the three circuit i have connect all so please kindly check it out if it correct or not im waiting for your reply sir thank you.homemadecircuits@gmail.com

      ReplyDelete
      Replies
      1. The connections are wrong.
        do it exactly as shown in the last diagram above.
        Use only one pwm circuit out of the two which are shown, either the one which uses the two opamps or the the one with 555 IC.

        Delete
    33. sir so you mean only two circuit should be connect not all the three circuit,i should chose any of them to connect the inverter isn't it sir? i have sapirate them see the connection if not please correct it and send it to this email address(
      danieladusie@gmail.com) this is the email address that i sent to(homemadecircuits@gmail.com)

      ReplyDelete
      Replies
      1. biannz, please see the last design in the above article.

        Delete
    34. thank you sir so can i use the one with ne555 too if want? i mean can i chose one of the two circuit to feed the sine input any of them with the same connection?

      ReplyDelete
      Replies
      1. Yes you can use 555 pwm input also, connect it in the same manner as done for opamp oscillator

        Delete
    35. ok sir thank you for respond,sir please i want to know if this circuit can handle or supply 5 BIRD ROM with one LCD flat-mar TV one refrigerator 5 ceiling fans and two computers? sir i want to use 4 12v solar the bigger and 0-48 Tranf and also good heat sink for the fets,sir if you confirm that this circuit
      Complete 1 kva inverter circuit design with 50 Hz sine oscillator can handle the house then i use solar panall instead of electricity to charge the BTT,thank you sir.

      ReplyDelete
      Replies
      1. Biannz, according to me the above design will be able to handle the specified appliances....however I cannot provide guarantee for anything.
        Better to build a smaller version by using two mosfets, two 12V 7.5 ah batts, if everything goes right as per the expectations, you can proceed by upgrading the stages appropriately.

        Delete
    36. ok sir i understand you very well it a good i dear i will do exactly as you said.

      ReplyDelete
    37. sir please i need your help i finish build this circuit but unfortunately i did not gets 0.2E so i used 0.22E the problem is when i connect the 0.22E and the fets got very hot and it almost burn.

      ReplyDelete
      Replies
      1. biannz, remove the sine oscillator input, and short circuit the inverter input to ground and then check whether the mosfets are getting hot or not.

        If yes, then there could be something not correct with the connections.

        Delete
    38. sir thank you sir please i did as you said but it still got hot sir i build the circuit as the way it is i go over and over i check every the circuit i connect everything where it should connected so sir my observation i didn't miss the connection so please help me

      ReplyDelete
      Replies
      1. without an input signal the fets will never heat up, i have the tested the design and it worked perfectly for me.
        you circuit has some fault for sure get it checked by a expert.

        i had cautioned you before not to try something which you cannot troubleshoot yourself.

        Delete
    39. sir i use Proteus and tell me IRF2907 have no model specified,simulation failed due to partition analysis error(s) sir tha is how it tell me so what does that mean? any help?

      ReplyDelete
      Replies
      1. biannz, for simulation purpose you can use any n-channel and p-channel mosfets in the circuit.

        Delete
    40. sir please in this circuit it Q8 AND Q9 N-channel or P-channel?

      ReplyDelete
    41. Hi Swagatam

      Recently, the transformer of my UPS (purchased from market 3 years ago) is becoming very hot, such that strong smell can be felt in the room.

      What could be the reason?

      ReplyDelete
      Replies
      1. Hi Abu-Hafss,
        May be it incorporates some kind of voltage regulation circuitry which has failed now and as a result excessive voltage and current is being fed to the transformer input winding.

        Delete
    42. Transformer = 60-0-60V/1000 watts/output 110/220volts 50Hz/60Hz
      what do mean 60-0-60?

      ReplyDelete
      Replies
      1. sorry, it should be 0-60V and not 60-0-60

        it's the voltage rating of the primary side winding of the inverter transformer.

        Delete
    43. how to we can 20 volt dc convert into the ac 220 volt please

      ReplyDelete
      Replies
      1. you can try the following circuit:

        http://homemadecircuitsandschematics.blogspot.in/2014/06/simple-high-voltage-generator-circuit.html

        Delete

    44. please lm555 will produce the same sine wave as tlo72 oscillator?

      ReplyDelete
      Replies
      1. 555 will produce pwm modified pure sine wave, A1, A2 will produce exact pure sine wave

        Delete
    45. sir

      i want to try this circuit again but my problem is the 15pf i search every where but i don't get it, it very difficult

      ReplyDelete
      Replies
      1. daniel, you can try any closer value, it's not so critical

        Delete
    46. sir please can i use variable resistor to adjust so that i can get 14k3 or 12k1 cos it difficult to get that value can i?

      ReplyDelete
      Replies
      1. yes you can use presets for adjusting the values

        Delete
    47. in the parts list you have a "2µ2" value for C4, C6, C7 I cannot find such a value was that a typo?

      ReplyDelete
      Replies
      1. yes it's a typo from the previous extraction, just remove the Â

        Delete
    48. ok one more thing the 2uf capacitors which I should put two in parallel are they the big 250v/450v caps found in fans because that's mostly what I see.

      ReplyDelete
      Replies
      1. No, these are small 25V rated, tantalum types are preferred for their low leakage properties and high accuracy.

        Delete
    49. if thats correct which voltage caps should I use.

      ReplyDelete
    50. sir
      please can i use this TL072 oscillator to connect to another circuit you named it simple pure sine wave? that simple pure sine oscillator also use tl072 but i don't want to use that circuit i prefer this the second oscillator, can i use it for that simple sine wave power stage? thank you.

      ReplyDelete
      Replies
      1. daniel, yes you can use the PWM version with that circuit input

        Delete
    51. ok sir thank you im going to try it

      ReplyDelete
    52. sir please i build this oscillator TL072 it work very well i got correct pure sine wave but if i connect it to the inverter the fets and the 0.22 ohm resistor got very hot can you help me with that? i tried to send you the pic but it couldn't go through but i well try again after hearing from you,please don't forget to answer this too,sir please can i use irf540n in place of irf2907? thank you

      ReplyDelete
      Replies
      1. on what situation are the fets heating up? on power switch ON... without input signal and without load...or under what conditions?? please specify.

        Delete
    53. ok sir
      im trying to troubleshot if i couldn't i well inform you so that you can you can help me,but please answer this for me sir please i want to use this TLO72 oscillate for center tap transformer may be one of your cd4017 circuit i think it have one in put or it can be possible?thank you hope to hear from you.

      ReplyDelete
      Replies
      1. i did not understand what you are saying....

        Delete
    54. sir i mean i want to use the tl072 circuit to feed cd4017 circuit so that i can use center tap transformer cos the cd4017 it have one input which is pin 14 the out put is many but we anomaly use pin2 and pin7,you have cd4017 inverter circuit so i want to cut it pmw and use this tl072 sine wave oscillator, can it work? sir please my English is not good so please try to understand what mean thank you.

      ReplyDelete
      Replies
      1. No, that's not possible! It doesn't work that way.

        Delete
    55. sir
      please i have sent you some wave form of TL072 oscillator check it out if it better cos if i connect to the inverter it dont work one side got very hot almost blow my fets any help sir?, thank you.

      ReplyDelete
      Replies
      1. Daniel, is the heating happening with loads connected or without loads?

        and when the input sinewave input is removed are the mosfets returning to normal temperature?

        what rating transformer did you use?

        did you check the quiscent current of the circuit.

        did you connect the two 1N4148 diodes at the collector of Q3?

        Delete
    56. yes sir the diode is connected, it got hot without load ,i use IRF540N in place of IRF2907 cos IRF2907 it difficult to get it,or can you please tell me common N-CHANNEL MOSFETS?

      ReplyDelete
      Replies
      1. daniel, do not connect any input signal, initially keep the input 22k end shorted to ground.

        now power the circuit with small 12V flashlight bulbs in series with the battery supply lines (+) and (-).

        If the bulbs glow brightly would mean something's wrong with your circuit.

        The bulb glow will suggest that the quiescent current is too high for the circuit and it has not been configured correctly.

        in a good circuit the bulbs will stay shut off

        Delete
    57. God day Sir
      I would like to ask for your help if you have a 5kw pure sine wave inverter. with an input/output 24Vdc/250Vac 60 hertz design. I'm very much fascinated with your designs. I would highly appreciate it if you could help me with this.
      Thanks and best regards.
      Radley

      ReplyDelete
      Replies
      1. Hi Radley, you could probably try the following design, you can try replacing the ferrite core trafo with a standard iron core transformer having 5kva rating

        http://homemadecircuitsandschematics.blogspot.in/2014/07/5kva-ferrite-core-inverter-circuit.html

        Delete
    58. I'm very much fascinated with your design. I would like to ask for your help if you also have a design for 5kw pure sine wave inverter and an input/output of 24Vdc/250Vac 60hertz. I would highly appreciate it if you share it with me.
      Thanks and best regards.
      Radley

      ReplyDelete
    59. hi sir long time yes am was very busy,so now am back to the blog th last time i said this circuit got hot you answer me but unfortunately i couldn't do it as you said so now i have a time am going to stat it so i will come for your aid if

      ReplyDelete
    60. sir plse can i use irf540n in place of irf2907? thank you.

      ReplyDelete
    61. the transformer used in this circuit has a 60v primary and 110/220 output at about 10amps where can I get such a transformer?

      ReplyDelete
      Replies
      1. 60v or higher trafo is used for minimizing the current requirement of the inverter, you could as well use a 12V trafo with a 12-0-12V batt for the same results, but that would mean the amp rating going up significantly.........

        Delete
    62. Oops forgot to mention in the tricky challenge.........it would be far better if a swich for sinewave,squarewave,traingle and sawtooth wave. if not at all possible,make it sinewave alongwith PAM/PWM/PPM controller

      ReplyDelete
    63. Could a 12-012 transformer at 10amp be used and does it mean I could only use a single 12 volt battery

      ReplyDelete
      Replies
      1. yes a 12-0-12 trafo can be used with a single 12V battery, in fact the trafo could be a 9-0-9v ideally.

        Delete
    64. In that case look at the connection in the diagram that the positive lead from the battery on the right connected to q7 would that connection still be made using one battery or just the portion with the battery to the left?

      ReplyDelete
      Replies
      1. I am sorry, ignore the previous comments by me...a center tap trafo and a single battery will not work for the above 1000w inverter concept....

        Delete
    65. The transformer i have is 12-0-12 i used on 12v battery and i didnt get any out out, the fets got hot in seconds so can i use 2 12v batteries in series and use that same transformer that i have

      ReplyDelete
      Replies
      1. yes a dual battery is required for the design so use two 12v batts iin series...
        in the transformer, use any of the 0-12 tap

        Delete
    66. I tried but still no volt out from the transformer the fets get hot

      ReplyDelete
      Replies
      1. remove the trafo and the input and then check if the fets are getting hot or not

        Delete
    67. Replies
      1. Dear swagatam r u test this design by ur self or just present your theoretical view on this design because your most viewers complaining about geting hot issue of fets's and 0.22 ohms resistor plz answer sincerely thanks

        Delete
      2. Dear Asim, it's based on theoretical simulation, but if I happen to make it i would be able to achieve 100% results from this design....if others are not able to succeed it's their inability.

        Delete
    68. The fets dont get hot at all when i remove the transformer

      ReplyDelete
      Replies
      1. it means something's wrong in your circuit, because without any input frequency and without any load the fets should not conduct and should not become hot....
        what's the quiescent current that you have measured?

        Delete
    69. sir please can you tell me what is the purpose of the two 1n4148 diode pleas tell cos i got 12v at the collector of Q5 and Q3 it is okay to to get that kind of voltage at these two Q3 and Q5?

      ReplyDelete
      Replies
      1. the two diodes help to get the required variable duty cycles from the IC

        if your batteries are 12-0-12 then the results are OK...

        Delete
      2. sorry if the batts are 24-0-24 then 12V across the fet gates is OK...

        Delete
    70. ok will connect and check if I am getting 12v accross each gate, but if thats the case and I re-connect the transformer and still no output what do you think would be the problem, because I am using a 24-0-24 battery setup and the transformer is 12-0-12 5amp

      ReplyDelete
      Replies
      1. please don't comment with different names...it gets very confusing...are you daniel adusei??

        you have been attempting the circuit since last 6 months and still having problems, i advised to quit this project and I repeat it once again....try some other easier inverter design... there are plenty of them in this blog.

        Delete
    71. I started the circuit last week im ainsworth lynch.... You told me to remove the transformer and test accross the gates of each fet...

      ReplyDelete
      Replies
      1. check the quiescent current by shorting the input of the circuit ground and trafo connected. it should be around 50mA, in the second last circuit

        Delete
    72. I got 12 volts accross gate and grounds of each fet...

      ReplyDelete
    73. probably Ill just try another design, I wanted to complete this but I dont know why I can get any output from the transformer.

      ReplyDelete
      Replies
      1. sure, there are many good designs in this blog, much effective and easier than the above design but will not produce pure sine wave...

        Delete
    74. Ill try the 3kva sine wave inverter that i see you posted

      ReplyDelete
    75. hi sir please i did not sent you a message with different name my name is daniel adusei and my profile pic is sine wave symbol sir i now got out put of transformer and the sine wave but what im facing now is if i power the circuit the out put of transformer raise up and it drop down within a seconds the upper fet got worm any help?

      ReplyDelete
      Replies
      1. daniel, you'll have to use large heatsinks to control the heating issue because since this is not a PWM based circuit, some heating will be take place.

        Delete
    76. hello sir,
      In your sine wave generator circuit, i cannot figure out ground pin of a1 and vcc pin of a2. are you missing them?
      and where should i add a trimmer in circuit in place of resistor to set the freq. precise to 50Hz.
      What should be min. input voltage and current to circuit?
      Please help.

      ReplyDelete
      Replies
      1. Hello Sherwin, A1, A2 could be a dual opamp such LM358,

        The design is already calculated for generating the required 50 Hz so there's no need for any further adjustments.

        voltage/current parameters will depend on the specs of the opamps used, typically it could be around 4.5V and 5mA

        Delete
    77. Yes sir,
      I will be building the sine generator circuit first and tell me:
      1. What is RMS value and what does it mean?
      2. Approx. what will be sine voltage and current at output if my input is regulated 5v.
      3. What is amplitude adjustment?
      4. Do i need any LC circuit at the sine output to further enhance the waveform quality.
      Please guide me,
      since i'm doing the inverter project i'm also preparing the charging system seperately.
      Again, you are really great in your works, i do appreciate it.

      ReplyDelete
      Replies
      1. Sherwin,

        RMS refers to the average voltage magnitude of a pulsed voltage.

        with a 5V supply sine peak will be 5V and RMS = 2.5V

        No LC circuit would be required for enhancing the sine, but could be required for eliminating unwanted harmonics or ripples.

        Delete
    78. Sir,
      I feel like building this inverter but, the transfo and the batteries is my problem.
      How I wish, the circuit can be build with any 12v, 9v or 8v transfo so that a simple 12v battery can be use.

      Anyway, thanks very much for this great work. May God help you and protect you.

      ReplyDelete
      Replies
      1. Aminu, without a center tap trafo it can be impossible to create a push pull effect unless two batteries were used or a full-bridge IC was used...therefore in the above design two batteries are preferred instead of the other alternatives, because using a couple of batteries is easily achievable...

        Delete
    79. I have a friend with a young child that has some mental problems and whenever they are out in stores or malls he will wander off . I am looking for 2 circuits in order to keep up with him . One to put on him and when he gets 12 to 30 feet from them. It will sound a buzzer or alarm on a circuit on them. Would you have any idea? Thank You tmitch51@gmail.com

      ReplyDelete
      Replies
      1. Please refer to the following circuit, it might just serve the purpose:

        http://www.homemade-circuits.com/2014/06/key-finder-circuit-pet-or-kid-tracker.html

        Delete
    80. Hello Swagtam,

      I have built your inverter circuit only. I am using a professional signal generator to provide the sine wave input. The circuit is built on a professionally laid out and manufactured FR4 PCB. It is being powered from a +/-15 volt lab power supply. All appears to power up OK with nothing getting hot. When I measure the output with no load there is a good clean signal with a gain of about 22 as expected.

      The problem occurs when a load is applied to the output. A 1k resistor across the output causes the output signal to drop from 22 volts peak to peak down to 8 volts peak to peak with the top of the positive peak clipped. Lower value resistors make the output lower. The power supply rails stay stable at +/- 15 volts with no AC ripple. I have changed the FETs and confirmed the transistor are connected correctly. The circuit is exactly as per your diagram.

      Do you have any idea why this is happening?. I can see that Q4,Q5 are a differential amplifier configuration, but am unsure of the purpose of Q3. Is Q3 a form of current source?.

      Would appreciate any help. Best regards
      Mark

      ReplyDelete
      Replies
      1. Hello Mark,

        The above design is basically a 300 watt RMS audio amplifier, so I believe that if the circuit is able to drive a 300 watt loudspeaker then definitely it would be able to drive an equivalently rated transformer too with the same amount of output.

        I have checked it in the form of an amplifier (using 4 fets) and with +/-25V, 5 amp supply and I could achieve well over 150 watts from it, raising the voltage could have allowed me to reach above 200 watts

        so i would recommend you to test the circuit like an amplifier first and then appropriately convert it into an inverter.

        use one of the last two circuits which uses two 1N414148 diodes for biasing the lower transistor section instead of the the shown preset in the first diagram....the use of two diodes relieves the user from the complex setting-up procedure of the quiescent current for the design

        Delete
      2. yes your assumptions are are right regarding the Q4, Q5 and Q3 transistors

        Delete
    81. hi sir Swagatam, my name is Amos Zaks i have been your follower for long on this platform and recently i came across one of your inverter diagram that uses a micro contoller pic16f72, i like the diagram and i want to biuld it for home use but the problem is i dont know anything about micro controller, sometimes i do here people say you must configure it or use a code before it will work in the circuit. i dont know anything about it so please i need your help on this before i start the project.thanks. iam looking forward for seeing your reply. my mail is:mrzakson@gmail.com

      ReplyDelete
      Replies
      1. Hi Mr. Amos, I am afraid it's not that easy....learning microcontroller can be a quite a long process and with some initial investments.

        you can go through the following tutorial or find somebody in your area who would guide you through all the required steps

        http://www.homemade-circuits.com/p/dear-manufacturers-and-interested.html

        http://www.homemade-circuits.com/p/pic.html

        Delete
    82. Hi swagatam can you please tell me that from where I can get this 1000watt transformer and how much it will cost

      ReplyDelete
      Replies
      1. Hi Shane, you will have to get it from professional trafo designer manufacturer....give him the details and he will make it for you

        Delete
      2. ..the cost could be anywhere around Rs.5000/-

        Delete
      3. We can get a microtek 1125va ups at around rs 5000 then why a single 1000watt transformer will cost around rs 5000 .then what is benefit of making a inverter ourselves if it will cost more than a ready made inverter?

        Delete
      4. benefit is that you get the oppurtunity to learn how to make your own inverter and tell the world that you can build your own inverter.

        moreover I was referring to a good quality iron core inverter not a ferrite core one...and also a single piece will always cost you 5 to 10 times more than when you buy the same in bulk.

        Delete
      5. Thanks swagatam for giving me such valuable information. Can you please give me a 15amp lead acid battery charger circuit diagram I want to charge my 150ah tobular battery.

        Delete
      6. My pleasure shane! you can try the following circuit for charging your 150AH battery

        http://www.homemade-circuits.com/2011/12/high-current-10-to-20-amp-automatic.html

        Delete
    83. Hello Mr. Swagatam , may you Please clarify How are batteries connected (Negative to Positive) Then this joint is connected to the ground ? And Since in Electronics usually the negative pole of the battery is considered as ground for the circuit , What would the ground in this 1KVA inverter schematic be ? I am so confused about this point , I highly admire your efforts for spreading knowledge thanks so much.

      ReplyDelete
      Replies
      1. hello Bilal,

        the use of two batteries and the relevant connections allow the transformer winding to switch from top to bottom and then from bottom to top alternately via the mosfets.

        since the transformer does not have a center tap therefore two batteries become essential for the alternate up/down switching of the trafo winding.

        the up/down switching ensures positive and negative half cycles for the AC at the secondary of the trafo.

        Delete
    84. Thank you Mr. Swagatam for this clarificatios, but still there's something not clear in my mind, what is the 'ground' in the schematic ? If I am to Implement this circuit what will be the ground that I should connect the two batteries poles to ? Thank you for the reply Mr.Swagatam.

      ReplyDelete
      Replies
      1. Thanks Blal, all the points marked with the "earth" sign will connect together and this becomes the ground line for the entire circuit, the transformer primary switches across the two batteries with the reference to this common central ground.....meaning for every switching the transformer is using power from a single battery..

        ..the use of two batteries is just for ensuring an alternately changing polarity for the trafo.

        Delete
    85. My dear brother, I have a reflective capacity of 800 watts , but not enough to run my refrigerator 200 Watt and I want to increase their value to appropriate what is the solution?

      ReplyDelete
    86. Hi Swagatham,
      Great resource.. I learned how inverter works, I actually needed some help, I bought an 1000 watt inverter couple of years ago, few days ago due to low voltage it started beeping, before i could turn it off I seen spark inside the inverter, I quickly switched it off.. Then after a while later I turned it on, from led panel everything was working fine, power flow remained continuous during AC on and battery mode or inverter circuit remained functional.. However with one exception the battery charging is not happening, I first thought my battery was totalled, I have had a seperate battery which I revived and put in to tickle charge for 12 hrs, put it back on and monitored it, the charge depleted after a day even it showed it was charging but upon checking it with multimeter on terminals I found out it's not feeding any flow to batt.. If I am not wrong is the spdt relay is gone?! Or the could be something else.. Please guide and help me out cause where I am we mostly face power outs.. If needed I can upload pics of internals of ups inverter...tha

      ReplyDelete
      Replies
      1. Thanks DD, actually a low voltage should not have caused any problems, because at low voltage the net power gets reduced so overload or over-current cannot happen, so it looks little strange to me.

        However from your analysis it appears that some part in the battery charging section has malfunctioned, you can track the wires which are responsible for carrying the voltage from the charger output to the battery, and check which part is causing this issue....prior to this confirm whether the battery charger is producing the required charging voltage or not, otherwise the issue could be in the charger controller stage.

        yes the SPDT could be also responsible for this....you can replace it with a wire link to confirm the same.

        Delete
    87. Hi Hitman, in your final diagram, you connect your sign wave direct to the input of the inverter circuit, now can you please tell me where the PWM of the sign wave is generated? As far as I know, the Mosfets are not analog devices, and can not handel the analog sign wave signal.

      ReplyDelete
      Replies
      1. Chris, if you think mosfets cannot be used in analogue circuits then how are mosfets used in audio amplifiers??

        the fact is mosfets can be used in digital as well as in analogue circuits, here the mosfets are connected as source follower meaning their sources will follow their gates in tandem...therefore if a sine wave is applied at their gates, then the output will be an exactly amplified sinewave.

        Delete
      2. here's an example simulation

        http://www.falstad.com/circuit/e-mosfollower.html

        Delete
      3. Please work on the simulation of circuit simulation and testing of electronic circuits program file

        Delete
    88. Hi sir,
      Thanks you so much for your post. But sir i want to make a drive circuit for my pulse transformer. the primary is only 10 turns. the output voltage is about 4kv. i have a sine wave input signal with frequency variable from 1khz to 100khz. So my question is can i use this circuit or which circuit is more suitable could you recomment? i'm waiting reply from you and thanks again.

      ReplyDelete
      Replies
      1. You are welcome WM
        you can use the same circuit which is shown in the above article, just make sure that the frequency is properly matched with the 10 turn primary and the core is a ferrite based material, otherwise the fets could instantly burn and get damaged

        Delete
    89. Hi Swatagam, how can this circuit be modified to work on higher voltage (380v dc) like ones found in dc-ac stage of pure sinewave inverter. Or I just have to use higher voltage transistors ? thanks !

      ReplyDelete
      Replies
      1. Hi Rax, yes it's possible, if all the BJTs and the mosfets are rated to handle this voltage

        the resistors will also need to be appropriately upgraded

        Delete
    90. I want full 1KVA UPS circuit diagram for simulation

      ReplyDelete
    91. this looks like an amplifier circuit, I was thinking about using a 12v battery but also I would have to build a circuit which can convert a single voltage dc supply into a high voltage dual polarity supply at 12v or even higher voltage. Do you think you can design such a circuit?

      ReplyDelete
      Replies
      1. you can search for a BTL amplifier circuit or a bridge tied load amplifier and use it for your desired application

        Delete

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