Simple 100W inverter circuit

Description.

Here is the circuit diagram of a simple 100 watt inverter using IC CD4047 and MOSFET IRF540. The circuit is simple low cost and can be even assembled on a veroboard.

CD 4047 is a low power CMOS astable/monostable multivibrator IC. Here it is wired as an astable multivibrator producing two pulse  trains of 0.01s which are 180 degree out of phase at the pins 10 and 11 of the IC. Pin 10 is connected to the gate of Q1 and pin 11 is connected to the gate of Q2. Resistors R3 and R4 prevents the loading of the IC by the respective MOSFETs. When pin 10 is high Q1 conducts and  current flows through the upper half of the transformer primary which accounts for the positive half of the output AC voltage. When pin 11 is high Q2 conducts and  current flows through the lower half of the transformer primary in opposite direction and it accounts for the negative half of the output AC voltage.

Circuit diagram.

Notes.

  • B1 can be  a 12V/ 6Ah lead acid battery.
  • Q1 and Q2 must be fitted to a proper heat sink.
  • T1 can be a 9-0-9 V primary, 230V secondary, 150VA transformer .
  • Do not expect much from this circuit. The is very simple one suitable for low grade applications.
Show Comments

292 thoughts on “Simple 100W inverter circuit

  1. Daniel

    how will i go about when i have a 15volt center tap transformer. and i need to use that transformer. will i put in a class ab amplifier to boost the signal or what. please help

    Reply
  2. RB CREATOR

    this circuit isn’t the right because it doesn’t have high power long lasting power when load is connected to it….so i suggest you look for a circuit that has high power efficiency it will be more preferable….please keep me updated soon as you have such circuits….. above you can send me mail via email address…thanks

    Reply
    • deepak

      You are using irf 540 as switching mosfet, of course the center tap will be positive, if you use Transistors 3055 then also it will work or use irf 540 this also work, but irf 540 has higher amp working.

      Reply
  3. Mensah Peter

    pls sir. i built 100 watts inverter the output is 210v when i connect load on it the voltage drop to 11o vols pls how can i solve this problem, pls help me.

    Reply
  4. Doug

    Can I increase wattage by adding transistors in parallel with Q1 and Q2? I will use stronger transformer. Can CD4047 drive more than 2 transistors?

    Reply
  5. abubakar

    hi sir I have few questions I need to ask based on this circuit .
    1. without an oscilloscope how do I measure d frequency to 50-60 hz?
    2. What would b the output voltage on cd4047 output pins(pin 10 n pin 11)?

    Reply
  6. Debashish

    hi,
    i have made this inverter circuit but i am not getting 230v output from the transformer. can you please tell is the fault?
    i am getting 12v at 11 pin but at pin 10 i am not getting sufficient voltage to trigger my mosfet.. so i connected the 100ohm resister to pin 13 where i am getting 12v. so i am getting 12v at the secondary side of the transformer (12-0-12) but not getting output at primary.. i am using a 1.5amp transformer.. please tell me what to do?

    Reply
  7. sud

    Hi,I have got the success to make the
    above invertor but the output freqency is
    68hz and i am unable to adjust it to 50hz
    by 1k pot.

    Reply
  8. Khaja

    Hi Seetharaman!
    I liked this circuit since its very simple to implement.
    I need to build higher ampere inverter with 36amps, 60hz output. Can I
    just change MOSFETs to IRF3205 and transformer rating to 40 amps to increase the load capability. Please suggest.

    Reply
  9. Parthiban

    Respected Sir,

    I want to know that how the Pin 10 and Pin 11 Signal is High and Low. How it is achieved. Is the IC Got programmed. Kindly clear my doubt Please sir.

    Reply
  10. seetharaman

    try by reducing r3 & r4 value to 100 ohms if output increases indicating the drive current is insufficient try adding a driver transistor between IC and the MOFET output

    Reply
  11. puneeth

    hello sir iam prepare in 330w inverter 555ic and 4017 ic used and irfz44n also complete the circuit one problem is connect the battery out put voltage is 53 not step up 230v what happen pls tell me sir

    Reply
  12. sud!

    Hi,I have got the success to make the above invertor but the output freqency is 68hz and i am unable to adjust it to 50hz by 1k pot.

    Reply
  13. sud!

    Hi,I have got the success to make the above invertor but the output freqency is 68hz and i am unable to adjust it to 50hz by 1k pot,plz help me.

    Reply
  14. vasudev

    hi setharaman ,but if i use 12-0-12v 5amps transformer the output voltage will be perfectly 230v but if i connect a 40w load it will drop to 208v what can i do to maintain just 230-240v,should i use pwm inverter?

    Reply
  15. vasudev

    hi setharaman when i checked the output of this inverter it showed 295v ac ,but i want to use it for my laptop charge ,for my laptop charger the max input voltage is 100-240 volts only ,is it safe to use this inverter wont it damage the charge by giving over voltage

    Reply
    • seetharaman

      It will kill your laptop charger, you may try to connect a night light bulb as load and measure the voltage if it is within 250 volts you can use with lamp also connected.

      Reply
  16. vasudev

    hi setharaman finally managed to get 200w of output with suitable transformer ,but can i power my laptop charger ,is it safe

    Reply
    • Seetharaman

      You can power any device. Ensure you use through surge protected supply sockets as the inverter is a square wave one. ( they call it commercially as computer power supply distribution board with filter and transient suppressor )

      Reply
  17. Colourfade

    Sir,
    forgive me if i am making any blunder.
    I wish to use this circuit for charging my laptop,mobile etc,will it make problems to laptop adapter (90 w)?
    will the primary coil get burned if i run circuit at no load ?
    for this will i need a 8A TFR (100w/12v)?

    thank you

    Reply
    • seetharaman

      Excess drive voltage can kill, but with zener diode it can be protected. Within the drive voltage range there can be no over current

      Reply
    • Seetharaman

      As the gate current increases the drain current in turn will increase hence more current through primary winding of the transformer, which will increase the power output.

      Reply
    • vasudev

      yes ,it can be used & it can handle 600w of output with suitable transformer say around 25-30amp for 300 to 450 watts

      Reply
  18. vasudev

    hi setharaman out of all other different types inverters,i found this is the best,reliable,strong enough inverter but connecting mosfets in parallel to increase output power did not work properly (the output power did not increase),i connected 3 mosfets in parallel ,ie totally i used 6 mosfets with 9-0-9v 5amps transformer ,the output is still 45 watts only

    Reply
  19. vasudev

    hi can i directly connect this inverter to 30ah car battery,doesn’t the gate region of mosfets or ic(cd4047) will blow due to inrush current.i am asking this question because, i have destroyed many mosfets & ic before by doing so

    Reply
    • Seetharaman

      Should not give problem in this application, provided you are not using a higher rating transformer and try to draw higher output than the above design.

      Reply
  20. vasudev

    hi setharaman check this website -www.circuitsgallary.com (simple low power inverter),here they have used 12-0-12v 5a transformer.i tried this circuit with 12-0-12v -5amps & it was a good quality transformer too,but it did not give 60w output

    Reply
    • Seetharaman

      The source drain drop will be approximately 0.6 to 0,8 volts, hence balance voltage of 11.2 to 11.4 will be available across primary winding hence the output voltage will also will be less at 200 volts instead of 230 volts. Check whether each winding is rated for 5a ms that is 12 volt 5 amps and 12 5 amps that is total VA rating is 120VA. not 60 va. In India if they say 12-0-12 @ 5 amps means it is only a 60 VA transformer. with an efficiency of say 60 to 65 % it can produce only 36 to 40 watts output.

      Reply
  21. vasudev

    hi setharaman what is the necessity of resistor r1,will it decrease the output power ,can i decrease the value. why i am asking this because ,i was testing this circuit with 30ah car battery ,it was working well yesterday but when i started it today it did not work at all & like this many ic’s are damaged .can u give me a solution for this problem

    Reply
  22. vasudev

    hi i have found an alternative for connecting mosfets in parallel ,i.e to use even more power full mosfets like irfz3205 ,which can handle upto 600w of output with suitable transformer

    Reply
    • Seetharaman

      Please go through my June 9th reply to your question on this. If you have better solution please go ahead implementing.

      Reply
  23. vasudev

    hi setharaman i am not at all getting how to connect mosfets in parallel,also i tried connecting mosfets in parallel in this circuit ,their was no increase in the output.

    Reply
  24. vasudev

    hi i want to use just 7-8 amp transformer because,i saw (in youtube)a guy running his tv,music amplifier,hifi,etc with just 7amp 9-0-9v transformer .he said he used ne555,cd4017& 6 mosfets in parallel ,he powered them all with 7ah battery

    Reply
      • Seetharaman

        How it is possible to get >500VA from a 72 VA transformer. Not practicable. No transformer can have 7 times over load. 25 to 30% over load is possible not greater than that.
        To increase the drive current from CD4047 (it is limited to 2mA appox) use NPN transistor like 2N2219 between IC out put pins and the MOSFET. (CD4017 is capable of 6.8mA drive current)

        Reply
  25. vasudev

    hi how much power can i expect if i use 9-0-9 volt 7-8 amps transformer with 2 mosfets in parall,i amp using 30ah car battery

    Reply
    • Seetharaman

      Hi Vasudev your transformer capacity is only 7 to 8 amps, say maximum of 72 VA alone can be expected why 2 MOSFETS in parallel? 1 pair itself can take care up to 150VA. If you want 300VA you can use 2 in parallel (that is 4 MOSFETs) Then your transformer must be rated for 25Amps @ 9-0-9 volts

      Reply
  26. vasudev

    hi setharam i used a good quality 12-0-12v transformer with 5amp rating instead of 9 volts transformer ,it did not do well at all ,i expected a 60w output & it is not coming ,can you tell me why it is happening. i thing using 9-0-9v at 5 amps is the best idea

    Reply
  27. vasudev

    hi setharaman i used 9-0-9v transformer with 5a rating, it worked well & gave 40 watts output but that cant do for me .so i wanted up to 200watts of output ,you suggested me to use more mosfets in parallel what should be the value of r3 & r4 . in the link you suggested the values are not properly given

    Reply
    • Seetharaman

      It is shown as 220 per MOSFET If you are using 2 MOSFETs 220 / 2 = 110 ohms say you can use 100 ohms per MOSFET. If it is 3 MOSFETs 220 / 3 = 73 ohms use 68 ohms for each MOSFET etc etc.

      Reply
  28. vasudev

    hi setharaman i used 9-0-9v transformer with 5a rating, it worked well & gave 40 watts output but that cant do for me .so i wanted up to 200watts of output ,you suggested me to use more mosfets in parallel what should be the value of r3 & r4 . in the link

    Reply
  29. sanjed arfin

    sir ,
    can i use (600va ) ups transformer safely for 100w inverter … coz i a old ups and i have got a transformer ???..

    Reply
    • Seetharaman

      No the loss will be quite high and the MOSFETs also may get damaged as the transformer impedance will be quite low. Still it can be used provided you take care of the maximum drive current through the MOSFETs. Make a 500 watts UPS as there are lots of circuit available on the net.

      Reply
  30. sanjed arfin

    can i use (600va ) ups transformer safely for 100w inverter … coz i a old ups and i have got a transformer ???

    Reply
  31. LordB1

    if I could recall, you made a statement about an inverter on which factors it depends on.. (i) the driven maximum current of the transistors and (ii) the transformer maximum current rating. now assume we have in the above circuit the required current rating and we want our inverter to produce more at the output, you said we should include mosfet in parallel?? sorry to ask, the leads how do we get to do that in parallel?? but a question I want to ask, why not in series?? though the question is ridiculous knowing the fact it has three leads… like I said earlier, sorry to ask. I just want to know how and why it has to be the way they are

    Reply
    • Seetharaman

      Please see the reply to Vasudev. Since we have to increase the current drive to the transformer we require more MOSFETs in parallel. Each MOSFET will share the current drive. Say each can drive 10Amps 2 in parallel can drive up to twice the current of one that is 20 AMps. So the energy available at the primary of the transformer is 12 volt X 20 Amps instead of 12 Volt X 10 Amps. The transformer rating should be taken care.

      Reply
    • Seetharaman

      Add a suitable driver transistor between IC output and MOSFETS. Use more MOSFETS in parallel to improve drive current to primary of the transformer.

      Reply
    • Seetharaman

      The power should not become a common impedance which will lead to instability, (due to power supply lead resistance etc) to avoid we have to decouple the power supply nearer to high current drawing device.

      You will get 100VA for little more than 1/2 hr. 500VA UPS also uses this same battery only, it will operate just for 5 minutes, the time for you to save the file on which you are working and to exit, when power fails during operation of PCs.

      Reply
  32. sanjed arfin

    can i use 220v / 12-0-12 3A center tap transformer … if i use it how much watts and VA i will get plz sir ?? is it mean 12-0-12v 3A = 24v*3a= 72VA or 72*.8= 58watts output ???? how to connect step down 12-0-12 center tap transformer wih this circuit coz i have no step up

    Reply
  33. Ramesh

    Sir what happens if i use 12v 10aAh battery to this circuit.and pls tell me how to increase output power of this circuit pls……………..

    Reply
  34. Ramesh

    I like very much this website. sir will you please tell me what is the function of mosfets in this circuit.pls give me answer urgent

    Reply
  35. Jamey

    Is there any way I can show 12v AC output from this circuit without connecting the transformer? My project supervisor is not allowing me to use transformer at all for safety reasons, so I can’t show him 12V AC. He just wants me to show him inverted 12V ac output. Please help me with this. Tell me what I need to add to this circuit instead of a transformer to show 12V AC output, please explain the procedure. Your help will be gratefully appreciated

    Reply
    • Seetharaman

      Use 1 K ohms 1/2 watt resistances in place of transformer winding and show either on AC range of a multimeter or on an oscilloscope (ofcourse measuring across the resistances.

      Reply
  36. jeo shaji

    Description.

    Here is the circuit diagram of a simple 100 watt inverter using IC CD4047 and MOSFET IRF540. The circuit is simple low cost and can be even assembled on a veroboard.

    CD 4047 is a low power CMOS astable/monostable multivibrator IC. Here it is wired as an astable multivibrator producing two pulse trains of 0.01s which are 180 degree out of phase at the pins 10 and 11 of the IC. Pin 10 is connected to the gate of Q1 and pin 11 is connected to the gate of Q2. Resistors R3 and R4 prevents the loading of the IC by the respective MOSFETs. When pin 10 is high Q1 conducts and current flows through the upper half of the transformer primary which accounts for the positive half of the output AC voltage. When pin 11 is high Q2 conducts and current flows through the lower half of the transformer primary in opposite direction and it accounts for the negative half of the output AC voltage.

    Circuit diagram.

    Notes.
    ◾B1 can be a 12V/ 6Ah lead acid battery.
    ◾Q1 and Q2 must be fitted to a proper heat sink.
    ◾T1 can be a 9-0-9 V primary, 230V secondary, 150VA

    Reply
  37. Jamey

    I tried connecting the transformer with inverter and got 230V output. Can you please tell me why the mosfets don’t show any output without connection of transformer? My supervisor for my project asked me to answer this,and I don’t have any clue about it. Please explain in details

    Reply
  38. Jamey

    i tried this circuit upto the transformer, it doesn’t show 12V AC! What might be wrong with my circuit?

    Reply
      • Seetharaman

        Both the MOSFET are alternately switched on use a scope across one of the primary windings. with a multimeter on AC range measure at the transformer secondary for 230 volts. If not check the 4047 circuit fo proper oscillation at 50 Hz check with a frequency meter.

        Reply
        • Jamey

          I did not understand the part ‘use a scope across one of the primary windings’ !
          I haven’t connected any transformer yet,I wanted to make sure the output from the inverter without transformer is 12V AC first, cause 12v DC from battery should be inverted to 12V ac,but its showing only 0.25!

          Reply
          • Jamey

            Is there any other alternative to not using the 0.1uF 600V capacitor in the transformer section, cause its risky and my university is not allowing me to order it. I bought the transformer though

          • Seetharaman

            Trough the transformer alone the MOSFETS are getting the supply without connect it you will never get any output at its Drain as it becomes an open drain circuit.

    • Jamey

      Any alternative to the 0.1uF 600V rated capacitor? In our university lab, we only have capacitors of 25V capacity!

      Reply
      • Seetharaman

        Hi Jamey you have to use 450V DC or 250 Volts AC capacitor only. Without transformer connected no supply is fed to the MOSFET drains, you will not get any amplification hence no output. You can try with a load resistance also for the MOSFETs, without transformer on an oscilloscope the square waveform will appear.

        Reply
  39. Khurram

    Seetharaman,Tell me the purpose of C4, what I think it shouldn’t place in parallel on out because it will short the output. In D.C we can use decoupling capacitor but in A.C if u use it in same fashion through capacitor C4 all the voltage will sink to the ground through it & output will become zero.

    Reply
    • Seetharaman

      Hi you are right but here the value is very low and it is used for smoothing the sharp edges of square wave output of the inverter. Such that the square wave edges will get rounded, the harmonic output also will get reduced

      Reply
  40. Jamey

    How can I make a battery charger circuit and switch circuit for this inverter? How would the all the circuits be connected together? I want that when my main AC power fails,the inverter switches on automatically. Is the relay work for this included in the switch circuit? Please help me out.

    Reply
  41. Chandrashekhar

    Sir i try the 100w inverter ckt it gives 220v ac but when i put a cfl to the output the voltage becomes very low about 85v. Please sir tell me the solution.

    Reply
  42. Jamey

    How can I make a complete UPS circuit from this inverter? I think I need relays and a switch circuit, how do I connect them? please help

    Reply
  43. kiran

    hai sir i checked in ur
    100w inverter ckt its
    working .but i have
    one small
    problem.when i give
    the load to ckt that
    time the vge will be
    reduced . example i
    give 20w cfl to load
    that time the o/p
    power reduced to
    20v . so pls give the
    correct solution. my cell number 8088394449 please help me

    Reply
  44. Akeem

    i want you to specify me the type of IR driver cct to trigger Mosfet power cct in order to give me 5KVA single phase inverter
    Thanks

    Reply
  45. pranjal

    Dear Sir, please give me eagle pcb layout design for the 100w inverter. I want to make that on copper laminated pcb.

    Thanks

    Reply
  46. Santhosh kumar

    Sir i done this project. It was working good. but i want to known about the ic 4047 internal constuction how it is giving 180 degrees phase shift pleace it is urgent am doing this my miniproject so i want to give seminar plz sir

    Reply
  47. Grousselas

    Hello,

    I do not practice English fluently so I am forced to use online translation .
    I am a modest French electronics and retired for 4 years , I have invested in renewable energy for personal use (2.5 KW Photovoltaic and wind)
    Everything works fine . But less than 4 years , 2 3 KW inverters sine did not take the road as unreliable.
    I decided not to buy expensive and impossible to repair converters. So for almost a year , I’m looking for a solution to build a converter 3 KW .
    Currently , I experimented with a 555 + SA 4017 CD . Power mosfets IRFP 250/ 260 IRFP . The transformer is a 3 KVA new. Several mosfets are connected in parallel when the development will be effective .
    The result is insignificant. Look here:
     http://libre-infos.eklablog.com/electronique-c19781471

    Do you think the use of CD 4047 will improve the power expected .
    What is the width of the pulses delivered by the 4047 CD , compared with the 4017 CD ?
    Watch here the draft very temporary mounting with a 120 W lamp that lights the secondary half . 120 volts measured with a digital controller.
    If you wish, thank you to tell me what you think.

    Regards
    Marcelin

    Reply
  48. Viques

    What is the function of that POT?.and is the transformer a normal one or do i hv to use a center tapped one?…i’m asking this cuz i’m having 3 wires in my transformer n i knw one handles 110V..wont it smoke up the shit?!

    Reply
    • Seetharaman

      i Viques it is to set the frequency of oscillation to 50 or 60Hz. You have to use 230 to 9V-0-9V center tapped transformer, use by interchanging primary and secondary.

      Reply
  49. Sarvesh Parab

    I wanted To Know Whether This Circuit Diagram Is Correct And Do It Work Properly ???
    Sry To Say That Because i Really Want To Make That Inverter So A Bit Serious About It..

    Reply
  50. rajesh

    hai sir i used in 12v 7ah battery , 12v/2amp transformer and 9v/1amp heavy transformer its not suited for the 100w inverter.
    Its not suit pls say how to increase the power .

    Reply
  51. rajesh

    hai sir i checked in ur
    100w inverter ckt its
    working .but i have
    one small
    problem.when i give
    the load to ckt that
    time the vge will be
    reduced . example i
    give 20w cfl to load
    that time the o/p
    power reduced to
    180v . so pls give the
    correct solution.

    Reply
    • Seetharaman

      Hi Rajesh it may be the quality of inverter transformer, its rating or the 12 volt power supply is not capable of providing the required current.

      Reply
        • Seetharaman

          Hi Manikanth if you increase the AH of the battery the inverter will work for a longer duration. say if you use a 12 volt 7AH battery for this inverter you will get the inverter going for 45 minutes if your load is 100VA. if you use a fully charged 12 volt 40AH battery it will work for 4 1/2 hours without needing for recharge for the same load.

          Reply
  52. rajesh

    hai sir i checked in ur 100w inverter ckt its working .but i have one small problem.when i give the load to ckt that time the vge will be reduced . example i give 20w cfl to load that time the o/p power reduced to 180v . so pls give the correct solution.

    Reply
  53. Devendra kurmi

    Hi, in this circuit I did not find C1 capacitor. Is it missing?

    Do you have any better circuits. Does this circuit works directly on solar panel?

    Reply
  54. deva prakasam

    dear sir/madam, Is there any controversial between astable multivibrator and mono,bistable according to thier application. answer me

    Reply
  55. chinna

    hello sir!
    Here we are using ic4047 as astable or monostable multivibrator.Can we replace with 555 timer.please reply me sir

    Reply
    • Anish

      555 timer has only one output. But 4047 has two outputs which are compliment to each other. Similar to a flip-flop. Moreover, conversions like this – DC to AC, AC to DC etc has more power loss. 4047 is a CMOS IC and hence consumes very low power compared to the TTL 555 timer. Any way the obvious reason may be the two kinds of o/p offered by 4047 and also, it uses minimal external components than 555.

      Reply
  56. stephin

    hi sir
    Which type of transformer i need to use for this circuit 9-0-9vAC primary or DC primary?please reply anyone..
    .can i use this for running my 21″ CRT monitor tv?

    Reply
    • rohin

      hi, you can use normal transformer which in E,I core.transformer always works on ac voltage.you can use 9-0-9 ac transformer with 10 amp.if your monitor wattage is less than 100 w than you can use this circuit.transformer can work both sides if you give input 220 v ac than it become step down 9-0-9 ac and if you give this side 9-0-9 ac then it can give us 220v ac and called step up transformer.so same transformer can work both things.

      Reply
  57. stephin

    hi sir
    whch type of the transformer can i use for this circuit,both the primary and secondary should be in AC?
    I need to run my 21″ CRT monitor tv by using this circuit ,do i ?please reply…..

    Reply
  58. Ankita kanekar

    hi
    can i use IRF540 mosfet to design 3 phase inverter ckt for controlling BLDC motor.? plz help what is the specification of this mosfet?

    Reply
  59. Vinod

    Hi, This is very good circuit. Do i need a special transformer for this?, What if i connect an ordinary 9-0-9 1A transformer ?.Please help.

    Reply
  60. vinay

    hello, i am new to electronics ,this circuit inspired me a lot, so i wanted to try it, but the capacitor c4 of 0.1uf/600volts is not available for me…so tell me any alternate..and by connecting the capacitors in parallel the capacitance can be added no,so can i try in that way……?m plz give ma a solution for that…….!

    Reply
  61. chandrasekar

    dear Mr. govindasamy
    IC 4047 is easily available one. In madurai(Tamilnadu) it costs only Rs.18. so try to your nearer big city electronic market.

    Reply
  62. FASIH

    hello sir i have constructed your circuit on proteus but all i am having is a 0V AC output…. please if u think that there might be some mistake let me know. i am using a simple 12V DC battery

    Reply
  63. chandrasekar

    sir
    In this circuit the transistors IRF 540 getting tooo much heat within seconds and Im not getting output. I use 12-0-12. 3A transformer.
    what is the problem?
    chandrasekar

    Reply
  64. chandrasekar

    sir.
    when the circuit connected to AC is the battery tobe charge automatically? or we charge from extra source?

    Reply
    • siraj

      hi chandrasekar!! you asked a question about the charging prob. right the same question too rised for me!! i have post the comment, no reply for that!! did you got the answer from or you got help from others? if so pls reply for me!!!

      Reply
  65. deepak seth

    sir, for a 90 watt, single phase motor will this circuit be appropriate ? or can u suggest some other circuit.

    kindly suggest something for 0.5 hp motor.220 volts. single phase input.

    Reply
  66. Anusha

    Hi sir.. actualy i m getting the output as 82v at secondary of the transformer.I checked all the pins then i came to know that voltage is getting droped at 4th pin there by m not getting voltage at 11th pin so the second mosfet is nt conductng completely where m gettng only 4.35v at primary of transformer connected to drain and center tap where in for first mosfet m gettng 9v.. so what would be the mistake..??

    Reply
  67. Allwin M.A.

    Hi sir,
    How can i calculate the efficiency and power factor of this circuit ?
    Is power elctronic circuits depends on power factor ?

    Reply
  68. Seetharaman

    Hi Nithin the transformer should be rated for 9-0-9 volt at 150VA. Use standard polyester or ceramic disc capacitor rated for 25 to 100volt 103 for C2 and 104 / 600 volt polyester for C4. What you have indicated some imported non standard capacitors their values will not be as you expect. Kindly nuse standard CTR / philips etc

    Reply
  69. Nithin Pradeep

    what kind of load will work in this inverter…..
    i used 9-0-9 500mA transformer …MOSFETS and transformers are heating enough but there is no output …
    will we get shock if we touch the o/p wire…??

    Reply
  70. Seetharaman

    HI Nithin you can use 1N4001, Preset to fix the inverter frequency at 50 or 60Hz, With the rcommended battery 30 minutes approximately.
    Hi Avinash you can get the current flow with respect to one wire in the other, hence both the wires are required. if you say that line tester is glowing on both wires(it will sinece the secondary of the transformer is floating) if you want to avoid this, you ground one wire of the secondary.

    Reply
  71. avinash

    Sir plz tell me
    out put of inverter ac volt come in both wire but i want to taking in one wire face in full 220vac what can i chang in

    Reply
  72. avinash

    Sir plz tell me when the out put of the inverter ac volt come in both wire …but i am taking i on. Wire what can i add/change in……plz

    Reply
  73. Nithin Pradeep

    Hei….Thanks
    Can IN4001 be used instead of 4007
    Is this circuit capable of driving a TV load …
    pls reply…

    Reply
  74. Umar garanzoi

    Sir, i want to build a circuit may i use IRFZ44N OR IRFZ46n insted of IRF540, Can it work. Also how to increase it to 500W?

    Reply
  75. Seetharaman

    Hi Sunil use 250volt tap, if available in the transformer. Hope the transformer used is 96VA rating. If taps are not available you can use a 230V/24volt 24VA transformer and step-up the voltage.(Like a step voltage regulator)

    Reply
  76. sunil

    i used 12-0-12/230 96A transformer the output voltage of the inverter is 210vac.

    what transformer do i ned to use in the circuit for 230vac output?

    please help……..

    Reply
  77. lin

    Hi,
    Thanks for this circuit and its working great…
    Could I increase the watts of this inverter by modifying this circuit?
    Please help me.

    Thankyou..

    Reply
    • admin Post author

      C2 can be a general purpose ceramic disc capacitor (they are generally available with a voltage rating around 1KV and it is well enough)
      All resistors can be 1/4W metal film or carbon film.

      Reply
  78. Leliance

    Hi,

    I am totally new to electronic but I have always been looking to make my own inverter circuit. Its just for fun or for my understanding purpose, I wonder if someone out here can guide me or share me their circuits. Basically, I’m not looking to generate lots of energy from 12v battery, I need a circuit which invert 1.5v/3v to some higher range.

    Write back to me if anyone can help. Thanx in advance.

    Reply
  79. Seetharaman

    Hi Kirthik your transformer should be low loss type. If you want 45 watts out put say at PF 0.8 then the VA at secondary should be 56VA and if the transformer efficiency is say 80% then the primary side requirement is around 70VA with 12 volt supply the requirement is 6 amps approximately. Your transformer should be for a primary of 10.8-0-10.8Volt and with a rating of 70 VA. Secondary should be rated for 230 volts. (a torroidal transformer will be a better choice)

    Reply
  80. Athish kirthik

    Dear Friends,

    I did the same circuit with the 2n3055 power transistor instead of IRF540 and i have used 12-0-12 ,3A transformer , so in this case , maximum how much Watts(W)i can able to consume from the transformer , that too even if i setted the frequency to 50 Hz at that time trafo output was 233V but after connecting the 15W CFl voltage came to 96 V, but if i am increasing the frequency to 300Hz then the voltage was around 172V AC ,i want to take min of 45 Watts output so what should be the rating of transformer???

    Reply
  81. santhosh

    SIR,
    I’M BEGINNER IN ELECTRONICS WITH SOME ELECTRICAL KNOWLEDGE IN MAINTENANCE OF HIGH VOLTAGE MACHINES.WHEN I INTENDED TO BUILD AN INVERTER FOR 3*25W CFL LAMPS I FOUND YOUR CIRCUIT.I’VE DOUBT ABOUT CHARGING OF THE BATTERY.IS IT NEEDED EXTRA CIRCUIT?IS THE VOLTAGE GETTING LOW IF CHARGE OF THE BATTERY GETTING REDUCED? PL. REPLY IMMEDIATELY
    THANKS
    SANTHOSH

    Reply
  82. Seetharaman

    Venkatesh you try one of the following MTP50P03HDL IRFZ44N, K2608 MOSFET, IRF1010E, IRF740 or any enhansment mosfet of 50amps 30volts ratings. you may contact texonic instruments for your requirement.

    Reply
  83. venkatesh

    Thank You Sir.,

    My Another Question, This is not related in this circuit , But i want your help., My Numaric 600 VA UPS in problem., MOSFET 85T03GP Not available.,
    Any other substitute for this mosfet?
    Pls give the Number pls thank you., sir

    Reply
  84. kiran

    sir can this be turned to pure sine wave inverter?and what is the ampere of the transformer to get 100watt?

    Reply
  85. Aditya

    sir.. today i have done this expt. with all u said equipments… its cost i payed 200rs…. so i made connections when i given 12v dc supply to it then the capacitor which is placed near power supply (c3 2200/25v) it got burned… can u tell me why this happened….?? connections was accurate… sir plz reply soon…

    Reply
  86. Seetharaman

    Hi Ali the battery capacity is given by 12 X 7AH that is 84VAH. say you draw 30 watts with 0.8PF and 85% inverter efficiency. The VA requirement will be 44VA. dividing the capacity with this value you will get the maximum operation duration of new fully charged battery. 84VAH / 44VA = 1.909H, that is 1hr and 55minutes.

    Reply
  87. Akash Ali

    Hi sir… So nice circuit but i want to ask one thing that how many time battery of 12 V (7Ah) will spend if the load is 30 watt… And whats the formula to find spending time according to load……?

    Reply
  88. gopal

    i have implemented this ckt but i am not getting out put. i check out all the connection, pls suggest where is thechances of mistake……

    Reply
  89. simarpreet

    can i use 12-0-12 /220v AND 500 ma transformer in this circuit and 6v , 4AH BATTERY? WILL IT WORK ?
    please help.

    Reply
  90. ganesan

    hi friends…i have few doubt on inverter…that i given below..

    1.how to recharge the battery?

    2.rectifier circuit need for recharge the battery?

    plz help me friends

    Reply
  91. Taimur

    What If instead of 12V 6Ah battery, I use a 12V 12Ah battery ? What would be its affect? can anyone please tell me about it? If its safe so I may use 12V 12AH battery instead

    Reply
  92. vikram

    i used 12-0-12/230 96A transformer the output voltage of the inverter is 210vac.

    what transformer do i ned to use in the circuit for 230vac output?

    please help……..

    Reply
  93. kiran

    dear sir,
    Can i use this circuit to switch on a 29 inch TV[not LCD a normal one] and what will be the backup?and what type of transformer should i use.

    thank-you
    from kiran

    Reply
  94. Udhaya

    sir,
    i would like to do this inverter. but before that i would like to whether it is a pure sine wave inverter or square wave inverter.
    thanks in advance

    Reply
  95. raja

    where can i get all parts of 40w inverter.
    sugest can i get this circuit board in market.
    am in chennai (tamilnadu, india)

    thanks

    Reply
  96. haidar

    hi seetharaman,im already build this inverter using 12-0-12/12va at primary..it can run 40w bulb but when i use 100w bulb it not run. should i change the transformer rating?

    -tq very much for your advice sir :)

    Reply
  97. Seetharaman

    Hi Haidar the harmonics are taken care by the output filter capacitor C4 you can increase it to 0.47uF 630V AC. This is sufficient to take care of all harmonics hence can be used with computer, Solid state TV etc (sensitive electronic gadgets)

    Reply
  98. seetharaman

    Hi Haidar all resistances can e 1/4 watt. You can use 9-0-9 75 VA transformer you will get higher voltage with low loads and at rated load it will be alright. 11-0-11 120VA is the transformer which suits better.
    Hi Azrin you can use 12-0-12 but output voltage will be around 200volts with 230V secondary winding and with 250V winding the output will be 220volts.

    Reply
  99. seetharaman

    Hi Nihar with a MOSFET transistor as their switch on resistance are quite low you can can use 12-0-12 transformer the right choice. dont use 9-0-9 transformer with MOSFET. use recommended transistors for 9-0-9 transformer use.

    Reply
  100. nihar kanta

    i have a 9-0-9 transformer from an old u.p.s .when i connect the transformer to the mosfet ,the mosfet becomes hot at no load condition ,output is 280 volt,when battery voltage decreases it works properly.i changed the transformer to 12-0-12 ,mosfets are not heating, the output is 220 volt .this is suitable.please tell me how can i use the 9-0-9 transformer safely . thanks in advance..

    Reply
  101. seetharaman

    Hi Dev with 9-0-9 you will get an output of 270volts with fully charged battery, if this is acceptable you can proceed.

    Reply
  102. seetharaman

    Hi Zafar it should be around 8 to 10Amps for 100watts with fully charged battery. with 12 volt 7AH battery it will supply for 30mts.

    Reply
  103. Rachit

    hi, i have made this circuit at the pcb board(holed).
    the current is passing through IC but there isnt any output at secondry winding of transformer . even that ihave checked the ckt. thrice and there isnt any mistake in connections . none of the joints is loose and each of them have been soldered. also please let me know an alternate transformer (with its current and voltage ratings) that can be used in same citcuit without alterations.please respond soon .also please send me its block diagram, would be really helpfull.

    Reply
  104. Seetharaman

    Hi Neo the battery voltage is switched on alternately to the primary of the transformer. The switching device is MOSFET the drop across them is negligible hence full battery voltage will be available across primary winding. if the transformer is 9 volt with 9 volt output will be 230volt square wave if it is 12 volt you will have 33% higher voltage at the output. without load you will get around 300 volt square wave.

    Reply
  105. neo

    Hi, I don’t know much about power electronics. I build this circuit with 9-0-9 v primary and 230 v secondary (115-0-115)transformer.
    I get output 240 v at secondary when I connect center tap of primary to 11 v and much higher when connected to 12 v. what is this relationship, is there a formula that I can use to work out what voltage center tap should be connected for this type of transformer.
    Thxs

    Reply
  106. Seetharaman

    Hi Sankalp CD4047 is a CMOS IC iy can give an output of around 1mA which is not sufficient to drive the transformer directly, hence you require transistor take care of the high current drive to the transformer. The MOSFETs used are enhancement type they require bias to conduct. These devices require voltage drive ( around 2.5 to 4 volt)with very little current. cmos IC can take care of this.

    Reply
  107. Sankalp

    Hey, I tried to build that circuit. It’s the same problem again. Getting output pulses from the CD4047 IC but ultimately, getting nothing at the end…

    and can anyone explain to me the working of the mosfets? I mean if i’m getting 23V AC from the 4047, Why not just connect it to the transformer directly??

    Reply
  108. neo

    Thxs VYSakh for ur reply, checked the mosfets pin connection, its not that.
    I even checked mosfets on thier own with 12v input to gate with source grounded but got no output at the load at drain ?

    Reply
  109. neo

    Hi, tried to build this circuit on breadboard, got output pulses from cd 4047 but not from mosfets. They are not switching on and off, any clues

    Reply
  110. darren

    Hi Seetharaman,tnx for ur quick responsed,i appreciate it so much,for this i gained more info on how your circuits work!!tnx for the additonal websites,,now i am searching parts,first for the transformer for this project.tnx GODBLESS.

    Reply
  111. Seetharaman

    Hi Darren you have to take saturation voltage of the final power transistor at 5 amps say it is 2 volt you require a 12 – 2 = 10 volt transformer (10-0-10). if you use 12 volt you will get 10 to 15% less out put voltage, if that is ok you can go ahead..

    Reply
  112. darren

    hi Seetharaman,definitely i can use more higher mosfet ryt?is it ok to use 6amp transformer?if not available 9-0-9,can i use 12-0-12 centertap x’former??..tnx.i need this circuit soon…GODBLESS

    Reply
  113. Seetharaman

    Hi Shashi One ceiling fan say 48″ it will consume 90watts, two CFL 18 watts so total requirement is 108watts say inverter efficiency is 85%. Then the primary requirement is 108 / 0.8 = 135VA if the battery voltage is 12 then the current requirement will be 11.25Amp. your battery capacity is 7AH so if draw 7amps it will supply for 1hr approx so if you draw 11.25 amps the battery can supply for 35 minutes. hence your back up will be for appoximately 35minutes

    Reply
  114. pravpa

    a normal transformer which we use for power supply can it be used reserved side or need spl. type transformer for inverters, please explain..

    Reply
    • guhan

      hi sir thanks for sharing the projects…i have done this project and it has worked…and to the visitors….use 9-0-9 tranformer and the ampere should be 2 and above….

      Reply

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