Description.
Here is the circuit diagram of a fully transistorized inverter that can drive up to 60W loads. Transistors Q1 and Q2 forms a 50Hz astable multivibrator. The output from the collector of Q2 is connected to the input of the Darlington pair formed by Q3 and Q4.Similarly the output of Q1 is coupled to the input of the pair Q5 and Q6. The output from the Darlington pairs drive the final output transistors Q7 and Q8 which are wired in the push pull configuration to drive the output transformer.
Circuit diagram.

60W inverter using transitors

Notes.

  • The circuit can be assembled on a vero board.
  • T1 can be a 230V primary to 9-0-9V, 6A secondary transformer.
  • Transistors Q4, Q6, Q7 and Q8 must be fitted with heat sinks.
  • Use a 12V, 7Ah battery for powering the inverter.
  • Slight adjustments can be made on the value of R3 and R4 to get exact 50Hz output.

Author

77 Comments

  1. Premdeepak P A

    Res Sir
    I want to make this circuit, Only question is whether I can use a 9-0-9 1 A or 2 Amps transformer and how would it differ from the output point of view

  2. abrar tabbasum

    hi SIR PLEASE TELL ME IF 7AH BATTERY AND LOAD30W HOW IT LONG

  3. how long the bulb will glow without any source?and how much time it will take to charge?

  4. what is application of 6ow inverter using transistors?

  5. sir am getting only 130v o/p so I can not glow the 40w bulb, help me to increse my o/p voltage

  6. vara prasad

    Sir am getting only 130v o/p so I can not glow the 40w bulb

  7. hi Seetharaman.. can i replace 2n3055 with TIP122 darlington pairin order to increase power.if yes what will be the o/p power.. pls reply fast

  8. Hi Mr Seetharaman,

    I just wanna ask how much current for this ?? Is it powerful enough to turn on the table fan ?

    • Or maybe a household appliances like blender ?

  9. hi i tried this inverter,it is not so much powerful like cd4047 inverter & how can i increase the power to 120w in this inverter

    • Seetharaman

      Hi Vasudev try using power darlington transistor capable of 20Amps continuous collector current in place of Q7 & Q8 OR use 2nos TIP142 in parallel.

      • Vara prasad

        Hi sir am not getting 200v, can u plz tell me that how to increase my o/p voltage and current

  10. can i power up my tv by this inverter ,i mean which is the best one this or cd4047 inverter

    • Seetharaman

      What is the load requirement if is 100watts use CD4047 inverter if it is 60Watts use this inverter.

  11. want to know for how long will the inverter stay up (working duration in hours)?? Thanks!

    • Seetharaman

      With a fully charged battery will stay for 60mts(1hr) maximum, when output is connected to 60 watts load.

  12. hi my name IS VASUDEV I BUILT THIS CIRCUIT ON BREAD BOARD BUT IT IS NOT WORKING,I USED TIP41C INSTEAD OF 2N3055 WITH 5A TRANSFORMER CAN U TELL ME WHAT M,AY BE THE PROBLEM

    • Seetharaman

      Are TIP41Cs getting heated up. It should work provided the Q1 and Q2 are oscillating. Check your wiring. Most important things to remember in BD140’s lead out are different from other transistors. As you view the printed side and while leads facing downwards. Left is emitter (not base) center collector and right is Base (not emitter). Please check.

      • thank you i followed u, it is now working well with tip41cs

    • Seetharaman

      Use for Soldering iron, light, shaver etc using car battery when you are away in your car. During power failure at home also you can use it for various uses.
      Hi Vasudev it can power 60 watt bulb but the efficiency of these inverters depends on transformer losses and power dissipated by final transistors. you cannot expect better than 75 to 80% efficiency. With a bad quality transformer it can be even worse <50%

  13. Hello,

    I don’t understand what the purpose of the two diodes (D1 & D2) is. Could you please explain. Might it be taking care of flyback from the transformer winding?
    Another question, all the circuits like this which I have seen drive either pnp transistors or a pnp darlington pair.Why not npn transistors. would it still work. Appreciate your help.

  14. plz help, i have used hcf4047, 12-0-12 xtransformer and irfz44 mosfets but no output, whats my problem

    • Seetharaman

      Pl try the following link use mosfet in place of power darlington

    • I want to make a 100w inverter i am working on it from 2 months and i change 3 circuit 2 with 4047 and 1 only with transistor but the same problem occurs in all circuit my -ve supply sparks and the last transistor heated and no output plz help me any one who any better circuit send me

  15. priyank jani

    what should be the minimum rating of input dc current in ampere hour.

    • Seetharaman

      The current requirement at rated load is 6Amps. if you want it to work for 1hr use 7AH battery if you want it to work non stop for 8 hrs use 60AH battery.

  16. is it necessarily 6A transformer…???
    plz give me circuit how to build up to 200watts???

  17. yatheendra

    hai sir can we use transformer of 9-0-9 1amp in this circuit.

  18. DEEPAK.P

    what is the specification of the transformer used in this circuit?

    • Jaisin jacob

      Hai,i have used a 9-0-9v,2A for the circuit for 18w.but it doesnot work.plz suggest what may be the problem?waiting for the replay.

      • seetharaman

        Ensure your transformer is rated for 9-0-9 24VA for 18watts load. what is your load inductive / resistive ?

  19. Seetharaman

    Hi Rajib The charge controllers are available in the market for Solar charging of batteries with 200 to 250 watts capacity solar pvcs. Use them they are most suited for your requirement

  20. Rajib Banerjee

    I want a circuit that works as a duel charger(600-800 watt)Inverter AC & Solar Parallel And If possible Need Separate Circuit of Solar Charging with battery full charging sensor with auto cut and if need after solar charging battery itself can get charge form AC.Basically Add on Circuit that be integrated with existing 600-800 watt Inverter used 12v 180Ah Inverter battery.Its Need if possible solution.reply

  21. Hey Guys…

    I am working on an engineering project.. using this circuit… but it only provides current up to the last resistors, I don’t get any o/p when I test the transistors 2N3055. So, the transformer shows nothing. Can you please help me… it’s critical, and, am stuck!!

    Appreciate your reply very much, Thanks!!

  22. NEVIL THOMAS

    WILL THIS CIRCUIT WORKS PROPERLY?????????????

  23. NEVIL THOMAS

    WILL THIS CIRCUIT WORK PROPERLY?????????????

  24. @Seetharaman
    Thankyou for your reply Sir. & I have got two questions please.
    What if instead of 12V, 7Ah battery I use a 12V 12Ah/2HR battery? What would be its affect on the whole inverter?

    Secondly by using a transformer (9-0-9)V & 6A, does it mean that this transformer will be giving an output current of 6A?
    Means that if I use a transformer which has more current rating at secondary side like lets say “10A” then does it mean that this inverter would be giving 10A to the load?

  25. Seetharaman

    The capacitor used are 16 volt or greater ceramic / polyester / paper / polycarbonate etc. (non polar type).
    You cannot eliminate the center tap, without which, the circuit will not work. All push pull designs require center tapped transformer and they are efficient designs.

    • man this my project, can ths circuit work properly with a 12-0-12 trnsformer?

      • Seetharaman

        Hi ntsoso the output will be less instead 230 volts you may get around 175 to 190 volts.

        • man i used a 555 timer what kind of the cap do i use for filtering? Hav done ths on simulation and the led lights for 1sec. Help plz my friend

  26. without a center tap transformer will this ckt able to provide the desired output

    • John Biasutti

      If you can not find a Centre Tap transformer use 2 off 0 – 9 V transformers connected in series with the 0 V connection between the 2 transformers.

  27. Hai could you please tell me how to eliminate center tapping freom this circuit. i am having a 0-9v transformer.

  28. jp2kumar

    i don’t understand what type of capacitor used here and voltage value any alternate solution there? pls tell me ….

  29. Seetharaman

    Hi Madhavan buy a step down transformer rated with primary 230 volt AC & secondary 9-0-9 AC rated for 6 amps. use the primary as secondary and secondary as primary.
    Hi Taimur for using with frequency sensitive devices, like line sychronised equipment etc, you have to adjust for the required frequency of the inverter, else they may mall function.

  30. mathavan

    RESPECTED SIR
    I AM BSC.,ELECTRONICS STUDENT FROM TIRUVANNAMALAI
    I WANT STEPUP TRANSFORMER
    IN PRIMARY 9-0-9V AND SECONDARY 230V.HERE NOT AVAILABLE
    THE TRANSFORMER.PLEASE SEND THAT TRANSFORMER DETAIL.

  31. Its mentioned here that by making slight adjustments of the resistors: we’ll be able to obtain an exact 50Hz output.. . What if i don’t make those adjustments, will i still get the appropriate output for my load(like bulb,charger or anything else etc)?

  32. Please i need a 60VA sine wave inverter circuit. 12vdc to 220vac….. how can i obtain sine wave outputs with this circuit.

  33. seetharaman

    Hi Ali the capacitors can be 16 volts or higher.

  34. Dear

    I found inverter circuit very useful.
    1-in the notes ,voltage operation of capacitores
    is not mentioned.
    2- application of inverter for solr cells and bipv systems
    it is better to have more practical information

  35. Shelly Jardin

    I have done this circuit also as a project but it only provides current up to the last resistors, I don’t get anything from there when I test the transistors 2N3055 they put out nothing. Thus the transformer also shows nothing. Is there something not included here that I need to ad? Thank you

  36. i want to design a 100 watt inverter using PWM technique
    if ny 1 have the circuit diagram so plz send it to me