How to make an Inverter- Simple 40 Watt Inverter

How to make an Inverter


This is the schematic of a simple 40W , 12 volts to 220 Volts inverter.You don’t believe, this is simple and cheap and working for me for last 4 years.The heart of the circuit is a CD 4047 IC which is wired as an astable multi vibrator here.Resistance and Capacitance at pin 1&2 determines the out put frequency.Here it is set to 60Hz.Due to this a two 180 degree out of phase ,120 Hz , 50% duty cycle waveforms will appear at pin 10 & 11.These waves are amplified by the complementary symmetry amplifier made of transistors BC 337 & TIP 3055 to drive the out put transformer.Don’t get feared of the technical terms, just wire it on a all purpose PCB.It is simple and will work.Don’t worry about the transformer windings ,buy a 220-110-0 primary,12-0-12 secondary , <50W transformer.You can select output voltage of 110V or 220V by a two way switch using such a transformer.Don’t worry if you don’t have such a transformer, a simple 220 to 12-0-12 will also do the trick sacrificing the 110V option or vice versa.The best way to get a transformer is to break all useless electronic devices in your trash.Most probably you will find the transformer or more components needed here!

If you are not familiar with the basics of electronics, CircuitsToday has provided a list of 4 really good books to learn the basics of electronics. To get a better practical knowledge in the subject you can buy these books from here:- 4 GREAT BOOKS TO LEARN BASIC ELECTRONICS.

Simple Inverter Circuit Diagram:

simple inverter circuit

Simple Inverter circuit

Tips :

First wire to oscillator part only.Then check out put Pin 10 &11 of CD4047 to obtain the required wave forms ( two 120Hz ,180 degree out of phase,50% duty cycle waves.

Then connect transistors ,transformer and load (25 W bulb for test).See it working!.

We have more Inverter circuits which may interest you:

1. Simple 100 Watt Inverter Circuit

2. 60 Watt Inverter using Transistors

3. 100 Watt Inverter Circuit – using 2N3055

Custom Search

Leave a Reply

63 Responses to “How to make an Inverter- Simple 40 Watt Inverter”

  • Aston Gemmy says:

    can I charge my inverter battery using the AC output of my inverter through a charger in order to ensure a continuous supply?

  • advaith p says:

    sir,can i use 10 ni-mh 1.2v battery insted of 12v battery

  • advaith p says:

    can i use 1.2v ni-mh battery insted of acid lead battery?
    please give me answer

  • shailandra says:

    Hello sir, i want to know that which type of transformer we can use in it. Please reply me very soon with detailed description of it.

    Thanking you,


  • Prashant says:

    Hello sir, I want to make circuit of led bulb works on 240 v ac. With high brightness for house use so,please help me for construction.

  • hamza says:

    hello sir i have a problem during designing this circuit that ic you have used is not in the softwares can you tell another equivalent ic number which can perform the same task
    reply as soon as poosible
    thankng u

  • Nitin says:

    Dear sir, I have one UPS normally used for backup for PC or LAPTOP for about 15 min. Please tell me what is power output of the UPS and can i increase the backup time. Thanking you

    • Seetharaman says:

      Normally they are 250 VA type, using a 12 volts 7 AH battery of C20 rating. That is you can draw 350mA for 20 Hours. That is 4.2 watts for 20 hours. That does not mean that you can draw 42 watts for 2 hours and 336 watts for 15 minutes. As you draw higher current the battery rating will come down drastically. If you draw around 200 watts it will work for 15 minutes with a fully charged fresh battery. 15 minutes is more than sufficient to save the work and shut down the computer. For longer duration operation you have use external higher AH rated battery provided the electronics in the UPS can take care of the longer duration of operation at higher VA rating. You have to us external charger for the battery as the UPS can take care of only 7 AH battery.

  • daniel omoha says:

    I love your work. I am a college student in nigeria,I will like to have more details about Inverter. circuit. thank you

  • binu says:

    can you please explain the design of the cicuit?

    • Seetharaman says:

      Hi CD4047 is the oscillator with two 180 deg phase difference output this is fed to a push pull power driver transistor pair BC337 & 2N3055. which in turn drives the primary 12 volt winding of the inverter transformer, which is a step up transformer its output is available as 100 volt or 220 volt at 60Hz square wave.

  • Joshua says:

    How can i build a contineous motor without fuel? And pls sir i need 500watts circuit

  • Joshua says:

    How can i build a contineous motor without fuel?

  • Sams ababio says:

    Great job! Please sir, send me 3000 watt circuit

  • Bharathi says:

    can you explain this project breifly…

  • Krismar says:

    Is it ok to use a 12v battery 38 AH for this project? what is the output? is tthat 20-40Volts?

  • Abubakar ibrahim says:

    Good work sir, please sir i need a high frequency inverter circuit so that it can drive a tiny ferrite transformer. Thank u sir

  • abel thomas says:

    Thank a lot for your technical support which you give to.

  • gokul says:

    please can you send me a 120 watts inverter circuit diagram

  • nagalakshmi says:

    need exact details about the components and accurate circuits

  • cyberpks says:

    Can I use a BC547/548 in place of BC337?

  • jeniffer says:

    hello,,what the output waveform of this inverter??square wave??

    • billy says:

      hello jennifer, it’s a sinusoidal wave.

      • Jon says:

        Are you sure it’s a sine wave output? Doubt it, 4047 IC outputs pulse square wave.. do you have any proof or tried already this circuit output on an oscilloscope? I think it’s just a square wave not even a modified sine wave.

    • Seetharaman says:

      Hallo Jeniffer No. it is only square wave. (people call this as digital inverter?!)

  • Pujan says:

    Sir, could you tell how to measure watt

  • Taimur says:

    Sir I don’t have oscilloscope or frequency meter etc to make sure Im having two 120Hz out of phase waves
    All this circuit told by you is perfect right? So may i just make it like the way you have drawn without any modifications or assurance to check the output wave?

  • vikram says:

    is it safe to use 2x6V (4.5Ah) sla battery in series as a power supply to the inverter?

  • saddd...............! says:

    can u please explain briefly…….?

  • vikram says:

    And also please mention the Ah rating of the battery for long backup for an 10w cfl load…..

  • vikram says:

    what type of battery do i need to use in this ckt for better power output(40W)?

  • Omega9850 says:

    Just a little heads up… This circuit is good, but may cause some confusion.

    The ZENER DIODE that is rated 10 VOLTS and .5 VOLTS is actually a 10 VOLT 5 WATT Zener Diode.

    All RESISTORS should be 1/2 Watt 5-10% Tolerance.

    All CAPACITORS should be Ceramic and 20+ Volts.

    All TRANSISTORS should have HEATSINKS!

    The Amp rating of the BATTERY, FUSE, and TRANSFORMER must match up! (A regulator can be used to regulate the battery power).

    By following the schematics and these instructions, you should be able to build a good Inverter. Remember, 120 Volts is a lot, and at 40 Watts is well beyond lethal. Electrolytic Capacitors will be OK, but Ceramics are recommended as they have a longer lifespan.

  • seetharaman says:

    Miloman send your enq. to i will send you the detailed circuit.

  • miloman says:

    Hallo, this be very good circuit, can you please tell me, I have many many wall wart transformers and my old power supply transformers, but not one center tap in thee whole mess. Short of stripping a core and re-winding, I read somewhere way back when, that two Identical transformers can be joined in such a way as to produce a centerTap, but that the polarity “-, +” on each trans should be Identified, and then hooked up,,,WHICH way? I cannot remember? Thanks so muchous for this circue,

  • mathew says:

    hi i had gone throug your site and itwas excellent,i saw how to make an inerter,please can u send circuit diagram to convert 20volts into watta. please help me ok, from nigeria

  • Kiran says:

    i had gone through your site and it was excellent. i saw how to make an inverter . can u please send a circuit diagram to convert 6 volts into 40 watts. Please send it as soon as possible.

    frm kiran.

  • Rithwik says:

    Donot use a 9-0-9 transformer,the output voltage will be very high.use 12-0-12.You can believe me because i made is working in good condition.use a medium sized heat sink for transistor.I lost one transistor because its sink was loose.its very cheap except for the 5A transformer.

  • Negin says:

    replace R and C

  • Negin says:

    The formula for calculating the frequency is: f=1/(4.4RC)
    R: between pins 1 and 3
    C: between pins 2 and 3

  • Biswas says:

    Can u plz send me a perfect 150-250watt inverter circuit diagram (pure 50hz).

  • Biswas says:

    Hi, i want to make 60watt inverter. And i have an transformer, can i use 12-0-12v to 230v 5A Transformer instead of 9-0-9v to 230v 5A. if yes what changes should i make to the circuit.

  • BOLTON MUZE says:

    Pls can i get a circuite diagram of a 2,500watt inveter & d names of all it component .Thanks

  • Pravin B. says:


    It really works.

    But I want to built an inverter having variable frequency 100-to-10K Hz. Will you pls give me calculations for the same.

  • Seetharaman says:

    IRF250 or its equivallent can be used directly in this same circuit. Standard 10-0-10volt inverter transformers can be used. If freewheeling diodes are not built-in in the IRF use IN5404 parellel in reverse biased with IRF.

  • Haseeb Haider says:

    thats nice
    but i want the output voltage to be 12 v
    i think removal of transformer would do that ? ?
    what do u say ?
    how much amperes would it give in case of 12 v ?
    i want to use it with a 12v dry battery for my network router + switch

  • ABDUL HADI says:

    HI please help me i have made the circuit for the model making competition but the problems is simple IT isnt working when i connect the circuit it draws 1.1A please sombody help meeee thanks in advance

  • jhong says:

    i just used a 3055 npn Q ,,,and a 470 .180, and capacitor,,,,,,,,,and a core of am antenna………in the output,,,but it works,,,,,

  • abdul says:

    what will be the value of resistor and capacitor at pin 1 & 2 to get 50hz and 220v.

  • Kamran S says:

    Hi, how can I clean up the output of an off the shelf 12VDC-120VAC inverter, with “Modified Sine WAve” output, so that I can operate an SCR type dimmer with it?

  • Jasveer says:

    its a simple and easy inverter design, please can u help me to design a circuit of 2.5k watts ?

    Thanks a lot

  • nick says:

    Thanks for the simple and easy inverter design, please can u help me to upgrade the circuit to 2000 watts ? , i know that more transistors and a bigger transformer should be added and that the power source should be no less than 48 volts DC , but i don’t know how to put everything together.

    Thanks a lot


  • Sty says:

    Instead of Bipolar TIP3055, is there any way to use MOSFET such as IRF?

  • VIRAJ says:

    hey this is great circuit.. it works ..
    could you show me a circuit where i can work with 9 volts dry cell instead of 12 volts.

    Reply:Dry cells dont work good with inverters.It is always good to use lead acid batteries.If you are planning to use a 9V battery then use a 9-0-9 / 0-110-220 V transformer as TRA

  • cool386 says:

    Use a 9-0-9V transformer, NOT 12-0-12 as shown.
    Output voltage will be low otherwise.