Simple 100W inverter circuit


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.


  • 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.
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290 Responses to “Simple 100W inverter circuit”

  • Daniel says:

    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

  • sreyas says:

    My gate voltage is only 2.7 volt.

  • RB CREATOR says:

    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

  • What we should make a simple Electical based experiment which have some use in daily basis

  • Mensah Peter says:

    i use irf 540, ic4047cd, then transformer primary 230v and secondary 12v center tap

    • deepak says:

      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.

  • Mensah Peter says:

    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.

  • SARTHAK says:


  • Husain alam says:

    Hi sir.
    How to charge a battery automatically of this
    inverter, please help me…..

  • Doug says:

    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?

  • abubakar says:

    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)?

  • Gopi says:

    wt s the cost of batrery and tranasformer

  • Debashish says:

    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?

  • sud says:

    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.

  • Khaja says:

    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.

  • Parthiban says:

    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.

  • asim says:

    can we use 12+12v transformer ? plz

  • seetharaman says:

    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

  • sir amar Akta vallo solar charger diagram dorkar plz help me?

  • puneeth says:

    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

  • speed says:

    Hi,i want to ask..if i replace battery with solar PV panels that provide 12V input,can this inverter works?

  • sud! says:

    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.

  • sud! says:

    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.

  • vasudev says:

    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?

  • vasudev says:

    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

    • seetharaman says:

      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.

  • vasudev says:

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

    • Seetharaman says:

      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 )

  • Colourfade says:

    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

  • vasudev says:

    does excess of gate current destroy the gate region of mosfet

    • seetharaman says:

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

  • vasudev says:

    hi setharaman if we increase the gate current does the output power increases

    • Seetharaman says:

      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.

  • vasudev says:

    if we increase the gate current does the output power increases

  • abubakar says:

    and pls if u knw formular for winding a transformer pls do post it or send to me via my e-mailadress.

  • abubakar says:

    can irf3205 be used coz I have couple of them serving no purpose

    • vasudev says:

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

  • vasudev says:

    hi what is drive current ,is it the gate current or the current through windings of transformer

  • vasudev says:

    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

  • vasudev says:

    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

    • Seetharaman says:

      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.

  • vasudev says:

    hi setharaman check this website (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

    • Seetharaman says:

      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.

  • vasudev says:

    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

  • vasudev says:

    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

    • Seetharaman says:

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

  • vasudev says:

    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.

  • vasudev says:

    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

    • vasudev says:

      he also told that it gave 500w of output,is it true

      • Seetharaman says:

        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)

  • vasudev says:

    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

    • Seetharaman says:

      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

  • vasudev says:

    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

  • vasudev says:

    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

    • Seetharaman says:

      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.

  • vasudev says:

    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

  • sanjed arfin says:

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

    • Seetharaman says:

      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.

  • sanjed arfin says:

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

  • LordB1 says:

    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

    • Seetharaman says:

      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.

  • vasudev says:

    i do not how to connect mosfets in parallel ,can you please help me

  • vasudev says:

    hi how can i increase the power to 200w or 300w

    • Seetharaman says:

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

  • vasudev says:

    why is c3 capacitor required,though we are giving pure dc

    • Seetharaman says:

      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.

  • vasudev says:

    can i realy get 100watts out put with just 7ah 12v battery

  • sanjed arfin says:

    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

  • Bhupender says:

    Can I use irfZ44 MOSFET in this ckt

  • Ramesh says:

    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……………..

  • Ramesh says:

    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

  • Jamey says:

    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

    • Seetharaman says:

      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.

  • jeo shaji says:


    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.

    ◾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

  • Jamey says:

    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

  • Jamey says:

    In which software can I try the simulation of this circuit diagram?

  • Jamey says:

    Can I use 1µF 450V 105°C Radial Electrolytic Capacitor instead of the 600V one?

  • Jamey says:

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

    • Jamey says:

      It shows something like 0.25V AC

      • Seetharaman says:

        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.

        • Jamey says:

          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!

          • Jamey says:

            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 says:

            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 says:

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

      • Seetharaman says:

        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.

  • Khurram says:

    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.

    • Seetharaman says:

      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

  • NILANJAN ROY says:

    sir is it can drive a mobile charger or adapter of 150-300vac , 50-60hz 0.15A

  • Jamey says:

    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.

  • Chandrashekhar says:

    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.

  • Jamey says:

    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

  • kiran says:

    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

  • okoye says:

    what is capacitor c2 rating?

  • Akeem says:

    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

  • Nitu says:

    Can i use 12v transformer

  • okoye says:

    is capacitor c2 a polarity capacitor or non polar?is q1 and q2 mounted on the same heat sink?

  • okoye says:

    what type of capacitor c2 are my going to used and the transformer details.

  • pranjal says:

    I am unable to find IC CD 4047 in eagle software

  • pranjal says:

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


  • cyril says:

    sir what transformer should i use.

  • Santhosh kumar says:

    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

  • santhosh says:

    sir circuit was working………i want internal structure of 4047 ic ………..plz sir….

  • pradeep says:

    hello sir u r using 0.1microfara 600v….. but we know that capacitor can blocks ac…… how we r expecting 230v ac

  • Grousselas says:


    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:

    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.


  • sandy says:

    for inverters and solar projects

  • Viques says:

    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?!

    • Seetharaman says:

      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.

  • peter k ngeno says:

    what is rate of the transformer used

  • 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..

  • rajesh says:

    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 .

  • rajesh says:

    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.

    • Seetharaman says:

      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.

      • manikanth says:

        if we increase the battery ah ,can the ckt is destroy or not?

        • Seetharaman says:

          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.

    • Do It Really Works Mr Rajesh ??

  • rajesh says:

    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.

  • Devendra kurmi says:

    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?

  • a.maharajan says:

    c2 capacitor 0.01 micro fared howmany voltage?

  • sanaullah says:

    Hello sir ! the circuit is not working …….. :(

  • Ahmar says:

    what is the wattage for resistors?

  • sushil says:

    why it is used R6 1k pot. ? what
    will b problem in using of 1k
    resistor instead of that pot. ?

  • sushil says:

    why it is used R6 1k pot. ? what will b problem in using of 1k resistor instead of that pot. ?


    the wattage of resistances are not mention.

  • hadi says:

    hello sir i need 250 watt inverter plz help meee.

  • sanaullah says:

    it does not work!!!!!!!!!!

  • wasimakram says:

    Hello sir I want to make a helecoptor with remote please sent me thank u

  • WAKHEEL says:

    Hello. plz i need of components equivalent DATA.

  • WAKHEEL says:

    Plz . I need component equivalent data

  • Azeez says:

    Hello sir i need 200w inverter circuit…so can u help me?

  • deva prakasam says:

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

  • chinna says:

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

    • Anish says:

      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.

  • chinna says:

    hi sir! can we connet 230v ac to bulbs or fans

  • gokul says:

    this circuit is work good but the battery is only use 7ah is used or increase the battery level….

  • stephin says:

    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?

    • rohin says:

      hi, you can use normal transformer which in E,I core.transformer always works on ac 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 same transformer can work both things.

  • stephin says:

    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…..

  • Ankita kanekar says:

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



  • mahi says:

    Hello sir, I also have 12-0-12v/230, 7A transformer.
    Will I use it to this circuit? plz help

  • kranthi says:

    This circuit is good for implementation

  • Vinod says:

    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.

  • vinay says:

    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…….!

  • cheralathan says:

    i want to buy an ic cd4047 in villupuram the ic does not pls send store name in pondy,or cuddalor.

  • jafar says:


  • jafar says:



    Is this inverter suited for 40w ac soldering iron?

  • chandrasekar says:

    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.

  • FASIH says:

    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

  • govindasami says:

    i need the ecavelent ic to use of cd 4047

  • chandrasekar says:

    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 says:

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

    • siraj says:

      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!!!

  • deepak seth says:

    and how can we control the speed of 90 watt motor with this inverter circuit?

  • deepak seth says:

    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.

  • Anusha says:

    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..??

  • what is the minimum current rating of transformer.???

  • Can You Show me How that Transformer looks like???

  • Allwin M.A. says:

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

  • Charles John says:

    Good job.

  • Seetharaman says:

    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

  • Can you please tell the current rating of the transformer…….

  • i used a 103M 2 KV for C2 and 01M 1KV for C4 will this affects the working of inverter…and can a regulated dc dual rail be used instead of a battery??

  • 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…??

  • Seetharaman says:

    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.

  • avinash says:

    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

  • avinash says:

    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

  • what about the Duration of load(time)
    What is the function of the preset

  • Nithin Pradeep says:

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

  • Umar garanzoi says:

    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?

  • Seetharaman says:

    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)

  • sunil says:

    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……..

  • lin says:

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


  • GREAT ATA says:

    Describe c2 fully (what is the voltage) and the size of all resistors

    • admin says:

      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.

  • Leliance says:


    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.

  • Seetharaman says:

    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)

  • Athish kirthik says:

    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???

  • Seetharaman says:

    Hi Santhosh you have to have a charger circuit similar to the one used in our emergency lamp

  • santhosh says:


  • Seetharaman says:

    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.

  • venkatesh says:

    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

  • Seetharaman says:

    Hi Kiran this cannot be converted.
    Hi Venkatesh it can be anything 16 volts or above.

  • Seetharaman says:

    Hi Venkatesh This cannot be converted.

  • Venkatesh says:

    Sir What is the Voltage value of c2 0.01uf?

  • kiran says:

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

  • Aditya says:

    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…

  • Prince kumar says:

    How will we the battery charge?

  • Akash Ali says:

    Thank u soo much sir 4 giving me this precious reply… :)

  • Seetharaman says:

    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.

  • Akash Ali says:

    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……?

  • Nuhu Chiduo says:

    Hi friends,how can i get an IC CD4047 in Multism NI circuits 11?

  • Seetharaman says:

    Hi Gopal check the output of IC1 at Pin 10 & 11. If OK. Check the pin details of Q1 & Q2

  • gopal says:

    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……

  • Seetharaman says:

    Hi Ganesan use the battery charger circuits appeared as our earlier project. You can use the following link or
    Hi Taimur you can use, the unit will run for a longer duration. You have to use a suitable charger to charge the battery.
    Hi Vikram you have to use 10.8 – 0 – 10.8 volt transformer.

  • simarpreet says:

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

  • ganesan says:

    hi friends…i have few doubt on inverter…that i given below.. to recharge the battery?

    2.rectifier circuit need for recharge the battery?

    plz help me friends

  • Taimur says:

    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

  • vikram says:

    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……..

  • kiran says:

    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.

    from kiran

  • Suman says:

    This circuit is fine.
    But may we use it to drive 200W load by using 220VA transformer?

  • Suman says:

    This circuit is ok.
    But may we use it for 200W load with a 220VA transformer? Your kind help needed.

  • Udhaya says:

    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

  • raja says:

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


  • john says:

    hi, can i ask? how many ampere transformer did we need to produced 100watt for load?tnx for the follow up this question..

  • john says:

    hi sir, thank u for sharing this ideas, looking forward for the positive output, thank u again, GOD BLESS ^^

  • john says:

    hi sir, thank u for sharing this ideas, i have`nt try it yet, but looking forward for the positive output, thank u again, GOD BLESS ^^

  • seetharaman says:

    Hi Haidar use minimum 120VA transformer for 100 watts load.

  • haidar says:

    hi seetharaman,im already build this inverter using 12-0-12/12va at 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 :)

  • Seetharaman says:

    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)

  • haidar says:

    hi seetharaman, this circuit can run tv?
    and how to reduce harmonic?

  • seetharaman says:

    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.

  • haidar says:

    hi seetharaman ,i have 2 question

    1) can i use 1watt for each resistor
    2)can i use transformer 9-0-9/230 , 75va

  • gopi says:

    hi sir,can i use transformer 12-0-12/230,75VA?
    hence what wattage i will get?

  • azrin says:

    one more question.. what transformer that u used ? and can i use 12v-0-12v transformer ?

  • azrin says:

    can this inverter turn on a TV,amplifier or fans ??

  • seetharaman says:

    Hi Kannan use the same inverter output for 3nos 23watts CFL lamps.



    plese snd me 3 cfl inverter circuet diagram

  • shajan says:

    i want inverter full circuit with chaeger

  • k t jayaprakash says:

    Dear sir,
    Please send me 3 cfl inverter circuit diagram
    Thanking you,
    Yours faithfully,

  • PrataP says:

    Can you send the exact circuit diagram and its components list to my mail… Thanks

  • seetharaman says:

    hi patil around inr500 including transformer.

  • how much amount required for this project except 12v battery.

  • seetharaman says:

    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.

  • nihar kanta says:

    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..

  • seetharaman says:

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

  • dev says:

    can i use primary 230v,secondary 9-0-9,10Amp transformer

  • user says:

    I in a quickly way have drawn the scheme. To whom it is interesting… To this address – of a photo, a file with expansion lay- i will send on mail.

  • seetharaman says:

    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.

  • zafar iftikhar says:

    plz tell me that how much current the input 12 volt battery should produce?

  • Ankush says:

    i am not getting out of this circuit… shud i get the output??

  • Please i want to design a 1.5Kva inverter i can i go about it please i need ur help it’s for my final year project or better still a 1.5kva ups

  • vipin says:

    is this a working inverter’s circuit diagram

  • Seetharaman says:

    This is a squarewave inverter

  • Rachit says:

    also tell me how to categorise it , a sine wave inverter or some other .

  • Rachit says:

    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.

  • Seetharaman says:

    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.

  • neo says:

    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.

  • Seetharaman says:

    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.

  • Sankalp says:

    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??

  • Jane says:

    anyone here can make a circuit 1.5V input and the output is 9V 1Ampere. Tnx a lot!

  • vani says:

    how many types of inverter are there?
    what is the use of mosfet in the inverter circuit and explain about its working?

  • rizwan says:

    lp-100g i need data book

  • m.rizwan says:

    iam a problem in inverter LP-100G 15HP chaingae(company) i wanna to compelet information about it plz reply me as soon as possible…..

  • neo says:

    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 ?

  • vysakh says:

    check mosfet pin connections :)

  • neo says:

    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

  • darren says:

    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.

  • Seetharaman says:

    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..

  • Seetharaman says:

    Hi Darren you can use 2nos mosfets in parallel or even more. you may have to add a driver transistor in between. Something similar to the following circuit

  • darren says:

    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

  • noufal p says:

    i want to know more about this inverter…..pls forward me a block diagram and detailed writeup…

  • Seetharaman says:

    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

  • Shashi says:

    Plz give it’s Backup Details with 12v, 7Ah battery with using one ceiling fan & two cfl bulbs of 9 watts each.

  • seetharaman says:

    Hi Pravpa you can use the standard step down transformers for stepping up no need for any special type.

  • pravpa says:

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

  • sattv says:

    from the old uninterruptible power supply.

  • adnan says:

    is the 9-0-9v 8.5amp transformer is best or the 17amp??

  • seetharaman says:

    Hi Adnan 150 / 9 = 17amps total each 9 volt winding should be capable of 8.5amps

    • guhan says:

      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….

  • adnan says:

    9-0-9v at 150va tell me how much ampere of transformer will required?

  • vysakhan says:

    khan, its a sqre wave
    max provide 100w load

  • adnan says:

    on 100 watts load how much backup time will the battery give?

  • adnan says:

    9-0-9V,150VA transformer
    how much ampere of transformer please tell me?

  • vimal says:

    it is use for 2 fan & one tube light plz tell me

  • Please tell me its output wave, sine,square or other ???