# 12v to 230v Inverter Circuit Schematic using Pulse Width Modulator IC SG3525

So far we have published so many inverter circuits here at circuitsgallery and now I think it’s time for me to introduce another one that has more inverter efficiency.

By using the principle of dc to ac conversion, an inverter system helps to prevent the problem of power failure in homes, offices etc. As the system convert dc to ac, it has got the name inverter.

This is a SG3525 based inverter schematic. Here we are mainly using the internal oscillator of PWM SG3525.

Note: You can buy this 12vDC to 120vAC inverter from our online store.

IC SG3525 is a pulse width modulator integrated circuit which has the following features:

• Wide operating voltage range from 8 to 35V
• Inbuilt oscillator and frequency range 100HZ to 500KHz
• Input and output synchronization terminals
• Soft-start facility
• Smooth shut down facility
• Input voltage checking facility
• Dual source/sink output driver

Recommended for you:

## Components Required

1. IC SG3525
2. MOFFETS IRF Z44 x2
3. Resistors (22,10K,56K,12K,470,33×2,)
4. Resistors(220×4 ½ watt)
5. Capacitor (0.01uFx3, 1000uF/25V ,2.2uF/25V ,1K100,102K, 47uF/25Vx2)
6. Transformer 12-012V /5A step down transformer(we use as inverted)

## Working of 100 watt inverter circuit diagram

• SG3525 has an inbuilt oscillator whose frequency can be determined by connecting capacitor and resistor on pin 5 and pin 6 respectively.
• The frequency of oscillation can be calculated by the equation

• Output is taken from pins 11 and 14 which are connected to the gates of Mosfets.
• Pins 11 and 14 operate as totem pole configuration or a push pull manner. It never turns ON two pins at the same time.
• The signal from two pins 11 and 14 are connected to the gates of power mosfets IRF Z44 which switch current to each winding of the transformer.
• Only one winding is activated at a time and both are energized in opposite directions.
• Activation of winding in opposite direction helps to produce an alternating EMF and thus alternating current (AC) on the secondary of the transformer.
• The frequency of the output AC is 50Hz which is determined by the CT and RT pins of SG3525(pin 5 and 6).

## 76 thoughts on “12v to 230v Inverter Circuit Schematic using Pulse Width Modulator IC SG3525”

1. In first Happy New Year !!!
Compliment for this very interesting site.
“Note: You can buy this 12vDC to 120vAC inverter from our online store.”

Best Regards.
Oscar

• Khaleel says:

Hey Oscar,
The link to our online store will be available soon. We are working on that..Keep visiting 🙂

• peter says:

hi, it’s my first time build an Inverter neh, thing is, The circuit diagram of The pwm, doesn’t seem to make sense as it shows The ic with all sided pins while The one at The bottom and The one I bought is two sided and also, it doesn’t say as to The porality of The ic or where The lines to The mosfets come from. could you please grant me some clarity and if possibles, email me a more detailed diagram.

am gonna be using The circuit system to drive a Brushless motor which I reckon it will work. besides, I have alert bought all The components. please, I need it like yesterday already.
thanks and God bless

2. Chibyskey says:

Can I increase the output power to about 1KW by just replacing the transformer and mosfets with suitable ones?

• Khaleel says:

Hi Chibyskey
Sure, you can do that.

3. Praveen says:

How to vary the magnitude of output voltage other than changing transformer? Is it possible?

• Khaleel says:

It’s possible by varying the frequency of oscillation specified in the working(see the equation), but you won’t be able to use it with common electric appliances as they operate on 50/60 Hz only.

4. mahaveer says:

Can I increase the output power to about 500W by just replacing the transformer , battery and mosfets

5. mahaveer says:

sir
if i made 500w inverter by this circuit then how many improved in this circuit.

6. mahaveer says:

if i made 500w inverter then connect any masfet in parallel and transformer then this is possible in this circuit?

• Khaleel says:

Hey Mahaveer,
Yes, you can increase output power by replacing transformer and increasing the number Mosfets (connect in parallel).

• vasudev says:

can u tell me how to connect mosfets in parall

• Yaseen says:

Hi Vasudev,
Drain and source are shorted and use separate resistors for the gate’s of each MOSFET.

• sarika says:

hi,

am designing dc to ac converter my output spec is 110v,400hz . as per formula u gave. if i apply values u tken in that formula am getting 20hz instead of 50hz. RT=68K,CT=1UF,RD=470 with these values am getting 20hz.

Thanks
Sarika

7. mahaveer says:

sir
how many applied maximum current in this circuit with 12v battery

8. mohsin says:

hi .. on which software you have drawn this circuit.????? plz tell me ASAP

9. devi says:

sir,
is it possible to convert 12V dc to 24V ac with minimum power loss??

• suresh says:

Yes id it possible

10. KJOSE says:

What may happen if I increase the number of FETs in parallel and don’t change the transfomer? Do FETs IRFP50N06 work well for a high power inverter using the above driver circuit because am done wiz its assembly? Thanks

11. KJOSE says:

Sir, I made an inverter one time using a two transistor astable multivibrator but it seems its power or current output is very weak because if connect a hair shaving clipper; it operates very weakly indicating either low voltage or power bt the transformer is big enough because I got it from a 1.5KVA AC voltage regulator and I altered i to a normal centre-tapped transfomer. And if I measure t output when on No load I get 250V AC output; I don’t know what may be the cause just help me.Thanks

12. Arun Dev says:

Hai…. very nice circuit…. Plz let me know whether i can connect any sophisticated devices like laptops at the inverter output ?
Also how could i regulate the output voltage of this inverter to make independent of load variations ?

13. vasudev says:

dose it really work properly,because i don’t want to spend money on it

14. vasudev says:

hi what do u mean by 33R &1k100,102k

• Yaseen says:

33R=33 Ohm
1k100=1uF
102k=0.001uF with 10% tolerance.

• Prashant says:

what voltage for 1k100=1uF ?

15. sarika says:

hi,

am designing dc to ac converter my output spec is 110v,400hz . as per formula u gave. if i apply values u tken in that formula am getting 20hz instead of 50hz. RT=68K,CT=1UF,RD=470 with these values am getting 20hz.

Thanks
Sarika

• Lee says:

First I made the same circuit by the same values as he described above. But the output was having some problems, it was flickering. Then I changed the value of Rt from 68k to 56k, now it was working fine.

If you got the frequency by calculating by the values, then why don’t you try some other values for that.

16. sanjed says:

i have done this circuit by using CT 0.1uf , RT =157.3k RD 470 and i got 50hz at pin 11 and 14

17. oliver says:

Hi,

can i replace RT with 100K preset to adjust the frequency?

• Yaseen says:

Hi Oliver
You can replace RT with preset to adjust frequency.

• oliver says:

Hi,

can i use this circuit for 1200W? using mosfets IRF3205 and a 1500W transformer. is their any modification?

Thanks,
Oliver

18. Anjan says:

What is the maximum watt load of the circuit.

• Yaseen says:

Hi Anjan
It can load maximum of 60 watt, it depend on the transformer rating.

• Anjan says:

Hi Yaseen Is there any circuit that can handle 150 to 180 Watt..

• Lee says:

Here he had shown as a simple pwm inverter circuit diagram by using a normal 12v 5amp transformer. You can try by changing the transformer and increase the number of MOSFETs

19. mhafe says:

it can be possible that i can redesign this circuit?..become 6v dc to 220v ac, 100 watt?..can you help me to design this can of inverter circuit?

20. Moro says:

21. Sandeep says:

Dear Sir if we using this circuit for 900w inverter the what will be the transformer construction?

22. M.ASLAM says:

our required frequency 50khz please tell me how value capciter and resister select of sg3525 ic

M quite new so need ur help in d project so i need to ask u dat pin no. 3,4,9 are non dey remains as it is ?????????

• Lee says:

In this circuit that pins are not using

Can I use IRFZ640 instead IRFZ44? last time is use IRFZ640 in your given circuit with NE555 it didn’t work.
kindly tell me more No.s of mos fete that we can use in this inverter instead of IRFZ44 please. . . .

• Lee says:

Yes. You can try by using IRF640

25. Paul says:

The SG3525 has a 100 Hz to 400 kHz Oscillator Range
ONSemi 100Hz minimum, ST Micro 120Hz typical.

26. Maria Waseem says:

HI. I am trying to simulate this circuit on proteus but it is not working. The mosfets give no output even though the output pins are.

• tertar says:

remove isolate the transformer from the cct and try it again

27. vikas says:

sir i have made this circuit but it doesn’t work i checked connections properly but still not work any o/p so plz give me solution

• Lee says:

Please recheck the circuit, because I tried the same circuit and it’s working fine.
Recheck the pins of IC capacitor and resistor specially the Mosfet Pins, because if the pins are not correct it won’t work. For IRFZ44n the pins are 1- Gate 2- Drain 3- Source

• Bhardwaj Rajyaguru says:

May Be Possible in your Circuit that’s transformer/Mosfet/IC are Damaged.

28. reshma says:

hi Sir,

can i use only one mosfet to vary pulse.Like output pin14 is not connecting to mosfet.But output of pin11 is giving to gate of other mosfet,drain is going to primary of transformer and source is grounding.is there possible to connect like this or not???pls ans…

• Lee says:

No. If you want to work this circuit diagram properly you must have to connect the two output pins to the Mosfet gates. Because the two sides of the transformer winding’s need to get the ground supply through the Mosfets

29. yogesh says:

how to change output voltage magnitude…………………why use resistor and capacitor parallel to the mosfet…………..any possible to connect this inverter to the grid

• Bala says:

Hi
Capacitor and resistor network used as snuber across the mosfet to protect it.

reg.

30. Godfrey says:

as anybody tested the circuit and confirm its working properly?

31. Ivan Gheorghe says:

Hi Sir,
I want to put 4 irfz44 in my inverter ,can you tell how to do it?
What kind of capacitor are 1k100 and 102k ?

32. Ivan Gheorghe says:

I want also to know if there is necessary a balance resistor between drain and source .

33. hector says:

Q.
Hello everyone can somebody help me.
I have a problem with this inverter i am using the sg3525 .. the frecuency just staid at 60 hrz for 5 seconds after that jump to 135 and like 10 seconds later to 385 .. how can it staid at 60hrz.

1. 1
—————————– — ————————-
0.7*112k+3( 1000 )*200nf. 78400+3000*0.0000002

Thank ‘s.

34. evans says:

this circuit is working,i have tried it but output is flicking.why

35. Em says:

Hi,Would you please tell me whether I can use ka3525 instead of sg? thnks

36. Anthony says:

Can you advice me if how many IRF Z44s I need to have a 1000W output? and what is the rating of the transformer do I need? Do I have to change the wattage ratings of the resistors, how about the capacitors?….Is it possible to have a pure sine wave output? Thanks

37. James Heires says:

Thanks for posting – I need a 12vDC to 110VAC inverter rated at ~100W, so this design is perfect.
The only question is where to buy a suitable transformer? What does 12-0-12 refer to?

38. Makarand says:

I have built the circuit but the output is flicking … Can you guide on this .. Values of all the components is checked . hey are correct.

39. MD_Blessing says:

with mosfet IRF250 connected IN parallel to make upto 2KVA inverter with 2KVA transformer, can this circuit carry deep freezer, also A.C and if increase to 5KVA as 24v inverter (input) can it power washing machine and pumping machine, thanks FRom Blessing…

40. dhaval says:

hello there,
in this ckt dc battery connected is of 12 volt, what is its current rating ? i mean ( for example ) if u r designing 220W inverter and output voltage is 220 volt then current must be 1 amp. so, what should be the current requirement from dc battery connected ? in general input power and output power are always same but because of losses input power should be little higher than output power. so if we r designing 100W inverter then input power must also be 100W, means 12V,8.5 A dc.
what is current rating in your given ckt.

41. Emmanuel says:

sir, if I use power amplification using like 10mosphet ,will there be an increase in my watt…. and if yes like how many watt can I derive?

42. Tanvir says:

Yaseen sir
Can I use ic sg3524 instead of ic sg3525???

43. rushab bhimani says:

how do we calculate the value of the resistances and capacitance used ?
my specifications of inverter: 50 Hz ,transformer ;12-0-12 v to 230 v ac ,1A current rating.
plz help.
urgent

44. syedarham says:

Where we will place the 12 V battery as input?

45. Fasil Ahamed says:

Hey you have any videos to made this

And I have question why use step down transformer

46. Enji says:

Hello. Is there any feedback control. ? How to make it’s output voltage exact 220 V ac ?

47. bossman says:

Sir by increasing the mosfet in parallel can I still increase the resistor and capacitor connected to the source and gate

48. tribo says:

I really – really confused with the pin 10, is there who can explain the function of pin 10?

49. Phan says:

Why the IRFZ44? There are more powerful so, why this one in particular?

Thank you,

Enrique

50. somapala says:

hai guys

i made tl 494 inverter cct.but it wont work perfectlly .it waste lot of my money for mosfets and ic s . when paralling two mosfet suddnly get burnt.
does eny one try this circuit with two or three mosfets in parallel.