Designing an inverter transformer can be a complex affair. However, using the various formulas and by taking the help of one practical example shown here, the operations involved finally become very easy.

The present article explains through a practical example the process of applying the various formulas for making an inverter transformer. The various formulas required for designing a transformer has been already discussed in one my previous articles.

An inverter is your personal power house, able to transform any high current DC source into readily usable AC power, quite similar to the power received from your house outlets. Although inverters are extensively available in the market today, but designing your own customized inverter unit can make you overwhelmingly satisfied and moreover it's great fun.

At Bright Hub I have already published many inverter circuit diagram, ranging from simple to sophisticated sine wave and modified sine wave designs. However folks keep on asking me regarding formulas that can be easily used for designing a inverter transformer. The popular demand inspired me to publish one such article dealing comprehensively with transformer design calculations.

Although the explanation and the content was up to the mark, quite disappointingly many of you just failed to grasp the procedure. This prompted me to write this article which includes one example thoroughly illustrating how to use and apply the various steps and formulas while designing your own transformer. Let’s quickly study the following attached example:

Suppose you want to design an inverter transformer for a 120 VA inverter using a 12 Volt automobile battery as the input and need 230 Volts as the output. Now, simply dividing 120 by 12 gives 10 Amps, this becomes the required secondary current.

Want to learn how to design basic inverter circuits?

The data in hand are:

Primary Voltage = 230 Volts,

Secondary Current (Output Current) = 10 Amps.

Secondary Voltage (Output Voltage) = 12-0-12 volts, that is equal to 24 volts.

Output Frequency = 50 Hz

First we need to find the core area CA = 1.152 ×√ 24 × 10 = 18 sq.cm

We select CRGO as the core material.

Calculating Turns per Volt TPV = 1 / (4.44 × 10^-4 ×18 × 1.3 × 50) = 1.96

Calculating Primary Current = 24 × 10 / 230 × 0.9 (assumed efficiency) = 1.15 Amps,

By matching the above current in Table A we get the approximate Primary copper wire thickness = 21 SWG.

Therefore the Number of Turns for the primary winding is calculated as = 1.96 × 230 = 450

Next, Primary Winding Area becomes = 450 / 137 (from Table A) = 3.27 sq.cm.

Now, the required secondary current is 10 Amps, therefore from Table A we match an equivalent thickness of copper wire = 12 SWG.

Calculating Secondary Number of Turns = 1.04 (1.96 × 24) = 49.

Calculating Secondary Winding Area = 49 / 12.8 (From Table A) = 3.8 Sq.cm.

Therefore, the Total Winding Area Comes to = (3.27 + 3.8) × 1.3 (insulation area added 30%) = 9 sq.cm.

Calculating Gross Area we get = 18 / 0.9 = 20 sq.cm.

Next, the Tongue Width becomes = √20 = 4.47 cm.

Consulting Table B yet again through the above value we finalize the core type to be 6 (E/I) approximately.

Finally the Stack is calculated as = 20 / 4.47 = 4.47 cm

##

The present article explains through a practical example the process of applying the various formulas for making an inverter transformer. The various formulas required for designing a transformer has been already discussed in one my previous articles.

**Designing an Inverter Transformer with the Help of a Practical Example**

An inverter is your personal power house, able to transform any high current DC source into readily usable AC power, quite similar to the power received from your house outlets. Although inverters are extensively available in the market today, but designing your own customized inverter unit can make you overwhelmingly satisfied and moreover it's great fun.

At Bright Hub I have already published many inverter circuit diagram, ranging from simple to sophisticated sine wave and modified sine wave designs. However folks keep on asking me regarding formulas that can be easily used for designing a inverter transformer. The popular demand inspired me to publish one such article dealing comprehensively with transformer design calculations.

Although the explanation and the content was up to the mark, quite disappointingly many of you just failed to grasp the procedure. This prompted me to write this article which includes one example thoroughly illustrating how to use and apply the various steps and formulas while designing your own transformer. Let’s quickly study the following attached example:

Suppose you want to design an inverter transformer for a 120 VA inverter using a 12 Volt automobile battery as the input and need 230 Volts as the output. Now, simply dividing 120 by 12 gives 10 Amps, this becomes the required secondary current.

Want to learn how to design basic inverter circuits?

The data in hand are:

Primary Voltage = 230 Volts,

Secondary Current (Output Current) = 10 Amps.

Secondary Voltage (Output Voltage) = 12-0-12 volts, that is equal to 24 volts.

Output Frequency = 50 Hz

First we need to find the core area CA = 1.152 ×√ 24 × 10 = 18 sq.cm

We select CRGO as the core material.

Calculating Turns per Volt TPV = 1 / (4.44 × 10^-4 ×18 × 1.3 × 50) = 1.96

Calculating Primary Current = 24 × 10 / 230 × 0.9 (assumed efficiency) = 1.15 Amps,

By matching the above current in Table A we get the approximate Primary copper wire thickness = 21 SWG.

Therefore the Number of Turns for the primary winding is calculated as = 1.96 × 230 = 450

Next, Primary Winding Area becomes = 450 / 137 (from Table A) = 3.27 sq.cm.

Now, the required secondary current is 10 Amps, therefore from Table A we match an equivalent thickness of copper wire = 12 SWG.

Calculating Secondary Number of Turns = 1.04 (1.96 × 24) = 49.

Calculating Secondary Winding Area = 49 / 12.8 (From Table A) = 3.8 Sq.cm.

Therefore, the Total Winding Area Comes to = (3.27 + 3.8) × 1.3 (insulation area added 30%) = 9 sq.cm.

Calculating Gross Area we get = 18 / 0.9 = 20 sq.cm.

Next, the Tongue Width becomes = √20 = 4.47 cm.

Consulting Table B yet again through the above value we finalize the core type to be 6 (E/I) approximately.

Finally the Stack is calculated as = 20 / 4.47 = 4.47 cm

**Table A**

**SWG**-------

**(AMP)**-------

**Turns per Sq.cm**.

10----------- 16.6---------- 8.7

11----------- 13.638------- 10.4

12----------- 10.961------- 12.8

13----------- 8.579--------- 16.1

14----------- 6.487--------- 21.5

15----------- 5.254--------- 26.8

16----------- 4.151--------- 35.2

17----------- 3.178--------- 45.4

18----------- 2.335--------- 60.8

19----------- 1.622--------- 87.4

20----------- 1.313--------- 106

21----------- 1.0377-------- 137

22----------- 0.7945-------- 176

23----------- 0.5838--------- 42

24----------- 0.4906--------- 286

25----------- 0.4054--------- 341

26----------- 0.3284--------- 415

27----------- 0.2726--------- 504

28----------- 0.2219--------- 609

29----------- 0.1874--------- 711

30----------- 0.1558--------- 881

31----------- 0.1364--------- 997

32----------- 0.1182--------- 1137

33----------- 0.1013--------- 1308

34----------- 0.0858--------- 1608

35----------- 0.0715--------- 1902

36----------- 0.0586---------- 2286

37----------- 0.0469---------- 2800

38----------- 0.0365---------- 3507

39----------- 0.0274---------- 4838

40----------- 0.0233---------- 5595

41----------- 0.0197---------- 6543

42----------- 0.0162---------- 7755

43----------- 0.0131---------- 9337

44----------- 0.0104--------- 11457

45----------- 0.0079--------- 14392

46----------- 0.0059--------- 20223

47----------- 0.0041--------- 27546

48----------- 0.0026--------- 39706

49----------- 0.0015--------- 62134

50----------- 0.0010--------- 81242

##
Table B

**Type-------------------Tongue----------Winding**

**No.---------------------Width-------------Area**

17(E/I)--------------------1.270------------1.213

12A(E/12I)---------------1.588-----------1.897

74(E/I)--------------------1.748-----------2.284

23(E/I)--------------------1.905-----------2.723

30(E/I)--------------------2.000-----------3.000

21(E/I)--------------------1.588-----------3.329

31(E/I)--------------------2.223-----------3.703

10(E/I)--------------------1.588-----------4.439

15(E/I)---------------------2.540-----------4.839

33(E/I)---------------------2.800----------5.880

1(E/I)-----------------------2.461----------6.555

14(E/I)---------------------2.540----------6.555

11(E/I)---------------------1.905---------7.259

34(U/T)--------------------1/588---------7.259

3(E/I)-----------------------3.175---------7.562

9(U/T)----------------------2.223----------7.865

9A(U/T)--------------------2.223----------7.865

11A(E/I)-------------------1.905-----------9.072

4A(E/I)---------------------3.335-----------10.284

2(E/I)-----------------------1.905-----------10.891

16(E/I)---------------------3.810-----------10.891

5(E/I)----------------------3.810-----------12.704

4AX(U/T) ----------------2.383-----------13.039

13(E/I)--------------------3.175-----------14.117

75(U/T)-------------------2.540-----------15.324

4(E/I)----------------------2.540----------15.865

7(E/I)----------------------5.080-----------18.969

6(E/I)----------------------3.810----------19.356

35A(U/T)-----------------3.810----------39.316

8(E/I)---------------------5.080----------49.803

## 149 comments

commentsHi Swagatam

ReplyThank you very much for all your effort and help, a very nice article. Is there any way to evaluate an already available inverter transformer (desi inverter 12v i think) for an estimated or exact wattage or amperage, voltage etc.?

Thanks and regards

Sam

You are welcome Sam!

ReplyThe current of any transformer may be found simply by through a multimeter.

The output voltage may be found by selecting the voltage range, and the current may be found by selecting the relevant range in the meter.

However current measurement should be done quickly to avoid heating up of the meter wire.

Best Regards.

Hi swagatam,great job with this piece;its very concise and exlanatory.I have very keen interest in electronics and will like you to mentor me on electronics and electronic design.I am a fast learner and will greatly appreciate any material you may recommend and may give to this end.my personal email is divinelyanointed@gmail.com.we can keep personal correspondence with each other on this matter Through this email.thanks for the support.once again,great work.

ReplyYou are welcome Sammie!

Replysir, i parthiban, i very much interested coil winding of transformer. please help my question is howmany turns in KVA? if any DATA SHEET? please send my mail, parthiban_ks@yahoo.co.in (example: KVA------SWG-------(AMP)------- Turns per Sq.cm.)

Reply[(i.e.,1KVA (1000w)transformer Ex SWG:10 Ex No of turns: 200

KVA--------SWG------- (AMP)------- Turns per Sq.cm.

1-----------10----------16.6---------- 8.7

2-----------11----------13.638------- 10.4

3-----------12----------10.961------- 12.8

4-----------13-----------8.579---------16.1 EXAMPLEs ]

Possibly I'll try to find the data and inform you regarding it, soon

Replycannot calculate tvp 1.96

ReplyTVP=1/(4.44*10^-4*18*1.3*50=1.96?

ReplyThat's right, it's 10^ -4.....

ReplyThank you - this is a very useful article.

ReplyHowever, although some of the numbers in the example are clearly variables (input and output voltage and current) and certain of the other numbers derive from them, it's not completely clear to me which parts of the formulas are constants or how they are arrived at.

For example, 1.152 is apparently multiplied by the square root of the voltage times the amperage to arrive at the core area. Is the 1.152 a constant, and what is that based on? does it change depending on the core material? In Calculating Primary Current, is the 230 multiplied by 0.9 simply to take into account that the transformer is not 100% efficient, or is it more complicated than that?

Perhaps I am simply missing these things because I did not find any link to the previous article you said you wrote specifically on Transformer Design, and they are all explained there.

Thanks again.

mjf

Thank you for showing interest in my article.

ReplyHere's the link of my previous article where I have explained the making of a transformer more elaborately:

http://www.brighthubengineering.com/diy-electronics-devices/96783-designing-your-own-transformer/

Regards.

Thank you! I will read this this evening!

ReplyHi,

ReplyI am not able to find any of your Inverter designs at Bright hub. Can you send me the link to all those?

Nowadays I am studying all sort of inverters. I hope your designs might help me alot.

Hi,

ReplyI have shifted all my inverter articles from BH to here, kindly find them through the search box....I am sure you would find them interesting.

Thanks and Regards

how is primary voltage 230 when it should be 12-0-12

ReplyJust invert the names....

ReplyDear Swagath, thank you for this input, can you give me a design details on a general purpose inverter transformer for a 600 VA Sqwave.

ReplyThanks!

ReplyFor 600VA, the specs would be:

Primary current = 600/total winding voltage at DC side.

Secondary current = 600/total winding voltage at AC side.

Hi swagatam

ReplyI need to make a transformer for my school project

Can I get some help

Hi Ekaansh,

ReplyIt is difficult, you cannot wind a mains AC transformer with ordinary tools....not feasible for school project, as far as i think.

Sir, any data's

ReplySo far no luck, I tried a lot to find it online but couldn't find any relevant data...

ReplyDear Swagath, Can you help me in designing a 600VA transformer for pure sign wave , not able to get one. I was able to source the board, with transformer design.

ReplyTechnical details of transformer given

up to 800VA800VA 4 No* 3Inch ( is this core detail?-what does it mean)

Input 230V Primary ( SWG 19-360 turns)

Out put (1) SWG 13- (3*11 turns)- out put volt 7.5V

(2) SWG 25-22 turns- out put Volt 14.2V

I am not able to understand the Core details,

i have a core of size 6.4cm * 4cm

can i use this if so then the SWG and turns would vary

I do not have any experience with transformer designing so I am sorry I won't be able to help you with it.

ReplyYou can ask a professional winder, he would certainly know more about it.

Thank you, it is hard to find people who can help like you, i shall try

ReplyThanks, It's my pleasure!

Replythanks alot for those useful information but could you please help me with simple specific instructions step by step to make a 500 watt (or even more )inverter

Replypleaasee

Thanks! I have tried to explain as much as possible in the article, it would be difficult for me to provide a step by step narration....

Replyok thanks again my friend but could u please tell me how can i make it a 600 watt

ReplyAre you referring to a transformer or an inverter....if it's an transformer, then I'm sorry I am not good at it...

Replyhello sir, please i want you to help with the equation that i can use to get the thickness of wire that i will use to wind a transformer for both the primary and the secondary and also equation to get the area of the iron core. the parameters that i have are; 220v supply to the primary, 2v,4v,6v,8v,10v,and 12v to be lead out at the secondary, 50hz, and power rating of 3000VA. my email is khennie12@gmail.com. thank you sir

Replyi'm asking for 600 or 800 watt inverter

Replyi have a 12V 60A car battary

many thnx in advance

:: i'm sorry for disturbing but i really dont know much in electric stuff and i need ur help

you can try making this circuit

Replyhttp://homemadecircuitsandschematics.blogspot.in/2012/02/how-to-make-simplest-150-watt-mosfet.html

i want to design and build 2000 watts inverter help with simple diagram and name the material for me am a mechanical engineer, i want to use for my house

Replymy

you can try the following simple configuration:

Replyhttp://homemadecircuitsandschematics.blogspot.in/2012/09/mini-50-watt-mosfet-inverter-circuit.html

Just attach more mosfets and an appropriately rated transformer for getting 2000 watts

hi could pls help me with any simple method in determine the actual wire guage without a micrometer screw guage cos i have some difficulties with that

Replysorry, I have no idea regarding it....

Replywhy 160v winding for charging

Replyhi Swagatam, i am starting a solar powered generator project in which i am building a 1000W inverter. does the solar charging source have any influence on the inverter design compared to an AC charging source? do you have any example 1000W inverter designs?

ReplyThanks, Derek

Hi Derek,

ReplyA solar panel source would be controlled by a charger controller, so the inverter or the battery wouldn't have any concerns with the panel directly, so there's nothing to worry.

I have one simple 1000 watt inverter design in this blog, you can see it here:

http://homemadecircuitsandschematics.blogspot.in/2012/05/make-this-1kva-1000-watts-pure-sine.html

Regards

Great thanks,

ReplyI am building a solar generator with 1500 W hours of charge. charge controller, batteries, inverter (1000W) @60Hz. i want to build the inverter and possibly the charge controller. Is this inverter circuit applicable? any other advice would be greatly appreciated. I have been searching and find your info to be the most helpful thanks,

Derek

Thanks!

ReplyAccording to me this inverter circuit is correct, and would work as specified.

As can be seen, the circuit is quite straightforward, and wouldn't be so difficult to build.

hi swagath ,

Replyhow to calculate the design of 12v 1amp transformer

hi swagatam sir, this mohan i want to learn transformer winding. please help me.give some ideas

Replyhi mohan,

ReplyI am sorry i don't have much idea regarding transformer winding.

Hello Everybody.

ReplyCan someone tell why the factor 1.152 is used in calculating the core area? where did it come from. and if possible, is there a formula to be used that states the core area depending on the frequency. I'm asking because i want to use high frequency transformers and i need to know what size for wha tpower

Hello Gober,

ReplyThe above explanation is solely for iron core transformers not for high frequency ferrite transformers...so the calculations won't work for you.

My answer is

ReplyTpv=1/(4.44*10^-4*18*1.3*50)=1.92?

Thise is right answer?

Please replay question?

Replyyes that's correct

ReplyHello sir. I appreciate ur link but im confuse. How do I do a calculation for 1kva inverter transformer. My values are not just falling in place with that of the table given. Help me pls

Replyyes, I think the above data is limited for upto 20 amp transformer not above that, so im sorry a 1kva could be too large and not within the range of the above data.

ReplySir, pls tell me that meaning of 120VA

ReplySir, i am ashok.V from hyderabad. i want design a 400watt inverter batteries. .So what is primary current of transformer and battery current.

ReplyAshok, please divide 400 by the voltage of the transformer to get the approximate current on the relevant side.

ReplyVA = watts - PF

Replyhi friend,how are you and your family.my friend,I want to make a transformer for ups to charge 200 amps battery in 30 minute approximately and give good back up and drive about deep freezer (triplet) an water-pump and five fans,five energy savers at once.please

Replyhelp me my friend.

hi imam,

Replyyou are probably looking at a 10kva inverter design, i have no idea how to design such a huge transformer, please consult a professional trafo designer

Sir,

Replysir,

i have just salvaged 2 Nos of ups transformers from an old working UPS "Luminous 750va" double battery, i just want to know that can i use them to build an inverter with a range between 200 to 500 watt power inverter for home. second is that i am confused about the connections of these transformers there are 7 wires coming out from one side and three on the other side. how to identify the wires and check their voltages. i have been posting this every where but i idint receive any response. i shall be grateful if you could help me resolve this thing. the transformer has this marking on it " TX-201-1000-02"

Gowhar, While removing you could have at least noted down which taps are terminated as mains outputs for the appliances.

ReplyAnyway, you can connect your home AC mains across the different taps of the trafo randomly with a 100 watt bulb in series....the taps which produce minimum glow over the lamp could be assumed as the 220V winding of the trafo....

Once you locate this you can keep the mains input with the 100 watt series bulb connected, and take a DMM for checking the AC voltages across the remaining taps...in this way you can go ahead with the required identifications.

....maintain extreme caution while doing the above as the procedure involves lethal mains current.

Replythank you very much for the reply

ReplyDear Sir,

Replyi have a question, suppose i will get an inverter and ups with same rating including batteries, will they give same back up time.

waiting curiously for your reply

thanks

Dear Gowhar,

ReplyYes they should have identical backup time

thankyou for the prompt reply.

ReplyGod bless you.

Good day sir! Nice work keep it up

ReplyHi swagatam, iam ahmad thank you very much for this article.Pls sir can i rewind a transformer rated 1000watts for an inverter that is to produce 850 or 750watts? Or let me say any transformer that its wattage is above my requirement(watts). Can i match the current i got using the above formula with AWG bcos there is not SWG wire in my place and even if there is the current i got is not within the above table. Pls assist.

ReplyYou don't need to rewind the 1000watt trafo, you can use the same trafo for obtaining lower wattages...the optimization will simply depend on the battery current which can be reduced as per the requirements.

ReplyHello sir! Iam ahmad. Thank you very much for the reply, god bless, may you continue to reign.Pls sir am i on the right path by building a 750watts inverter using SG3524, L7809 voltage regulator, and four IRF3205 mosfets, 1000watts trafo?.what will be the voltage of 104 caps? Iam using 2k2, 10k, 1k, 200k resistors,will they be a quarter watt?. I want to replace 260k with 200k resistor and 100k variable.I appreciate alot

ReplyThanks Ahmad!

ReplyBy default the 104 caps can be 50V rated, the resistors 1/4 watt rated. I am not sure about the resistor replacement of 200K...can you show me the exact link?

Ahmad-i bought three 104 polyester caps, two of the caps have; 1A 104J,while the third one have 104k 100v writting on it.pls sir will they serve?

Reply104 means 0.1uF, if your circuit requires 0.1uF, then all these capacitors would be OK.

ReplyAhmad* Ok sir, but what about the replcement(260k with 200k resistor and 100k variable),and the mosfets? I want to use four IRF3205 (two connected in parallel on each side),and i need 750watts as the final output. Is it okay? Thanks

ReplyYour link did not open the circuit page, it opened the homepage of the site....provide the exact link of the diagram, only then i would be able to say anything.

ReplyAhmad, I have checked the link, yes you can use 200K + 100k variable preset a pin#6.

Replyfirst try with single mosfets only...if it works perfectly then you can add one more mosfet in parallel on each channel.

Ahmad****Thank you!!! Very much sir, you are one in a million. Once am through with the inverter and it start working i will let you know.thanks again, my boss

Replyyou are welcome Ahmad

ReplyAhmad*** good day sir! I encountered problem while selecting a trafo, my aim was to purchase a 12v-0v-12v ups trafo that would match with my requirement;750watts,12v car battery(though,later i would replace it with a truck battery),but when i went for it i only saw trafos with these specs:6.8v-0v-6.8v(650va), 150v-0v-150v(1200va), 800va(no voltage written). Am confuse right now. Pls sir i would like to know weather ups trafos can perform the task(based on inverter circuit on the website:simplecircuitsandprojects), if they can, what specs should i look for? And if they cant, what type should i go for? Pls explain comprehensively. Pls sir can i use 220k resistor in place of the 200k? 200k is currently unavailable in my place. Thanks

Replyyou can use the 6.8v-0-6.8v trafo for the referred circuit application, it will surely work.

Reply220k will be ok in place of 200k.

Ahmad*** thank you boss! I feel relieved now

ReplyAhmad***Hello sir! Iam doubting weather 6.8v-0v-6.8v trafo can give me 220volt output with 12v input, can it? The trafo was salvaged from 650va ups,what amount of load can it carry? ---can i use any salvaged ups trafo with primary volt above 12v-0v-12v to give out 220v using 12v bat input? Let say 15v-0v-15v or 16v-0v-16v. Thanks

Reply6.8v trafo will give 400v at the output, you will need to adjust the PWM pot or the load correction pot for adjusting it to 220V.

ReplyYou can try 12v or other trafos also, if you wish.

Ahmad*** thank you very muc sir! Pls dont mind my too much question, this is my first time in building a circuit. Sir, based on my understanding mosfet(particularly irf3205) has three pins, and pin 11 and 14 of an ic are connected to the gate(mosfet first pin),and trafo wires to the second pins(drain),while the third pins(source) grounded.But yesterday i saw a ups circuit and its trafo wires connected to transistors metal(metallic surface through which screws are bolted) and i was a kind of confuse. Pls explain to me in detail how mosfets are connected. Thank you sir

ReplyAhmad*** hi boss! Does all the different components share the same copper plane when grounding?

ReplyAhmad, don't bother about such details, concentrate on the basic technique and use only the three leads of the mosfet,

Replyuse the metal tab for attaching heatsinks only and nothing more.

what is copper plane? do you mean PCB copper ground track?

Replyyes, that's correct

Ahmad***thank you a million times boss! I have started coupling and nearly done.

Replyyou are welcome!

Replyhi,

Replycan we make an inverter for very small voltages like .5 volts using amplifying transistors like 2n2222 or 2n3904, and the output should be around 3-4 volts ac, that can power 2 leds. if yes can you tell me such a circuit. also about transformer, how does it is built for such a low voltage ?

i need it because i am participating in inspire award.

is the self looped motor generator is real?

Replyif so why yet, it hasnt come to real world?

I think we have discussed this earlier, anyway just to remind you we can use a joule thief circuit for this, you may refer to this article for more details:

Replyhttp://homemadecircuitsandschematics.blogspot.in/2012/10/1-watt-led-driver-using-joule-thief.html

it's fake...

Replyyou can study Adams motor for getting cold electricity, which is a true concept.

well I am making an inverter which should be of 100 watt using 12v 7Ah battery. Can you tell me a circuit, also I am a beginner in making inverter.

ReplyAlso my teacher insisted me to put an cooler( i dont no why) off coarse a fan, but i told them that it is not necessary but he made it strict to add an fan. so can you tell me how to add a pc fan to an inverter circuit.

it would be a great help.

thankx

You can try the following circut, it will easily handle 100 wats provided the trafo is correctly rated.

Replyhttp://homemadecircuitsandschematics.blogspot.in/2012/09/mini-50-watt-mosfet-inverter-circuit.html

Fix the fan over a suitable slot on the cabinet facing the mosfet heatsink such that it throws the breeze on the mosfet heasink.

I know but where do i connect the power supply for the fan?

Replyobviously it will from the inverter battery

ReplyPlease do design a 5Kwatt inverter transformer.

Replythis will be much more needed since we are all globally going for green energy. And 5kwatt inverter is much sought after, than low power inverter.

thanks! I'll surely try to present one in this blog sooner or later.

ReplyHai Sir,

ReplyFor secondary winding should we double the turns that is 49 centre tap 49 total 98 turns or after 24 turns should we take the centre tap and again wind another 24 turns.

Hi Vijeesh,

Replyplease explain your question detail, I could not understand what specification you are trying to make.

In the above calculation you got 49 turns for secondary winding.(means in the secondary winding first we will wind 49 turns with 12 swg wire then we take the centre tap then again wind 49 turns,total 98 turns) or we have to take the centre tap from the middle of 49 turns that's after 24.5 turns we take the centre tap and again wind 24.5 turns.

ReplyIt will be from the center of the 49 turns, that is after 24,5 turns or after 24 turns.

Replyi have an 200watt inverter with two irfz44n mosfets. how can i increase its power to 400watt.? can i add more mosfets in parallel? plz reply soon.

Replyyes it can be tried in that way.

ReplyI really appreciate your tremendous effort in help others out. Please sir, I want you to help me calculate the core size for the primary and the secondary, number of turns, the lamination size for 1kva transformer for inverter. I tried using the method you used above but I halted when it comes to choosing thickness of wire for the secondary in the table because I couldn't find there. Please sir. I want you to give me the wire table that starts from 1 and not 10 and also that of lamination table. I had be very grateful if you do that for me sir. Hope to read from you soon sir.

ReplyPls sir. I want you to help me with the calculation for 1kva transformer inverter. I used the above method but the challenges was that I couldn't find the wire thickness from the table you gave above. Please I will be very grateful if u can upload a table that will start from 1 and not 10 for both thickness and lamination. Or if there is another way of doing the calculation let me know sir. Hope to read from you soon.

ReplyThank you khennie, but I am sorry I won't be able to help you with the calculations because I too have no idea regarding the wire SWG calculation which would handle 1000 watts. I got the above data from one of the electronic magazines and I personally do not have any info regarding the specific data that you are asking.

ReplyI would advise you to seek the help of a professional transformer maker, he would charge a bit but finally you would be able to achieve the perfect design as per your requirement.

Thanks for your reply,I don't know any professional online but pls if you know one, kindly link me to him

Replygetting it online will be difficult, you will have to find it locally in your area, or in your nearest electronic market

ReplyHi Swagatam,

ReplyCan you please help me build a 200amp inverter.

Hi Shyam,

Replyplease provide all the required specifications, i'll try to help

Thank you sir for replying,, actually I am stuck with giving the time delay for the igbt switches in a dual half bridge inverter config. Its for simulation purpose..... because of the dual config. m always getting wrong o/p. please suggest anything.

Replyyou mean dead time? It's internally fixed in the IC, You can refer to the following diagram for some clue:

Replyhttp://easy-electronic-circuits.blogspot.in/2014/05/100-watt-to-1000-watt-pure-sinewave.html

Pls I will like to know the type of transformer that can be used for 1kva inverter and also the rating of the transformer. Thanks

Replydivide 1kva with the battery voltage to get the transformer secondary current. the primary voltage will be as per the specs of your country.

ReplyThanks for ur reply that surelly works

Replysir,

Replythe article is really interesting. In order to design a distribution transformer, will the core designing be same as sir has done? Or is there any difference? if so, i would like to request your kindness to elaborate on it.

Thanks

Hi Dozo, yes since all transformers are basically intended for controlling voltage and current parameters, their design calculations will use the same standard formulas and systems.

ReplyHowever the range provided in the above article is quite limited and it won't probably have the essential data for a distribution transformer.

Hi sir,

ReplyIn calculating turns per volt, Is the 1.3 a constant no? Does this refers to the magnetic flux density or the saturation of the core?

Hi Jerico, it's the flux density and is constant, you may refer to the following post for a detailed info:

Replyhttp://easy-electronic-circuits.blogspot.in/2013/07/how-to-design-and-make-transformer-at.html

Sir can you plz give me details of inverter transformer with bibbin of E20..and plz tell the details of its windings..

Replyhello anonymous, along with the bobbin you will also have to provide other details such as the amp, volts, watts, primary, specs, secondary specs etc,

ReplyHai Sir good morning,

ReplyLast week I went to a local transformer/inverter maker for a 800 watt 12-0-12 transformer for an inverter project,he said the primary will be 21 gauge and secondary will be 12 gauge,because of his reputation for supplying good inverters I gave the order for the transformer.as per above calculation 800 watt/12 volt is 66 amp but the chart is saying 12 gauge can carry only 10amp.He is giving a surety that it will carry 800 watt load.What is the trick they are using.

Hi Vijeesh,

Replyyou may be right, as per the chart 12SWG should be used for currents not above 10amp but this may be under ideal conditions which will ensure no heating up of the trafo even under full load, however 66 amps is way too high and using 12SWG could be dangerous for this much current.

although I am not an expert in this field, it looks quite obvious that 66 amps will simply smoke the transformer if a 12SWG is used, or perhaps the person may use many 12 SWG in parallel, that could be a valid possibility, and that would be quite OK....suppose he uses 5 nos of 12SWG strands in parallel then it would just do the job.

Can I use Ferrite core for 50 Hz inverter transformer?

ReplyIf yes give winding details for a 9-0-9 / 230 volt 500 VA transformer

ferrite cores don't work with low frequencies, it will require a minimum 10kHz for proper functioning, so it's not possible

ReplyCan I connect solar panel to an inverter without a battery?

ReplyI have 6x12 volt 100 watt solar panel and a 12 /230 volt 500 VA inverter.

Any simple circuit ?

yes you can do that, but make sure that during peak sunshine the panel voltage does not become too high than the inverter specifications.

ReplyMy inverter circuit board has LM3525, LM 339, 12F508 ic's and IRFZ 44 Mosfets . It is square wave output. Can I change this circuit with adequate components to get pure sine wave out put. If so please give the circuit. Expecting your valuable reply soon.

ReplyThank you

right answer is

Reply1/(4.44*10^-4*18*1.3*50=1.925 not 1.96

it could be a modified sine wave or pure sine wave equivalent, can't say with confirmation, although the presence of a microcontroler IC 12F508 and also opamps LM339 indicates a highly sophisticated circuitry which could be a sinewave inverter

ReplyI am sure, it is not a sine wave because when I connect an inductive load like fan, a humming noise is produced. Your sine wave inverter circuit using TL 494 is very simple. If any kit or assembled board available online using this circuit please inform details or link

ReplyOK may be it's not a sine wave inverter then.

ReplySorry I do not have a kit or assembled board for solving this problem, you may have to inquire it online or in the local market

Dear Sir ,what do we mean by the primary and secondary winding area and what is its significance while winding?

Replydear prathamesh,

Replythe winding area determines the specified number of turns that it can accommodate optimally...that's the only significance it has.

how to make 1000 w transformer from above method

ReplyWhere did you get the (0.9) when calculating the primary current?

Replyit's the approximate efficiency count of a transformer, and is a standard fixed value

ReplyDear Sir,

ReplyThanks for such a good document, sir I required 50W transformer for 12V system. So, please help me out.

Thanks Saurabh,

ReplyI have provided all the details in the above article, please calculate the parameters accordingly....

Hello boss! Hope everything is going smoothly. Am sorry I promised to notify you(7,dec.2013). The circuit(oscillator,power stage) worked,and I have been using it, thanks once again,it was because of your assistance,I sincerely appreciate. Can I connect two identical transformers in parallel (center taped) to my inverter? My aim is to multiply the wattage. Extend my regards to your family.***Ahmed***4rm*****NIGERIA*****

ReplyYou are welcome Boss!

Replyyes you can connect two transformers in parallel but only for the primary side....the secondary must be used and terminated separately to separate loads.

Hello Swagatam, My name is Tobi. Thanks for the tutorials. I'm an Electrical/Electronic Engineering student and I love electronics so much. I've been trying to design an inverter of 100watts or more, just for my personal use. I've seen a lot of inverter circuits on google and youtube but each time I simulate them on my circuit wizard software, they don't work properly. So please can you help me out with a cool circuit that works fine or give me a link or something. I'm very good with theories but I want to be good with practicals as well. Please I really need your help. Thank you.

ReplyHello Omoregbee,

ReplyAll the circuits that you have tested on the simulator were probably good...because it's your "wizard" that's not efficient enough to check their results, so leave it aside and try one of the selected inverter designs practically, that's the only way you'll learn things correctly.

Ok. I will try them out practically, and

ReplyI will get back to you. Thanks.

Hello sir,this is Abdus, plz show me in figure where is core area part?

Replyhello abdus, the central pillar cross sectional area of the "E" stack is the core area

ReplyHello sir,plz tell me which type of area in sence that primary and secondry winding area are to be maitained,i.e circular,cylindrical or other types?please tell me

ReplyHello Abdus,

Replyit will be as per the structure of the E core. that is rectangular

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