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    This DIY 12V to 220V DC to AC converter is built with CMOS 4047 that is the main component of this small voltage converter that transforms a 12VDC into 220VAC. 4047 is used as an astable mutivibrator, at pins 10 and 11 will have a symmetrical rectangular signal (square wave) which is amplified by 2 Darlington transistors and finally reach the secondary coil of mains transformer (2x10V/60W).

    Video Presentation 1 – without load

    Video Presentation 2 – with load (light bulb)

    With the help of P1 the output frequency can be adjusted between 50Hz to 400Hz. Although this is not part of any professional dc ac converter it can be used quite effective on some home appliances. Be aware that the output signal is square and not sine wave. So you cannot use it for powering TV, Laptops, monitors. Use it only for lighting, power tools and other non-expensive equipment.

    60 Watt DC to AC Converter Circuit Schematic

    DIY 12V to 220V DC to AC converter built with CMOS 4047

    I used BD651 transistors instead of BD699.

    For more DC to AC voltage converters check the related posts.

    Check out the tags for more 12 Volts to 220 Volts converters.

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    211 Responses to "12V to 220V DC to AC Converter Circuit"

    1. Darshan Jhala says: on October 5, 2008 at 10:05 am

      Very informative site.Please keep it up.

    2. Hi! it is possible to use this with a synchronous ac motor?

    3. How about the program code for the 4047?

    4. Gabriel Aizcorbe says: on February 9, 2009 at 11:13 pm

      Jens, don’t get me wrong, but I’m pretty sure that CMOS 4047 it is not a micro-controller either a plc, is just a monostable/astable vibrator, there is no program for this IC, the only thing is to do some soldering and done.

      May be you are confused with other IC?

      Regards
      Gabriel

    5. Garba James says: on March 11, 2009 at 1:16 am

      wonderfully!the precise.

    6. is it okay with frequency that can change .

    7. ELELCTRO ISAM says: on April 30, 2009 at 10:44 am

      any one try to make inverter DC 12v To AC 220?

      • base on your advert, i think i am in need of ypur help

      • yes I have, I did the tony roan/ Harry Lynthal “version, very simple using the 2-2n3055′s a couple of resistors and a re-wound Microwave transformer. only where I live it is 110Vac so I wound my center tap accordingly. Worked very well till I took her to her limits and burnt up my 3055′s But now I know and will build another with a second step on the 3055′s to handel more current draw,,or find more powerful transistors.

      • how did you rewind the trans?

      • Can you post the.. I did the tony roan/ Harry Lynthal “version schematic with resistor values. or the link to this schematic version.

        ThanX

    8. my oppinion is to know how to come up with aconvater and have more knoledge about it

      thanks
      remain your
      sserunkuma musa

    9. based on your advert i believe i need your asistance

    10. common that’s what i need

    11. Magdalene says: on July 1, 2009 at 12:09 pm

      What is Z=1,5A/T?
      Is there any replacement for CMOS 4047?

    12. what is Z helpppp

    13. houssein jamal di says: on August 27, 2009 at 9:21 am

      that is a very importly site . thank you very much

    14. Hi,i really admire your good work there but is it a square wave or a sine wave stuff and if its a square wave how can it be converted into a sine wave?

    15. I want asking all friend here
      how do a inverter square wave to sine wave. Give me scematic diagram.thk

    16. Type IC 4047 is same with Type ic other example like type ic is…

    17. How nuch the IC, because i’m interested of the circuit & the IC is available in the market. I’m in the philippines .

      • D.MOHANKUMAR says: on November 11, 2009 at 2:54 am

        IC CA3130 is a 15MHz BiMOS operational(8pin) amplifier with MOSFET inputs and CMOS output.Gate protected MOSFETs are used in the inputs so that the IC has very high input impedance. It is very sensitive and requirs very low input current.It is a general purpose Op-Amp which is commonly available
        D.MOHANKUMAR

      • Chinmoy Mitra says: on August 8, 2010 at 5:22 pm

        You have mentioned IC CA3130 in this post, but I cant see it in the circuit schematic of the inverter.

      • yah. you mentioned CA3130. but i didn’t see it in the schematic?

      • cdhrew says: on May 29, 2010 at 9:55 pm

        je to výborny.amíci

    18. Ramakant Kumbhar says: on November 14, 2009 at 11:04 am

      What means the Tr= 2*10v/3amp

      Transformer of 3 amp I understood but what about 2*10v cant understand
      It is inverter transforer or any other.
      Plz guide us

    19. Good site.pls mention the transformer& transistor specifications for high wattage output like 600w,1000w.

      • i have an generator of 220 volt but the invertor module is demaged i want to make a connection with the 12 volt ac means direct from coil output to 220 volt
        but i need 1000 watt output is thee some genius can help me with a diagram or etc

    20. Abhishek says: on April 20, 2010 at 6:48 am

      What is P1 here??????? and can i use a 12V transformer in place of current 10V????

    21. GOURANGA says: on May 27, 2010 at 4:46 pm

      Can this inveter charge the battery?

    22. Nice diagram, It is very simple. more info about the transformer, please?

    23. VERY GOOD SIR!! Is that a buck transformer there I saw? I have many many different “used transformers and most are bucks so I was wondering because I would like to try this, and then,,,move up two a M.O.T with the secondary rwound to a center tap what do you think?? I have a few M.O.T.s too.
      Basically I have a bunch of stuff I scanvanged from old throw aways,,, even a flat screen I found in the dumpster!

    24. Johnny Beloved says: on June 13, 2010 at 11:18 pm

      I need a clue on the general methods of how to convert a square wave to a sine wave. thanks.

      • You can find this circuit by “Googling” “12Vdc to 120Vac sinewave inverter circuit schematic. I too was wanting to build one, but found the circuit a bit to complex for my limited knowledge and experimental funds. So for now,,just little steps. The sinewave you are looking for is graduated squarewave steps, still square but the peaks/pulse intensifies up a few steps to the desired peak then down in equal steps then up again and so on. Done with microprocessor to manage the pulse train

    25. its good inverter

    26. Nischay Kumar says: on August 9, 2010 at 6:42 pm

      one can build a better,robust and PWM featured Inverter using SG3524 and IRF540 or IRFZ44 mosfets.

    27. sir can u plz tell me wat type of component is “z=1.5A/T” waiting for ur reply

    28. pleas I want a circuit diagram that can convert 12vdc to 220vdc without the use of any transformer.thank you

    29. Pls sir P. marian I also want a circuit that can convert 12vdc from a 12v/200ah battery to 220vdc without the common EI lamination transformer just like converting 12vdc to 24vdc using an op-amp ic and a torodial inductor. Pls this will lead to a perfect standalone transformerless pure sine wave pwm inverter.

      • I have a very good converter with mosfet transistor and a pure sine wave of the out

      • Hi Zaher, your circuit please, “pure sine wave” can you posy it or tell me please, where I find it to make me one

    30. sir
      ineed help.c5591 any replace

    31. hi my quastion
      what mean z=1.5A/t are u mean resistance

    32. how can i repair a circuit wich is patend with some hard black soked material is just like a blackbox of a car

    33. its a inverter module eurom IG 1000

    34. zelelow says: on May 28, 2011 at 5:33 pm

      can i use it efficiently? and please tell me what r the t1 and t2 transistors are? r they normal or special ones?
      regards

    35. how many watt output.

    36. i have inverter no output

    37. hellow sir ,what is the replacement of BD699?

    38. Can this circuit be modified to use the omni available 555, 40xx to hard to locate here without high dollar shipping

    39. for thee price of shipping the 4047 plus about $40.00, I can have a 800watt/1600watt peak modified sine from almost any auto supply store w/ a 1 year warranty, how about we try to post circuits with readialy available parts from local electronics store’s. Radio Shack has 555′s and 741′s ect but not these odd ball ic’c

    40. can i replace transister to IRF540 N-Channel MOSFET?

    41. Hey,can i replace transister(BD699 Common Collector) with IRF540N N-Chanel MOSFET?

    42. Hola voldria saber si 12 v. de poténcia es sinonim d’ alguna altre mesura de poténcia com per ejemple en watios.
      Grácies.

    43. can I use 12V to 220V Voltage Converter Circuit as an inverter circuit.if not do help me with an inverter ciruit that would power 2 air condition. Thanks

    44. david silas says: on August 13, 2011 at 1:26 am

      that is a very important site, thank you very much

    45. i need to know is it possible to transform 12v dc current to 220v ac and getting an output of 3000 watts using some kind of transformer of diodes

      • To run this 3000watt inverter from 12 volt you will need a 12 volt supply giving 255 amperes! THAT IS A STARTER MOTOR TURNING A DIESEL 6 CYLINDER ENGINE!! Be realistic you must allow for losses ……

    46. i want this project with circuit idea

    47. hello cai i use transitor D1047 instead of bd699 thx in advance w8ing 4 u reply

    48. simple circuit to build,,very great schematic…. keep it up

    49. sir i am doing a miniproject in our college on this inverter please help me.
      what is meant by tr=2*10/3A tell me the transformer code.what is meant by p1.and again what is z=1.5A/T can i get this outside specially or we have to make it

    50. Dear Mr D., This CD4047, can I with changed componets replace the 4047 with a 555 timerusing pin 3 output open and close gated mosfets? or is it to slow of a Ic?

    51. Cont- Mr. D. I quess what I am asking is the 555 chip capable of producing 50-60Hz signaling to the control mosfets?

    52. What means the Tr= 2*10v/3amp
      Transformer of 3 amp I understood but what about 2*10v cant understand
      It is inverter transforer or any other.
      Plz guide us
      Reply

    53. Hasan Yassine says: on October 27, 2011 at 10:27 pm

      1.how many watt output ???
      2.is it possible to transform 12v dc current to 220v ac and getting an output of 3000 watts using some kind of transformer of diodes???

      Best Regards:)

    54. Ronak patel says: on October 31, 2011 at 3:20 pm

      can we convert 2.5dc into 110ac or 220ac ?plz help me bcz i cant understand that??????

    55. Assalam Alekum!
      nice work sir can you please tell me the name of the transformer mean how i can bye this from my local shop with pakistani name>>>..?thanks

    56. zaiban ali says: on November 20, 2011 at 3:40 pm

      sir can i use 12 0 12 /220 5amp transformer please tell….

    57. wiretapped says: on December 6, 2011 at 1:14 am

      hi, its a simply circuit yet looks efficient, one thing i want to tkow is the transformer’s specs. iwant to wind my onw transformer with an output of thousand of volts with 2 to 5amps. can you guys help me? thank you very much.

    58. Please help me i dont find ic4047 can i use another ic help please…….

    59. hi sir i want 12v automatic battery charger circuit please help me

    60. I need to know which is the inductor I will use and how many truns and how much henry I need this as impossible as you can to reply me thank you.

    61. kundan singj says: on January 16, 2012 at 6:12 am

      sir, plz tell me equialent mosfet/ transistor of BD699 . I can not get it.Can i used IRFZ44, or IRF540, transistor 2N3055: Plz, Tell me Thanks, you sir

    62. any replacement for cmos ic 4070

    63. sir i know transformer will nor for dc
      because dc does not varying flux.can u explain how it works please sir from
      enginneeing student reply immediately
      i eagerly waiting for u r reply.

    64. sorry i made spelling mistake,transformer will not work for dc
      how it works

    65. what is the wattage of this inverter? and secondly how to increase wattage?

    66. what is the current rating of this transformer?

    67. very nice I will try

    68. What is the replacement for BD699?

    69. rajni kant says: on February 2, 2012 at 4:47 pm

      nice method

    70. I can’t see anywhere a clear statement of the max continuous output. Surely this is a strange oversight.
      I note also the absence of a pilot light & fuse, easily added I know, but why post a circuit without?
      You offer to build for $18 but say the component cost might be $50; I guess that’s a clear statement of your intent.

    71. sir plese this circket circuit diagram or brieg ditels send me this e mail address

      rathodsandeep48@yahoo.in

    72. Adeleke Zakariyau says: on February 11, 2012 at 9:18 pm

      I came across this site lately, what i want to know is, how many watt of the inverter output. I in need of 2000watt.

    73. What is difference between Zener & MOV

    74. What is advantage of this will comparing with chopers

    75. Upasana Dash says: on February 19, 2012 at 6:43 am

      Hi,
      Can you plz tell me how to get a simulation result of this inverter circuit using CD4047?Is there any simulator in which CD4047 can be simulated?

    76. Jayakarthigeyan P says: on February 19, 2012 at 5:06 pm

      Where can I get the internal circuit of IC 4047… Please give me a link or post it here… I got the pin configuration but I want to know the internal circuit…

      • zener used for breakdown voltage if you want to clampdown particular voltage u can do that where as mov is used once high voltage occurs at particular say mov for 220v more than that occurs it shorts and there will be know power beyond

    77. Dear sir,

      I need Transformer details and circuit diagrams, please do the needful
      Best regards

      raju

    78. vivek soni,harsh patel,sunil rajput, rohit sharma says: on February 29, 2012 at 10:36 am

      there are no BD 699 transistor in my state and u r using outdated parts…

      so be helpful enough to anyone….

      • Rutam Sable says: on March 20, 2012 at 10:59 am

        You can use equivalent transistors. Even i made the circuit with one BD699 and the other with the equivalent one and it worked as expected.

      • RK Murthy Challa says: on June 12, 2012 at 9:53 am

        Dear friends,

        I have seen your comment today. But I don’t know you are succeeded in procurement of transistor.
        If so plz drop a comment again. shall tell you
        Than Q

    79. Rutam Sable says: on March 20, 2012 at 10:57 am

      I have made the circuit and it works beautifully. One thing everybody are mistaking, the z=1.5A/T is not a fuse, it is an impedance coil.

      • RK Murthy Challa says: on August 11, 2012 at 4:56 pm

        It is a fuse for safty. If any means if the Transistors draws excess of current, it may blow up to avoid damage.

    80. To get the transistor BD699 replacement, go to Google search, type “BD699 equivalent, or BD699 replacement”, avoid datasheet, Doc files and PDF files if you are using Java Phone

    81. please, I need the component listing for a 12VDC to 220VAC converter

    82. David Paul says: on March 27, 2012 at 6:21 pm

      BD699 transistor equivalent are ‘MJ3055, 2N3055

    83. gs biju says: on March 29, 2012 at 4:20 pm

      i think a 12 v transforner also can be used insted of 10v by adding 3 nos 6amp diodes in series with d fuse

      • mr. biju, first thing you are mistaking is that the 1.5A/T is not a fuse, but an impedance coil. and yes you can use 12V transformer and it will surely run as you have used a battery of the same voltage.
        and let me tell you, that i have also used a 12V transformer and yes my circuit has worked very well. i had also mistook the impedance coil with fuse before. but later i understood…

      • electron_revolution says: on October 8, 2012 at 3:54 pm

        555 timer IC is much cheaper :-)

      • thank u

    84. thanks

    85. Nice and simple…..

    86. Anandhan Varatharajan says: on April 9, 2012 at 8:59 pm

      sir
      how much amps we get in out put

    87. Anandhan Varatharajan says: on April 9, 2012 at 9:00 pm

      i need input 6v into 230 v output with 3Amps

    88. Salman bacha says: on April 11, 2012 at 12:27 am

      Sir how can we increase its output watt means power.

      • RK Murthy Challa says: on June 12, 2012 at 9:47 am

        Dear Salman Bacha,

        The Power Can be increased by;
        1. Using 2 more output transistor of same specification
        2. Use of transformer with increased Current rating

    89. jayapradap says: on April 13, 2012 at 11:57 am

      What means the Tr= 2*10v/3amp
      Transformer of 3 amp I understood but what about 2*10v cant understand
      It is inverter transforer or any other.
      Plz guide us
      Reply

    90. Rutam Sable says: on April 15, 2012 at 8:51 am

      2 * 10V means the input of the transformer has two tapings like that of an auto-transformer with one neutral in between them. so there are two 10V inputs to the transformer.

    91. thank you sir,please help me to make 100-120 va inverter with automatic cut off&charging,sir whether it possible that converting&charging doing by single transformer?or use capcitor for charging?please give complete details
      -unnikrishnan

    92. Sir,
      I am thinking to use solar panel instead of batter, Does it works ?

      Please can you share trasnformer detasil as well.

      Thanks

      -Guru

      • Dear friend,

        Your idea use of a solar panel for the 12V to 220V is good and naturally. When you have such idea, you must have a concept on the Solar panel, i.e., How it works, When it works. means it delivers its maximum Current when the sun is in full illumination. 2. It is not source of Static energy like a battery. 3. A converter/ Inverter of above type always requires a study DC current, to give a study VA output, i.e., your load applied to the converter. So now you can easily imagine the use of solar panel.

        Coming to the Transformer details, a transformer with 12-0-12/5A=6Amp rating is needed for the above circuit and the transistor BD699

        Than Q

    93. Hola!

      Puedo sustituir los darlington por transistores de potencia en paralelo? Supongamos (usar varios 2N3055 en paralelo)

      salu2

    94. sir weather it work please tell me

      • RK Murthy Challa says: on June 12, 2012 at 8:49 am

        Dear Vishnu,

        It works definitely. As I have done the same and using for the Laptop of my Son during power failures for more back periods
        Try it very simple.

    95. what is 470 before t1 and t2 weather it is resistor

    96. i dont get bd699 transistor instead of that what i have to use

    97. send me ur mail address i face a small problem its output is only 7v……..

      i have seen in video u have used diodes and capacitors but i has used connection as per the circuit diagram …it s output is 7v.only…..please help me………..

    98. i don’t get the transformer 2*10v, i have a Transformer of 2*12v /3amp,I can use it…

      n what transistor can i use in the place of BD699.

    99. can it possible without transforme ,, if so ,,so tell me boss

    100. aakash says: on July 5, 2012 at 3:07 pm

      PLEASE MAIL ME THE COMPLETE CIRCUIT DIAGRAM WITH CONNECTION,COMPONENTS SPECIFICATION …,

      THANKS IN ADVANCE…,

    101. Adelusi Tosin says: on July 14, 2012 at 1:29 pm

      i don’t really understand what you mean by, “z =1.5 A/T” moreso, can 100nf can be subtitude? if so, what are the equivalet subtitution. With kind regards.

    102. David Paul says: on July 18, 2012 at 1:07 pm

      The problem am having with this circuit is the IC, i replace the transistor with LEDs, instead the LEDs just on instead of blinking. The conclusion is that, the output voltage is 40v, i need your help

    103. NILESH KAPURIYA says: on August 10, 2012 at 10:00 am

      Dear sir,
      please tell me about total cost of this project. i want to make it as my final year diploma project

    104. RK Murthy Challa says: on August 10, 2012 at 2:38 pm

      OK. Well Mr. Nilesh. The cost of components varies from one to another location. I do not know which state/district you belongs.

      Any how, the Transformer ( 220V-12V/6Amps) may cost much more i.e., INR/100-200/- and the remaining will be up to Rs.100/- and a total of less or more Rs.300/- will be incurred against this project.

    105. the transformer u have used is center tapped. can a normal transformer can be used instead???

    106. RK Murthy Challa says: on August 11, 2012 at 5:01 pm

      Yes. Otherwise the out put will be half. Instead of 60VA, you will get 30VA and the load to be connected should be in the range of 30VA to work properly.

    107. .,Sir ,,,’hi will advise the post of dis circuits to replace cd4047 to sg3524 becoz cd4047 is not suitable for standard inverter is a low astable multivator …..d best Ics for inverter project is Sg3524….and some descrete component… Dis chip hav 16pin while pin16 have constant 5volt ..while pin10 is shutdown,and pin6 and pin7 is frquency calculation, hi will post 1000watt inverter circuits using sg3524 which u can ever found dis circuits in any website hi a can asure of dis….absolutely ………speaking..aslo post inverter low battery shutdown circuits dat can can b connect to pin10 of dis chip also changeover circuits,,more details add me at facebook john jay,and eskimi john1904 …u can meet at electroshematics.com ..capacitor

    108. M.Shaheryar says: on September 9, 2012 at 11:57 am

      ,Sir ,,,’hi will advise the post of dis circuits to replace cd4047 to sg3524 becoz cd4047 is not suitable for standard inverter is a low astable multivator …..d best Ics for inverter project is Sg3524….and some descrete component… Dis chip hav 16pin while pin16 have constant 5volt ..while pin10 is shutdown,and pin6 and pin7 is frquency calculation, hi will post 1000watt inverter circuits using sg3524 which u can ever found dis circuits in any website hi a can asure of dis….absolutely ………speaking..aslo post inverter low battery shutdown circuits dat can can b connect to pin10 of dis chip also changeover circuits,,more details add me at gta3vcsr@gmail.com

    109. sir/madam, iam from 2nd ece department .noew iam doing my mini project based on the circuit from the internet.my mini projects is solar based multipurpose charger,through this charger iam going to charge 3 batteries (i.e.leadacid battery,nicd battery, and mobile battery)the total voltage iam getting from the panel is 22v to charge this batteries,instead of that can i store that charge in some other other batteries ?and also if i want to convert that into 230v is that is possible?plsss tell me the result as soon as possible.

    110. shivuu yadav says: on October 3, 2012 at 6:24 pm

      nice for giving the holy information….i expect that u give wholesole information about ele…thanx..
      bt give me more knowledge about the dc to ac convertor

    111. ابو محمد ساتhttp://www.abumohamdsat.com/vb

    112. Govt Property says: on October 20, 2012 at 11:01 pm

      The converter can’t charge battery due to lack of rectification, and battery sensing level. It’s advisible to build a battery monitor and battery charge

    113. it was good!
      i need a circuit for convert 12v AC to 220v AC
      thank u

    114. Mehdi if you have 12 volts A.C. then just use a transformer in reverse

    115. Dalagan Aldrin aldrin1234 says: on March 16, 2013 at 11:48 am

      can you send me the schematic diagram of a 1100 watts, 12VDC-220VAC inverter power supply? plz.. it’s for our group project… tnx a lot GOD BLESS! :)

    116. musjava says: on August 1, 2013 at 2:34 pm

      thank for these info. Please i have a question,how do i use a car battery 12V to power my refrigerator compressor(220V-240V,50Hz,65WATT,0.75A)watt kind of inverter can i use.thank you in anticipation.

    117. a refrigerator compressor has nearly always an under-oil induction motor, which is started by an auxiliary winding. This is quite normal and usually you would use a capacitor to generate the phase shift between main and auxiliary winding. But in order to save it, the refrigerators have a resistive auxiliary winding. The capacitor is replaced by a resistor, and also this is saved by making the winding partly bifilar. There is a starter relais, which switches the aux winding shortly on and very quickly off again when the motor is running. This starter relais reacts on the main winding current. During startup it is high and the simple relais activates the auxiliary phase. When the current drops, this auxiliary phase is switched off.
      That means a high current peak during startup. I have measured up to 10A on a 120W compressor. When connecting the refrigerator to the inverter (similar as above) the inverter voltage broke down, and the motor did not start. It tried again, did not succeed etc. This instability damaged the contacts of the starter relais without ever starting.
      I solved the problem by using a 600W inverter for the 120W compressor and putting a large capacitor in series with the auxiliary phase to reduce the current at equal phase shift. I think it was around 20uF MP type.
      In your case I would guess you need an inverter of about 300W and the mentioned capacitor to handle the start problem.

    118. @joribo thanks for giving a straight forward answer.you explain eloquently like a lecturer or even better than most…..if i understand you correctly all i need to get is a 20uF capacitor MP-type and a 300watt inverter…… i would give it a try

    119. …well, I wrote so much to give background info. So that you have a better start when solving the problems which will certainly come.
      Yes, i recommend to use an oversized inverter at first, then try the capacitor. It needs to be put into the auxiliary phase. Also, I recommend compensating the motor to reduce the current, and take care that there are strong freewheeling diodes in the inverter, else it cannot handle the inductive load of the compressor motor.

    120. …made a hand sketch how to connect these thingies, but how can I add a JPG to the comment?

    121. thanks, http://imgur.com/uuPLwuD
      valid for “normal ” refrigerator compressors using a resistive auxiliary phase. It is a troublesome load for an inverter.

    122. This diagram worked out for a 220v 50Hz. 20 watt motor without any load.
      Alas for my projects it didn’t work out properly, the voltage collapsed when I pulled up the frequency.
      I need a stable 220v ~ at a higher and adjustable frequency (50 to ± 200 Hz.)
      In the Capstan motor ( Papst 220v.50Hz 2.5w ) the magnetic field collapses when the voltage drops.

      So I’m working on this one now ,with thanks to http://www.circuitstoday.com and Nickk.
      Got all the parts here,want to buy the PCB from NICKK.

      http://www.circuitstoday.com/pwm-inverter-circuit

      —————————————————-
      I use The PWM output (0-10v DC) of the PLC to generate a resistor parallel over potmeter R1 (100K)
      with a LED shining INTO the LDR using the LDR as variable resistor depending on the light output of the LED. http://led.linear1.org/1led.wiz

      The LED/LDR are in an enclosed housing.
      this works , is tested with THIS Oscilloscope http://www.sillanumsoft.org/prod01.htm (THX Alfredo)
      REMARK :Be VERY careful with your audiocard/voltage !!

      —————————————————-
      So work goes on and on ;-) T L.

    123. the voltage needs to rise about linearily with frequency when driving a motor with variable speed.

      In the schematic according to the link above, are 3 transistors as darlington, this costs a lot of voltage drop, roughly 1.5V are lost in fully conducting state, so the transformer should have a reduced voltage winding.

      The LED-LDR will work. In 1981 ELV had an inverter where they used a small lamp and an LDR together in a closed casing and called it “effective value coupler”.
      Because the lamp lights as bright as the effective value of the voltage is, no matter if rectangular or sinusoidal.

      I have just made a 160W inverter. If someone likes to have the schematics pls mail me, will send them. The IMGUR picture platform is down.

      • I would like to see the schematic!

      • Hey Joribo,

        That’s why there is potmeter R9 on the feedback from the ‘created’ 220v ~.
        I might have to do there something similar as what I do with R9 in conjunction with potmeter R1 , we’ll see.
        That’s the beauty on this inverter, adjustment of voltage .AND. frequency.
        Nickk made an addition to it, up to 5000 wattt !!

        http://www.instructables.com/id/250-to-5000-watts-PWM-DCAC-220V-Power-Inverter/

        See also the pictures a bit lower in that page.

        I first have to build and try it out.
        If this inverter doesn’t do the job I got a circuit with pure sinus laying around as well.
        Alas , ‘Time’ :/
        Primary working on the PLC now , the software Simulation over the Ethernet and REAL-time switching are .NOT. exactly the same.

        THX for your input,
        RGDS, T L.

    124. You should remember when cascading power transistors in an invertor like this the output Q(impediance) becomes lower to the point where an almost dead short can be applied to the the output of your invertor also note that the current now controlling your invertor can make your power supply go up in smoke if the parammeters is being exceeded. Also note the Q on the primary winding should be updated as well where some guys rewind a microwave transformer where 2mm wire is being used the thickness of the wire should rise proportionally to the amount of cascaded transistors being used….

      • Hey Philip ,
        You’re fully right about the wiring sizes.
        On Instructables , the site where the circuit diagram came from , Nickk has also noted this under
        tab 7>
        You can also see it on the pictures of the transformers.

        For me that is less important ,
        I need only 2.5 watts output from the inverter
        at a steady 220 volt with a variable frequency.
        Even starting the motor will be from the standard 220v. mains and then completely taken over, when needed, with interlocked relays. (both ~ .AND. N )

    125. Rashid Ansari says: on October 23, 2013 at 12:21 am

      Hi, wonderful circuit. Will it work for 100W fan ?
      Please help.

    126. ..if the fan has an induction motor, it will run at both rectangular and rectangular-with-gaps voltage, but at reduced power. The motor should be compensated to relief the inverter from unnecessary reactive current. For example, I have operated a laundry spin-dryer.
      If the motor is a “universal motor”, which is a series-wound DC motor with commutator, the motor will run well. But if there is a phase-cut control unit for speed control, this will not work.
      If the motor has an auxiliary winding with capacitor, the capacitor size needs to be changed by test and trial. And the power is reduced.
      As a special problem, it might happen that an induction motor runs up to a partial speed and stays there and becomes hot. In this case it helps to use an LC filter (L in series and C in parallel to the motor) to round off the sharp edges of the rectangles. This will reduce the harmonics content.
      Refrigerator motors are something special and very difficult to operate on inverters.

    127. Rashid Ansari says: on October 23, 2013 at 8:05 pm

      Thank you joribo for your answer. Actually I just want to know that ceiling fan 220V (A.C) 100W will work on it or not ??

    128. yes, as above, you need to tell us what motor is inside. If it is like in India, it is an induction motor with rather bad power factor, needs compensation. I can try to give support by mail, have experimented a lot with such things.
      br George (georg.bohmeke@futurepower.fi)

    129. Rashid Ansari says: on October 24, 2013 at 10:06 am

      Yes it is just like in India, it has a capacitor in it which has value of 4.3uF, 250V.

    130. ok then it is an auxiliary phase induction motor, will run on the inverter but with reduced power, higher losses and needs two small modifications.
      One is to compensate the motor by adding a compensation capacitor in parallel to the whole motor (basically to the secondary side of the transformer), and the second is to optimize the capacitor which is now 4.3uF. It might need to be enlarged a bit. I would start with the compensation capacitor and try to get best possible operation with least current. Rough estimate for starting: 10uF.
      The 4.3 uF is the phase shifting capacitor, that may be better with 5 to 7, but I can just guess as I have not seen the motor. Aim of this capacitor is a 90 degree phase shift in the winding currents between main and auxiliary winding. You can optimize this quickly if you have a 2-channel oscilloscope. Else just need some trial and error.

    131. Rashid Ansari says: on October 25, 2013 at 10:06 am

      Thank you Joribo, secondary side of the transformer is which one! 12v or 220v ??, because in this circuit stepdown transformer is used in revers.

      And also what would be the value of this compensation capacitor ?

    132. It belongs to the 230V side (in some countries 220V). The reason for this compensation capacitor is to neutralize the reactive current of the motor. If this is done correctly, the inverter will supply only the needed power to the motor and not additionally a lot of reactive power, circulating around. This circulating around of reactive current happens through the transformer and the freewheeling diodes on the 12V side into the battery and back again. Although the reactive power is no real power which is consumed, it makes real losses when circulating, so we try to avoid it. I would roughly guess as a starter value for experiments that 10uF might be ok. (pls try some 5 to 20uF)

    133. Rashid Ansari says: on October 28, 2013 at 5:34 pm

      Thanks a lot joribo! really appreciate your help.

      Thank you again.

      Best Regards.

    134. This is an old technology for amateur!!!

    135. Amature,professional regardless the situation it still is a nice little circuit to experiment on most of the ppl on this site is not professionals nor do they have doctorates in electronics thus leave the kids let they play with their electronics.

      “Men grow old so is technology”

    136. Yes, true (old technics)
      But this is why I like this forum.
      There are many other electronics websites, and often on high level. But we need something to help the beginners to climb up the ladder. And we need explanations, because the electronic device has few value. The value is KNOWING HOW IT WORKS and there it is good to start with simple things.
      Next step would be a sine-inverter. I have tried some circuits at home but I am not yet fully safisfied. When it runs well, will put it here (sorry, some delay due to my work).

    137. hello….
      plzz tell me how to convert 150v(8.3amp)dc to 230vac…plzz rp fast.

    138. No simple solutions on this one –there are two means:

      1. A 1:2 115 to 230VAC 60HZ step-up transformer driven by a bridge inverter consisting of (4) high voltage MOSFETS.

      or
      2. A 1:2 boost converter to generate 325VDC, and a 230V bridge inverter using high voltage MOSFETs.

      High voltage bridge inverters work –I have done this for AC motor controls, but they are very unforgiving if not EVERYTHING is done properly –not recommended for the casual experimenter.

      • Good info from joribo

        I forgot to mention IGBT power devices –they are preferred over MOSFETs as high voltage switches. Big issue is how to drive the gates –International Rectifier has nice half-bridge drivers. And a microcontroller is required to generate the “6 step” or PWM waveform and handle voltage feedback & current overload issues.

        Also, this is considerable power involved –1.25kW!

    139. …two reasonable ways:

      1. Like the above mentioned 12V to 230V inverter, but using high-voltage MOSFET’s as switching elements. The transformer should be an autotransformer (if you dont really need the galvanic separation), so there are two windings with 150V and on top of this winding the rest to make 230V. The transformer operates at 50 Hz and has a metal sheet core. Preferred is ring core or U-core.

      2. Like most of the far-east inverters. The 150V is switched with ca 25 to 40 kHz to a transformer with ferrite core. The output voltage is rectified with fast diodes. A DC smoothing capacitor makes smooth DC. Detail: dont use electrolytic but foil capacitors. Now you have DC which shall have a voltage level of the output peak voltage. Now comes an H-bridge (four MOSFETS) which alternatively switch over cross with a zero time in between. At the output you get a rectangle with gaps, same as with proposal -1.

      1 is simple and needs more space, is heavier.
      2 is more compact, lighter, tricky, needs some filters against EMC, and is sensitive to capacitive loads.

      Both 1 and 2 give “modified sine” which is just a rectangular wave with gaps, providing both correct effective and peak voltage values. If you need pure sinusoidal output, its more complicated. Recommended reading (german):
      Franz-Peter Zantis: SCHALTNETZTEILE, published by ELEKTOR (= ELEKTUUR), page 173 ff.
      FUNKSCHAU Nr. 9 -1991 they published a four page article with schematics and PCB for a small sine inverter, from which the power part could of course be modified or enlarged.

    140. how can we use power supplies for water purification ?

    141. what can be done with dirty water water:
      1. normal filtering (no energy besides pumps)

      2. active carbon filter (no energy besides pumps)

      3. desinfection, alternatively or in combination
      3.1 generating Ozone with a high-voltage power supply and mixing this into the water
      3.2 passing the water slowly through a quartz glass tube inside of a transfer mirror which has elliptic cross-section, in one focal point is a strong UV-lamp and in the other focal point is the water tube.
      3.3 mixing up desinfecting substances into the water, usually based on chlorine.

      Suitable power supplies can do this job, but the above mentioned 12V / 230V inverters are not especially designed for just this purpose.

    142. What voltage is condensatoru.

    143. Which one?
      the smoothing capacitors which are in parallel to the supply (usually battery) should have a certain safety in voltage because in case of inductive load the freewheeling diodes push some current back into them with 2 x operating frequency. This gives additional stress. An electrolytic capacitor does not like strong charge/discharge. So, for 12 V supply you can select 16V or 25V rated capacitors (standard values) , and in my private opinion I would use 25V just for safety.

      A capacitor on the secondary 230V side to supress voltage spikes should be rated at least 400V better 630. This is a foil capacitor for example type MKP.

      The capacitors for running a motor on the inverter will usually be MP (Metal-Paper)types and should be rated around 400V. For getting the right uF values please browse for STEINMETZ-circuit or HILGENBERG-circuit.

    144. Can this circuit be used to control the speed of a synchronous motor? What will be the transformer specs for a 110volt synch motor?.

      Thank you

    145. yes, you can basically drive a motor with this inverter. If the motor is 3-phase it has to be switched into a single-phase connection according to STEINMETZ, for startup possibly according to HILGENBERG. Or using the STEINMETZ connection with two capacitors, one for continuous operation and one in addition, parallel, for start.
      And you should add one more capacitor in parallel to the output transformer winding with the connected motor, in order to keep the reactive current as low as possible. The inverter transfers both active and reactive power to the motor, so the motor shall be compensated as well as possible.

      The transformer:
      If using full square wave and 12 V supply it would have 2x 12 / 1 x 110V. There should be a bit of additional winding to compensate for losses and transformer voltage drop due to leakage flux. For example 110V plus 10V plus 10V so you can connect the best one.
      Using the method of a half-time pulse (5msec pulse plus 5 msec pause plus 5 msec negative pulse plus 5 msec pause) the transformer is reasonable with 2 x 12 / 1 x 168V plus some additional windings for compensating losses.
      This will very probably work, I have operated a laundry spin dryer this way but on an induction motor. If you have a synchronous motor, it needs possibly a starting aid. This can be an additional short-circuited winding around the poles (damper winding). With good luck, it starts as it is.
      For example, a bicycle dynamo runs on AC as a small motor although it is synchronous.

    146. Please can you e-mail me the schematic design for the DC to AC Converter 12v to 220V. Thank you in advance.

    147. http://www.electroschematics.com/9176/12v-dc-to-220v-ac-inverter/

      there is the one which has gaps between the pulses,
      some others (pls look under POWER SUPPLY) are directly square wave.
      It depends on your consumer, which one is preferable.

      Best is pure sine wave, I have a schematic from the journal FUNKSCHAU in paper mode, author is Franz-Peter Zantis, from the 1980ties. I have built it but was not yet satisfied and need to redesign it. Is under work, hopefully ready in a few months.
      If you like this schematic i can give it privately to you (I have no legal right to put it into the internet)

    148. I need a solar panel of an AC output with about 1500w to 3000w and of 220v. What is the price range. Thank u

    149. http://www.wholesalesolar.com/gridtie.html#SolarSkyAstronergy

      the above link as an example, you would need about 5200 US-Dollar for 3000W. This would be without battery, and with a German-made grid-tied inverter. In case of a stand-alone system you need more money, as the battery comes in addition. If you can get Chinese components directly, the price level would be lower, maybe roughly only 75%.

    150. Please help. We got circuit made but when we wire there is no power coming out. Powertransistors getting hot fuse blow but no power out.not even power a globe. I’m using the transformer 220v 10-0-10 60w centre tap.

    151. which one, the simple rectangular wave with the CD4047 or similar?
      Recommendation:
      1. to check the transformer without inverter at grid voltage, are the 2 x 10V comming out in correct phase? So, two times 10V and between the outer lines 20V?
      2. To check without the basis connection to the transistors, there must be no current, else the transistors are defect. In case of MOSFETS you need to connect Gate to Source, they might pick up any kind of static voltage.
      3. Look at the output signal which feeds the basis (or gate) with an oscilloscope. You can make a simple improvisation by feeding this voltage into a LED and put it on a short stick and swing with your fingers. You see a chain of small light dots. If no dots but a continuous light, then there is a bug in the impulse generating circuit.
      Checking this, you may use a trick. The frequency generating parts can be replaced just for test by a larger capacitor or larger resistor to make about 5 to 10 Hz instead of 50Hz. This frequency you can see with a LED. If the oscillator makes the LED flicker correctly, you need to replace the original values back before connecting the transformer, but at least the oscillator seems to work.

    152. suvas patel says: on August 5, 2014 at 5:01 pm

      sir, I want dc to ac converter so Pl. help me

    153. ..you would need to tell us more about the driven device, your voltage source, the type and power of inverter etc. Then we could give you some hints what is best. You find several schematics here in the forum, generating square wave or square with gaps (this is called modified sine by some manufacturers, although this is not really correct).

    154. Bom in detail sir. What are the values. Tried many times what now

    155. ..all values are given in the schematic. The schematic is correct, my inverter works fine. Please follow the above given hints from 1 August.
      Somewhere is a wiring problem or defect component. Have you especially checked that the transformer windings are in correct phase? If you operate it on grid voltage with disconnected transistors you should measure 18V between the connection of the collectors / drains and 9 V between these points to the “plus” wire. If this voltage is not 18V (2 x 9V) but somwhere around zero, one of the two transformer windings has to be inverted.

    156. @nico

      Well, I can understand that it is very frustrating if something does not work. Especially when you dont have an oscilloscope at hand.
      But please believe me, that the schematic is correct, as my inverter works well.
      There is any kind of wrong wiring, or a component is defect. You should check the project from the transformer backwards. So, first to ensure that the windings are connected to make 18V as a whole, with the center tap being connected to the PLUS of the battery. Then, check the driving transistors individually. For example, just on the workbench, using a bulb as a load. Then, check the pulse generating circuit by enlarging the frequency-determining capacitor by a factor of 20. You should see the pulse-generating outputs blink, when you connect LED’s for test (dont yet connect the driving transistors). If they blink correctly, revert the capacitor back to the correct value. You will find some defect parts or wrong wiring.
      A simple oscilloscope is an old plastic ruler with a LED attached to the end. You press it on the desk and let it vibrate. Or swing it through the air. A pulse frequency appears as a chain of small light dots. DC makes just a strip of light.

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