Sunday, March 10, 2013

How to Convert 12V DC to 220V AC Using IC555 Boost Circuit

The article explains a very simple method of acquiring 220V AC from a 12v DC source. The idea utilizes inductor/oscillator based boost topology with the help of the IC 555.


We are quite familiar about inverters which convert a DC potential to higher AC potentials at mains levels.
However these units involve complex and expensive configurations for acquiring the required outputs.

A much simpler approach of achieving the above results is by employing a oscillator mosfet boost converter circuit.

If the waveforms are not critical for your applications this method can be a lot simpler and cheaper to implement.

Referring to the circuit diagram below, we see that the entire idea is based upon the versatile, evergreen IC 555.

Here it's configured in its standard astable multivibrator mode for generating the required pulses at a frequency determined by the resistors 4k7, 1k and the capacitor 680pF.

The duty cycle may be appropriately adjusted by experimenting the 1K resistor.

The output is received at pin#3 of the IC, which is fed to the gate of an N-channel mosfet.

When power is switched ON, the positive pulses emanating from pin#3 switch ON the mosfet into full conduction.

During the above periods the 12V high current potential is pulled to ground via the coil by the mosfet.

As we all know inductors always try to oppose instant changes in current polarity through it, therefore during the negative pulses when the mosfet remains switched OFF, forces the coil to dump the stored potential in it in the form of high voltage EMF pulse into the output. This voltage may be equal to 220V and gives rise to the required potential at the shown outlet of the circuit.

The above straightforward operation is repeated continuously at the given frequency providing  a sustained 220VAC at the output.

The BC547 and its base network is introduced for limiting the output voltage to the required degree. For example if the required output is 220V, the 47K preset may be adjusted such that the220V mark never exceeds, irrespective of the coil back emf rate or the input voltage fluctuations.

The mosfet can be any 30V, 50 amp type, for example a NTD4302 may be used.

The coil wire should be thick enough to hold up to 30 or more amps.




117 comments:

  1. nice one .. :))
    how much watt/load can i put on output ? ..

    ReplyDelete
    Replies
    1. up to 200 watts if the coil is appropriately dimensioned....

      Delete
    2. hello again,
      i need to make a just opposite project converting 220v AC to 12v/24v DC help me please or please give me link of the same :)

      Delete
    3. It would be dangerous to use the above type of configuration for your requirement, you may try the following design:

      http://homemadecircuitsandschematics.blogspot.in/2013/06/0-300v-variable-voltage-current.html

      Delete
    4. Obaid just take out 220V AC, add a step down transformer that makes it 24V and then add a bridge rectifier and two filter capacitors electrolytic 10uF 25V and a 7812 IC, u'll get 12V

      Delete
  2. what about protections in the circuit?
    What are the resistor wattages (1/4 watt to be used)?

    ReplyDelete
    Replies
    1. only the 10k zener resistor needs to be rated at higher wattage may be a 1 watt would do. rest all can be 1/4 w

      Delete
  3. can we give input inform of normal battery

    ReplyDelete
  4. dear sir, the output is pure sine wave ? can i connect 2 fans (230 volts A.C) ?how can i make the coil? iam going to do this circuit. please help me.

    ReplyDelete
    Replies
    1. No you cannot connect any applliance except lights

      Delete
    2. how can i make the coil?

      Delete
  5. how to make ac powered 3 watt led circuit

    ReplyDelete
  6. Can this circuit be slightly modified to design DC to DC by placing a diode to acquire 36V or even 48V to feed a pure sine wave inverter?

    ReplyDelete
    Replies
    1. the coil is the main component which decides the output voltage, it can be appropriately dimensioned for acquiring any voltage level at the outpt.

      Delete
  7. hello and thenx for your job in this blog.. i have a question what is the herz in this circuit and how with no transformer give 220AC ?

    ReplyDelete
    Replies
    1. sorry... frequency would be in kHz....the coil does the step up function.....

      Delete
  8. Sir, how many hours can i watch on my 86watts of television if i use and follow your components device? if ever i want to increase the hours what componets can i change?

    ReplyDelete
    Replies
    1. this circuit can be used for battery charger, and lighting applications only.

      Delete
  9. Hello Swagatam,
    I have 6 Pl lamps of 15 watt each, and 2 of 26 watt each the total is 142 watt
    I use an ups fed by 12 v 110 Ah battery can the above circuit replaces my ups.
    Best regards

    ReplyDelete
    Replies
    1. Hi Basem,
      if you design the inductor optimally, and get 1 amp from it @ 220V then it would do the job.

      Delete
    2. Good day
      Thank u what AWG shall I use to make the inductor

      Delete
    3. Good day,

      it's not critical, approximate a thickness which would comfortably handle the specified current, you can go for plus sized wire....added thickness will not do any harm.

      Delete
  10. Hello Sir,

    I guess the Coil should be wound on Ferrit Toroidal Core..please correct me if I am wrong.

    ReplyDelete
    Replies
    1. yes using toroidal core would be more efficient

      Delete
  11. Hi Swagatam,
    Is IRF3205 a good for this circuit.
    wish you good day

    ReplyDelete
    Replies
    1. Good day Basem,

      At 55V/110Amps, it's a hugely robust mosfet, no doubt it would be good for most high power applications.... same for this circuit.

      Delete
  12. WHICH MOSFET SHOULD BE USED?HOW MANY TURNS ARE REQUIRED FOR THE COIL?CAN THIS CIRCUIT BE USED TO LIGHT CFLs?

    ReplyDelete
    Replies
    1. any 10 amp, 50V mosfet will do, coil turns will need to be experimented practically, yes can be used for cfls.

      Delete
  13. First Thanks for this nice model.
    Sir what will be the overall cost for building this circuit.

    ReplyDelete
    Replies
    1. Sir can you please explain me why we are not using any transformer in this circuit... because on net i have found that all circuits are have transformers.

      Delete
    2. The above design is a simple boost converter without negative half cycles, it will provide a pulsating DC only...a transformer type will provide full wave AC and will be isolated from the input.

      Delete
  14. Sir,
    I made a circuit which you shown in figure,in using of bc547 and lm338p....
    but in this circuit output ok is 12.70 v ,but current is 0.01a
    So what i do....
    I want minimum current 10 to15amp...so which circuit i do...

    ReplyDelete
  15. It is really very interesting Project

    ReplyDelete
  16. sir where is the coming - terminal from 12v dc

    ReplyDelete
  17. can i use to supply my wooofer.

    ReplyDelete
  18. Sir,

    How can I apply this circuit convert 12V DC to 50 V AC , at about 20 milliamp at 1hz per 10 to 20 minutes for an electrolysis project. (so I don't have to swap polarity every 10 min. on a DC battery.)

    ReplyDelete
    Replies
    1. use a 10uH inductor, you will get the required output.....

      Delete
    2. Isn't the frequency determined by the resistors 4k7, 1k and the capacitor 680pF. Do we not need to change this values??

      Delete
    3. frequency has no connection with the output voltage.

      Delete
  19. Hi sir
    We had a innovative since fare project
    So I thaught of doing the circuit
    Sir have u tested it?
    And what is the coil rated
    Please help me sir

    ReplyDelete
    Replies
    1. yes i have tested it, it works, the coil will need to be experimented for getting the required output.

      Delete
  20. hi sir iam going to do the project

    sir have u tested the circuit?

    ReplyDelete
  21. Sir,
    Somewhere on the net I came across the information about the coil to be handmade and that would be perfect for this project.
    Toroid Core (T106-2) with 0.8mm wire, 55 Turns for 40uH.
    Could you describ which type of coil you had used?
    What do you suggest???

    Regards,

    ReplyDelete
    Replies
    1. PP, yes hand wound torroidal coils would work nicely here...however I have not yet checked the circuit practically....i would hopefully do it soon.

      Delete
  22. Sir please is it possible to connect a ferrite transforme between the inductor.if not please how can we do that so we eliminate the regulator part of the circui and use ferrite transformer

    ReplyDelete
    Replies
    1. you may connect the primary of the ferrite transformer in place of the shown inductor, the output then may be acquired from the secondary winding of the transformer.
      but anyway the regulator part would be required for getting a stabilized output.

      Delete
  23. Sir thank u for your reply.please is it possible to get two frequency output each with different duty cycle at each output with one ic, like 555 or 4049.please help me on how to do it.thank u sir.

    ReplyDelete
    Replies
    1. what do you want to make? without knowing the exact application it will be difficult for me to design the circuit.

      Delete
  24. can i use p80nf55 mosfet

    ReplyDelete
  25. Good day sir,please how can we get 50hz from this circuit.thats why iam asking if we can get 50hz from the 555ic so that after the output is rectified we can oscillate it back to 50hz.thank u sir and sorry for my question.

    ReplyDelete
    Replies
    1. Good day Abubakar, try different values for the 680pf until you get the required 50Hz...you may take the help of an online 555 calculator.

      Delete
  26. I always like your work Majumdar. I am an ICEN engineer and i always find your work interesting. keep up!

    ReplyDelete
  27. Hello Mister,
    Lately i have been working on a project that requires 400v dc supply. this 400v dc is to be pursed on an inductor to create a strong magnetic field every 0.02 sec. Now, when i try to use a thyristor, it requires a forced commutation circuit which i haven't made. when i use irf840- which is capable of carrying such load, it burns out.
    could the problem of my mosfets burning be as a result of my mosfet driving circuit?
    I can really appreciate if you gave me a possible circuit that can solve my above problem. be it with a thyristor or using a mosfet.
    God bless you.

    ReplyDelete
    Replies
    1. Thanks!

      you can try this circuit:

      http://homemadecircuitsandschematics.blogspot.in/2012/05/making-adjustable-electromagnet-circuit.html

      replace the transistor with an appropriately rated mosfet.
      connect the inductor upper end to 400VDC while the circuit positives to a well regulated 12V supply.

      Delete
  28. Hello,

    I want to get 40V-50V output and around 100mamp current out of 3.7 V battery. Can this circuit do this with some modification? if yes please a Hint would be great help.

    Thanx

    ReplyDelete
    Replies
    1. yes it is possible by suitably adjusting the inductor turns, more number of turns will produce more voltage

      Delete
  29. output of 555 is AC or DC?

    ReplyDelete
  30. May i try it at home
    if yar
    what are tha main pricaution

    ReplyDelete
  31. can i use this circuit for lighting 40W TUBE LIGHT WITH ELECTRONIC BALLAST?

    does the output voltage remain same even after connecting some loads?

    for 40uH how many number of turns of coil should be?

    can i use 100uF/250v in place of 10Uf/250v capacitor?

    thank you.
    Good day sir.

    ReplyDelete
    Replies
    1. yes it can be used.

      output voltage will remain constant if the coil is calculated as per the load.

      i do not have the coil data, you will have to experiment with it.

      100u/250V will be OK.

      Delete
  32. what appliances can i run through this circuit?

    ReplyDelete
  33. SM sir, I tried this circuit, the IRF3205 is getting very hot and the wires used to link pins in the bread board gets burned , Pin config of IRF3205, pin 1 connected to pin 3 of IC via 1k resistor, pin 2 connected to inductor out and pin 3 to ground.

    ReplyDelete
    Replies
    1. It will be difficult for me to identify exactly how you fixed the mosfet, I hope you've put it correctly.

      What kind of inductor did you use and is your IC generating the required high frequency?? these two factors determine the correct operating conditions for the circuit.

      Delete
    2. Sir, i do not have scope to find out the frequency, can i use the DMM? if so how?, ferret core inductor 41uH 00440A

      Pranav BM

      Delete
    3. Yes you can use a DMM which has a frequency feature in it.

      Delete
  34. Sir,your response pls to my above query,IRF3205 print facing us, 1st pint Gate, 2nd pin Drain, 3rd pin Source.

    Pranav BM

    ReplyDelete
    Replies
    1. Please refer to this post, it has all the details:

      http://homemadecircuitsandschematics.blogspot.in/2013/05/55v-110a-n-channel-mosfet-irf3205.html

      Delete
    2. Thanks for the input sir, few query
      1. how to use the DMM to test the frequency, what should be the frequency for this circuit.
      2.can you help in understanding an inducted and its config in a circuit.

      Pranav MB

      Delete
    3. Your DMM should have a frequency measuring option, normally indicated with "kHz" symbol, otherwise it won't help.

      In response to the 555 frequency triggering, when the mosfet is in the ON state, the inductor stores the specified amount of electrical energy in it and during the mosfet OFF state reverts it to the output. This back emf from the coil constitutes the 220V at the ouput...

      Delete
    4. thanks sir,
      DMM has the square wave symbol in it.
      I checked all the configuration, however the IRF is getting hot. I shall try one more time reassembling them and let you know the status.

      Pranav BM

      Delete
    5. you can use the square wave symbol range for checking the frequency operation of the circuit.....

      if it's not working with a mosfet you can try a transistor instead, try a TIP122.

      Delete
  35. Hi Sir, sorry to ask this question here as I could not find a dc to dc step up circuit in your forum. I am thinking is it possible to modify this circuit to step up 2vdc to 12vdc? Thank you.

    ReplyDelete
    Replies
    1. Hi Unknown,

      the above circuit will require a minimum of 4V to operate correctly, I think you should try the following circuit, might just work:

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

      Delete
    2. Dear sir ,
      I have a battery 12v 32ah sf sonic jet , how can i charge by home made circuit ,I would like to use it as 200 Watt CFL inverter, kindly help me to making a 3 amp constant current battery charger,
      thanking you,
      Jayanta Roy

      Delete
    3. Dear Jayanta,


      You can try the second circuit shown in this link, but I am not sure about the transformer details you may have experiment with its size and wire gauge:

      http://homemadecircuitsandschematics.blogspot.in/2013/09/half-bridge-mosfet-driver-ic-irs21531d.html

      Delete
    4. ..actually I could not understand your need, what do you want to make, an inverter or charger??

      Delete
  36. Thank you sir, I had tried joule before but the problem is the current supply is not high enough.I need at least 100mA. Can I know how to increase the current or is there any way to do it?

    ReplyDelete
    Replies
    1. Use parallel wire winding, meaning use two or three wires together and then wind them as per the data, this will increase the current of the transformer,also you will have to use more number of cells in parallel for supplying the required amount of current.

      Delete
  37. okay sure i will try that and see what is the result, Thanks again sir.

    ReplyDelete
  38. Hello Sir,

    How can i modify this circuit to run a 150 or 100W fan.

    Thank you in advance.

    Rashid

    ReplyDelete
    Replies
    1. Hello Rashid,

      you will have to modify the coil by experimenting a little with the no of turns and wire gauge until it satisfies the conditions.

      Delete
  39. Thank you sir for your reply, I'll try it.
    Rashid

    ReplyDelete
  40. sir can i use the polyester fluorescent ballast for inductor...

    ReplyDelete
    Replies
    1. It will depend on the output voltage requirement, if the inductor is able to produce it then it would be fine.

      Delete
  41. Hi Swagatam

    I am considering to use this transformerless circuit to provide high voltage in CDI. Any comments/modifications?

    ReplyDelete
    Replies
    1. Hi Abu-Hafss,

      Yes, it's worth trying.

      Delete
    2. Hi Swagatam

      As per my usual practice, I have simulated this circuit and got following findings;

      The frequency is 510Hz. If it is decreased to 50-100Hz, the output becomes more than 1kV.

      The inductor is 250µH. The capacitor is 10µF.

      Following is the wave pattern:

      https://dl.dropboxusercontent.com/u/20969135/230V%20output.gif

      There is one issue i.e. how do we convert it to 230VDC? The CDI capacitor needs HV DC for charging which is provided thru a diode (half wave rectification) but, this output cannot be rectified, neither thru half wave rectification nor full wave.

      If the capacitor value is increased, the output decreases.

      Delete
    3. Hi Abu-Hafss,

      You can experiment with the number of turns of the inductor for getting different voltage levels at the output, because that's the only component that is directly related with voltage boosting.

      Delete
    4. Hi Swagatam

      The out put is sort triangular waves of AC 230V (fluctuating between 0-230V not between 230 and -230 at 510Hz. How do we convert it to DC??? Single rectifier or bridge rectifier is not working, the output remains the same.

      Maybe, the simulator is experiencing some difficulties in performing the rectification. Based on your experience, if you simulate in your mind, do you think the rectifier/capacitor should work to give a smooth DC output?

      Delete
    5. Hi Abu-Hafss,

      Just connect a couple of 10uF250V(in parallel) across the output, no diodes are needed.

      Delete
  42. Hi Swagatam

    Can this circuit be used to power a 30-40W soldering iron?
    If yes, would 12V-5A input be enough?

    ReplyDelete
    Replies
    1. Hi Abu-Hafss,

      yes it can be used, 12v/5amp would be just enough for that.

      Delete
  43. Hi Swagatam

    I am working to use this circuit (excluding the transistor network) as a simple laptop charger from car battery.

    1) One option needs a mosfet with following properties:

    25V, 5A and RDS(on) 3.5 Ohms

    I am not sure if such mosfet is available because such RDS(on) value is for small current mosfets.

    2) The second option is to reduce the input voltage to 6V but, that needs high current regulator.

    Which of these two options is more practical?

    ReplyDelete
    Replies
    1. Hi Abu-Hafss,

      The first option looks fine, you can use a higher rated mosfet such as IRF540 etc. it would also work as good and fulfill the results.

      Delete
    2. But that is 44mOhms whereas I need 3.5Ohms!

      Delete
    3. it's 44 milliohms which is a lot better than 3.5ohms, meaning the ON resistance of the drain to source will be just 44 milliohms.

      Delete
  44. hello sir nice work...i m planing electrick go kart powerd by sewing machine motor can i use this circuit??
    i have 30ah battery ..sorry for bad english...reply fast..thank u sir....u r genius,

    ReplyDelete
  45. Replies
    1. hello nitin,
      please tell me all the technical details of your project, only then i would be able to suggest regarding the above circuit integration.

      Delete
  46. Replies
    1. you will need a 400 watt inveter for that, the above circuit will not work

      Delete
  47. hi swagatam majumdar,
    is possible with this circuit to fed an solenoid water valve (7w) as valve of washing machine or an little motor (4w) as flat of wave oven?
    maybe is better to think an inverter circuit more complex as that you have posted in other pages?
    thank you so much
    regards
    andrea

    ReplyDelete
    Replies
    1. Hi Andrea, for a DC application, the above circuit could be used, but for AC devices an inverter would be more preferable.

      Delete
  48. hi iam doing a project in which i need to convert 6v DC to 230v AC . after converting can i use any electrical appliances from the output of 230v AC

    ReplyDelete
    Replies
    1. search for any IC 4047 inverter circuit and you can use it for your application

      Delete

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