I need curcuit 220v ac to 12v 3A output for my school project., help please

Discussion in 'Homework Help' started by iamprincejoy, Aug 12, 2017.

  1. iamprincejoy

    Thread Starter New Member

    Aug 7, 2017
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    I need curcuit 220v ac to 9v or 12v 3A output for my school project., help please.
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
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    DC or AC output?
    Look for a Wall Wart, you may even find one at a re-cyclers if you have one near you.
    Or 'borrow' one from a current piece of equipment.
    Lap-tops are a possible source.
    Max.
     
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  3. AlbertHall

    AAC Fanatic!

    Jun 4, 2014
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    Definitely better to buy one (or recycle one) than build one - cheaper, safer, quicker, and more reliable.
     
  4. iamprincejoy

    Thread Starter New Member

    Aug 7, 2017
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    9v or 12v Dc output, the current output is 3 to 5 ampere, I need a schematic diagram for the circuit because I explain it to my professor of how its work.

    Thank for the reply, I need the schematic diagram so that I can explain how its work.
    T
     
  5. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    What did you learn about powersupplies upto now?
    What have you done to solve the project?
    Did you do any reseach?

    Bertus

    PS I moved the thread to homework help
     
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  6. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Last edited: Aug 12, 2017
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  7. WBahn

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    Mar 31, 2012
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    You probably won't be able to get a schematic for the particular supply you find. There are lots of ways to make a supply with lots of different features. Linear supplies are the easiest to understand, but almost any supply you run across these days is going to be a switch-mode power supply, which are a lot more complicated.

    How much detail are you expected to give?
     
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  8. bertus

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  9. jayanthd

    Active Member

    Jul 4, 2015
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    I can provide you a schematic diagram for both 12V DC output using Buck converter LM2576-12. A step down transformer is needed to step down 220V AC to 12V and this is rectified and fed to LM2576 Buck regulator which can provide max 3A output current.

    Will this be sufficient ?
     
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  10. WBahn

    Moderator

    Mar 31, 2012
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    What is your actual assignment? To find a power supply for a project and then be able to explain how that particular supply works? Or to design and build a suitable power supply for your project and be able to describe how it works?
     
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  11. jayanthd

    Active Member

    Jul 4, 2015
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    Hi

    If 12V 3A DC output is sufficient then you can use a 220V to 12V step down transformer and rectifier circuit with this module.

    http://www.dx.com/p/lm2576hv-dc-dc-...NlIIJUdwPZVum9o1svgaArysEALw_wcB#.WZE_5VEjF9M

    I was talking about this step dowm Buck regulator.

    http://www.ti.com/lit/ds/symlink/lm2576.pdf

    If you need 12V 5A DC output then I can make a Buck Power Supply using Microcontroller, PIC12F or 18F, Power Mosfet, inductor, capacitor. and a few additional components like IR21xx FET driver.
     
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  12. iamprincejoy

    Thread Starter New Member

    Aug 7, 2017
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  13. iamprincejoy

    Thread Starter New Member

    Aug 7, 2017
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    Thanks for the reply,
    Maybe 9 or 12v and
    3 to 5 amperes is what I need.
    That can supply an audio amplifier.
    From AC source to transformer to rectifier the current that pass trough that part what I need to know and the current that will supply the circuit and also the output current.

    My professor said he wanted an combining IC and discrete in one circuit of power supply.
     
  14. iamprincejoy

    Thread Starter New Member

    Aug 7, 2017
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    Thank you for the reply sir,
    That's ok sir 12v and 3A,
    That my professor he wanted
     
  15. iamprincejoy

    Thread Starter New Member

    Aug 7, 2017
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    Thanks for the reply,
    I needed A circuit proposal first then I explain it how its work, and if its approved by my professor, I will build it and prove that it is working.

    I wanted a 9v or 12v and 3 to 5 amperes DC output, with Discrete and IC type combining in one circuit.
     
  16. iamprincejoy

    Thread Starter New Member

    Aug 7, 2017
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    Thank you very much, I hope you can make me for that.
     
  17. WBahn

    Moderator

    Mar 31, 2012
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    You really should have included this information in your first post. Just think of all of the posts recommending that you get wall-warts and such that could have been avoided. Also, knowing that you need to include both discrete components and IC's narrows the possibilities as well. Furthermore, the fact that you need to build and demonstrate the supply in the schematic narrows the field to supplies that are relatively easy to construct for someone new to electronics.

    The next question is whether you want it to be adjustable between 9V and 12 V? If not and if a fixed-voltage supply is adequate, then pick one.

    You also need to pick a current capacity. Is 3 A enough, or do you need 5 A?

    With all of that in mind, and given that 3 to 5 amperes is a significant, but not outrageous, amount of current, I would recommend using a circuit based on either an LM317 adjustable voltage regulator or a LM7809/LM7812 fixed voltage regulator. To get that kind of current, use a circuit that uses a bypass transistor (which will check of the box of needing to use discrete components nicely, since it's possible that capacitors/resistors/diodes and the like are not what that requirement had in mind).

    Look at the data sheets for the IC's I mentioned. They generally contain several power supply circuits and sometimes decent explanations of how they work.
     
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  18. jayanthd

    Active Member

    Jul 4, 2015
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    I will provide the circuit. If you are a student then you can order LM2578HV-12 samples from TI.com

    You need to buy one 100 uH 3A Toroidal Inductor. 2 electrolytic capacitors. 1 6A rectifier diode.

    There is no LM2578HV-12 model in my schematic software. I will make the schematic only model and draw the circuit. I will post the circuit today.
     
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  19. WBahn

    Moderator

    Mar 31, 2012
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    @iamprincejoy: I would strongly recommend against just having someone provide you with a schematic and parts list, unless your goal is to learn little to nothing and possibly get a failing grade when you aren't able to adequately explain how your supply works, since that appears to be a key element of this assignment.

    Wouldn't it be better if you could describe exactly what each component in your design does and how it does it and why that component was chosen?
     
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  20. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    I guess @jayanthd has agreed to be your "go to" person for all your designs if you get a job.

    I wonder how many more we can recommend to him.
     
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