AC/DC Converter

Discussion in 'The Projects Forum' started by RobertEagle, Jan 13, 2013.

  1. RobertEagle

    Thread Starter New Member

    Jan 13, 2013
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    Hi,

    My desire is to build an AC/DC converter.

    First of all, I'll talk about the inputs. There are 2 inputs channels, and on each channel there's an AC sinusoidal signal of 2kV at 2.04mA at 12.5kHz. The inputs are coming from the coils of a transformer. The sine waves complete each other.

    Now, what I want is to down step this voltages and turn this energy into some useful form. Like 18VDC at 0.224A at best. (I didn't count the loses)
    The problem is that I'm not familiar with converter circuits and I don't know where to start looking.

    Some say, it may work with a buck converter, other say with a transformer or SMPS.
    Please, can you guide me regarding this circuits and situation?

    Thank you,
    RobertEagle
     
    Last edited: Jan 13, 2013
  2. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    Can you wind some turns ont he original transformer (the one making 2kV)?
     
  3. RobertEagle

    Thread Starter New Member

    Jan 13, 2013
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    Okay, and what should I get?
     
  4. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    Sorry you need to provide more info, a photo and schematic would be nice.

    My point was; if the transformer type allows you to easily wind some turns on it, you could wind a separate low-turns winding on the transformer, to give you the 18v otuput you need.

    Also, if you don't need the 2kV winding, you could remove it and instead add the low voltage winding in its place.
     
  5. RobertEagle

    Thread Starter New Member

    Jan 13, 2013
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    Yes. I got it.
    But unfortunately, it isn't that type of transformer. And also, it's a part of a challenge.

    I tried to make a converter. It succeeded, but after I built it, I realized my bad. It was a linear converter.
    So, it's useless to show you a schematic which dumps 98.96% of the energy.

    The only thing I have is a photo from the scope. It shows the 2 channels at 250V/div with no load.
    http://img191.imageshack.us/img191/5092/28549146.jpg

    I mean, for an AC/DC converter, what more information do you want? (the impedance is very high due the high frequency and the resistance of a coil is 50Ohm)
     
    Last edited: Jan 14, 2013
  6. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    Now you said you can't wind turns on the original transformer, then you need another transformer, something capable of 2kv->18 volt conversion at very low power.

    You could try an off the shelf HF transformer like a drive transformer or some type of audio transformer. Or wind your own transformer using any of the readily available cores you can buy from the hobby elec suppliers. :)
     
  7. RobertEagle

    Thread Starter New Member

    Jan 13, 2013
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    0
    I see. It's a good idea.

    Thank you very much, THE RB.
     
    Last edited: Jan 15, 2013
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