voltage changer

Discussion in 'The Projects Forum' started by rakesh696, Jan 2, 2009.

  1. rakesh696

    Thread Starter Member

    Dec 15, 2008
    10
    0
    i need a circuit of different voltages (dc)
    input 12v dc 5A .....output ll b +12V 5A ,
    5V or 6V 2A ,
    0V
    -12V 2A ,
    -6V 2A
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,649
    2,348
    Hello,

    Your output power is larger than the given input power.
    This is impossible. For all the voltages you require you will need more input power.

    Greetings,
    Bertus
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Input:
    12vdc 5A

    Output:
    12V @ 5A
    5V to 6V @ 2A
    GND
    -12V @ 2A
    -6V @ 2A

    As Bertus says, you can't get out more power than you put into it. If you could ever figure out how to do that, you will be a very rich person indeed.
    You say you want the source to be 12v @ 5A, yet your very first output is 12v @ 5A. This could be done by using a straight piece of wire with a 5A fuse in it, if you did not require voltage regulation.

    If you require regulation for the +12v, you will have to use something like a buck/boost switching regulator, which will be somewhere between 80% to 95% efficient. This also means that since power will be consumed in the regulation process, you will have to have more current coming into the circuit than will be going out.

    The other voltages could also be created using switching buck regulators, the -12v, -5v would have to be an inverting topology. These would be somewhere around 85% efficient, so you will require more power in than you will get out.
     
  4. rakesh696

    Thread Starter Member

    Dec 15, 2008
    10
    0
    tnk u for clear xplanation of power consumption ..
    ill tr dat in alternate circuit
     
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