Electronics experts--help with dual bipolar supply

Discussion in 'The Projects Forum' started by drogheda1, May 9, 2017.

  1. drogheda1

    Thread Starter New Member

    May 9, 2017
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    ive searched all over the internet for ideas to create my bipolar supply but been unsuccessful,
    What I want is a DC supply,
    +/-14V, +/-13V from a 9V source
    1 idea I did have was to use an LT1054 DIP chip with capacitors and some voltage division with resistors.

    Thanks
     
  2. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    What is the 9 Volts source?
    How much current do you need on the +/- 14 Volts side?

    Have a look at the LTC3265.

    Bertus
     
  3. drogheda1

    Thread Starter New Member

    May 9, 2017
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    dont think that IC comes in DIP format, i dnt really do SMD stuff.
    i think i need 250mA not sure i can do it tho, this is what i have come up with

    [​IMG]
     
  4. Papabravo

    Expert

    Feb 24, 2006
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    In order to guide you to a satisfactory solution, it would help if you could further refine your specifications in terms of output power levels and and battery capabilities. Is there any particular reason why the two bipolar outputs are different by 1 volt. Would it be just as good to have two ±14V outputs?
     
  5. BobaMosfet

    AAC Fanatic!

    Jul 1, 2009
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    Bertus is asking the right question-- how much current does it need on the output.
     
  6. Papabravo

    Expert

    Feb 24, 2006
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    NOTE: if you pull 250 mA through the 7815 with a 3V drop from 18V to 15V you will have to dissipate 0.75 watts which I'm going to guess will require a pretty good heatsink. Charge pump converters and inverters are not know for their ability to handle much more than a couple of tens of milliamps. I urge you to take the suggestion of @bertus and go all switchmode. You be be more satisfied with the results.
     
  7. drogheda1

    Thread Starter New Member

    May 9, 2017
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  8. Papabravo

    Expert

    Feb 24, 2006
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    Trying to duplicate the operation of an antique circuit that you do not understand well is not likely to end well either. I did not ask what you were trying to do, I asked you to clarify you electrical requirements in terms of REQUIRED power. In other words, how much current is needed to come out of +13V, -13V, +14V, and -14V. If the answer was 250 mA on each of those I can tell you pretty quickly that using a 9V battery to replace a device that runs from the mains is just not going to result in happiness.

    This is a variation of the Micawber Principle:
    "Annual income twenty pounds, annual expenditure nineteen pounds nineteen and six, result happiness. Annual income twenty pounds, annual expenditure twenty pounds nought and six, result misery."
     
  9. drogheda1

    Thread Starter New Member

    May 9, 2017
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    Last edited by a moderator: May 10, 2017
  10. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    The circuit you are showing in your last link uses an AC adapter.
    A DC adapter will NOT work with that circuit.

    Bertus
     
  11. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Have a look at figure 44 of the attached LM2577 datasheet.
    You will need a special transformer for the circuit, but it seems to meet your requirements.
    When you use the -ADJ version with two resistors, you can set the output at 13-14 Volts.
    The chip is in a 5 pins TO-220 housing.

    Bertus
     
  12. drogheda1

    Thread Starter New Member

    May 9, 2017
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    thank you
     
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