Connect with us

adjustable multi output regulator

Discussion in 'General Electronics Discussion' started by secretreeve, Feb 25, 2012.

Scroll to continue with content
  1. secretreeve


    Feb 25, 2012
    i everyone, firstly, thanks for taking the time to read and hopefully help me out.

    im not an electrician but have some fair know how for small electrical projects, but i could use some majour help on this project i have going.

    basically im looking to take 1x 12v NiMh rechargable battery and run 3 devices from it, but i would like to be able to route its power through to 3 outputs where i can manually adjust the voltage and amperage of each output.

    the outputs im looking at getting are 12v, 2000Ma and 2x 5v 1amp outputs, but both factors for each output MUST be variable between 1v - 12v and 0.5A to 2.5A (or higher).

    im looking at placing the circuitry onto a basic breadboard for testing initialy then over to one of those copper plated boards with the holes in, (project boards?)

    so i'd really appreciate some straight forward/easy to read instructions or schematic with what components to use.

    can anyone help me out with that?

    thanks again for reading and hope someone can help me out.
  2. davenn

    davenn Moderator

    Sep 5, 2009
    hi there
    welcome to the forums,

    what you are asking for is a little difficult. The main problem is the 12V supply.
    There are boost DC-DC convertor chips like the LT1111 available, that will give you
    a regulated 12V output from a 12V input and alternatively a lower output voltage like 5V.

    But I have yet to see in any of the various convertor IC's I have looked through, ones that you can continuously vary the output.
    What you are asking for initially ... variable output voltage can easily be achieved with standard Adjustable V.reg chips like the LM317 and higher current models BUT the ALL need ~ 2 V input more than the max output voltage required. ie. if you need 12V reg out then you need at least 14V input

    Do you really need current limiting ? that adds a whole new level of complexity
    or can each output rail just be capable of supplying a max of 2.5A or so ?

    Keeping in mind that any device placed across the supply will only draw what it needs in current. ie you have a device that is 5V @ 750mA. you have one of the rails set to 5V, then 750mA is all that will be drawn regardless of if the rail can supply 1 Amp or 10Amps

  3. secretreeve


    Feb 25, 2012
    i suppose i can for go the amp control on it.

    mostly i need the 3 voltage outputs to be adjustable and not go over where they're set to.

    can you help out with a diagram for the 3 psu's? im ideally looking to add them all to the same prototype board but can figure that out myself.

    not so good at reading schematics
  4. secretreeve


    Feb 25, 2012
    oh and i can use a higher voltage battery too.

    ideally i would REALLY like to limit the rails at these specs (assuming the use of a higher voltage battery)

    ___________ -------> 5v @ 750ma
    input -> 14.4v ------> 12v @ 1amp
    ``````````````````` -------> 5v @ 2amp
    Last edited: Feb 25, 2012
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day