+ Post New Thread
Results 1 to 7 of 7
  1. #1
    Member level 2
    Points: 315, Level: 3

    Join Date
    Dec 2017
    Posts
    42
    Helped
    0 / 0
    Points
    315
    Level
    3

    Step Up- Down Converter type

    Greetings everyone :)

    I am currently working on a project where i have the need to step up 8-16V to 380VDC, since the cores i have can not handle such winding numbers, i was wondering if i could do this.

    Generally i have a working ~10.5V to 14V step up converter to 380+ Volts. So i need at least 250-300Watts of power and i want to step up/down 8-16V (this is my range) to stable 12V output BUT with a huge current apparently. around 40A @8V converted to 25A@12V. Do you thing this is possible? Have you seen anything like this? It can be isolated or not. I dont mind about this stage to be isolated.

    Its like i want to connect the 2 converters one after the other. 8-16v to 12v and then 12v (stabilized) to 380v.

    Thanks in advance.

    •   AltAdvertisment

        
       

  2. #2
    Advanced Member level 4
    Points: 7,161, Level: 20

    Join Date
    Aug 2015
    Posts
    1,117
    Helped
    431 / 431
    Points
    7,161
    Level
    20

    Re: Step Up- Down Converter type

    For efficiency reasons - it would be better to have one converter going from 8-16V to 380, at 300W this is 41.2A ( 8Vin, 91% eff) usually a choke input full bridge or push-pull is used for this - with energy recovery winding on the input choke for when the fets all go off.

    Easiest to choose an ETD44 for the Tx and the input choke, good input de-coupling needed and tight power layout...

    good luck ...



    •   AltAdvertisment

        
       

  3. #3
    Advanced Member level 1
    Points: 3,662, Level: 14

    Join Date
    Feb 2014
    Posts
    466
    Helped
    171 / 171
    Points
    3,662
    Level
    14

    Re: Step Up- Down Converter type

    Is this a product with any volume or a one-off?

    The first stage is easy and there should be readily available modules/designs to handle it:
    http://www.vicorpower.com/documents/...ckBoost_GP.pdf

    The second leap is a bit harder. Few off the shelf modules or designs output 380. 'PFC' modules do but they expect 90 in or close too it. The linked module go can up to 48V out but won't get you to 90.

    But still, although labeled as AC-DC boosting PFC's are really a rectifier then DC-DC boost. So my thought is you could adapt a PFC module or reference design to run continuously off 48V fairly easily.



    •   AltAdvertisment

        
       

  4. #4
    Member level 2
    Points: 315, Level: 3

    Join Date
    Dec 2017
    Posts
    42
    Helped
    0 / 0
    Points
    315
    Level
    3

    Re: Step Up- Down Converter type

    Quote Originally Posted by asdf44 View Post
    Is this a product with any volume or a one-off?

    The first stage is easy and there should be readily available modules/designs to handle it:
    http://www.vicorpower.com/documents/...ckBoost_GP.pdf

    The second leap is a bit harder. Few off the shelf modules or designs output 380. 'PFC' modules do but they expect 90 in or close too it. The linked module go can up to 48V out but won't get you to 90.

    But still, although labeled as AC-DC boosting PFC's are really a rectifier then DC-DC boost. So my thought is you could adapt a PFC module or reference design to run continuously off 48V fairly easily.
    Hey,

    This converter is for the range I want but not for amperes :) I want 12V@20A at least this is far more lower by seeing the datasheet. What I really want is to step up 8-16 to 12v stable with output current of 20-25A



  5. #5
    Advanced Member level 1
    Points: 3,662, Level: 14

    Join Date
    Feb 2014
    Posts
    466
    Helped
    171 / 171
    Points
    3,662
    Level
    14

    Re: Step Up- Down Converter type

    Well why do you think you want 12V? Do you already have a 12->380V design in mind? You haven't provided a whole ton of context.

    In general if you go to the trouble of having two stages (as easy peasy points out you don't necessarily need two) you might as well get some boosting out of the first stage too. So two of those modules in parallel doing 24-48Vout could cover that first stage well.



  6. #6
    Member level 2
    Points: 315, Level: 3

    Join Date
    Dec 2017
    Posts
    42
    Helped
    0 / 0
    Points
    315
    Level
    3

    Re: Step Up- Down Converter type

    Quote Originally Posted by asdf44 View Post
    Well why do you think you want 12V? Do you already have a 12->380V design in mind? You haven't provided a whole ton of context.

    In general if you go to the trouble of having two stages (as easy peasy points out you don't necessarily need two) you might as well get some boosting out of the first stage too. So two of those modules in parallel doing 24-48Vout could cover that first stage well.
    I have the converter for 12 to 380V and I need something to feed it with. But my voltage goes down to 8volts and I need to keep it stable 12V. So all I want is some ideas or propositions about 8-16V to 12V stable about 250-300W. :) Any suggestions?



    •   AltAdvertisment

        
       

  7. #7
    Advanced Member level 5
    Points: 30,070, Level: 42
    Achievements:
    7 years registered

    Join Date
    Sep 2008
    Location
    cambridge
    Posts
    6,289
    Helped
    466 / 466
    Points
    30,070
    Level
    42

    Re: Step Up- Down Converter type

    you need a casdcaded boost.
    I send you soon here

    it includes an ltspice simulation , (ltspice is free)


    1 members found this post helpful.

--[[ ]]--