I need help in [design of buck converter]

Discussion in 'The Projects Forum' started by Noah Shum, Feb 14, 2017.

  1. Noah Shum

    Thread Starter New Member

    Feb 14, 2017
    Halo, I am new in electronic.

    My project is going to design of buck converter that can transfer from 28V to 5V for charging iPad. The attachment shows the calculation steps. And I know that the inductor cannot sustain too much current. Therefore, I decide to put maybe 8 or 9 inductors in parallel. Is the calculation correct for designing a buck converter?

    And now I am in the stage of prototyping, I have bought the following components already. But I think maybe wrong....
    - 1 x Arduino for control the MOSFET switch frequency
    - 1 x Electrolytic Capacitor, 22µF, 10V, MS5 Series, RubyCon
    - 8 x Inductor, 680µH
    - 1 x NPN Power MOSFET, IRFP450, 14A, 500V, 190W
    - 1 x Diode, MIC 1N4001, 50V, 1A

    Is everything alright? Anyone could left some comments for me, please? Thanks for your help!!!!!

    (Moderator's note: image rotated and reduced to gray scale to reduce file size and make it possible for people to read. -dc)
    Last edited by a moderator: Feb 15, 2017
  2. AlbertHall

    AAC Fanatic!

    Jun 4, 2014
    I can't read sideways writing. If the 1N4001 is going to be working at the switching frequency then it is not going to work well - it is too slow. Try a 1N4933 or UF4001.
    Noah Shum likes this.
  3. Noah Shum

    Thread Starter New Member

    Feb 14, 2017
    Is the diode should be the type of fast recovery?
    So that the 1N4933 and UF4001 belong to the type of fast recovery diode?
    I have uploaded the new calculation photo!
    Thanks your reply!