Flyback converter

Discussion in 'The Projects Forum' started by Alwaleed, Nov 21, 2014.

  1. Alwaleed

    Thread Starter New Member

    Nov 13, 2014
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    Hi everyone

    I have designed a flyback converter that has the following parameters:

    Lp = 150uH Lsec = 600uH

    vin = 5v MOSFET : IRF040 D: D1N914 C = 350uF Rload = 5

    my current Vout is : 9V but my aim for Vout is : 23.5V

    how to increase the voltage output in order to reach to my required value ????
     
  2. Alwaleed

    Thread Starter New Member

    Nov 13, 2014
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    I have simulated the circuit in Pspice
     
  3. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    My sim tells me that to get anywhere close to that average output voltage you need to have primary peak current somewhere around 100A, which in turn requires you to lower the frequency about 100 times to get such peak current.
    From the perpective of real world, and with the requirements you set, it is not possible using that transformer.
     
  4. Alwaleed

    Thread Starter New Member

    Nov 13, 2014
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    Hi kubeek
    what is most suitable frequency value to use in this circuit to make it work in pspice ???
     
  5. Alwaleed

    Thread Starter New Member

    Nov 13, 2014
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    Hi kubeek
    what is most suitable frequency value to use in this circuit to make it work in pspice ???
     
  6. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    I changed the transitor to an ideal switch (1u Ohm on and 1gig ohm off), and set the control voltage to 90us on time and 100us period. Also changed the diode to 1N4007. Output voltage settles at 23V and peak primary current 52A.
     
  7. Alwaleed

    Thread Starter New Member

    Nov 13, 2014
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    I don't have the 1N4007 in my pspice library, is threre any way to add it in the library, or are there any alternative types that can be found in pspice 10.6
     
  8. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    Code (Text):
    1. .MODEL 1N4007 D (IS=3.507061N N=1.695189 BV=1K IBV=100.000001P RS=121.232918M
    2. + TT=7.213475N CJO=34.327536P VJ=700M M=473.117165M RL=200.140386MEG)
    This is my model for it from micro-cap, you will need to place it in one of your lib files for pspice. There also may be a way to put it straight into the simulation, but I don´t know how.
    Or just use some diode that has higher current rating than that 1N914
     
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