Switch Mode PSU design

Discussion in 'The Projects Forum' started by dhooker, Jun 17, 2009.

  1. dhooker

    Thread Starter Member

    Jun 9, 2009
    11
    0
    Anyone got any good reference designs for switch mode power supplies. I know there must be hundreds!
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,649
    2,348
  3. dhooker

    Thread Starter Member

    Jun 9, 2009
    11
    0
    Input 90 - 264VAC : Output 1 = 24VDC @1.5A : Output 2 = 5VDC @ 1A
     
  4. bertus

    Administrator

    Apr 5, 2008
    15,649
    2,348
    Hello,

    Only one of the outputs can be stabelized.
    The second output is dependend on the stabelized one.

    Greetings,
    Bertus
     
  5. dhooker

    Thread Starter Member

    Jun 9, 2009
    11
    0
    Mmmmh. Surely if I regulate the 24V to provide the 5V (@ 1A) I will be wasting about 20watts in dissipation across the regulator.
     
  6. bertus

    Administrator

    Apr 5, 2008
    15,649
    2,348
    Hello,

    You can make a smps with two outputs by putting two windings on the transformer.
    One for 24 Volts and one for 5 Volts.
    You can only regulate one of the outputs.
    The other will follow the changes in the regulated one.

    Take a look at the attached PDF.

    Greetings,
    Bertus
     
    Last edited: Jun 17, 2009
  7. Tahmid

    Active Member

    Jul 2, 2008
    344
    25
    Hi,
    For such output, you can use flyback topology. You can take a look at Power Integrations' TOP series ICs, or UC384x series.
     
  8. Tahmid

    Active Member

    Jul 2, 2008
    344
    25
    Hi dhooker,
    Here is a circuit for PSU for 24V @ 1.5A and 5V @ 1A. It is made using TOP246 from TOP-GX series of flyback converter ICs from Power Integrations Co. of USA. I personally made this circuit and still it is working fine. You can try this circuit.
    I have attached it and also uploaded it to ifile.it. Here is the link:

    http://ifile.it/rse43zu

    Hope this helps.
    Tahmid.
     
  9. dhooker

    Thread Starter Member

    Jun 9, 2009
    11
    0
    Many Thanks
     
Loading...