SMPS with multiple output

Discussion in 'The Projects Forum' started by boatman1008, Oct 17, 2006.

  1. boatman1008

    Thread Starter New Member

    Oct 17, 2006
    Hi guys,

    I am trying to design a SMPS with the following outputs:

    I can not figure out what is the best topology I could use for this power supply. Does the Half Bridge topology work for this type of power supply. Please help or guide me to the best web site, which I could found some sample circuits. Thank you very much for your help.

  2. mrmeval

    Distinguished Member

    Jun 30, 2006
    You'd probably need a custom solution for that. It's a hell of a lot of power.

    You could build five independant powersupplies.

    Input range would be 10-25 volts, not sure of current requirements, this can be raw from a transformer of suitable rating.

    5V 15A

    8V 5A

    15V 3A

    -15V 3A
    not sure

    18V 1A
  3. n9352527

    AAC Fanatic!

    Oct 14, 2005
    I assume it is an off-line switcher? If so, then either flyback/forward or half bridge topologies are suitable, although with higher power half-bridge does have advantages of distributing the load to two switches instead of one. However, the cost would be higher and the transformer design is more elaborate.

    I would probably go with flyback, just to keep things simple.

    If you want to see some example circuits of off-line switchers, I found that the onsemi site is quite excellent. There are many application notes and design examples on their AC-DC offline controllers.

    You'd probably also need a PFC for that.
  4. vigneshwaranj

    New Member

    Oct 10, 2006
  5. Gadget

    Distinguished Member

    Jan 10, 2006
    How about modifying an ATX or AT computer PSU by rewinding all but the 5 volt windings on the Output transformer. Not sure which line the regulator ref is taken from (possibly the 12 volt) so modifying the divider to give the proper ref from the new 15 volt line would probably also be required.