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Which topology for isolated AC/DC @ 120W ?

Hi.

I am looking to build an isolated SMPS that takes 120/240 AC and provides DC, 0 - 12 V output, loads 0 to 10 A. I am looking for suggestions on topology and magnetic / switch selections.

The PS will drive high-power/high-output LEDs, so I will need to run it in constant-current mode. I'm hoping to be able to use it in CV mode as a bench-type PS at some point too.

Can this be built with off-the-shelf magnetics or do I need to roll my own transformers/cores?

I've heard the flyback's useful range is about ~100W, but will require custom magnetics.

I've built DC-DCs before, boost & buck, no AC/DC.

Thank you. Richard.

Reply to
R Jones
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Flyback is fine at that power.

Go to

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and download as many of their fabulous app notes as you care to read. They cover just about every imaginable aspect of flyback designs. They also have a simple CAD program that will calculate all the magnetics info you need and it's tweakable too !

Be aware of safety regs implications with AC-DC converters. I like to use triple insulated wire to get the necessary isolation and I recommend it. Makes for more efficient use of the winding area too.

Graham

Reply to
Pooh Bear

If you're really keen on doing your own, there is much to learn. Don't try anything more exotic than a 2-switch forward converter. There are lots of design resources at the TI, On Semi, Fairchild, ST, and Power Integrations websites. However, if you just need to get the job done and realize that life is short, look for a nice Xantrex bench supply in the used market. Paul Mathews

Reply to
Paul Mathews

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