Electronics > Beginners
Choosing off the shelf transformers for flyback converters
Buriedcode:
For your specific example, these may eb an off-the-shelf solution:
http://www.cooperindustries.com/content/public/en/bussmann/electronics/products/eaton-magnetics/eaton-transformers/eaton-versa-pac-inductorsandtransformers.html
I realize yours was just an example, but for low turns ratios/low voltage the above can be handy - especially handy for creating bipolar supplies with just a boost converter.
T3sl4co1l:
Thing is, if your application needs a standard transformer, you can do everything so many times cheaper with a standard PSU module -- that already carries agency approvals. |O
Transformers aren't all that cheap from distributors, either:
https://www.digikey.com/products/en/transformers/switching-converter-smps-transformers/168
And obviously(?), nothing is more expensive than the one it takes an hour to wind, by yourself (unless your time is discounted to ~zero). Designing and winding transformers is a valuable skill, and the two go hand-in-hand for designing manufacturable transformers as well; but winding more than a few for prototypes? Geez...
Tim
T3sl4co1l:
--- Quote from: blueskull on December 13, 2018, 05:28:43 pm ---I might be biased, but most of the time I mess with flyback, I get some bad losses. Bifilar winding can help, but then you need to trade with EMI and SRF.
--- End quote ---
The last one I did, I wound the transformer as twisted pairs -- following TLT theory. Damn good performance, the capacitance was low (switch and diodes dominate) and leakage was exactly as expected: low enough to just barely need R+Cs across diodes.
PITA to wind, though. In a TLT, primary and secondary come out together, on the same side of the bobbin. Easy to run out of pins, for a multi-winding transformer. It's also a lot of wires connected in parallel (the primary from every pair gets wired in parallel), loading up the pins a lot.
It was still just a bit more complex than that, because I made a 2:1 (Guanella type) section, because the overall converter was step-down.
So that was fun. Fun to realize a design of high optimization. I don't recommend trying to buy them from a coil winder. :P
Tim
Navigation
[0] Message Index
[*] Previous page
Go to full version