The most V.s per turn you can apply, for a given (cored) transformer, is independent of what you do with that core (e.g., gap).
Another way to state this: A_L * At(sat) = constant, this being the V.s figure of the core.
The core's inductivity has no effect on performance, though you want it high enough that magnetization is insignificant.
A fairly basic observation, but I thought it important to note that gapped or ungapped cores don't matter in the least to transformers.
Tim
"Tim Williams"
** That last sentence is very misleading - cos gapping the core of a transformer has a dramatic effect on performance.Your post is entirely without a context so is all but meaningless.
Try to do better next time - pal.
..... Phil
Bsat is dependent material and temperature.
Cores stressed to higher B will self-heat, reducing Bsat for ferrites and some other materials.
This core loss has a positive temperature coefficient at the upper end of the temperature range in most materials - setting up the potential for thermal run-away.
Cores heated by their windings will also show reduced Bsat and similar temperature problems.
For simple 'DC' transformers this may be true. Avoiding core saturation is only of primary importance in saturation-limited designs, where minimal support of volt-second withstand is provided at a minimum operating frequency.
Throughput power is typically increased for a fixed core size when higher frequency operation is permitted and core loss limits are probed.
If your topology is saturation-limited, it's only natural to investigate possible improvements available using other materials that exhibit a higher saturation limit - to see if the altered core loss effects of the different materials are over-ridingly detrimental.
Alternately, if your circuit uses resonances to regulate power throughput, you might consider operating more consistently above resonance or at higher resonant frequencies.
RL
On a sunny day (Sat, 13 Jun 2009 14:18:10 -0500) it happened "Tim Williams" wrote in :
If a transformer winding has a DC component, then a gapped core may be needed. A typical example of old were the filter chokes in the tube DC supplies, and the class A audio output transformers, gap to prevent core saturation. Horizontal output transformers [] cores for TVs always had air gaps too. I'd imagine that with ferrite ring-cores there is enough other stuff then iron in teh mixture to double as 'air gap', but then again... Any idea?
Ah yes, saturation limited should be emphasized!
If you've got a kilogram or two of metglas, I'd love to have it! ;-) Otherwise, I'm stuck with ferrite.
I haven't seen many extremely-fine-laminated-iron cores, though I'm willing to bet they might work at 10kHz.
For my purpose, the problem is resonance may be as low as 10kHz.
Tim
...
Hey Phil. Have you ever had a conversation with someone in real-life? Was the result something other than...
... they never spoke with you again
... they started talking about your mother
... they slapped you upside the head
That is a rhetorical question, Phil, everyone knows the answer.
You should find another orphanage, Phil, for not quite grown-up foulmouthed misfits.
news.astraweb.com!border1.newsrouter.astraweb.com!nntp.club.cc.cmu.edu!feeder.erje.net!news.musoftware.de!wum.musoftware.de!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail
"John Doe"
** This anonymous, criminal scumbag needs shooting in the head.Plus his parents and his kids - if any .....
.... Phil
Have something to add? Share your thoughts — no account required.
Ask the community — no account required