The gap can be created outside the core itself.
My first attempt of a toroidal transformer for audio, was 8KHz width 🙁
I don't known anything about this name. But if you wind the wire with a diameter higher than the core external one (The cross sectional perimeter of the iron), then, part of the magnetic lines will close in the air, like a "manageable" gap.
Does this really prevent the core from saturating? As far as I can see, this primarily will increase stray inductivity.
Best regards!
The C-cores that are available here have precisely grinded and high-gloss polished cuts, and they are sold in pairs that have to be assembled in a certain manner, given by markings on them. So, why should there be a bigger gap than in EI stacks, if not intended?
Best regards!
I can't say exactly, I'm not a magnetics expert, but I saw this in battery chargers to create a deliberately low coupling coefficient increasing secondary leakage inductance, so self current limiting.
I'm used to see magnetic bypasses (yokes) in transformers in battery chargers, arc welders etc. for this reason. Adding stray inductivity might not be the option we want to see in an output transformer, do we?
Best regards!
Best regards!
Sure! But I say that I watch it in battery charger where a intrinsic current limit is desirable to protect the trafo itself and the battery. Obviously in OPT it is undesirable, although in some circumstances it may be wanted as a way of increase the false bass of the speaker's bass resonant frequency, for example.
The "flatness" or polish of the surface is only one aspect of the airgap equation and if that is all that is looked at then indeed a C-core appears superior. The other aspect that must be considered is the surface area of the gap and again for a traditional "butt gapped" (all the E's on one side and I's on the other) the surface area remains constant to that of a C-core. However when you use your ability to alternately stack the E's and I's, suddenly the surface area of the gap is increased substantially making the effective gap possible with laminations much smaller than possible with C-cores.
This concept is taken to the extreme with a toroid where the entire surface area of the tape is the airgap which makes it so effectively small that many texts say its effects can be ignored.
There have been several attempts and making the gap of a cut core smaller the most interesting being the Uni-core which is pictured below.
dave
These gap constructions can best be translated into power loss / kg.
When I check power loss of these Uni-cores and compare the specifications with HiB c-cores as manufactured by Nicore, these HiB cores are still better.
Apart from air gap structure IMO it is best to start with the better core material.
When I check power loss of these Uni-cores and compare the specifications with HiB c-cores as manufactured by Nicore, these HiB cores are still better.
Apart from air gap structure IMO it is best to start with the better core material.
The natural air gap in quality C-cores is very useful both for output transformers and interstage for PP amplifiers. It takes care of reasonable amount of imbalance without compromising permeability. For the interstage it is useful even if the DC currents of the drivers are perfectly balanced as power tubes (one pushing and the other pulling) do have grid current when driven hard.
The fine tunability of air gap in EI laminations is very useful with high permeability materials because they are more "sensitive" (i.e. lose permeability very quickly with too big air gaps). These also don't have the distortion disantavage of GOSS laminations vs GOSS C-cores because the ones I know are non-oriented.
The fine tunability of air gap in EI laminations is very useful with high permeability materials because they are more "sensitive" (i.e. lose permeability very quickly with too big air gaps). These also don't have the distortion disantavage of GOSS laminations vs GOSS C-cores because the ones I know are non-oriented.
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