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Air-Core Selenoïds vs Flat Flux-Concentrating Magnetics

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Salutations everybody,


1st of all there are some basic principles evoked in previous related posts already mentioned in this other one below, hence it may prove suitable to keep them in mind:


[ https:// www.opengrow.com/topic/58014-bridge-the-gap-joining-clean-burning-butane-plan-b-ih-driven-lavacapsules/ ]
Bridge the gap: joining clean-burning butane "Plan-B" + IH-driven LAVACapsules

Except this time my susceptor's layout is going to depart quite significantly from round shapes.


Here's some visual hint to guide the reader forward, it's a simple disposable distribution system applied to "repeating pistol" toys;  those tape reels were called "Bang Caps" or "Boom Caps", for example Kilgore's multiple shots per roll system:




Now imagine that's actually a jetable food-safe porous temperature-resistant susceptor substrate coated with cannabis noble molecules...


The micro-dosing aspect of it spontaneously feels most appealing but then how would we be supposed to toke on this??  :oeps


Well it may be necessary to explore a much larger perspective in order to better re-focus on tape-vaporizing issues, eventually.  The merits of Induction Heat will contribute here again, more than ever as the "bowl" (a figure of speech, so to speak...) now happens to be moving as some roll of cannabic substrate tape gets depleted.  So it's kind of a paradox opposing the need for convenient movement and a stationary IH "head" capable of enough "Hot-Spotting" to serve the prupose of single dosing.  My previous work on Pulse-Heating should provide a neat solution but this calls for flux-concentrating concerns IMO:




A classic air-core selenoïd (left) can NEVER complete its "magnetic circuit" while half of that is dispersed outside, stepper motors improve their energy conversion through savvy flux-concentrating materials in comparison, displacing the strong force fields deep inside where these shall benefit most as mechanical torque.  That's a precious design resource to put into the tool box because similar flux bending paves the way to more complex concepts even including multi-phase systems, this one solved thanks to a legacy trick initially iherited from ancient greeks:




Later re-discovered by a 17th century italian thinker who's name finally got associated to it.


The prospect of juxtaposing 2 magnetic circuits in a manner to only share 1 common susceptor sounds thrilling at least to me as it invites duplex/dual-band scenarios possibly exploiting this other dimension i mentioned previously:




Apparently the Curie-effet should be expected to be frequency-dependent too, consequently one may find justified to go to extremes in hope to get all the corners covered, ultimately:


large.1296161278_Egzosets7x7cmEddy-CurieSemi-TorodDuplexCardan-TopologyIHDriverwithRFChokes(2020-Oct-20)300x300.PNG.e288e916b6527e71dd68925227878a71.PNG large.517785321_EgzosetsUniv.IHWorkCoilsAssy.16mmID2xSTMicroTDA7498(upto400Watts)200x200.PNG.233e8a1764e7cdc5d41c01c1cc7c5681.PNG


Using a Texas Instruments TPA3255 a preliminary evaluation suggests this could be rated up to 1.2 Kilo-Watts for a 7 x 7 cm IH WorkCoils Assembly with 2 chips, or a modest 400 Watts for TDA7498 chips instead.  Go figure where Gallium Nitride replacements will take us next!...


My point here was the puzzling idea that perhaps a flux-concentrating core can get shaped to support double-function assignments.  In this present case the chip's Class-D power H-Bridge requires RF Choking so i started to wonder about split toroïd coils where the fields cancel each other.  Globally there won't be much residual "unbalanced" energy exchanged between both systems i believe, so if it's a correct assumption then the parts count can be significantly reduced by mounting the twin RF Choking coils on a shared magnetic core.  As for the pair of slotted-toroïds cardan-topology IH magnetic circuits i find a transition to tape reels is one great opportunity to simplify:




That was good enough to invent cassete tape machines which served us fine for a few decades, so lets go back to the slotted-toroïd with a twist:




Would i have ever envisioned such possibility without my previous reflexion on the more difficult problem of a "universal" multi-mode WorkCoils assembly?...


Anyway there's still one essential part missing as i ain't got it drawn just yet.  The RF Choking side of it is obvious, and those paying attention may realize it's 2 slotted-toroïds sharing a common pair of central arms between half toroïd sections.  While fields of the peripheral magnetic circuit mainly cancel 2 more coils inserted on those horizotal arms can get hard-wired to work as a tandem where the fields add up constructively and once again cancel at the other circuit's level - kind of a magnetic "duplex" design allowing 2 different functions to co-exist within a same solid-state structure...


Hopefully the central cut can be made sufficiently large to accomodate glass-based (purist) confinement of the cannabis path without any compromises thanks to wireless heating, in addition to a pair of optional LAVA Hybrid Core layers meant to generate some temporary convective/radiative heat burst around tape-shaped substrate passing through that ain't necessarily also behaving as susceptor anymore...  Presumably each tape "dot" might provide multiple tokes before the tape reel dispenser must advance to its next position;  dual-band "Eddy-Curie" applications probably even remain an option via the inclusion of capacitor power switching in the resonator itself, e.g. to "tune" it down (or up) with the direct addition (or substration...) of a second "tank" capacitor using 1 same workcoil inductance.


Etc., etc.




May this have seemed entertaining if not inspiring.  :popcorn:


Good day, have fun!!  B)

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