Salutations Giraut,
Salutations M5amhan,
Relatively to the Loto Labs Evoke IH Pipe...
I didn't want to hijack Vaping Griffin's thread and derail...
That's one of those threads i once considered for posting about alternate methods to the series-parallel battery connections (because each scenario comes with its own trade-offs and corresponding consequences): series connection cumulates (multiplies) overall internal series resistance while i vaguely recall reading about "balance" issues using parallel connections, if i'm not mistaking.
Given the nature of this site's main favourite application (which is to vaporize e-Liquids by creating heat out of batteries, to put it briefly) i started feeling seriously puzzled (read quite "challenged") when searching for numbers from the Evoke Team actually: the problem being that their only demonstration(s) ever rendered public (to support some really successful "crowd" financing campaing) has turned out to be based on a 26 Watts @ 9 Volts IH driver... But they've mentioned the use of a 3.7 Volts battery instead.
So, how does one convert electric power from a single 3.7 Volts battery in order to transform it into 26 Watts of IH heat?...
Well, the readers are probably aware of limitations related to dealing with imperfect electronic valves where a lossy conduction channel (characterized by less-than-ideal Rds-on performance) implies the conversion can never reach 100 %... In addition it happens that IH drivers also suffer from a similar limitation and that's why IH cookers are typically built around a High-Voltage supply, to optimize the chopping action of those imperfect valves by making their Rds-on less predominant. Please correct me if this interpretation sounds wrong.
So, if we compare switching-supply conversion and IH drivers it becomes tempting to avoid chain (double!) power conversion since the final goal is to turn this power into heat anyway. In other words half of a power converter looks so similar to the chopper stage of IH cookers one has to wonder if it's a viable concept, because then the load becomes magnetic instead and hence wireless as a bonus - which is one of the major benefits Induction Heating has to offer, another being on-demand thermostatic heat at the point of contact if it's based on the Curie effect.
Yet, we're talking in terms of a few hundred Volts in IH cookers while Evoke's project pushes the challenge as far as to suggest the technology can be miniaturized enough to depend solely on portable battery power...
Now, here's a real-life implementation exported from a market addressing the needs of laboratories, it's called a Curie Point Pyrolyzer and this were its wireless heating element resides:
Capacity within that quartz-glass vial is ~0.6 ml (wrapped inside a metal IH foil) and its power requirement happens to be 48 Watts @ 600 KHz... Here's the IH driver below, it's clearly more transportable than portable as it has a 2 m power cable attached for some reason (...):
Not to mention such tiny bowl is 60 % smaller than that of an Evoke as planned!
M'well, the IH pyrolyzer above is said to reach way beyond the necessary thermostatic temperature in a matter of ~¼ sec, on another hand... Meaning with a few compromises to make there may be IH vapes in the futur, yet to be honnest i think the Evoke team should have made more modest claims, like to offer a 2-parts IH pipe where all of the electronics would reside inside a separate IH base: heat retention in the pipe would suffice to get a good puff and then the user can put it back in place, ready for a "recharge" as with grand-ma's iron on a fire stove, so to speak. Personally i'd find that convenient enough and batteries remain an option, except in a custom portable IH driver there would be room for as many batteries as this shall require... If the Evoke team ever manages to make it a reality, that is!!
Indeed, though i can't but notice those guys demonstrated a constant determination to control all discussions, especially criticism that's only matching those claims, euh... At least when seen from my perspective, after i've given it a few good tries (elsewhere) only to find
some basic questions remained ignored consistently.
Which takes me back to this simple interrogation: where's their 3.7 Volts proof-of-concept exactly?...
The answer being there just was no plan when THEY contacted me personally last spring, even less a proper prototype proving it's even possible in the 1st place. As a matter of fact another company had to be hired to figure it out for them, eventually,
after they got their money if memory still serves me well...
Another thing I'm waiting for personally is laser heating, to replace the coil. It's possible...
Yes, i've seen an equivalent idea demonstrated many years ago and the power level was 15 Watts using green light. Too bad the human eye is optimized for 550 nm or so: the owner - and everybody around! - would need to wear protective googles as a safety precaution, unless the vaporizing bowl is garanteed to be totally isolated/contained at all times!
So my guess is this could likely take a long while though not completely impossible.
As for Evoke's solution i think we'll be waiting as well but they're most welcome to show their secret ingredient.
...maybe this can come handy as a taser...
I'll agree we could view this as a selling argument, perhaps. After all, if it's built to provide sufficient modularity then there's going to be plenty of magnetic power to supply an optional taser cartridge: it just needs their pipe layout to allow it...