Stupid "My Posts" sort order thing burried this thread 4 pages back...
Please excuse the bump.
I am monitoring, and thanking all of you for the information.
I had assumed that the ultrasonic method would be much more energy efficient. How fast it clogs though....Hmmm. Also induction cautions abound with ultrasonics. They can be used to peer though skin, or even have military applications (e.g. lethality) and who know what. So..... Caution.
However, these results are VERY interesting. Particularly the low power levels.
It may not produce a phase change at all (although it COULD...you are inducing kinetic energy into a small droplet so it may actually get excited enough somehow to vaporize...IDK...total guess and maybe not scientifically correct.)
And of course I too was curious why they aren't all ultrasonic now (hence this thread). Maybe coils are just easier. Or safer. Or warmer. Or any/all of the above.
Ultrasonic misters create Cagvitation, that is tiny bubbles that pop, I think this is the mechanism for the mist creation, I could be wrong.
Its perfectly feasible to build a protype that will vapourise PG, they already use a PG mist in hospital air con to kill airbourne pathogens, and in nebulisers.
The problem you have is not with current draw, the problem is with creating a 142Khz AC power source from a 3.7v DC battery, the electronics needed for that is the challenge,
I had a Pond fogger / mister and that thing was a single piezo electric plate inside a metal casting, I would have opened it up but it was all sealed.
The transformer for it was huge. But they are cheap, you could make a modified home Shisha pipe with one.
The pond fogger I had, I put in the garage sink and it misted up half of the garage, I'm pretty confident you will get probably even better vapour from PG because that it is what they use in Disco smoke machines and nebulisers, and it is used in E-cigs because of its easy vapourisation. The Glycerine is what gives us the majority of our exhale vapour but would be hard to vapourise with an ultrasonic device in large concentrations but you will have to experiment.
I don't still have my pond fogger or I would have tried this a long time ago.
https://www.youtube.com/watch?v=cill_IbtXiw