There you go!!!
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That is awesome
NOICE
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Just sharing some of my spares
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Yes you damn leader types have more than double us “Member” peasants 
Trickle down likeconomics?
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Your time read and posts liked numbers make this Regular look like a noob, sure it’s only a matter of time before your account gets kicked up a notch.
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I’ll hit regular on the the 5th of May… Not that anyone is counting 
Frankly I just want wiki edit permissions… and the badges… I like the “shiny” badges…
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Even I’m not a leader, so good luck with that one
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Yeah, the leader one, email reply one and new user of the month feel unobtainable 
The gold tier badges regarding following links and getting likes also seem fairly unobtainable ATM.
Thing’s like regular are pretty straight forward though, I would have hit it regardless of my love of “shiny” badges
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What if the bracelet had multiple power antennas, think 
where the core stores power, and the charms are the antenna?
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So my next step was going to be printing a form for the coil with my 3D printer and using thinner wire.
I stumbled across this ferromagnetic filament:
https://filament2print.com/gb/special-pla/795-ferro-magnetic-pla.html
Do you think it is worth experimenting with @Satur9?
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Nah, I don’t think so. Besides being out of stock, it’s mostly plastic
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For the driver part (not antenna) would it be possible to utilize an pn532 or rs522 board, replacing the antenna with a custom one?
Almost none of the stuff I ordered a month ago has arrived, but I’d like to give this a go if someone could consult on what to remove or where to cut🙂
The RS522 can be quite small if the antenna is removed
So my LCR meter finally showed up…
I tested my coils, and unsurprisingly the inductance was well off (like an order of magnitude), especially the one above that I malformed around my wrist. So that bodes well me thinks. This weekend I have been doing some spring cleaning but over the week I plan on making a coil formers based on my wrist shape, much like the last attempt with the 3d printer then I’ll really try to dial in the resonance with the LCR meter, hopefully it goes well. I’ll also try to make the model parametric so anyone else with an interest and access to a 3d printer can have a go.
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Sooo, is there anything I can do to help out? I’d be really interested in putting this project forward in whichever way I can.
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Well, first things first.
Nice to meetcha. Welcome to the forum.
I guess I’d say it depends on your skills, which I know nothing about, but you got the right attitude for sure. You might try knocking up a circuit similar to some of the ones above that work, then seeing if you can improve it a little here and there.
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So, I’m thinking there are two places we can go with this.
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HF “Dumb” bracelet
Basically that circuit I posted at the beginning, driving a mosfet at higher voltage and current so we can get greater distance. @NiamhAstra is gonna try this out with some parts he has lying around. Here’s an example schematic:
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LF “Smart” Device
When operating at 125kHz, we’ll naturally get longer range. We’ll also be below the clock speed of most microcontrollers. This means after we chip our teeth on the HF dumb version, we can make a smart version that reaches farther and responds to commands from your smartphone over bluetooth for notifications and such. Downsides are that it will require more development and the inductor coil will need many more turns.
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We could also have a HF smart device. Where the smarts is just turning the coil on or off. Or use a chip that has a high enough PWM for HF.
I quite like the HF option purely because of
I was thinking something like a RN4872
alright, thats it, i’m interested. I’m ordering an an led implant and beginning development, give me a few weeks to get a prototype together.
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Building an oscillator from discrete components is unnecessary really. 13.56MHz is pretty standard and packaged oscillators such as this are readily available. DC in 13.56MHz RF out 
https://eu.mouser.com/ProductDetail/Microchip-Technology/DSC1001BI5-0135600?qs=Cv1v43EOJpqpoFx%2F8gxmMw%3D%3D
I’d use that (might need buffering) to drive something like a HF class E amplifier, as these are reasonably efficient. A few SOT-23 packaged BS170s’ in parallel can easily produce 5 watts. House it in some cheap large faced watch casing with a small lipo or two. Probably would try ribbon cable as the strap, offset by one conductor to form a muti-turn inductor for the antenna.
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