Thanks
@RedEyeFlightControl - at that price I'll go the extra $10 for the full kit with sketches and the MP.
We're definitely on the same page for the wand concept. I very much want the IH to be the torch, not the base station. The little HalfPint is not ergonomically shaped for this but it will work, of course. Long tether, palm-sized form-factor, and a variety of ways to fire. As it sits now, it is a nice little desktop heater.
A Sip'n-Dip'n Siren tempting sailers to madness.
I can see HalfPint, like Flix, working very well with varieties of bubblers. The nice thing about this latest design is that for woodworking, it is easy to house.
Although I see a few tweaks I would like to make, this one is done from the prototype standpoint. I am loving the VC cap-removing magnet, finally. I didn't think these would work as they are not diametrically polarized. But the cap centers and stays centered non the less. It also holds my lightweight stems but that is not the purpose. I just need to see the darkness of the ABV without waiting for the cooldown. Also in case I need to quickly remove the cap due to a flame-out or something else catastrophic. the magnets are 1/4"D*1/8"T and I've sunk them 1/2 way. The heat they transfer from the cap is insufficient to affect the PETG plastic, which is simply holding the magnet as a press fit. Rmoving the cap picks up HalfPint! Obviously, HalfPint is a little on the lightweight side coming in at under 4-oz!
Again, I don't know how I ended up with this Flix-like arrangement but a lot of kudos to
@mr_cfromcali for making that product available. Hell, I haven't even touched on variable voltage yet and this thing already rocks. But as we know, duplicating existing effort is not my goal. The next big thing is my goal. I think MagHeaters has got the right idea. Therefore, you DIY savants and wannabees, here above is a complete guide on how to make a HalfPint and the challenges you will see in doing so. If anyone want to pursue this build and would like some help or pieces, holler at me in PM or here.
@RedEyeFlightControl - when you say Stand, is that a charging stand and batteries reside in the IH wand or are you still remoting power? I had it in mind to do a cradle unit as a stand-alone with limited battery power since 'parking it' would keep the cells topped off. With tests, I can do 18350 with good reliablity. I find the 14500 IMR cells capable but it stresses the hell out of them. And don't forget 16340... not sure where that tech is, worth exploring. I still want to get to 2S for fully portable unit. The HalfPint FlatPack is the platform for now. It has room for battery management.
Speaking of battery management - I am following a very different school of thought than most. Right now, you need exactly 12.6V from a wall charger. That is so unrealistic that the range is suspect to start with. But that is a requirement of the standard issue BMS. Typically, you would also have a voltage regulator in front of that circuit so you can feed it 12V-ish and it will boost or buck the output to exactly 12.6V. The onboard chips of the BMS are very loose with li-ion specs. They are meant to be the last resort for protection while charging. I have enough experience with li-ion chargers to tell you that a cheap charger can cost one their home. They are no joke! And you see the level of risk makers take knowing this little fact. It is one reason I don't subscribe to 3D printed cases, or plastic cases for that matter, when building these high energy circuits. In safety speak, plastics are "fuel to a fire". You want the product to either extinguish itself or have nothing to burn in case of a fault. The only thing that can burn on the board is maybe the capacitors. I mean flame, not just smolders. Fire safety must be dealt with in choosing a proper housing. So back on subject, I will be exploring the hobby version of the 2S and 3S chargers. They take in a large input range and manage each cell individually like the BMS. But in this case,it is normally meant to be external of the device or pack. It does not manage the device's current load either, like a BMS does. Therefore, if a device cradle has the li-ion 2S/3S charger, the only thing the IH needs is 4 low power connections going to each cell. This can be done with spring type battery contacts in the cradle and contact points on the IH. Every time you park it, it charges. It doesn't take long to put back the 1-2 watt-hour you just used in you last session. How long would a super-cap hold up in an IH one asks? That would solve all this. But the stand-alone unit needs a revisit with regard to the charge regime. Portable means less crap. A BMS can be replaced with a fuse, easy. Due diligence safety demands a thermal fuse; okay if I have to; MOSFET switch is redundant and a welcome space savings; and I've always found the on-off switch redundant in this circuit w/caveat. MOSFET's fail closed, meaning they will push current when they fail. This thing will go stupid if left in this state. It may not even trip the 10 amp fuse because it may limit the power draw to (not likely but possible). This is the condition for the thermal fuse. HalfPint as built actually still has room for a thermal fuse under the magnet.
My next efforts need to go back to the FlatPack. I still want a 2S version that puts out 70 watts. That's 10 amps on the input. There are advantages to going one less cell.
In the past, what, 3 weeks or so I've dedicated the development to coils. Learned a lot! Mostly I learned how to manage the power levels of the IH with the number of winds and the overall length of the wire. I learned that under-gauged wire get hot, which changes the circuit while its heating, and that efforts are typically made to keep the coil temperatures manageable. I've determined that the ZVS "Standard" unit uses 30" of 12 gauge magnet wire for up to 120 watt operation. This is the baseline I use for varying operational parameters. Each coil-turn added represents roughly 5 watts of energy requirement reduction; each coil-turn reduced represents roughly 5 watts of energy requirement increase. I've played with 'over-coils' (multi-layers) and found them to be effective at tuning the circuit. A quick google search shows people have learned that length matters. Rather than put the extra length elsewhere, just continue to wrap the coils on the outside. I've also learned that a 20mm long coil is 9 turns of 12 gauge wire and that a 16mm ID is a good coil size. Your insert will probably determine the exact piece you need. However, that coil will be too short in wire length (impedance) so the additional length is carried on the outside of the coil contributing to the inductive coupling all the same.
I feel I've made a breakthrough in 'packaging' this latest housing. Time to go celebrate
Sneak Peek.... A very tempting housing for the FlatPack. I picked up a couple of these for under $10. They come in gray, pink and this blue. They're great speakers but they make an even better housing for a tabletop IH.
JLAB Crasher Mini ~$20
Need to find a failed one on eBay before I re-purpose the case. It even has covered I/O on two surfaces and a rubberized back plate!
Definitely a candidate for the remaining studies. FlatPack has significant space available for electronics north of the cells. 5v cell charger input cable would be the bomb with a little built-in boost converter. A 2 amp charger would be just about right for 12.6V charging at a 1/2 amp. Even faster if I can get this down to 2S and still have a good power delivery to the coil. That level of charge-tech is available on very simple chip-sets.
Feature list for an IRIH - 5v chage jack, 2 amp capable; metal flameproof housing; Atmel based chipset/Arduino based code; (goal) 2S 18650 cells; 75 watts power limit (longevity); pseudo-power regulation based on available power levels in the cells; IR themal regulation; Interface - Readback UI, intrusion detection interrupt, wake on contact, manual override, system status monitor, touch-slider temp control. And of course Zigbee with a computer controlled interface as a stretch goal.
Damn, this sounds like a go-fund-me project! LOL
One other thing since this is a DIY section. The standard ZVS module is a fairly tall structure. If you want a shorter version of the ZVS, and a more robust one at that, I might suggest starting to look at this unit. It is basically the same unit with more robust fets to drive it harder - read; tougher circuit. You'll still only use 12V and it will still output about what the little module does. But since the DV craze has warped the pricing on modules, it is worth looking at these lower profile layouts. Perfect DIY boards!
Followed by a whole lot of fuck-ups.
www.researchgate.net
Quick delivery. Source please - @RedEyeFlightControl.
