VapCap Induction Heater for Desktop and in Car Use

[Pipes]

Batteries will stay installed and be a necessary part for it to function.
The charger is just a 1 amp charger and can't see why one can't use the unit while charging.
I think you'll find most will just leave plugged in, as there is overcharge protection going on. However, as with all products using this scheme, not the best battery maintenance practice. But they can always be replaced if need be.
Getting triple digits for puffs per full charge, (VCT4s) you'll likely rarely have empty battery troubles. If heading on a long weekend camping excursion, maybe take an extra 3 cells. Which will likely not be used...?

The batteries will be pushing 10-12 amps for the heating duration of well under 10 seconds per hit. No need for expensive cells but not cheapies neither.
I will NOT be providing the batteries because of shipping regulations but the owner will need 3 each, flat top cells rated for at least 20 amp continuous.
So voltage will be around the 11 - 12 volts for the most part.

 

[danald2000]

Thanks for the responses @Pipes! I'm very much an electrical and diy noob... And so I ask how will the batteries be able to be changed and operate at the same time? Will they use power quicker than they get it, or is the quick bursts of power need not significant enough for that to happen?
Also correct me if I'm wrong... But because the power supply would only have 12 amps; it is the constant 20 amps that make the battery option more powerful, and thus more appealing?

 

[Pipes]

The battery rating is just to ensure they are not overpowered, themselves.

The charging while using is not magic. It's just charging and when the extra load kicks in, by turning the heater on, the charger won't be doing much of anything but assisting the current by adding an amp.
As far as using more power than it getting goes, you have to remember the charging is happening 100% of the time. Therefore, if the device puts out 12 amps for 10 seconds, it needs 12 X the time or 2 minutes to recover on the 1 amp charger. So, I'd say, it will get more then it's using.

 

[danald2000]

Ok I think I get it. You mentioned a couple pages back how you had made some tweaks so you were getting the click in 3-4 seconds and that this new faster time improved vapor quality. Will this new battery setup accommodate that fast heating time? Would the home use only unit have the faster heating time?

 

[Pipes]

Yep, your getting it. I have yet to receive the better quality battery pack so can only test with the cheapy packs I have. They have loses as the wires and spring connections are not up to the task. But with it, there was some improvement (speed wise) over my 60 Watt supply. The car battery put out 14 volts and had good wiring. I'm expecting something in-between with the better battery holder. Vape quality was great and biggest factor was it caught me off guard with the speed.

So here's my current enclosure plan. I have one of these on order to make a beta and if goes well, I'll order 40 more from DHGate when all in, comes to $8-9 per unit. Cheapest I can find and delivery will be quick with FedEx.

 

[danald2000]

Sorry to keep pestering but the battery pack with provide a slight slower time to click compared to the direct wiring to a car battery, but will still be much faster than the regular wall out power supply?

 

[Pipes]

No troubles.
If you get a 12 volt, 12 amp supply, you would be golden. This is where the earlier decision came into play. Both @Andreaerdna and myself have being having a hard time getting lower rated supplies to work well. Seems they either cut out or drop output and do not behave consistently even between same models. I found some of my supplies will even cut out where other ones hold firm. This means we are working right at their limits.
So rather than sorting through different cheaper supplies to get working setups, it left me 2 options. Finding a 12 amp supply, which is doable but they are expensive and fairly big. Or, the option I am venturing down. Keep the power on-board with decent batteries and BMS.

 

[danald2000]

So a 12amp 12 volt power supply would be equal to the battery option, power wise? And where do these fit in compared to the one directly wired to the car battery?

 

[Pipes]

Just checked it out for you. Couldn't find a 12 amp but did find a 8.5 amp 137 watt supply. Notice how the size grows fast when getting into the higher rated supplies...

This cuts the click speed to 5 seconds.
Honestly though, going this route makes me nervous. So much amps outside the box, means the lead cable should be beefed up as well. And any bad connections could micro arc, thus heating them up. I'm staying in my comfort zone.



I've being starting to play with the 16 AWG wire and really see little difference except placement can be more focused. Have yet to do current measurement to see if there is any real benefit.
EDIT:
***NOTE***
Now, if the coil can be configured to use less power, the smaller supplies will come back into play.

 

[rz]

The royer osc. has serious munchies! It's not so simple to reduce it's consumption since it's a self-resonating circuit (Z=R for the tank, lowest impedance->highest current). If it were not self-resonating, you could de-tune it by driving at a different frequency. One way may be to PWM the whole mosfet gate supply to slow down pouring power into the tank. Another, simpler but maybe less influential, is increasing the choke inductance. I'm looking into *simple* current limiting. Haven't found one too suitable yet.. (ie, most will reduce voltage which risks locking the mosfets). It may be more suitable with higher voltage/lower current (~20v even). Either way, since the intended use case is short sporadic burts, such beefy power supplies do seem overkill. The battery solution does indeed make a lot of sense..

 

[hardboiledfrog]

Now, if the coil can be configured to use less power, the smaller supplies will come back into play.

a double layer work coil wastes a lot of energy through self heating, try going back to a single layer.
a larger diameter work coil will reduce transformer coupling between the coil and the work piece. this will draw less current at the expense of increased heating time.

 

[Pipes]

I have some more experiments to do but I think the use of a 6 amp supply is within our reach.
@hardboiledfrog , are you sure about the multi layered coil heats it's inside wraps? My testing is not indicating this. It seems to more focus the Eddie lines as the inner coils are part of the force creating them.

My recent tests indicate a 24 " of 16 AWG enamel coated copper wound 4 base winds and the rest wrapped around the first 4 turns.
Seems to use about the same current in idle mode and 5.5 amps under full VC load. Click speed is about 7 seconds which is the same as original coil at 8 + amps.

Sooooo.... Here's the test results of a few coils and click speed.



Seems the wire length plays the main role in idle current and focusing the Eddie lines is the key for the current for small target. I assume the extra current was from heating the VC up into the heat sink fins.

I tried a few coils. Even tried reverse looping the end wraps on one. Wow, current jumps to like 15 amps as we force the Eddie line to clash. Coil on the left. No benefit there. lol



Going to clean up the winning coil tonight and do some longer term tests.

As far as the coil heating up goes. Seems about the same as the thick gauge if not a little less hot.
Experimenting with this is really giving some un-expected results. And in our favor. The phrase, you never know unless you try, certainly holds true with this technology.

 

[Pipes]

Had a productive evening performing many experiments with different coils.
Good news has come out of it. I think we have two winners, one for a 6 amp supply and one for a battery or larger supply.
But not an outrageously rated supply. A 8 amp supply will do.

I used some wiremans tie string to hold the coils firmly together. This is a wax coated cord that is very strong and heat resistant. Nice to work with as easy to tie and holds itself while adding more knots. Don't need the third finger.



The three coils along the top are considered failures because the time was too long for the click and current needed.
The two on the right both performed the same and can work with the more common 12 volt 6 amp supplies without them cutting out or lowering its output. So, in theory, will act the same in your car, bringing the use of an accessory adapter back on the table.
This puts the original design back to life!!!

The coil that is mounted is not doubled up and is 7 winds which covers the VC from bottom to just under it's heat sink grooves. Takes 6 1/2 amps and gives you a 2 second quicker click. This would be the candidate for a beefier supply or battery option.

Seems life is never simple and full of decisions... Or options.

So I also found that you can adjust the click to the desired temp by moving the coil closer or further from the end of the cap where the clicker resides. I found about 1/2 way about right and is where VC recommends the torch to be applied as well.



Here is a visual of the wiring layed out for those thinking of making one of theses.

I haven't gotten any of the better battery holders yet but this is the basic hookup.

It's looking good guys.

 

[virtualpurple]

@Pipes, you are on a roll my friend!

Folks, is this guy on another level or what? These are great steps forward for us!

 

[GreenHopper]

@Pipes thanks for not only undertaking this awesome project but also for taking the time to include us all in the process.

I understand about 10% of this but am fascinated by 100%.

Thank you bud.

 

[hardboiledfrog]

@hardboiledfrog , are you sure about the multi layered coil heats it's inside wraps? My testing is not indicating this.

yes, I am sure about this aspect.
from Conduction and Induction Heating by E.J. Davies:
"Using normal hollow tubular coils, it is not desirable to use multiple layers, as the outer layers, i.e. those further away from the workpiece, heat the inner layers as well as the work."
https://books.google.com/books?id=j...onepage&q=multi-layered induction coil&f=true

is it a huge concern? probably not in this instance.
just speaking from personal experience in my brief 3 year career in the industry, at the place I worked I don't recall them using any multi-layer coil designs.
however, there is research in the book quoted above and elsewhere on the interwebs making a case for multi-layer designs in certain applications.
your results are very interesting and encouraging.
is all about experimentation so I would say carry on, looking forward to seeing where this goes.

 

[Diggy Smalls]

This is coming right along. I'm super excited. Thanks for sharing the updates

 

[Andreaerdna]

having to stay in a hotel for couple of days I have with me the black station with a VC as my only delivering system. It works like a champ.

I have the click a little faster than butane but I do not mind having 1 cycle more. I even prefer it (less chocking, easier to ghost the hit)

can't wait to play with 16awg enameled wire and a voltage/current meter (as a good Pipe's disciple I have both on order already )

 

[Pipes]

What did you pick up for an amp meter. Reason I ask, is not many go over a couple amps max. My meter is in my power supply and my multi-meter can not go that high. And it's a really good one.
You forgot the "flat waxed sewing string" which I did not know what to call it. This stuff is very close to what I'm using.
I have disciples...? Cool. And I'm not even religious.

 

[Andreaerdna]

I have disciples...? Cool. And I'm not even religious.

The barrier of language sometimes can be funny, I am not religious neither, I meant student like there was in old times around big artists, the ones old Italians called Maestro (still a very good compliment, even better if i may)

Had ordered a 5-30v and 50A if I am not making mistakes, from banggod

Thank you for the waxed things too!

 

[Pipes]

Well thank you for the praise and kind words.

@hardboiledfrog, thanks for the information. Very informative. Good job I didn't catch that earlier or may not have tried the overlapping. I looked deep now and did find some multi level builds and were actually geared for hitting a smaller area as a target. That and the target temperature we seek are the criteria that's making it work for us. I don't think we could drive this to get metal bright red hot as that is out of this build's league. At least that's my theory.

Tonight I set out making the coil as narrow in diameter as possible as the Eddie lines are stronger the closer you get to the coil.
I found some 14mm tubing for the task.
In a nutshell, it fails, as it wants too much current to drive it. Although a nicer "looking" fit, I found with it being so tight, the cap can slip if not pulling straight up. This build wanted 10 amps and clicked in 5 seconds.



So sticking with the 17mm tubing is likely the best bet.

I made a more or less portable setup for some longer term testing.
This is the 20" 6 turn coil which draws between 5 and 5.5 amps which is right where we want it for a 6 amp supply. Click from cold is 8-9 seconds but is adjusted so the click is it, huge clouds. No 1-2 seconds pass type thing. Unless you want that, which "is" possible by moving the coil closer to the tip. My belief is this is the winner.



I'm getting the tactile switch mechanism figured out. A piece of drilled out dowelling with a couple O-Rings will support a post to make contact between the VC and switch at the bottom. The tactile switch will be held in place by a rubber cap. This method makes for easy adjustment or repairs. The tube length will be decided once the enclosure arrives and I figure out the component placements.



So, if the testing doesn't burn my house down, it looks like a non-battery unit will be back on as an option.

 

[Hogni]

Waiting for the first custom car with integrated induction heater for VCs.
If I sometime should get my desired '72 Ford Ranchero it will have one aside a rifle rack in the back for sure!

 

[hardboiledfrog]

awesome @Pipes !!! I really like the compact setup.
I like the 10A setup too. I wouldn't call it a fail, I'd call it the Lightning Option. for people who don't have time to wait or are just impatient.

the tube and switch arrangement is very innovative, really nice work!

the only problem is now I have to go buy a VC just so I can build one of these.
I rarely vape flowers anymore since I got my e-nail & rosin press setup but this would be great for out in the garage or just outdoor use.

 

[danald2000]

So for the battery powered unit which has a little over 10 amps available do you think the 14mm would still be an option? it's super cool that you've been able to find a 6 amp build, but the battery powered option with a super fat click and ability to be charge in use, still seems like the optimal set up to me. Any thoughts on which design you're leaning towards @Pipes?

 

[Pipes]

Both.
You are correct that we have more available power to play with using the battery option so why not take advantage of it.
Finding a lower current solution was to get the original design back on track and to allow folks to make their own as cheap as possible.
My plans tonight are to change the coil in my Beta Cup unit to the more efficient one and work more on the tactile switch mechanism.