eVic-VT mini?

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scaredmice

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Would you be so kind on telling us in layman's terms on what to do ;)
Because I am in ph and my room temperature is a lot different from yours :)

" life is about making decisions and not looking back "
If you fool the device to think that some hot resistance is at room temperature (locking it or re-attaching it to force the 'new coil...' question), you obviously shorten the difference in resistance between room and working temperatures, and that forces the device to go beyond the set parameter.

If you lock or set with the 'new coil' question an atomizer at 80 ºC and you've put 240 ºC as set parameter, it'll really go up to 300 ºC....... that solves the anaemic vape for sure, but you might find its cousin, damn dry-hit vape, instead.... Think that when you lock or set the base resistance, you're telling the chip that, at 20ºC (98ºF), the base resistance is that one found, precisely.

It is working very well for me.

For me too, just exactly as the IPV D2. Now and then I've got issues, on both mods, always related to a bad calibration of the base resistance, for whatever reasons, and I always fixed them quickly and easily. I'm sure that some of you didn't get how it works yet, but I'm also sure that so big complaining group cannot be just wrong procedures, or the procedure is far too complex and Joyetech should study how to solve or improve it....

I'm just starting to suspect that TC is not the natural choice for those who like strong vapours and usually vape on drippers at high power settings, or the cloud-chasers. TC-enabled vaping is like driving a Ferrari with all ABS, EDS and all that jazz, electronically-controlled assistance for the driver. The Ferrari continues running well, but you cannot drive it crazy enough, the sensors and computer assistance do not grant it. As a matter of fact, at least on YiHi chips, TC strategies are much like ABS for brakes....they enable PWM (like stroke-driven pressure on brakes) to not go beyond the set temperature....

... but some folks do like to go beyond that, and are unimpressed, when not directly ...... off, if they cannot leave their trails of rubber in the asphalt..... It's O.K., you can always switch off the TC..... (or get rid of the fuse on the ABS central calculator......;)).

The so-called 'tottle-puffers', instead, should enjoy TC-enabled, and properly set, vaping. I surely do. And my e-liquid consumption is even bigger, so may be, just may be, I'm running at steady, faster paces that at first sight may appear.....:p

So I think I may be one step closer to finding the error in the code. I got my device to vape well again by warming up the coil a little by going ahead and vaping on it while it was putting out the weak vape. I then unlocked the coil, and removed the tank, hit the fire button, and put the tank back on. My .35 Ohm coil was now registering @.55 Ohms, which is to be expected. I opened up the air flow on the tank, and drew cool air through the coil, and kept screwing on and off the device until it cooled enough to register as .4 Ohms. I then locked the resistance and it has been vaping very well since then, even after soft sleep.
So after reading a post over on the Joyetech Social forum about board temp playing a role in correct resistance locking, I did some pondering and experimenting. I went and read the thread here about the Temp Coefficient of TI wire, and did some calculations about corresponding atomizer resistance to number of degrees that the board temperature is off from actual room temperature. So I have made a spread sheet, and have been playing around with the device by first checking board temperature, and how many degrees warmer than room temp the chip is, and then looking up what the resistance of my atomizer should be at that temp. I then make the two match by using the above method, and locking in the resistance that matches board temp difference.
So far it has been working very well this way, and if it continues to work, I think I may have stumbled onto the error in the Joyetech source code. If that is the case, I wonder how long it will take them to fix it, and what address do I send my bill to?

I've told you, in one of my former-famous long mathematical posts, that the VTC mini appears to be using a slightly low TCR for nickel, and surely much less than IPV D2, which appears to be too big. Actual resistivity figures for Ni-200 say that the correct TCR should be 0,00575 1/ºC and the VTC seems to be using something between 0,0052 and 0,0055. And that's a way of always obtaining less actual temperature than the one set up. Couple that with a wrong locked resistance and the anemic vape is guaranteed.

But, you know, you can go up to 315 ºC (550 ºF), so....... what about setting it at apparently dangerous temperatures if you positively know that it is not so hot? I'd rather choose that than fooling the device with an actual-hot, posing as room temperature, locking.
 
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vitorchapas

Full Member
Nov 1, 2014
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Portugal
Been reading this thread from first post. Sorry for my English but my native language is Portuguese. Been reading lots of complaints about how the resistance changes when the mod sleeps. Never happened to me. Been using a 0.30 ti dual coil on my goblin and never experienced that. Even when I change attys. It always reads 0.29/0.30 and capes like a charm... I can just assume that, in fact, there are lots of defect units...
 

Tpat591

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Only a few of the thousands of units are affected and only then within very narrow parameters. Those that are affected are more likely to seek out a forum like this and to be much more active in sharing there experiences in seeking a solution to their issues. That is just the way it works out, but great information to know if you experience any issues in the future.
 

vitorchapas

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Nov 1, 2014
31
31
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Only a few of the thousands of units are affected and only then within very narrow parameters. Those that are affected are more likely to seek out a forum like this and to be much more active in sharing there experiences in seeking a solution to their issues. That is just the way it works out, but great information to know if you experience any issues in the future.
That's why I keep following this thread ;) If my unit starts to behave weird I already know some workarounds :)
 

EDO

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Ok guys I am going to say how mine works so people can compare.

If you are in TC mode and you don't lock the the resistance:
1)When you change atties and the new atty has a lower resistance it will automatically think you changed to a new coil and will adopt the new resistance as the base resistance.
2)When you change atties and the new atty has a higher resistance it will ask you same or new coil. If you pick new coil it will take the new resistance as the base resistance.
3) If you change to a new coil that is Kanthal coil it will automatically go to VW mode (the setting will be the last VW setting that you had)

If you are in TC mode and have locked the resistance all of the above go out the window. It will never ask if same coil or new coil. It will always assume the locked resistance is the base resistance no matter what TC coil you put on it. However, if you put a Kanthal coil on it it will not fire and it will say "Atomizer res low". Then you have to unlock the resistance and it will switch to VW mode automatically (of course you can change it manually).

Honestly this mod works perfectly if you don't lock the resistance. I have been switching between 4 atomizer (3 tc coils and 1 kanthal) and I have had no problems. I only have to adjust the temp on the TC coils. While with the Kanthal coil it remembers my last setting. If for some reason you insist on locking the resistance.....then you have to unlock the resistance before changing atties. And then lock the resistance again after you change atties.

Hope this helps.
 

TrollDragon

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So when I take the Kafun I set up with the 0.15 ohm Ni 200 build and put it on the VTC mini it will vape properly until the mini goes to sleep. Then it is constant Temperature Protection within a second on all the subsequent vapes.

The I take that exact same Kayfun after it has cooled to room temperature and put it on the IPV D2 with the same setting and have absolutely no problem whatsoever. The vape from the D2 is quite similar to a Kanthal vape.

This is a Kayfun V4, not a high powered unit or by any means a cloud chaser.

It is starting to grow old that I am supposedly doing something wrong and my expectations are too high. I shouldn't have to set the VTC to 550F and 45W just to get the same vape I am getting on the D2 at 400F and 25W...

You can tell as soon as the VTC hits TP as all power disappears from the vape.
 

Tpat591

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So when I take the Kafun I set up with the 0.15 ohm Ni 200 build and put it on the VTC mini it will vape properly until the mini goes to sleep. Then it is constant Temperature Protection within a second on all the subsequent vapes.

The I take that exact same Kayfun after it has cooled to room temperature and put it on the IPV D2 with the same setting and have absolutely no problem whatsoever. The vape from the D2 is quite similar to a Kanthal vape.

This is a Kayfun V4, not a high powered unit or by any means a cloud chaser.

It is starting to grow old that I am supposedly doing something wrong and my expectations are too high. I shouldn't have to set the VTC to 550F and 45W just to get the same vape I am getting on the D2 at 400F and 25W...

You can tell as soon as the VTC hits TP as all power disappears from the vape.
You are saying that following the instructions in Iowa31 post https://www.e-cigarette-forum.com/forum/threads/evic-vt-mini.695518/page-38#post-16632078 did not work for you? Sounded like he was on to something real.
 
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Max0819

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You can almost bet that there is an internal hardware tolerance issue going on. I'll say again, at such low resistances (below .5), any internal temperature change along with external (lets say for example it is warming up insude, but cooling down outside) the change in the circuitry alone is problematic. If I get a chance this weekend, I guess I will play with mine (though to now I only used ,5, 1.0, 1,5's). Using some tricky software you can fake it around, but unless there is a probe doing proper compensation, fluctuations are expeted. Truth be, electronic temperature sensing is a fine bit of art and science combined, under the best of circumstances. AT least on the few thousands sensors I've been involved with.

One thing does seem particularly bothersome, when you LOCK the resistance, why does it change?

Out of curiosity, anyone try and place it in the freezer for a few minutes, for funsies? Together and separately with the Atty?

When someone one has a properly compensated probe at the coil, then TC has finally come of age (Maybe the New Innokin, maybe not).

Max
 

Jim_ MDP

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Sep 24, 2015
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You aren't doing anything wrong TD. This isn't my first rodeo either, same issues.

If it were just the temp range being low, ala the iStick 40TC, I'd just set it higher and go about my vape.
But it's not. When the VTC wakes, it behaves as though the res is locked about 0.05 lower than actual resistance. Thus... anemia. The exact opposite of the trick of re-locking the res that much HIGHER on mods that allow it (helps with some combos, I've done it often).
 
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Kaiser Bob

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You aren't doing anything wrong TD. This isn't my first rodeo either, same issues.

If it were just the temp range being low, ala the iStick 40TC, I'd just set it higher and go about my vape.
But it's not. When the VTC wakes, it behaves as though the res is locked about 0.05 lower than actual resistance. Thus... anemia. The exact opposite of the trick of re-locking the res that much HIGHER on mods that allow it (helps with some combos, I've done it often).

Indeed. I feel like the quick and dirty fix on Joyetech's part would be to simply code it to not allow the device to waiver from the locked resistance reading.

Sent from my SAMSUNG-SM-N920A using Tapatalk
 
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eddiea

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Ok guys I am going to say how mine works so people can compare.

If you are in TC mode and you don't lock the the resistance:
1)When you change atties and the new atty has a lower resistance it will automatically think you changed to a new coil and will adopt the new resistance as the base resistance.
2)When you change atties and the new atty has a higher resistance it will ask you same or new coil. If you pick new coil it will take the new resistance as the base resistance.
3) If you change to a new coil that is Kanthal coil it will automatically go to VW mode (the setting will be the last VW setting that you had)

If you are in TC mode and have locked the resistance all of the above go out the window. It will never ask if same coil or new coil. It will always assume the locked resistance is the base resistance no matter what TC coil you put on it. However, if you put a Kanthal coil on it it will not fire and it will say "Atomizer res low". Then you have to unlock the resistance and it will switch to VW mode automatically (of course you can change it manually).

Honestly this mod works perfectly if you don't lock the resistance. I have been switching between 4 atomizer (3 tc coils and 1 kanthal) and I have had no problems. I only have to adjust the temp on the TC coils. While with the Kanthal coil it remembers my last setting. If for some reason you insist on locking the resistance.....then you have to unlock the resistance before changing atties. And then lock the resistance again after you change atties.

Hope this helps.
Mine functions exactly as you described EXCEPT it automatically switches to Power mode when I put a Kanthal build on it - regardless if I have the resistance locked in Ti mode.

EDIT: I have hardware v1.00 and firmware v1.10.
 
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eltaros

Full Member
Oct 1, 2015
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Malaysia
You can almost bet that there is an internal hardware tolerance issue going on. I'll say again, at such low resistances (below .5), any internal temperature change along with external (lets say for example it is warming up insude, but cooling down outside) the change in the circuitry alone is problematic. If I get a chance this weekend, I guess I will play with mine (though to now I only used ,5, 1.0, 1,5's). Using some tricky software you can fake it around, but unless there is a probe doing proper compensation, fluctuations are expeted. Truth be, electronic temperature sensing is a fine bit of art and science combined, under the best of circumstances. AT least on the few thousands sensors I've been involved with.

One thing does seem particularly bothersome, when you LOCK the resistance, why does it change?

Out of curiosity, anyone try and place it in the freezer for a few minutes, for funsies? Together and separately with the Atty?

When someone one has a properly compensated probe at the coil, then TC has finally come of age (Maybe the New Innokin, maybe not).

Max
Ived tried using the freezer but it didnt step down low enough ohm. I have a nic coil at 0.08 freez it till max i got only 0.07 only .01ohm diff. I need it to be at least .02 or higher step diff. to hav the mini to detect new coil when it comes back to room temp(in my case 0.08).

Thus that got me thinking of building two tanks/coils with one higher then the other instead of freezing to lower it.
So now i have 2 atty setup one with 0.15ohm and the other 0.08.
Now for the ultimate test,...
First i placed the lower ohm first on mini detected as expected 0.08ohm. Removed it and placed the 0.15ohm atty hoping i could trick mini that im having warmer higer ohm atty. and Wallah! Mini asked if its a new coil. I press yes n its at 0.15ohm.
Dissapointingly mini still doesnt vape as expected. Low firering low smoke basically still the same problem.

Ived givenup all hope now as i tried many other ways to go around the problem.

So the best way to still use this mini is
1. Place new atty.(exp mine 0.15ohm)
2. Increase the temp so as to warm up the coil n have 2 long puffs..
3. Off the vtc mini by clicking 5 times.
4. Turn it onn again quickly and i would hav about .02ohm or higher increase in ohm(in my case i usually get 0.17 or 0.18ohm depending on how long i warm it on step2.

And ut works perfectly till i leave it to rest for agood 5 or more minutes in which the coil will cool back to 0.15 and u hav to repeat those steos again.


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TrollDragon

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TrollDragon

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You aren't doing anything wrong TD. This isn't my first rodeo either, same issues.

If it were just the temp range being low, ala the iStick 40TC, I'd just set it higher and go about my vape.
But it's not. When the VTC wakes, it behaves as though the res is locked about 0.05 lower than actual resistance. Thus... anemia.
The exact opposite of the trick of re-locking the res that much HIGHER on mods that allow it (helps with some combos, I've done it often).
Thank You.
 

iowa31s

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Feb 1, 2013
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I am still playing with the temperature of the board/temp of the atty thing. There seems to be a correlation, but it isn't as direct as I thought originally. I can tell you that 70 degrees Fahrenheit seems to really upset my particular device, LOL. If I have both the atomizer and the device at 70, and put it all together, I get almost no vapor. I am also finding that I have to lock the resistance of the atomizer when it is a little bit warmer than the displayed board temperature to get it to hold when the device soft sleeps. I get a good vape if I calculate the resistance difference of the coil in relation to the chip temp of the device, but that locked resistance changes when it soft sleeps. I still feel like there is a formula to all of this, but I am getting tired of messing with it for today to be honest. Right now, I have the resistance locked back at .05 ohms higher than the actual resistance of my TI coil, (.35 coil locked at .40) and it is vaping well, and holding it when the device soft sleeps, it is the question of WHY that is driving me insane.
 

eltaros

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Oct 1, 2015
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Malaysia
Can't say it's important or not but... could you (everyone?) give the wire type and resistance, please?

Myself, it's the factory 0.4 Ti head that's an issue.
0.15 and 0.2 Ni heads were working and no problems with Power Mode.
Dint buy the combo just the vtcmini mod.
I tried building using atty Subox mini /lemo2/velocityRDA n atty3Rda tried wit ni200 28/26 and
Ti A1 24. my coils Ohm range between 0.08 to 0.15ohm. All face the prob(loosing it after idle for few minutes).

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eltaros

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Oct 1, 2015
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Right now, I have the resistance locked back at .05 ohms higher than the actual resistance of my TI coil, (.35 coil locked at .40) and it is vaping well, and holding it when the device soft sleeps, it is the question of WHY that is driving me insane.
I am never able to raise it by .05 ,max i could get is an increase of .04. Curious if you able to maintain the vaping after idle at an increase of .04 . I know mine cant.
 
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