I only have one experience with TC and it wasn’t a pleasant one, I just assumed the mod dealt with it all and you didn’t have to worry about how it worked.
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You’re not. Far from it IMO.
You’re not alone. I’ve been trying to make sense of “the TC landscape” across the variety of implementations that I’ve both had in hand, as well as read about. Unfortunately, I’m at the same crossroads, or perhaps it’s an “impass”, because it seems like every time you are about to “get a grip” on a particular companies approach… They up and change the game (parameters) on you, as to the “standards” that are in play (and that includes Evolv; latest example replay, prior example TC dominant, before that, power dominant -but without an option for ‘dominance’).
Most recently, I was looking for consistency with Smoant, and while they definitely and unmistakably deliver consistent signal for the “end vaping result”, it appears (preliminary impressions at least) that aspects have been changed in the approach. I have no idea if this is the chipset alone (unlikely, but possible), or the adjustment of the base assumption of what they think the customer expects (succumbing to the latest buzz-phrase of “it hits harder” hoopla in reviews and community chat that they might peruse on occasion), but regardless, there’s so many things at play, and possible reasons and explanations of “ways to manipulate” the process to achieve a desired affect…that it’s downright maddening.
I’ve posited more than once (usually internally) that different manufacturers seem to have different “TCR’s” in play even in power mode, though most might not think so, or realize it. But it’s the only way I’ve been able to justify in the most basic “power mode” (specifically when two different brands get the same resistance reading, but still require two different power settings.
Like you said (with respect to Ohm’s law) , if one changes, the other has to make up for it. And if the resistance reads the same, then while they can adjust both voltage and current, the bottom line should be that unless you’re at one end or the other of the spectrum, then the numbers should be the same. But we know that hasn’t been the case. In fact, it’s rarely ever the case (at least IME, with the mods I’ve had hands on for any reasonable length of time). So I am strongly inclined to believe that they have a “predefined TCR value” even in power mode.
I’m usually vaping between 32-46 watts (typically liquid dependant), and that’s far from the technical limits of available voltage, or current (at least with respect to the batteries), so ideally there should BE NO cause to have to manipulate the I/E (current/voltage) if the resistance is the same, and power is “within center mass” of the target (not sagging on one parameter, where the other has to make up for it)…yet we have it happening, even with a full set of identical batteries in both mods, and using the same atty and build. (yes, I’ve tried it. lol - Call it the part of things I’m curious about that led me to the suspicions above.)
Anyways, you’re not the only one wondering…
That’s the best way to approach it (and stay sane). But it’s nice to see others start to fall closer in line to the approach of the “big boys” in the TC field!
I had other things to ask/address as well, and I was hoping to keep this short 
but I’m getting a bit fuzzy (“oxy-focus” setting in) at the moment damnit. =/
So I’ll shut down here.
Great subject though (as usual) bud!
Curious about others thoughts as well.
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I’ve never gotten around to TC. I remember the Smok XCube bashing on the “other” forum a few years back.
It was a piece of crap because there was some software involved and certain people felt that when you buy a $50 mod it should work straight out of the box and shouldn’t require any fiddling.
Ironically the same people ended up raving about the DNA mod. A, at that time, $250 mod with escribe software that required a hell of a lot more fiddling than the XCube 
Until I can get my hands on a reasonably priced replay device I will stick to power mode.
I’m sure that I could wrap my head around all the tech requirements if I set my mind to it but I just want to vape without all that hassle.
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TC is a real monster to wrap one’s head around primarily due to how the industry applies the concept. The IMHO is inferred. Like @anon96069639 I don’t see process itself difficult to work with. I have witnessed manufacturer’s offer TC that is everything from total bull shit to very fine monitoring and controlling of a vape. That can be difficult to work with. After testing numerous devices, I have relegated TC to relative as opposed to concrete, e.g. 450°F is cooler than 460°F. The end result we feel includes many factors of physics beyond just the temperature of the coil. Without knowing each unit’s TC algorithm, it’s sample rate, etc. it’s not possible for me really determine what a mod is doing in TC beyond my perception of the experience. I have seen mods to little or nothing different from VW mode to alter the voltage applied for minute changes in airflow. I have also seen mods that only react to major changes in environment such as a coil going dry.
I have to agree also with @anon96069639 that trying to work with someone regarding TC is extremely cumbersome within the confines of a forum. It’s not surprising given the lack of industry standardization regarding TC that peoples perception of TC vary wildly. Having twelve people tutor on how to achieve what they perceive to be TC at once is a clusterfuck.
Regarding high quality TC, I believe Yihi still does it the best. Even that is an ambiguous statement. Where Yihi has an advantage is that they make a mod and a chip and the entire unit is well calibrated. I believe DNA is a better TC chip in as much as it is more sensitive and responsive but many of the manufacturers that utilize the DNA do a poor job of calibrating the mod to the chip which degrades the quality of the experience. The difference between the Yihi G class and the Paranormal 250C are indistinguishable to me. Having said that, 450°F are two slightly different temperatures with those two units. My perception is even with the best TC set temp is relative.
Wire; Another book that could be written, lol. Plain round wire will be the most discrete. It is reacting solely per the physics of TCR although different wires can be different compositions. As coils increase in sophistication e.g. clapton, now other physics are introduced that determine temperature of the coil, i.e. induction, convection, etc. Depending on the degree of influence of these non TCR physics, results in TC will vary.
Enough rambling. Gotta go by ribbon for programs for my grandsons wedding. Don’t ask. I don’t get it either.
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I found this with the GBOX as well. It seems that they use SS304 for their SS TC benchmark rather than SS316L. 0.00105 is the TCR for SS304. So I’m left needing to use manual TCR for my SS316L wire.
And this is a very worthy topic, not one borne of confusion or ‘full-of-shittedness’, and I appreciate its’ existence.
Oh, and thank you for noting this. I will be using manual straight away when I get the Charons.
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I had already considerably cut down on smoking when I switched to vaping so that’s not a problem for me.
That’s sound advice if you ask me 
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Also, this begs me to mention that things like this can surely cause confusion as well. It’s not easy if at all to find out what benchmarks are used per manufacturer, so that could obviously lead to confusion, aggravation, and disappointment among folks new to TC who can’t understand why Andy’s mod works so well but they can’t seem to get their dialed in. Just one more turd in the toidy for consideration.
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I should have better stated this as:
Even still, with that added, part of what I wanted to cover, but couldn’t remember at the time, was that I also have wondered about the effect(s) of using improper wire gauges within the mod itself, and how that could conceivably throw off the either the measurement OR delivery of the power that’s intended to be applied (once it’s past the 510 connector).
@SmilingOgre extremely nice writeup bud. And some real nuggets of wisdom in there. I wish my head was as clear as I need it to be to get clearer thoughts out… The subject, and folks understanding of the situation certainly needs it!
@anon96069639 again, great topic!
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Got another break between wedding things to do. What I know about mod considerations, by Ogre…
Definitely wiring and etc. influence TC. Total resistance of a set-up would be the resistance seen by the output side of the regulator or DC/DC converter. That would include wiring to the mod’s 510, the mods 510, the base of the atty, and the coil. Each reading of the coil resistance would have to include subtracting the mods internal resistance from the total resistance read. Just to make things even more interesting, every conductive metal used in the electrical path also has a TCR. Every conductor has a TCR (I thought I would get lynched for saying that on anther forum, but it is fact) so now we have things changing resistances at different rates as part of the internal resistance to contend with. In the interview between DJlsb and the Replay engineer, the engineer alludes to this and the inherent challenges. Now we have a rather complex calculus calculation with multiple delta rates.
DNA devices give the end user the ability to measure internal resistance as well as a mod’s thermal dynamics in a static fashion which goes a long way to help calibrate a mod to the chip. DNA and YiHi give the user the ability to program the offset or “cold resistance” of the coil. I have no idea which other manufacturers allow for these parameters to be addressed in manufacturing or no. Obviously they do not offer the ability to change these parameters to the end user.
This is where Ogre has to stop babbling. It has been far, far, far to long since I have done any calculus for me to attempt to figure something like this out. Quite frankly, even though we “knew” calculus, we created Fortran models of our designs and a main frame computer did the math for more complex problems like worst out case analysis which would be similar in complexity to what we are looking at here imho.
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My guess is, All of Them.
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Not sure yet, but just like the energizer bunny, so far so good!!!
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I hate that frickin’ rabbit; why don’t you eat that damn thing.
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Sorry, too much excellent cuisine to mess with the rabbit.
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In my neck of the woods rabbit is considered excellent cuisine, right under squirrel and deer on my list of favorite woodland critters lol
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But have you had human sirloin?? Ogre raves about it 
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But not this time. Very salient points made.
To also be considered is PWM. I am of the opinion that the tighter the PWM, the more ‘accurate’ to benchmark or textbook TCR compensation the draw cycle is. That in itself I believe can also explain some of the perception that a mod is hot or cool compared to another.
That said, @anon96069639 you hit on it with how complicated this all can be. And for the sake of keeping mass-produced mods affordable, I also believe manufactures and consumers are satisfied with close-enough. Myself, as well as any vaper, really, can easily compensate for any mod’s tolerance simply by adjusting a parameter or two until you have a vape you can approve of. To that effect, I do not think it is all-important that chipsets be 100% true to the spirit of the intention, be it power or TC. If it can get close-enough, we humans can take it from there. It’s only when geeks like you sniff around that the differing inaccuracies among chipsets are noted or mentioned.
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That dish is probably a bit salty for some. That’s funny!!
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You’re 99.9% on fop of this. You are still over thinking one point. TCR is SIMPLE. Not even logarithmic. SS316 TCR .00092 is a simple decimal stated ratio. Every 920 micro ohms of resistance increase equals 1°C increase. That’s it.
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You raise an interesting point, and just for curiosity’ sake, I think I’ll try and put bounce the same atty/build (after I recoil and rewick) back and forth between the Cylon and Charon Mini in TCR mode over the course of a few days and see if there’s any discernable difference there. (Fingers crossed there won’t be)
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This really encapsulates what we can determine regarding a mod’s performance. We can look at rather vague and or “Macro” results that the mod achieves, but we really have no idea what it is doing. I can look at resistance down to 1/100 of an ohm and on some mods even down to a milliohm but this doesn’t tell me anything about how the mod is dealing with micro ohm changes involved in temperature change. The only thing I know for sure is that one mod appears to read resistances better than another. I can also look at the max temperature of a wire at a particular temp setting but again it is only a glimpse that infers relative accuracy. How often does the mod sample? Does it consider each sample down to the micro ohm level or does it “dither” the data and use the data at a lesser resolution for calculations of change in voltage. What and how many calculations is it performing, only change of resistance or change over time as well. Maybe other parameters that indicate change that I wouldn’t consider having not designed a mod. Theoretically, some of these measurements could be taken such as sample rate. There is an oscillator in there somewhere and the scope I have surely should be able to read it’s frequency, but, I not going to attempt it. I would love to sit down with a design engineer and chew the fat about this but I’m not interested enough to make finding out a new career choice. Don’t get me wrong I love musing about how all of this might be achieved. I think half the fun is leaving it in that realm.
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