I will use TC if they make a device that will handle a Kanthal and will Control the Temperature rather than Limiting it.
Is temperature control worth it?
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I will use TC if they make a device that will handle a Kanthal and will Control the Temperature rather than Limiting it.
Not sure what you meant by "controlling rather than limiting". I think my EVIC-VT does a pretty good job of controlling and, by extension, limiting temp.
First a Big ol'e hit off my IPV-D2.....................
Then.................
Yep, Well Worth It
Then.................
Yep, Well Worth It
Temperature Control limits the temperature the coil is allowed to heat up to. The name temperature control is actually a misnomer because these devices lack any thermostat or temperature sensor. Mods using this technology do not sense the actual temperature of the coil but instead rely on the change in resistance as the coil is heated.
But, I would wait when they come up with a device that uses kanthal for tc.
pretty much the gist of it.
What do you mean control rather than limit? I set the temp I want it to stay at and it does. It doesn't hit a max temp then shut off, it controls the temp where you set it.
I see zero reason to specify kanthal. Nothing wrong with Ni or Ti when used with temp control.
It's just that there are easier ways to vape at ~3 watts
What would be the point of vaping at 3 watts? I doubt either my Nautilus or my Micro GDC would even make vapor that low.
That would require a separate sensor, which might have all sorts of real world problems and might be difficult or impossible to implement in a rebuildable, for example. But that is the only way Kanthal would ever work since Kanthal's resistance changes so little as it heats up.
At a practical level, I don't find the indirect measurement based on resistance to be a problem, except that the temperature setting becomes a somewhat imaginary or arbitrary number. In other words, I have my own share of problems getting the coil properly calibrated and other voltage drops controlled (I guess) but I don't have much trouble maintaining a given temp once it is dialed in. It may drift a bit over time but not radically enough to cause problems (except with new coils on occasion, for some reason I don't understand). But once a coil has burned in it seems to settle in and behave well, even if different coils (or maybe even the same coil on different days) varies by 50-100F, making the actual temp number a bit meaningless.
The resistance changes based on temperature. And it is very consistent. Far more accurate than some temp sensor would be. An IR sensor would be thrown off by the vapor, and a contact sensor would be accurate only where it is touching the wire. Plus, the contact sensor would use resistance to feed a signal to the board. That is how most electronic temp sensors work, as the heat increases, the resistance of the signal sent through them changes and that change is interpreted by a computer. So, even if the coil doesn't rely on resistance to measure temp, the sensor used on the wire would still rely on the same method.
Here are some reasons...
1. I am a few others here have a nickel allergy so we don't want to do experiments in that area
2. With Titanium you have to be careful about Titanium Dioxide, can't dry burn the coils like most of us do, and etc. That is not a deal breaker for me, but I would rather use Kanthal that we all know and love. Right, wrong or indifferent.
3. I have to dedicate tanks for TC, although using Ti I might be able to use those coils in a standard mod (if the mod can handle a 0.3R or so coil). But I might not want to do that, for various reasons. It would be far simpler with standard Kanthal builds.
More and more mods are doing temp control on stainless. The Smok has updates for it from what I've heard.
But then something like or more like a thermistor could be used, that has a much wider temperature swing. The problem with the current method is that the sensing wire also needs to be suitable for vaporizing a coil, and the temp swings are so minuscule, even with Ti or Ni, that tiny voltage drops elsewhere in the circuit can throw the calibration way off.
Why do Ohms matter? All that matters is the quality of the vape, of which ohms have no bearing. Ohms only matter on mech mods.
The voltage drop would remain constant regardless of temp. A non-issue. The temperature induced resistance change would still be the same.
Nah. That is only the case on a mech mod where there is no DC-DC switched mode converter. Resistance of the coil has no bearing on watts (power). On a regulated mod, a .01Ω coil @ 40 watts will drain your battery at the same rate as a 2Ω coil at 40 watts. As is sometimes said, "watts in/watts out." A battery that is charged to 3.6v (and has minimal sag) will push about 12A at 40 watts regardless of the resistance of the coil.
Tell me what exactly is your definition of "measuring temperature." Just because something is not using a thermocouple doesn't mean it is not measuring temperature. Do you know how a thermocouple works? It works by using two metal wires welded together that measure voltage changes at the junction. Those voltage changes are then correlated to a temperature. So, by your definition, a thermocouple (sensor) does not measure temperature either -- it measures voltage changes.
Likewise, a good old fashioned mercury bulb thermometer measures the change in the volume of mercury, which expands with heat. Therefore, we can say that this device does not measure temperature, but mercury's volumetric expansion.
The problem is that Ti and Ni only vary by a couple tenths of an ohm over the temp range we are dealing with. A 0.1R voltage drop elsewhere in the circuit is a huge resistance relative to the couple tenths of an ohm that the coil varies. A thermistor, for example, would vary by thousands of ohms, making the 0.1R or so incidental drops meaningless.
I = P/V where:
I = current (for which we are trying to solve)
Power = 40 watts
Voltage = output voltage of battery under load (our batteries are 3.6 nominal).
Let's assume the battery can put out 3.6v under the current load. Therefore:
40/3.6 = 11A
I am assuming 100% efficiency (which wont happen in practice, but it's close enough for illustration purposes).
So, 11A is what's coming out of the battery (input current into the mod). Not to be confused with the output (which is where everyone gets confused). When you see that the mod needs 7v to obtain a set power level, it cannot magically pull 7v out of a 3.6v battery (unless we want to violate the laws of physics). So, how does it do it? By pulling more (input) current from the battery to convert to output voltage. Go read up on switched mode DC-DC converters.
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