In the common power modes (variable wattage/VW) you can choose the wattage setting of your mod. The wattage takes into account the coil’s resistance and controls how much current will be constantly driving to the coil. This heats up the coil and vaporizes your liquid. If you keep pressing the fire button, the coil’s temperature will keep increasing over time.
Eventually, if your saturated wick starts to run low on liquid, this will result in a “dry puff” and possibly ends up burning your cotton. The same will happen if you adjust too much power to be delivered on your coil, even if you don’t press the fire-button for long.
The first is the result of providing a certain amount of power to your coil for a longer time and the second is the result of providing a larger amount of power for a shorter time. We’re actually talking about the same amount of total energy provided to the coil. Both cases have to do with overheating your coil by “over-driving” it, either in time (by pressing the fire button for long) or in current (by over-powering it).
More About This Situation
The above two improper situations might occasionally happen even to experienced power mode vapers (perhaps by accident). But, they know how to sense when a dry puff is coming. Inexperienced vapers, though, may come across dry puffs or burned cotton taste frequently, until they get some experience.
The same is valid for the voltage mode (Variable Voltage/VV) of operation, where the controlling parameter for vaping is the voltage provided to the coil under constant power/wattage.
On the other hand, the temperature control mode of vaping obviously means that you adjust your mod to “directly” control the temperature of the coil rather than the wattage or the voltage. So, instead of regulating your mod to drive your coil with “constant” current/voltage for as long as you press the fire button, you choose to control the temperature of the coil, to not let it get hotter than your chosen/preferred temperature.
Temperature Control Mods
Temperature control mods (TC-mods, for short), which are the ones providing TC function, ultimately operate at a set/locked wattage (some even let you choose your “ramp-up” wattage). But their main aim is to limit the coil’s temperature at whatever value you’ve set. When your coil reaches that temperature, the mod reduces/stops the power provided to your coil to maintain the chosen temperature.
Roughly speaking, it looks like “driving” your coil under a temperature’s “cruise-control” limiter, where you set your coil’s temperature limit and vape either lightly or heavily ( using either lower or higher wattage values respectively and pressing your fire-button for as long as you want). The rest is up to your temperature control mod to not exceed the coil’s selected temperature.
Obviously, for not overheating your coil, you need to know your coil’s temperature “cruise-control” limit to select it on your temperature control mod.
What temperature control mode provides to your vaping?
In two words, vaping by primarily controlling the temperature of the coil can provide to vapers a way of limiting the coil’s temperature, for preventing burnt wicks or dry puffs (and the formaldehyde they bring with them) or simply for keeping the vapour from getting hotter than a vaper prefers.
Actually, when there isn’t continuous and adequate liquid saturation of your coil’s wick and the liquid has already vaporized as a result of your power setting and of the duration of the fire button pressing, the temperature of the coil will quickly approach the temperature limit you’ve set and the mod will prevent a dry puff (by stopping to fire it).
This also means that you can vape with no “anxiety” of emptying the tank from the liquid (useful when you use tanks that don’t allow you to check the amount of liquid left inside). You can even use a higher-VG-percentage liquid in a tank with a not-so-adequate constant liquid-feeding of your wick. Also, in persistent chain-vaping, where you might risk of getting a dry puff, TC-mode will ease-off the power before that happens.
Vaping with power-mode, a second/third dry puff often leads to burning your wick. But, vaping with TC-mode prevents this. Your coil’s setup lifespan will also be increased with TC-mode, since the maximum temperature protects your wick from getting burnt.
However, there aren’t that many coil-heads (with the suitable for TC-type of wire) for using clearomizers with TC-mode. If you’re an inexperienced vaper, I suggest you look for clearomizers using coil-heads with Stainless Steel (SS) wire. These can be used both in power and in temperature control modes of vaping. They’ll give you the chance to adequately learn to vape with both vaping modes.
With TC-mode, you can even “dry-fire” your coil (with no liquid on your wick) and not face problems, as long as the TC setting is below 410°F/210oC (the cotton won’t get burnt). This can also help you to extend the lifespan of your coil builds with TC-mode.
In addition, at different temperatures, your liquid may produce different vapor compositions, providing different “tastes” (e.g., under higher temperatures, PG will produce methyl alcohol, which is toxic).
Finally, as different flavours are vaporized at different temperatures, you have to keep each liquid’s vaporization temperature fixed, in order to experience a “consistent flavour/taste performance” of vaping with your liquid. With temperature control mode, you can select each liquid’s “sweet spot” temperature (that is the vaporization temperature where each liquid’s flavours “flourish”) and keep it constant.
Experienced vapers are usually searching for the appropriate wattage adjustment that “succeeds” the “sweet spot” of each liquid they use.
Inexperienced vapers, too, can easily use temperature control mode to also experience consistency in flavour.
How temperature control mode actually operates?
A regulated mod only drives the coil with current under a certain voltage (that is power: wattage=voltage X current). It always regulates current drive to the coil with the available voltage (or vise-versa), under a certain wattage setting. The whole thing has nothing to do with temperature.
However, the relation of voltage and current under certain wattage has to do with the coil’s resistance. The mod regulates the current/voltage to the coil under certain wattage and coil’s resistance. Wattage = the current squared times the resistance or wattage = the voltage squared divided by the resistance.
The coil’s resistance may change with temperature. Then, the TC-mod can re-adjust the current/voltage drive to the coil, according to the coil-resistance change due to temperature change in order to keep a certain selected wattage steady.
Temperature Control Mode
Temperature control mode actually operates by detecting/monitoring a given coil resistance. This changes with temperature (using as reference its initial resistance value at room temperature, before you fire your coil up). Then, estimates/calculates the corresponding temperature changes (because resistance’s increases are linear and predictable with temperature changes).
When you’ve set the temperature limit for your type of wire, the TC-mod knows the resistance value at room temperature. Then, it subtracts that from its current value under drive, restricting thus the voltage/current provided to the coil under the selected locked wattage (for not exceeding the set temperature). Temperature is just an understandable interface-readout “translation” of your coil’s resistance changes (due to heating it), which is incorporated in the regulating chip as “software” calculation.
Temperature Control Mode
To accurately detect variations in coil resistance and temperature, the TC-mod needs the points listed below:
- An internal mod’s resistance that is adequately low (compared to the coil’s resistance value and its changes) and steady with temperature, in order for the coil’s resistance variations to be accurately detected/monitored by the mod’s chip.
- An initial coil’s resistance value, accurately measured by the mod (when the coil is cold, the first time you connect your coiled atomizer on the mod) and kept constant.
- A coefficient of the wire’s resistance change with temperature, for the mod’s software to accurately calculate the temperature change in response to the measured coil’s resistance change when heated.
Temperature Coefficient of Resistance
This coefficient (of the wire’s material that expresses how much the wire’s resistance linearly changes with temperature) is the “TCR” (Temperature Coefficient of Resistance), or, synonymously, TFR (Temperature Function of Resistance).
TC-mods provide different factory-preset TCR values (in individual specific TC-modes). For the most common TC-coil types (yes, there are specific types of wire suitable for TC operation and these are Nickel 200, Titanium and Stainless-Steel316). These specific TC functions/operations let you easily use TC effectively (if you’re inexperienced) with no hassle.
But, many TC-mods also allow for a manual adjustment of the TCR directly. These mods let you “play” with TCR values. With TC-mods, you can more accurately adjust how the mod interprets changes in resistance into temperature, thereby providing more precise control over your TC vaping.
This allows you to set up dedicated TC-modes with different wire types or tailor how the temperature control mode operates with the different grades of wire materials available (presenting different TCR values from different manufacturers). The whole thing implies that accuracy is critical for properly setting-up the TC vaping.
I am not in the vaping business. I found vaping as the escape door from my 25 years of smoker’s imprisonment. It just took me four days of attempting to totally get out of it, thanks to the appropriate –for me- “equipment” (includes e-liquids). Now, vaping “equipment” has become another one of my fields of interest, for helping others to discover, on their own, their personally appropriate “equipment”.
I am a hands-on enthusiast… by genes. I am triggered by everything that evokes any data already stored in my knowledge base, been a Physicist and an Electronics Engineer (for more than 35 years). I am intrigued by everything new that my knowledge-filter considers interesting enough to be analyzed for entering into my memory compartment. That’s why you will find me open-minded and out-of-the-box thinking. I have an urge for unfolding hidden “pictures” of design thinking on everything man-made.