E-cigarette technology has been advancing at an incredible pace over the last few years, and it shows no sign of slowing down. Early devices were either mechanical or delivered a constant, regulated voltage to the atomizer. Then came variable voltage mods, which let you fine-tune your vape exactly the way you wanted.
The next upgrade to that was variable power, which did basically the same thing but in a more convenient way – the mod could detect the resistance of your coil, so even if you changed coils it would automatically adjust the voltage to maintain the power output you were looking for.The basic principle behind temperature control is simple.
Instead of selecting the voltage or power output the mod should deliver, you set the temperature you want the atomiser to run at. When you press the fire button the mod monitors the temperature and automatically adjusts power to bring the coil up to that temperature as fast as possible, then keep it there.Do you want to know more about ecigs, come to the ecigs forum.
TC is the next logical step. After all, the temperature of the coil has a huge influence on how your vapour tastes – too hot and it’ll start to taste burned, too cool and your liquid won’t evaporate at all. Meanwhile, the ability of the device to keep the coil at that temperature will affect how much vapour you get. If your amazing wick is delivering more juice than the coil can cope with the temperature will drop. On the other hand if it can’t keep up the temperature will rise rapidly until you get a dry hit – and that isn’t good news. Obviously, if you can set the coil temperature and it then stays constant it’s going to be much easier to get the vape you’re looking for every time.
Working within limits
There are some technical challenges, of course. The biggest one is that mods don’t actually have any way of sensing how hot the coil is. It would be possible to build an atomiser with a temperature probe built in, which could then send that information to the mod’s chip, but there’s no way to make that work with a standard 510 connector – it just doesn’t have enough contacts. A 510 fitting only has the positive centre pin and the negative screw, and they’re both already tied up carrying power to the coil. Temperature control would be a lot less attractive if it meant saying goodbye to all your favourite atomisers because they couldn’t take advantage of it.
Metal is a good conductor of electricity because each atom’s electrons aren’t tightly bound to it. When there’s a voltage difference between each end of the metal the electrons are attracted to the positive terminal and move in that direction, allowing the battery to feed in more electrons through the negative terminal. The electrons can’t move completely freely, though; they do have to push their way through a mass of atoms which are all vibrating slightly.
If the temperature rises there’s more energy in the metal and the atoms vibrate more energetically, so it’s harder for the electrons to force themselves through. In simple vaping terms, the resistance has increased. So your TC mod isn’t actually measuring the coil temperature; it’s measuring the resistance – which all modern mods can do anyway – then tracking how it changes. Unless you’ve frozen your mod to liquid nitrogen temperatures (which we don’t recommend) the relationship between the two is very predictable, so from the increase in resistance the chip can easily work out the increase in temperature.
Purity is a virtue
The chip’s ability to work out what’s happening to the coil has limits, of course. For one thing it can’t, with a few exceptions, tell exactly what the coil is made of. This is a problem, because different metals – and especially alloys, like kanthal – change resistance at different rates as they heat up. For TC to work the coil needs to be made of a pure metal, not an alloy, and not all pure metals are suitable. The first coils suitable for temperature regulation were made of Ni200, a high purity form of heat-treated nickel wire. Ni200 is still the most popular material for these coils, although titanium is now increasingly common. Both of these metals are heat-resistant and have very good conductivity, so they’re ideal for making coils that will stand up to the demands of high-power vaping.
Right now it’s not possible to build a chip that can analyse the coil and tell what kind of wire it’s made from, but it is possible to make one that can recognise one or two specific types based on their electrical characteristics. For example the iStick TC40W can identify a nickel coil, and if it does temperature control mode will be available. Otherwise it will default to VW mode. Many other devices can also detect titanium (Ti) coils, and switch to a TC mode optimised for them.
tags:TC Vaping, vaping ecigs