volts/amps/ohms explained in detail on single and dual coil atty/cartos

[schaedj]

Just a couple of quick comments. As to the surface area issue, there is a significant difference in the area in a dual coil versus a single coil. If the gauge of the wire is constant (it typically is), the dual coil has 4 times as much wire surface area (5.0 + 5.0) vs 2.5. This does translate to a direct difference in heat delivery to the juice. Typically, they are arranged vertically, so, as an earlier post indicated, it is a challenge to keep the whole thing wet enough. dc carts have a tendency to burn at the top, since the juice flows downward, and you have to keep them wetter to maintain a good vapor flow. Also, because it is so easy to dry one out, they can often be burning at the top while producing good vapor from the bottom, yuck! The real reason I switched to dual coils is durability. At the same (total system) wattage, assuming you don't burn it up by letting the carto dry out, each section of a dual coil is seeing lower current, and actually heats up less than the single coil. The heat dissipation is the same, but is distributed over 4 times the surface area. In the early days of dc, I couldn't run my GG at 7.2V on a lr atomizer, because it would pop like a fuse the second it ran low on liquid. Switching to the dc, I could still use the low resistance on a higher voltage (producing the wattage output I wanted) without having to carry 4 spares in my pocket to make it through the day. I got used to the volume of vapor (admittedly cooler vapor) that was produced on the dc, and now, it's the experience I expect. To each his own, just letting you know there is actually a real reason someone might choose dc over lr sc.
FYI, I do have the Ody, and I never wrap a dc on it. a single coil at higher resistance actually produces that same level of full vapor I like, and I can drive it harder with a higher voltage. The difference is, I control the gauge and length of wire (Kanthal) I use in the Ody, so I can use heavier gauge wire to give me the combination of resistance and durability I'm looking for.

 

[John D in CT]

There are several major points there with which I strongly disagree, and I'll comment in detail as soon as I can.

Preview:

" ....each section of a dual coil is seeing lower current, and actually heats up less than the single coil. The heat dissipation is the same, but is distributed over 4 times the surface area".

To me, there's an optimum temperature for a coil to be at for a given juice. When you say (correctly) that (at the same voltage) each coil of a dual coil will be cooler than the same voltage to a single coil (effective resistances being equal), I'm not sure it's helpful to say that "heat dissipation will be the same". Yes, the total watts will be the same, but if a single coil at 6 watts gives good vapor and flavor, can the same necessarily be said for two coils that are each producing 3 watts? That seems to be the implication, and I have to think that the answer is essentially "no".

And if a single coil keeps "popping like a fuse", I think that maybe it's being fed too many volts.

 

[schaedj]

And if a single coil keeps "popping like a fuse", I think that maybe it's being fed too many volts.

That's my point. I want the wattage that a LR coil on HV can provide, but can't get it from a LR SC, because the voltage is too high for the coil to handle. To get there, I chose to go with a DC. No, I didn't mean that the vape was identical. There may be an "optimum" temperature for a coil for a single juice, but for me, a lower per coil temperature with the same amount of wattage delivered over a wider area means that I produce fuller, cooler vapor (although the cooler is relative, the vapor at 7.2 V on a dc is still pleasantly warm, without being burning hot, like the vapor from an LR SC (no popping liquid, either). It is a purely personal preference, but there is a noticeable difference, and it happens to be the experience I am shooting for.

 

[John D in CT]

That's my point. I want the wattage that a LR coil on HV can provide, but can't get it from a LR SC, because the voltage is too high for the coil to handle. To get there, I chose to go with a DC. No, I didn't mean that the vape was identical. There may be an "optimum" temperature for a coil for a single juice, but for me, a lower per coil temperature with the same amount of wattage delivered over a wider area means that I produce fuller, cooler vapor (although the cooler is relative, the vapor at 7.2 V on a dc is still pleasantly warm, without being burning hot, like the vapor from an LR SC (no popping liquid, either). It is a purely personal preference, but there is a noticeable difference, and it happens to be the experience I am shooting for.

I'm wondering how you might enjoy the vape on a single coil that is not LR, but rather a higher resistance that could take full advantage of higher voltage, like 7.2V. At 7 ohms, you'd have a little over 7 watts and a good amount of surface area, on a single coil that is immune from the disadvantages you described of two differently-saturated coils; a disadvantage that Ihave stressed for some time.

In addition, and as I'm sure you know with a single coil you'd have the obvious advantage over a dual coil of doubled battery life at a given coil wattage/temperature.

And rather than "fuller" or "cooler", I just shoot for a vape with single coil at the best temperature I can get for a specific juice, and find that a single coil gives me plenty of vapor. I would note that many well-regarded devices use a single coil, among them the Vivi Nova, the GG Odysseus, the Bulli atomizer, and others.