Single Coil vs Dual Coil

[invididual]

So I found the sweet spot (for me) on my VTube at 4.3v on a 3.0 ohm Single Coil cartomizer, and im attempting to outfit my eGo with roughly the same wattage (6.16) so I ordered a 2.0 ohm Single Coil for it as the rough estimations i can find everywhere is that under load it runs around 3.4v (makes the wattage roughly 6.0).

I know on my VTube that single coil is much better, but after all that, my real question is this:

What are the differences between single coil and dual coil and why would one be better on a VV device and one on the fixed voltage device?

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[John D in CT]

Start here; http://www.e-cigarette-forum.com/fo...ined-detail-single-dual-coil-atty-cartos.html

Excellent thread; answers a lot of questions, then raises a few more.

The basics of what I took away from that thread:

1) A dual coil (DC) atty/carto of a given resistance will contain two coils wired in parallel, each of which are twice the resistance (ohms) of the rated ohms of the atty/carto, and each of which will get half as hot as the coil in a single coil (SC) atty/carto of the same resistance (ohms).

Example: a 2.0 ohm DC will be wired with 2 x 4 ohm coils, which in parallel will draw 2.0 ohms, but each of which will heat up about half as much as would a single 2.0 ohm coil. More resistance, less heat. Although that suddenly seems backwards. But I don't think it is.

2) Single coil makes more sense to me than a dual coil for the simple reason that even in a tank, the lower coil will be a little more saturated than the upper coil. Without a tank, the upper coil is almost certain to run too dry much of the time.

***

Open question, and one that I'm going to post in that thread, but will ask here before I forget it:

A) It seems to me that as long as you can keep them surrounded by wet polyfill, or with proper wicking in a carto-less tank, would you not get more total vapor from two separate coils in a single carto than you would from a single coil, assuming each coil gets warm enough to reach the temperature at which a coil best vaporizes juice.

B) If A) is true, and it's also true that each coil in a DC gets about 1/2 as warm as the coil in a SC at the same resistance and at the same voltage, would it not make sense to power the DC at twice the total watts of the SC, making each coil in the DC as warm as the single coil in the SC.

Example:

A) DC 2.0 ohm carto at 4V = 8 watts, each coil drawing 4 watts

B) SC 2.0 ohm carto at 4V = 8 watts, single coil drawing 8 watts. (Coil twice as warm as (A)?)

So, would this (C) give a better vape than (A)?:

C) DC 2.0 ohm carto at 5.6V = 15.68 watts/call it 16, each coil drawing 8 watts. Coils at same (higher) temperature as in (B) = better vape than (A)?

(Yes, this is about 2.85 amps. The ProVari can handle 3.5, so let's leave switch capacity out of it).

Brain ... hurts ... must ... stop ..... now ...

(And a gentle note to prospective respondants to my question; I am so very weary of snarkiness and put-downs, and would really appreciate as much civility as you can muster. I'm just asking a question to try to arrive at a scientifically sound answer. I'm not saying that I know much of anything for sure, so please bear that in mind if you choose to offer your opinion - TIA)

 

[sandscards]

That makes perfect sense to me but I am not an electrical guru. I have asked this question before and not really got an answer I could understand. Your question makes a ton of sense. Let's hope the answer does too.

 

[Slurp812]

If I try to compare my SD MKII (ScrewDriver MKII) with its 18350 battery fully charged, and my Provavi, I notice the same thing. With the same 1.7 ohm carto no matter how low I set the Provari, it still gives me a stronger hit. I have a V1 Provari so the minimum voltage is 3.3. So I can conclude that my SD MKII isnt able to supply even 3.3 volts under load. The question is how much voltage can your Ego (and my SD MKII) really supply under load?

 

[*ASH*]

Nice Information , Know I also know the diferent betwen both.

 

[D. Waterhouse]

The main problem people have with dual coils is that their batterys can't handle the amp draw these things need to work at full power. I love a 1.7ohm DC @ 3.7v but only with an AW IMR high drain battery. I get mine here and they are the only batteries I run anymore.

 

[invididual]

what i got out of the thread you linked is that the only real difference is in heat produced and power draw. a SC produces more heat with less power vs a DC producing less heat with more power (at the same voltage)

Brain ... hurts ... must ... stop ..... now ...

I couldnt agree more.... I get into reading it (not just your post) and about halfway into it everything all starts to blur together lol

 

[tj99959]

Bottom line; a 1.5ohm DCC is the same as having two 3ohm cartos. So in order to get your 6.16 watts you would need to have 4.3 volts.

Another problem with a DCC is figuring the amount of nicotine you are inhaling.
ex: using a 24mg e-liquid in a DCC would be about like using 36-48mg juice in a SCC.

 

[WA3PNT]

Example:

A) DC 2.0 ohm carto at 4V = 8 watts, each coil drawing 4 watts

B) SC 2.0 ohm carto at 4V = 8 watts, single coil drawing 8 watts. (Coil twice as warm as (A)?)

John, the thing you're missing is that though each coil in a Double Coil is only producing 4 Watts of heat, the TOTAL heat from the DC is 8 Watts, the same as the SC, so the heat would be the same.

George

 

[John D in CT]

John, the thing you're missing is that though each coil in a Double Coil is only producing 4 Watts of heat, the TOTAL heat from the DC is 8 Watts, the same as the SC, so the heat would be the same.

George

Too tired to fully contemplate that right now, but I just want to encourage you to read the thread I linked to, which goes into this in great detail, and I think comes to a satisfactory conclusion about this whole issue.

I'll give a better reply tomorrow.

http://www.e-cigarette-forum.com/fo...ined-detail-single-dual-coil-atty-cartos.html

 

[wickedalibi]

Another problem with a DCC is figuring the amount of nicotine you are inhaling.
ex: using a 24mg e-liquid in a DCC would be about like using 36-48mg juice in a SCC.

Daily I use (2) 36mg juices one on a 1.7 single coil @ 3.7 volts, and the other on a 2.0 dual coil @ 4.8 volts. I don't notice any difference in nicotine level. If a juice is 36mg it's 36 mg. Otherwise we could all lower our nic level by using dual coils. I am confused by this statement.

 

[sandscards]

I think he is saying if the dual coils put out much more vapor then you would be inhaling more vapor and therefore inhaling more nicotine with each puff. That makes sense if there is actually that much more vapor with the dual coils. I still have some questions that I haven't sorted out in my mind regarding the single versus dual coil. I use both and am experimenting a little. I am kind of wondering if a juice tastes burnt on a single coil at a certain voltage, it might do better with a dual coil putting out a little more vapor but at a lower temperature. Just trying some different voltages to determine advantages and disadvantages.

 

[RickMc]

I think part of the missing connection here is the fact that it's HEAT that vaporizes juice. Electricity (in watts) is just a mechanism to produce heat, right? So to say that two cooler coils at 4w produces the same amount of vapor that one hotter coil produces at 8w doesn't necessarily have to be so.

Now my head hurts, too....

 

[John D in CT]

I think part of the missing connection here is the fact that it's HEAT that vaporizes juice. Electricity (in watts) is just a mechanism to produce heat, right? So to say that two cooler coils at 4w produces the same amount of vapor that one hotter coil produces at 8w doesn't necessarily have to be so.

Now my head hurts, too....

Yes, I think you have it 100% correct. I would add that as you probably are already thinking but just didn't say, that (IMO anyway) it's not just the amount of vapor, but how the little juice molecules are being excited by the heat, and whether or not they are sufficiently excited to let go of x number of little flavor molecules into the air, as opposed to keeping them locked up in suspension inside the juice; say, bonded to a water molecule, and thereby not happening to bounce off of a particular taste bud, but rather just getting inhaled along with the molecule they're attached to.

I'm curious to know what temperature a coil should be at to properly motivate the average juice, how that temperature varies between flavors and PG/VG ratios and maybe even nic levels, and how many total watts it takes to achieve that temperature, whether on a single or dual coil atomizer/carto - and also how it might vary depending on how well the juice is being delivered to the coil.

In other words; as long as the DeLorean hits the wire travelling exactly 88 MPH at precisely the same moment that the lightning hits the clock tower ... we have nothing to worry about.

 

[LucentShadow]

Bottom line, IMO, is that the dual coil carto has two coils each running at half of the wattage generated in the carto, thereby reducing the risk of burning the juice or the filling around the individual coils. They have twice the wicking, and twice the coil surface area, providing better overall wicking and vapor production, without stressing the coil as much.

The single coil has less overall wicking ability and higher concentrated heat, so it may struggle to pull in the juice fast enough, depending upon the type of carto, juice, and wattage.

I also don't like the fact that one coil is higher in the carto on DCs, and single coils seem to generally work great for me at 7-9 watts. If you're looking to double that wattage, as some like to do, the dual coil carto (with a tank, preferably) and a higher voltage device is the way to go.