Question about Dual Coil vs Single Coil

[suspectK]

A single coil I'd run at 7-10Watts. A dual coil I have to run over 10Watts. I've even had some flavors that wouldn't work at 15. I don't think I've gotten that high with 1.5 dual coils, but I know I have with 2.5 ohm duals. That extra surface area really can distribute that heat..if only there was a way to keep the top part of the cartomizer wicking as well as the bottom. I like 1.5 ohm dual coils, but I don't use them much because of that reason. I'd rather just use a single 3 ohm carto if I want to get around that same temperature.

 

[Myk]

OK, so slightly off topic here, but it makes more sense than starting a new thread. I'm happy with the amount of vapor I'm getting but would like more heat and TH without lowering my resistance. Would dual coils do this for me?

You don't give enough information. Don't know what you're going from or what you're going to or what you are powering it with.
Generally the opposite is what happens, especially the heat.

 

[suspectK]

You like 1.5Ω singles at 3.24v.
You make a dual with those exact same coil builds, it's not a 1.5Ω resistor as far as the battery is concerned, it is a .75Ω resistor. The voltage remains a constant through the circuit and the coils are a constant, so the voltage to make those 1.5Ω coils satisfy shouldn't change.

3.24v @1.5Ω = 2.16 amps/7w
3.24v @.75Ω = 4.32 amps/14w

Parallel resistance is the reciprocal of the the coils added together.

A 1.5 ohm dual coil:
1/resistance= 1/3+1/3
1/resistance=2/3
Resistance= 3/2= 1.5

EDIT-Sorry, I misread your post myk. I'll leave the formula up as a reference, regardless.

 

[dr g]

Actually I know where it was going and was bowing out. I gave the OP my numbers, I told them what happens around the forum when people jump to duals without the right equipment, I even warned him about what dr did with me when I was having the same questions. If they choose to listen to dr it shouldn't be too expensive of a lesson.

If someone can't increase their power, they will have .... same drain, different performance.

And yes dr g, I know different weights of wire play a part. If you remember (which I'm sure you don't because this seems to be a game you play here with everyone) it was wire weight that you tried to confuse me with, although you were claiming the other direction. Your heavier wire is going to take more to heat up. Time or energy the mah will add up, TNSTAAFL.

Telling you something that is true in all cases, versus telling you something that is true in some or even most cases -- I will pick the first every time (or specify I am telling you the second).

 

[DKP#]

OK, so slightly off topic here, but it makes more sense than starting a new thread. I'm happy with the amount of vapor I'm getting but would like more heat and TH without lowering my resistance. Would dual coils do this for me?

For a given voltage and resistance, a dual coil will be cooler.

Assuming a dual coil is built with the same wire (and has the same total resistance), the dual coil will spread the same power (heat) out over 4 times more area which will be cooler.

With the heat more spread out like that, you can double the voltage (which will double the current) and get 4X more power (total heat) and have no more risk of burning the liquid. (in theory anyway, with the heat spread out like that, the liquid has further to wick).

Its kinda like having a single 10 watt speaker at 8 ohms. It's not very loud but you can't exceed 10 watts or you will blow it, and your stereo is made to power a certain ohm load. If you hook 2 in series, it will double the ohms and if you hook them in parallel, it will half the ohms. Neither is acceptable.
So, make two series (double R) branches with 2 speakers each and then hook the two branches in parallel (1/2 R) to end up back at the resistance of a single speaker.
Now if you didn't adjust the volume, the total loudness is the same but spread out over 4 speakers. BUT, now you can crank the stereo up to 40 Watts without exceeding the speaker ratings.

single:total resistance is R
|
R
|

Dual:total resistance is still R (but can handle 4 times more power)
|
|_
| |
R R
| |
R R
|_|
|
|

I don't have much practical experience with single/dual coil atomizers but I tinker with electronics.
Hope my speaker example made sense.

 

[dr g]

For a given voltage and resistance, a dual coil will be cooler.

Assuming a dual coil is built with the same wire (and has the same total resistance), the dual coil will spread the same power (heat) out over 4 times more area which will be cooler.

Ah but you can't make that assumption.

 

[Rader2146]

In theory, except in practice you need more power to power the higher ohm coils that the battery sees as a lower ohm coil. That means more amps.

I believe the word that you are looking for is principle; "In principle, except in practice..."

The basic laws of electromagnetism have been around for some time now. The theories have long passed.

The problem here is that no one has drawn a line between the electrical side and the thermodynamic side. I'll try not to confuse anyone with the facts...

We all know the coil(s) generates heat. Some might say that the amount of heat generated depends on the type or style of build; ie: single/dual/quad/centuple coil, microcoil, monstercoil, etc, etc. This is 100% wrong. The amount of heat generated is exactly EQUAL to the amount of electrical energy consumed (converted). Meet the Joule. The Joule is used to quantify energy (heat energy in this case), where the Watt is used for for electromotive or mechanical power. Sparing the details of how they are derived, they boil down to:

1 Joule = 1 Watt for 1 second
1 Watt = 1 Joule per second

So if we use 10w as an example, then for every second that we press the fire button: 10 watts of electrical power are converted into 10 joules of heat energy. Period.

DKP...I'm not picking on you, just using your post as a teaching point because it represents a common misconception.

For a given voltage and resistance, a dual coil will be cooler.

Assuming a dual coil is built with the same wire (and has the same total resistance), the dual coil will spread the same power (heat) out over 4 times more area which will be cooler.

A dual coil could be perceived as cooler, but the amount of heat generated is exactly the same (it must be the same, it's the law). The perception comes as you are not inhaling all of the heat that is generated. Some is absorbed by the wick and juice that remains liquid, some is absorbed by the metal of the atomizer, and the remainder is absorbed by the vapor/air mixture that is inhaled. When you add a second coil and wick, you also add additional points of heat absorption.

Now the curveball...the proportion of absorbed (wasted) heat to the amount of heat that is perceived (inhaled) changes as the power increases. In the case of RDA's it is common to get a dual coil to outperform a single coil of the SAME resistance and voltage. Granted, the style of the build plays a BIG part, but once you dive into sub-ohm resistance the scale of wasted heat to inhaled heat is tipped to the other side compared to lower power levels.

 

[Myk]

I believe the word that you are looking for is principle; "In principle, except in practice..."

Perhaps you would be right if we were having a professional or scientific conversation but since this is an internet forum and we are having casual conversation about actual use and not discussing scientific hypothesis, theories or laws, colliquialisms are allowed. I said what I meant and you obviously understood what I meant.
I bet you really would've thrown a fit had I used the more often "TANSTAAFL" with the double negative and all.

On another note, does it ever confuse the begeezes out of you when someone says you remind them of Sheldon Cooper while you look nothing like that television character?

 

[zhentipede]

wahhhhhhhhhhhhhh **crying like a pendejo.... i am now officially con..fhuuz..zed =(

 

[Arnie H]

Thanks for all the info. Very intelligent discussion. I have only wrapped single coils so far, and I think I will stick with it. Perhaps I will try a micro-coil in the future.

 

[Katya]

Why do you insist on confusing the issue for people? You pulled this exact same crap on me when I finally got my head wrapped around what was going on with dual coils. Luckily I had people other than you explaining it to me to go back to.
In real life situations I have NEVER heard of anyone turning down the power on a dual coil, not bought duals or homemade duals.

The OP's example does "lower" the resistance because inside of the 1.5Ω dual coil atty is two 3Ω coils that will need to be treated like they were a 3Ω coil. 1.5 is lower than 3.

My suggestion to the OP is disregard everything dr g has to say on this, he is obviously not trying to help, only to confuse (like usual).
If you can't increase your voltage or you don't like 3Ω coils you will not be happy buying 1.5Ω duals. This can be seen all over this forum with people buying duals when all they have are eGo batteries or some other fixed voltage device.

What he said! ^

And if that's too complex, imagine you're vaping two 3Ω coils attached to one battery at the same time.

You'll get more vapor, but not more heat.

And the drain on the battery doubles. You'll be draining your battery and usiing up your juice at twice the rate of a single 3.0Ω coil.

And that's assuming that your battery can supply the amps needed. If it can't supply the amps, something will have to give, and since you can't changer the resistance--the voltage will drop.

The Ohm's Law can not be defied.

 

[suspectK]

Write a blog if you feel the need to explain physics, and direct period there. If they're interested, they'll read it. No need to overwhelm people that just got 5 posts and/or could be confused or put off and so forth.

 

[Rader2146]

Write a blog if you feel the need to explain physics, and direct period there. If they're interested, they'll read it. No need to overwhelm people that just got 5 posts and/or could be confused or put off and so forth.

That would be a fantastic way to stifle learning. Not to mention unneeded additional work on my part. I do not assume that the reader is intellectually inept based on thier post count. I also don't tailor my posts to an individual poster as I know for every question that gets asked there are many more readers that have the same question but didn't ask. I'll explain things to the best of my ability and if it doesn't come across clear enough for complete understanding then, last I checked, this is an open forum and they can ask for clarification.

Additionally, no one is being forced to read my posts. Don't like what I have to say? Don't care for the depth of technical information. Don't read it. Or.....if you find my posts so offensive that you feel the need to tell me how I should convey the information, then click the link. Then, maybe we can get back to a usefull conversation instead of this useless banter.

 

[Myk]

you feel the need to tell me how I should convey the information

You mean like,

I believe the word that you are looking for is principle; "In principle, except in practice..."

If that ain't the pot calling the kettle black.
I believe the word I'm looking for is "hypocrite".

 

[Rader2146]

So much for a useful conversation.

It is a far stretch to think that I told you to do something. I don't see how any reasonable person makes that connection.

I have no desire for unreasonable people and ad hominem arguments.

 

[LucentShadow]

I'd like to state that Rader2146 and dr g have posted most of the factual information in this thread. Somebody needs to encourage that, even if it doesn't seem helpful to some.

My take on the questions in the Original Post, without specific details that have already been mentioned to some degree. Answers included in red:

I have a question for those more knowledgable than myself in this area.

I see some replacement heads/coils that are listed as dual coil @ 1.5 ohms. So I am wondering what is the difference between a dual coil @ 1.5 ohms and a single coil @ 1.5 ohms?

The difference is that the single coil version is a single 1.5 ohm coil, and the dual coil version is two 3 ohm coils in parallel. Both equal 1.5 ohms of total resistance, and both can have the coil configured in a multitude of different ways, though the dual coil offers more complexity.

Does the dual coil require more power and drain the battery faster?

Using the example in the previous question, both will drain a battery at the same rate if both are run from the same voltage, as they both have the same total resistance. Some may choose to run the dual coil at a higher voltage than the single coil, which would incur a higher drain, just as it would if they ran the single coil at a higher voltage.

Any other pros and cons between them? Vapor production/etc.

This is something that can't really be generalized, IMO. It totally depends upon the design and manufacture of each. There are a multitude of ways that each can be built, and a multitude of factors that can affect performance with each. Unless one is comparing very specific designs for each, there can't be anything better than an opinion that is based upon generalizations that may or may not be true for the product that you may get. There are simply too many products with differing specifications out there, to effectively answer that.

Thanks for the input.

I'd suggest mentioning specific brands and model numbers to any saying anything about single coil vs. double coil designs, though that may be difficult with this market of products, often with dubious origins. Try a couple and see, I say.

 

[suspectK]

Write a blog if you feel the need to explain physics, and direct period there. If they're interested, they'll read it. No need to overwhelm people that just got 5 posts and/or could be confused or put off and so forth.

That would be a fantastic way to stifle learning. Not to mention unneeded additional work on my part. I do not assume that the reader is intellectually inept based on thier post count. I also don't tailor my posts to an individual poster as I know for every question that gets asked there are many more readers that have the same question but didn't ask. I'll explain things to the best of my ability and if it doesn't come across clear enough for complete understanding then, last I checked, this is an open forum and they can ask for clarification.

Additionally, no one is being forced to read my posts. Don't like what I have to say? Don't care for the depth of technical information. Don't read it. Or.....if you find my posts so offensive that you feel the need to tell me how I should convey the information, then click the link. Then, maybe we can get back to a usefull conversation instead of this useless banter.

I'm just going to say this.

 

[suspectK]

What about dual coils on RMS? Stressful on your battery, but I'm going to test it out with some dual coils. Anyone have direct experience between using direct voltage and RMS with dual coils? Bennefit outweighing the negative stress on your battery? Is there a bennefit?

http://www.e-cigarette-forum.com/forum/blogs/rader2146/3499-what-rms.html
One typo..I guess it doesn't have to be, cuz they were talking about watts equaling the "..square, or voltage ÷resistance." Since it's an equation I think "voltage ^2" needs to be there, but actual equations were correct.

Sorry, for derailing. People have been .....ing at me for getting to tech/physics oriented. I took my wrath out on yous.

 

[gdeach]

We are talking heating coils and not light bulbs (and subjective taste also) ....When talking about just Ohm's law all the numbers are set values as stated in other posts. The battery "sees" just one resistor and R total is less then R1 or R2. The voltage remains constant across both and amperage is cumulative..............BUT!!!!!
Heating coils do have a certain need of a start up surge. Any electric motor will draw 5 or 6 times the current at start up that it does while running. Like a car with cold crank amps
That being said I think its a gr8 innovation because you get 8 wraps of wire around each wick in a dual coil, 16 total as compared to 5 or 6 in a single coil. More heating coil surface to boil more juice, and all this at the low Ohms that everyone raves about
Personal experience, battery life is easily 90% of a single coil for me. Juice use? hard to tell cuz I've just recently switched
I've been using the Innokin 16 and love, love, love the performance,

NEW at vaping but Electrically experienced

 

[Zombieslug]

I like 1.5Ω coils. If I was vaping a 3Ω coil I'd have slightly more volts going to it than I do when vaping a 1.5Ω coil.
Making a 1.5Ω dual I can't run it at the same wattage I normally run a 1.5Ω coil. I have to crank it up (nearly double the wattage I'd normally run a single 1.5Ω). I have to do this because it's actually a 3Ω coil I'm trying to heat up which I require more volts to run (it's 2 3Ω coils but electricity doesn't really care about that).

Forgetting about wattage, when using a dual 1.5Ω I have to run it at the same voltage that I'd run a 3Ω coil at. This draws more amps which not all batteries can supply (the battery only sees the total resistance and doesn't care that it's actually 2 3Ω coils).

In theory vapor production is increased. If you're buying a premade dual that should hold true. If you're making your own, IME, that's not always the case.
IME even when vapor production isn't increased flavor production is as long as you're able to push them as if they were the 3Ω coils they are and not the 1.5Ω coil the battery sees.
IME a 1.5Ω dual takes a while to heat up, to speed that up by adding more voltage leads to burning flavors.
IMO dual works out much better at sub-ohm or as low of ohms as your mod can handle.

Now, I've just gotta say that this is THE most straight-forward explanation I have seen in regard to the OP's questions.
ALL of the other feedback (other than useless bickering) adds to a better Understanding of the Principles at Work - but as far as Real World Application, there's a lot of people playing games with semantics/hair-splitting/explaining how THEIR coil-building knowledge and expertise can defy the above plainly-stated post.

Not Everyone blindly clicking around the forum to gain Understanding of Dual Coils vs. Single Coils has the scientific Understanding/Background that others do... and I can say from Personal Experience that MANY posters confuse rather than state what needs to be stated.

Truth is, these charts:


can be seen EVERYWHERE, and are proffered as Gospel/Be-All-End-All explanations.

Yet, when DUAL COILS are introduced to -THE MASSES- it should be Understood that -THE MASSES- don't necessarily Understand how it will effect their .

If I were to simply Follow These Charts - as others have suggested - well... this iClear 30S which reads 2.2oHms on my SVD "should not" go beyond 4.2 Volts or so. -4.5 volts would be "teetering on the brink of danger!"
(same for watts: "8-9.5" entering the zone.
Well... I can barely taste my cold Liquid on this specific 2.2oHm DUAL COIL at 4.2 Volts... or at 8 Watts.

But at 12.5 Watts?:
(for THIS PARTICULAR JUICE in THIS PARTICULAR TANK (iClear 30S) on THIS PARTICULAR MOD (iTaste SVD) with THIS PARTICULAR BATTERY (AW IMR 18650) with MY PARTICULAR VAPE STYLE).

Watts=Power.
On a Pre-Made Tank with a Pre-Made Coil attached:
2.2oHm DUAL COIL requires (and can HANDLE) more Power than a Pre-Made 2.2oHm SINGLE coil.

And Not Everybody Has a Device that puts out more than 4.2 Volts.
(My old eGo-style Halo Triton system regular batteries were 4.2 Volts FULLY-charged,
but quickly went down in Power Output {watts} because the Current Source {known as Voltage - the Force that Pushes the Current} is UNregulated...
and therefore did not supply a continuous level of Force/Pressure/Voltage
-if you will... and I know MANY hair-splitters will enjoy refuting my simplification of this process, but there it is-
to my tanks {which were 2.2oHm SINGLE COIL Resistance} resulting in loss of Vapor/Flavor as the batteries became "tired".

Sooooo... if someone with an UNregulated device were to put a Dual Coil tank on their battery and start ing - they might find it a bit disappointing.
(Don't believe me? Throw an iClear 30S on an eGo-style battery and tell me what you think.)
Just my (LENGTHY) 2 cents.
Have a nice day and Happy ing!