Mech vs Regulated device - same wattage

[rdeezy74]

I have a question regarding the differences between running a high ohm coil at high watts on a regulated mod vs. running a lower ohm coil at high watts on a mech mod.

Example:

You run a 2 ohm coil on a dna 20 at 20 watts. Your voltage is around 6.3V and your current is about 3.16A.

Conversely, you run a 0.88 ohm coil on a mech with a freshly charged battery at 4.2V, which also gives you 20 watts, but a current of 4.76A.

What are the differences going to be? Which device will perform better at 20 watts? My instinct says that the mech would perform better because of the higher current????

Edit: forget the thing about the mech. I wanna know about the difference between running a high ohm vs low ohm coil at the same wattage, and what effect the increased amps have on the vape.

 

[suspectK]

Regulated beats a mechanical to deliver desired wattage, every time..Boost circuits make up for resistance loss from the battery and mod..

 

[rdeezy74]

yeah, i understand that, I'm more wondering about the amp difference i demonstrated between a high ohm coil and low ohm coil running at the same watts and what effect that has.

 

[BobC]

Thicker/shorter wire will produce more heat at the same voltage/wattage

 

[vapdivrr]

Not sure if you would really notice the difference in the amps, however imo, the difference would be noticed in the flavor and vapor because of the wire gauge. I would think the wire gauges would have to be different in both examples. Imo the best gauge for the .8 coil would be 26g and as an average let's say 9 wraps. Now you really wouldn't use this gauge for the 2 ohm coil because it just would lag to much because of the 20 or so wraps. So most likely you would need to use 30g for the 2 ohm coil. So imo a thicker gauge wire build will produce better flavor and a thicker vape

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[jstjoehere]

Not sure if you would really notice the difference in the amps, however imo, the difference would be noticed in the flavor and vapor because of the wire gauge. I would think the wire gauges would have to be different in both examples. Imo the best gauge for the .8 coil would be 26g and as an average let's say 9 wraps. Now you really wouldn't use this gauge for the 2 ohm coil because it just would lag to much because of the 20 or so wraps. So most likely you would need to use 30g for the 2 ohm coil. So imo a thicker gauge wire build will produce better flavor and a thicker vape

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Thank you. I was wondering how this would be answered.
Also you may want to read the warning of sub ohm that been flashing around ecf.

 

[rurwin]

The total wattage may be the same, but the watts per surface area will be very different. A thin wire has more surface area per unit volume, but of course the volume isn't the same either.

Here's a handy spreadsheet I wrote to investigate: https://dl.dropboxusercontent.com/u/96640124/Coil Efficiency.xls

wire diameter: 0.25mm
coil: 2mm dia 4 turns
resistance: 0.861ohms
driven with: 4.2V 20.5W
power density: 0.9W/mm2


wire diameter: 0.2mm
coil: 2.2mm dia 6 turns
resistance: 2.099 ohms
driven with: 6.5V 20W
power density: 0.7W/mm2

The mech will heat up faster, maybe the VW will put out more vapour.

 

[vapdivrr]

Thank you. I was wondering how this would be answered.
Also you may want to read the warning of sub ohm that been flashing around ecf.

You mean the warnings in the sticky notes? always a very good idea.


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[suspectK]

You can use the same wire gauge for either...same wire gauge -higher resistance will be cooler.. more surface for heat distribution.

Edit- if you use 30awg+ with normal single and dual coils at high wattage, the wire might be meeting its max "rating." Hot-burning kanthal. I don't know if kanthal has a max Watt rating.. I'd look into that if you're curious. I'm not.

 

[rdeezy74]

thanks for the responses. i've been wondering lately what exactly it is that causes more vapor etc. at higher wattages. it seems intuitive, but I'm the kind of person who likes to know why and how. obviously it has something to do with the kanthal heating up more, but i'd never really thought about the extra surface area that results from building a lower ohm coil on a lower gauge kanthal. just looking for explanation behind all this, ya know.

 

[suspectK]

Look into joules law. Calories and heat with relation to electricity.

I'm curious about the difference at the subatomic scale of higher voltage vs higher current at the same wattage with vaping.

 

[WattWick]

I don't own any regulated mods, but that's not stopping me from speculating. Take it for what it's worth. Which is not much at all.

Since a mechanical mod needs a certain resistance to achieve a certain output wattage, I imagine a regulated mod will offer more flexibility in how the coil is made. You can run 20 watts through a thick wire or a thin wire. A lot of wire or very little wire. Resistance would not matter as much with a regulated mod as a mechanical one. Which is one of my pet peeves. The focus on a high-wattage regulated mods ability to do sub-ohm.

(This is of course disregarding the low ohm limitations of many regulated mods. Purely theoretical speculation. Then again... why run low ohms when you can up the voltage?)

 

[suspectK]

(This is of course disregarding the low ohm limitations of many regulated mods. Purely theoretical speculation. Then again... why run low ohms when you can up the voltage?)

I would imagine the low ohm builds offer more heat, but I think most people that get dna or other boost chips use deciohm coils because it's what all the cool kids are doing...after I take a pull from my 0.3ohm dual-wire dual coil build.. why is parallel the term for that? I think that may cause confusion to people trying to understand basic electrical theory..

 

[Chelonian]

low ohms allow a set output from a battery to surpass any readily available regulated, of course.

however, surface area beat wattage every time.

a quad coil 1 ohm dipper setup with 28 gauge on a provari will produce fog banks.

 

[rurwin]

my 0.3ohm dual-wire dual coil build.. why is parallel the term for that? I think that may cause confusion to people trying to understand basic electrical theory..

It's called parallel because the wires are not twisted but are lying parallel to each other. Electrically there is no difference between the two; both parallel wires and twisted wires are in parallel electrically. What you have is a quad coil with each pair of coils occupying the same space.

 

[lavender1742]

Ive always wondered how the vape difference would be with a standard dripper and a battery at its regular vape range which is I believe 3.7v on a mech and a regulated device also at 3.7v. You would think it wouldn't be different but people say it is.

 

[rurwin]

That might be down to the rattlesnake effect. Many VV mods use a fixed high voltage and then pulse it quickly to get the same effect as a lower voltage. The standard frequency to do that is 33Hz, which is fine for normal clearomisers in normal circumstances. The thermal mass of the coil and wick average out the temperature.

However sometimes you can have a build with a low thermal-mass where the hissing from the atomiser can be heard to stutter like a rattlesnake's tail. In that case the 33Hz pulses are not being averaged out by the mass of coil and wick and there is sufficient time between pulses for the coil to cool below the vaporisation temperature.

One supposes if that is the case, that, while the pulse is on, the coil may well be heating up to beyond the point that it should if fed with the correct constant voltage, and that might burn the liquid. There may be subtle taste changes, even if the rattling noise was not heard.

So in certain circumstances, a VV can give you low vapour production and burning, where a mech would not. An efficient dripping coil would probably be one of those circumstances.

Many VV devices now on the market do not have this 33Hz pulse behaviour. The Provari uses 800Hz IIRC, and the DNA and SX chips provide a constant voltage, as does the MVP2.