Watts do not matter. Its all about wire temp. Read on

[Skepticide]

Here's another left-field hypothesis:

Injection of heated air into a volume of fluid. If the air is at or above the vaporization temp of the juice, then it should create vapor on contact.

I imagine an apparatus of this design would end up resembling a water pipe - hot air is introduced at the bottom of the reservoir, and the vapor bubbles out. Probably not very practical (or power efficient), but would be fun to play with.

 

[DrSeuss]

Here's another left-field hypothesis:

Injection of heated air into a volume of fluid. If the air is at or above the vaporization temp of the juice, then it should create vapor on contact.

I imagine an apparatus of this design would end up resembling a water pipe - hot air is introduced at the bottom of the reservoir, and the vapor bubbles out. Probably not very practical (or power efficient), but would be fun to play with.

It would be better to pass the hot air over a wick. Remember, passing heated air through a reservoir means you are trying to heat the whole volume of fluid up to vaporisation temperature.

Raidy explored this idea, some time ago, I can't remember his conclusions. This can work well, it is used successfully in many herb vaporisers, but often seems to require a little preheat time and requires a precise control loop to cope with variation in airflow.

In general, the heater wire, is one of the best methods of heating due to the power density and relative simplicity. But it is a little crude.

 

[Anon63]

I wonder if that would make life easier for those struggling to build a coil, a self pulsing setup?
Or would it make it harder, ie your not going to get it to work unless you can wind a nice coil first?

 

[Anon63]

magnetic induction coils are being used in welding with remarkable results, even under water, you would probably need to be connected to a high amp mains supply though.

 

[Skepticide]

Magnetic induction is worth exploring. Of course it requires massive amperage to weld steel, but at the scale of an e-cig it might be reasonable.

 

[Robber]

very nice thread..some questions:

i understand that more coil touching the wick provides more vape/flavor.
but i'm also interesting in using lower amperage..as a quest for effeciency or something

i'm experimenting with dual coils on a single wick, so in stead of twisting a wire i have 2 wires running side by side.
with 6 wraps (12 coils) on 2mm wick 32 gauge this gives a 2ohm dual.

this provides a nice vape for me at 3.7volt
but the coils need some more time to heat up, so i take 2 or 3 vapes a time

what would be the difference to say this setup and a 28gauge single coil of 2ohm ?
what about using 34gauge dual coil with less wraps, say roughly 4 to get a 2 ohm coil

i assume on 34 gauge it would kick in faster as the wire is thinner ?

an other thing, doesn't the restance of the coil change when it's get hotter ?
and how would this be related to wire thickness ?

 

[jasl90]

If you're looking for for more efficiency (more heat using less power) try switching to a thinner wire gauge.
All other things being held equal (power, ohms & wire alloy), thinner wire gets hotter and gets there faster, than thicker wire.

 

[gdeal]

very nice thread..some questions:

an other thing, doesn't the restance of the coil change when it's get hotter ?
and how would this be related to wire thickness ?

Resistance change is very minor. Typically less than 6% for the temperature range, if you brought the wire to its failure temp. But with cooling factors during vaping, you really cant detect it at all. It you have coils setup with no hot spots it would be less than 2%.

The other factor with round wire to get them to heat faster and hotter is to bring the coils very close together.

 

[cckk]

gdeal,

Great thread. Thank you very much. Its humble offshot is here: http://www.e-cigarette-forum.com/fo...buildable-atomizers-throw-away-ohm-chart.html.

 

[gdeal]

gdeal,

Great thread. Thank you very much. Its humble offshot is here: http://www.e-cigarette-forum.com/fo...buildable-atomizers-throw-away-ohm-chart.html.

Read that thread. Not sure what the OP's theory is. The thread does touch on wire temp, but all the factors effecting wire temp are not cohesively pulled together.

I saw your post. if you are comparing the same atty on two different devices with the same power delivery, it should not vape differently. The question is: are you sure that you were actually comparing the same power levels? Vamo has PWM and the Natural is a mechanical correct?

Did you use a DMM to test for actual voltage being delivered under load in each set up?

 

[jasl90]

Just read that thread myself. I'm with gdeal on this one... There's nothing being discussed that hasn't already been asked and answered many times over. The OP's assertion that confined space, lack of airflow and minimal wicking are the reasons that stock attys can't handle the kind of wattages that get thrown at RBA's, isn't insightful it's just a lack of knowledge.
The actual reason, as has been stated many times before, is wire gauge... Plain and simple.

The cig-alike and eGo type batteries is still the most popular e cig batteries on the market by a very wide margin. Nearly all stock, off the shelf, attys are designed to be compatible those types of batteries. Because these batteries types are very limited in the amount of power they can output their attys have to be able to heat up with very little power. This is accomplished by using very thin wire (at least by RBA standards). It's the use of thin wire that allows them to work on small batteries and its also what causes them to pop when you hit them with the kind of power typically reserved for thicker wire and RBAs.

 

[Ill_Rev_J]

Just a thought, didn't read through the whole thread bar the first few pages and last two. I'm a noob at vaping, but have some electrical knowledge (I'm an EE tech). It wouldn't be the most efficient in terms of using power for what you want to (heating the coil), but if a person wanted to use lower gauge (i.e. thicker) heating wire, one could always toss in a resistor to the circuit (providing the resistor can dissipate the amount of power it would without melting). E.g. if a person wanted a 1 Ohm coil, using a 0.5 ohm 10 Watt resistor (10W .5 ohm 0.5 ohm Wirewound Resistor: In Stock Buy Now - West Florida Components) would allow a person to only need to wrap roughly half as much, say, 24g coil in order to achieve the same net overall resistance. Problem then is a person would be limited to only 20 W total, and only 10 would be available, as it were, to the heating coil...though it seems to me most good vapes are in the region of 8-10 W anyways, all the other factors notwithstanding.

Just an idea for anyone who might have or build a custom mod that could incorporate said resistor....and careful, at 8-10 W it would get a little warm...

 

[jasl90]

Just a thought, didn't read through the whole thread bar the first few pages and last two. I'm a noob at vaping, but have some electrical knowledge (I'm an EE tech). It wouldn't be the most efficient in terms of using power for what you want to (heating the coil), but if a person wanted to use lower gauge (i.e. thicker) heating wire, one could always toss in a resistor to the circuit (providing the resistor can dissipate the amount of power it would without melting). E.g. if a person wanted a 1 Ohm coil, using a 0.5 ohm 10 Watt resistor (10W .5 ohm 0.5 ohm Wirewound Resistor: In Stock Buy Now - West Florida Components) would allow a person to only need to wrap roughly half as much, say, 24g coil in order to achieve the same net overall resistance. Problem then is a person would be limited to only 20 W total, and only 10 would be available, as it were, to the heating coil...though it seems to me most good vapes are in the region of 8-10 W anyways, all the other factors notwithstanding.

Just an idea for anyone who might have or build a custom mod that could incorporate said resistor....and careful, at 8-10 W it would get a little warm...

There's no reason for anyone to do that... Ever...
Ideally you want your mech mod to have as little resistance as possible. You want to get as much of the battery's power to the coil as possible. If you want to increase the resistance without adding more wire, it makes more sense to move to a higher gauge (thinner) wire.

 

[Ill_Rev_J]

I know, I'm just saying for those who want to be able to use thicker wire in smaller spaces, it COULD be an option, though as I admitted, not very efficient since you'd be effectively wasting half of your battery power.

 

[cckk]

gdeal,

In fact i didn’t bother too much with the concepts by tomzgreat. I followed your ideas and now I’m testing long coils on both RSST and AGA-T2. The preliminary results are very interesting so I’m very glad that someone recommended me your thread.

The same power delivered to the same atomizer produces the same results. A MOD doesn’t matter. It’s obvious. I’m more concerned with the question of the power itself. I discuss that question here: http://www.e-cigarette-forum.com/forum/vamo/446351-vamo-v2-problem-effectiveness-device.html.

As for the digital multimeter I didn’t go so far as you suggested. I even have no idea how could I do that.

Thank you for your kind reply.

 

[gdeal]

gdeal,

In fact i didn’t bother too much with the concepts by tomzgreat. I followed your ideas and now I’m testing long coils on both RSST and AGA-T2. The preliminary results are very interesting so I’m very glad that someone recommended me your thread.

The same power delivered to the same atomizer produces the same results. A MOD doesn’t matter. It’s obvious. I’m more concerned with the question of the power itself. I discuss that question here: http://www.e-cigarette-forum.com/forum/vamo/446351-vamo-v2-problem-effectiveness-device.html.

As for the digital multimeter I didn’t go so far as you suggested. I even have no idea how could I do that.

Thank you for your kind reply.

Ok, I read your thread. I think I understand where your are going here. But you may not be delivering the same power to the atty.

Seems like you came up with an explanation on the effect on the battery for PWM vs. Mech. But my point was just because the VAMO is telling you what your power output is, it may not be "real". The electronics are pushing the device to output at the voltage setting. With the mechanical, you will experience voltage drop based upon additional resistance of the mod/atty/battery added to the measured coil resistance. So while you think you are vaping at the same voltage, you are not. So I was suggesting to measure voltage of the mechanical under load (at the atty terminals while firing the device. This will be anywhere from .2 to .5 volts lower (just an example range of typical voltage drop of mechanical devices), so perhaps that may further assist in your effort. BTW what is a "long coil"?

 

[cckk]

gdeal,

Inspired by your ideas I test my devices with “long coils” – that means the coils using more wraps and producing as a result the higher resistances. In fact I do two things simultaneously:

1. On The Natural with RSST atomizer I compare the taste of the vapor using shorter and longer coils.

2. On VAMO V2 with AGA-T2 atomizer I test the battery voltage drops during vaping the entire 3 ml tank.

I own just one type of the resistance wire: Kanthal D 0.25 mm (30 AWG). You used as the examples two wires: 28 AWG and 32 AWG. So I’m with my wire somewhere in the middle.

● With RSST atomizer which has 3 mm wick hole my 30 AWG wire produces the following resistances:

– 7-wraps coil – 2.5 Ω *
– 6-wraps coil – 2.2 Ω *
– 5-wraps coil – 1.9 Ω *
– 4-wraps coil – 1.6 Ω *
– 3-wraps coil – 1.3 Ω

● With AGA-T2 atomizer which has 2.5 mm wick hole my 30 AWG wire produces the following resistances:

– 7-wraps coil – 2.0 Ω *
– 6-wraps coil – 1.8 Ω
– 5-wraps coil – 1.6 Ω *
– 4-wraps coil – 1.4 Ω

The tolerance of my hand made coils is ±0.1 Ω.

So far I managed to test the setups marked above with the asterisks.

● The Natural with RSST atomizer:

– 7-wraps coil (2.5 Ω) – very smooth, greasy and thick taste.
– 6-wraps coil (2.2 Ω) – smooth, a bit greasy and a bit thick taste.
– 5-wraps coil (1.9 Ω) – aromatic and a bit sharp taste.
– 4-wraps coil (1.6 Ω) – distinctly aromatic and sharp taste.
– 3-wraps coil (1.3 Ω) – not tested so far.

In all cases I used the wick made out of mesh 400 25×35 mm (1×1⅜″) where 25 mm or 1″ is the width of my wick so I use so called “straw wicks”.

The taste at 7 wraps was barely acceptable for me. The taste at 5 wraps seems the best for me.

● VAMO V2 with AGA-T2 atomizer:

– 7-wraps coil (2.0 Ω, preset 3.5 V, No. 1 mode) – it’s possible to vape the entire 3 ml tank using one 18650 3400 mAh battery, the battery voltage drops from 4.0 V to 3.4 V, and it’s possible to charge the battery back to 4.0 V.
– 6-wraps coil (1.8 Ω, preset 3.3 V, No. 1 mode) – not tested so far.
– 5-wraps coil (1.6 Ω, preset 3.1 V, No. 1 mode) – the same result as with 7-wraps coil.
– 4-wraps coil (1.4 Ω, preset 2.9 V, No. 1 mode) – not tested so far (theoretically VAMO doesn’t offer 2.9 V setting).

In both cases I used the wick made out of mesh 400 25×40 mm (1×1½″) where 25 mm or 1″ is the width of my wick.

For the comparison: using VAMO V2 working in No. 2 mode with preset 6.0 W I was unable to vape the entire 3 ml tank, the battery voltage dropped to 3.2 V, and after a few cycles the charger wasn’t able to charge the battery back to 4.2 V. Moreover VAMO used in that configuration with the same battery for a few times worsened it so now it’s possible to charge it merely to 4.0 V. These are the reasons for which I use now VAMO in No. 1 mode and I preset the voltage in order to get the same 6.0 W as before for the comparable results of the tests.

***

According to your suggestion I tested the voltage drop on The Natural.

● When the real battery voltage was 4.1 V the voltage under the load was in the range: 3.7–3.8 V – from 0.3 to 0.4 V lower than the real one.

I tested also the voltage drops on VAMO V2.

● Mode No. 1 – setting the voltage:

voltage set	voltage measured	real average voltage
3.0 V	2.94 V	2.94 V
3.1 V	3.05 V	3.05 V
3.2 V	3.13 V	3.13 V
3.3 V	3.24 V	3.24 V
3.4 V	3.25–3.33 V	3.29 V
3.5 V	3.32–3.40 V	3.36 V
3.6 V	3.42–3.45 V	3.44 V
3.7 V	3.48–3.55 V	3.52 V

So the real voltage is always lower than the set one.

● Mode No. 2 – setting the wattage:

wattage set	voltage counted	voltage measured	average voltage	resistance measured	real average wattage
5.0 W	2.92 V	1.60 V	1.60 V	1.7 Ω	1.51 W
5.5 W	3.06 V	1.75 V	1.75 V	1.7 Ω	1.80 W
6.0 W	3.19 V	1.99–2.00 V	1.99 V	1.7 Ω	2.33 W
6.5 W	3.32 V	2.28–2.45 V	2.37 V	1.6 Ω	3.51 W
7.0 W	3.45 V	2.27–2.36 V	2.32 V	1.6 Ω	3.36 W
7.5 W	3.57 V	2.56–2.70 V	2.63 V	1.7 Ω	4.07 W
8.0 W	3.69 V	3.18–3.56 V	3.37 V	1.7 Ω	6.68 W

I used in these tests 6-wraps coil which has 1.7 Ω resistance but sometimes when I overheat it the resistance drops to 1.6 Ω. So after measuring each voltage I checked the resistance as well.

For the lower voltages VAMO delivers a stable current but for the higher ones the voltage oscillates across some range as I reported that in both tables.

According to the last table the real wattage of the device has nothing in common with the set wattage. So when I tested VAMO setting it to 6.0 W in No. 2 mode the real wattage was about 2–3 W – from two to three times lower than preset one. Taking into consideration that VAMO working in No. 2 mode with preset wattage drains the battery a lot and worsens it over the time I think that both No. 2 mode and the wattage preset are completely useless. In No. 1 mode with the preset voltage the real voltages are much closer to the set ones.

The result for the preset 7.0 W which is lower than the result for 6.5 W isn’t my mistake. VAMO sometimes delivers significantly lower voltage than it should. There’s no rule so the next measure for 7.0 W may be completely different. No. 2 mode and preset wattage are simply completely unreliable.

I’m very glad that you suggested me to perform those tests. Thank you very much for your suggestions. In fact I tested not only The Natural (the mechanical MOD) as you suggested but also VAMO V2 (the electronically controlled MOD). The most interesting are the results for VAMO in No. 2 mode with the preset wattage.

 

[gdeal]

cckk. very thorough analysis. :Thumbs:

Very Interesting results too. I guess you answered the question, "when is a volt not a volt" (it when you use a VW VAMO ) So all that you describe adds a bit more complexity with comparing two devices even with the same atty setup, right?.

I now understand what you mean by long coils.

BTW I wasnt really recommending "long coils", more that lower guage wire provides more surface area for vaporization and when properly tuned can provide a better thermal zone with the batteries we use. And that you really cant compare a stated "sweet spot" because it is meaningless unless you can pass the device to the person next to you and say "try mine".

 

[cckk]

gdeal,

Thanks for the positive feedback.

As you see now my post fits your “Watts do not matter” thread perfectly because in the case of VAMO V2 in No. 2 mode watts don’t matter at all (though some user may believe that they matter something and most users believe that unfortunately).

I know what you recommended. It was a mental shortcut. I can’t write each time two full sentences to reflect your idea perfectly. So I prefer to say: “Long coils which you recommended”.

 

[gdeal]

No problem cckk. Its sometimes hard to read exactly what the other person is saying even thought its right there in print...(at least for me...) That is why I often ask the same question twice differently. But that was a really interesting post you made. Thanks again for doing the tests and sharing it here.

gdeal,

Thanks for the positive feedback.

As you see now my post fits your “Watts do not matter” thread perfectly because in the case of VAMO V2 in No. 2 mode watts don’t matter at all (though some user may believe that they matter something and most users believe that unfortunately).

I know what you recommended. It was a mental shortcut. I can’t write each time two full sentences to reflect your idea perfectly. So I prefer to say: “Long coils which you recommended”.