Provari on an Oscope vs Vamo

[PLANofMAN]

Seems to me like this has come to a point where it's one of those you have to try it to believe it things. You can tell a smoker all day about how great vaping is, but in the end, they're going to have to try it to believe it. Same with just about everything else in the world. When it comes to perception, everybody is different That's what we're talking about at this point right, perception of vapor?

Yeah, that pretty much sums it up. At least we're back to discussing it and not just flaming each other.

 

[GrimmTech]

AMEN! Im all for sensible discussion.

 

[Rader2146]

I've been following along for a little while and since things have calmed down a bit (and I was reminded of this thread in another thread), I'll weigh in from an un-bias (I dont own a mainstream VV/WW mod) and scientific view.

There is good relevance to the frequency argument. The word that you all are missing is Joule. It is a measurement of heat defined as:

1 watt x 1 second = 1 joule(J)

First the VAMO (or any other 33Hz mod)
Assumptions:
Set at 4.2V_RMS (50% duty cycle)
2.0Ω Coil

Calculations:
1 second / 33Hz = .030 = 30 milliseconds(ms) cycle time

30ms * 50% duty cycle = 15ms pulse duration

We know the the VAMO fires at 6V during the on time.
(Ohms Law: W=V² / R)

6*6 / 2 = 18w

Now that we have the duration and the power, we can calculate the joules.

18w * 15ms = 270 millijoules(mJ) per pulse.

Provari (or any other DC output)
The Provari's frequency is irrelevant. It's a flat DC voltage with a little bit of ripple to it. We don't have to figure out the pulse time because realistically, there is no pulse. So all we have to do is figure out the output in joules for the same duration and compare it to the VAMO.

Same assumptions:
4.2v and 2.0Ω coil.

(Ohms Law: W=V² / R)
4.2*4.2 / 2 = 8.82

8.82W * 15ms = 132mJ

So we end up with 270mJ per pulse compared to 132mJ over the same duration. If we look at the heat output over the period of a full second they are relatively equal, 9.0J compared to 8.82J (the error is due to 4.2V_RMS not being exactly 50% duty cycle). However, burnt juice, even if only 15ms at a time, is still burnt juice.

By increasing the frequency of a pulsed output device, you are shortening the pulse duration and thus lowering the joules per pulse. You will never get equalization compared to a DC output, but eventually the frequency will be high enough, and the joules per pulse low enough, that you wouldn't be able to tell the difference.

Another interesting note is that as the duty cycle increases (higher voltage/longer pulse duration) the difference in joules between the two devices will decrease. Meaning, by setting both devices at 5.0v the difference in the heat output will be less than if set on 4.2V.

 

[junkman]

I've been following along for a little while and since things have calmed down a bit (and I was reminded of this thread in another thread), I'll weigh in from an un-bias (I dont own a mainstream VV/WW mod) and scientific view.

There is good relevance to the frequency argument. The word that you all are missing is Joule. It is a measurement of heat defined as:

1 watt x 1 second = 1 joule(J)

First the VAMO (or any other 33Hz mod)
Assumptions:
Set at 4.2V_RMS (50% duty cycle)
2.0Ω Coil

Calculations:
1 second / 33Hz = .030 = 30 milliseconds(ms) cycle time

30ms * 50% duty cycle = 15ms pulse duration

We know the the VAMO fires at 6V during the on time.
(Ohms Law: W=V² / R)

6*6 / 2 = 18w

Now that we have the duration and the power, we can calculate the joules.

18w * 15ms = 270 millijoules(mJ) per pulse.

Provari (or any other DC output)
The Provari's frequency is irrelevant. It's a flat DC voltage with a little bit of ripple to it. We don't have to figure out the pulse time because realistically, there is no pulse. So all we have to do is figure out the output in joules for the same duration and compare it to the VAMO.

Same assumptions:
4.2v and 2.0Ω coil.

(Ohms Law: W=V² / R)
4.2*4.2 / 2 = 8.82

8.82W * 15ms = 132mJ

So we end up with 270mJ per pulse compared to 132mJ over the same duration. If we look at the heat output over the period of a full second they are relatively equal, 9.0J compared to 8.82J (the error is due to 4.2V_RMS not being exactly 50% duty cycle). However, burnt juice, even if only 15ms at a time, is still burnt juice.

By increasing the frequency of a pulsed output device, you are shortening the pulse duration and thus lowering the joules per pulse. You will never get equalization compared to a DC output, but eventually the frequency will be high enough, and the joules per pulse low enough, that you wouldn't be able to tell the difference.

Another interesting note is that as the duty cycle increases (higher voltage/longer pulse duration) the difference in joules between the two devices will decrease. Meaning, by setting both devices at 5.0v the difference in the heat output will be less than if set on 4.2V.

Interesting calculations

But your calculations completely omit thermal inertia. You do have the first half of the equation, now bring it home.

 

[rotku]

thermal inertia and millijoules? Man, am I dumb.

 

[Rader2146]

Interesting calculations

But your calculations completely omit thermal inertia. You do have the first half of the equation, now bring it home.

There is no need to figure for the thermal inertia. The "rattlesnake" tells us enough to know that the thermal inertia is low enough to not have any appreciable effect on stabilizing the coil temp. If it did, there wouldn't be a rattlesnake.

But, in the interest of being a good sport...if you find me the thermal conductivity, density, and heat capacity of a specific grade of kanthal, then I will figure the thermal inertia. But what will you do with it then?

 

[zapped]

Interesting posts.

You gave the millijoules for a Provari at 4.2 volts.

What would they be at 4.3 volts?

Reason Im asking is because ANY Provari user can tell you just from trial and error, raising the voltage up or down in .1 volt increments that there is a difference in flavor between 4.2 volt and 4.3 volts.....its slight but becomes even more pronounced the higher up or down you go. If there wasnt a difference we'd never be able to "dial-in" our juices just right.

Many people use this method to get that sweet spot for their juices without ever consulting a wattage chart.

I would be interested in seeing the difference between those two voltages because if its less than the 138 millijoule difference in a Vamo and Provari at 4.2 volts maybe we can finally put this to rest.

 

[junkman]

There is no need to figure for the thermal inertia. The "rattlesnake" tells us enough to know that the thermal inertia is low enough to not have any appreciable effect on stabilizing the coil temp. If it did, there wouldn't be a rattlesnake.

But, in the interest of being a good sport...if you find me the thermal conductivity, density, and heat capacity of a specific grade of kanthal, then I will figure the thermal inertia. But what will you do with it then?

I haven't been able to find the thermal inertia figures, though I did look when this thread was young.

Really, I can't buy the "rattlesnake" stuff is indicative of different coil temperatures, and I have never experienced it on my vamo.

But really, the millijoules calculation without thermal inertia is just the varying coil temperature presumption all over again.

 

[Rader2146]

I haven't seen $1,000,000, but I know it exists. There are plenty of threads and videos that demonstrate the rattlesnake effect. But there are also many reasons why you have not experienced it yet, such as: the condition of your hearing, voltage setting, attachments used, ect. The fact remains that is does exist, and for those of us that can hear it, it clearly demonstrates that thermal inertia has no appreciable effect of stabilizing the coil temp.

However, in the interest of being a good sport ...

The thermal inertia of Kanthal A is 6014.898 J m⁻² K⁻¹ s^−1/2

Building the model to determine the frequency at which the thermal inertia does have an effect on stabilizing the coil temp is on you.

 

[Rader2146]

Interesting posts.

You gave the millijoules for a Provari at 4.2 volts.

What would they be at 4.3 volts?

Reason Im asking is because ANY Provari user can tell you just from trial and error, raising the voltage up or down in .1 volt increments that there is a difference in flavor between 4.2 volt and 4.3 volts.....its slight but becomes even more pronounced the higher up or down you go. If there wasnt a difference we'd never be able to "dial-in" our juices just right.

Many people use this method to get that sweet spot for their juices without ever consulting a wattage chart.

I would be interested in seeing the difference between those two voltages because if its less than the 138 millijoule difference in a Vamo and Provari at 4.2 volts maybe we can finally put this to rest.

I'd have to figure out the duty cycle for the VAMO @ 4.3v to give accurate numbers. I just did a fresh wipe and install on my computer and havent installed Excel yet. I have zero desire to longhand those formulas.

 

[junkman]

I haven't seen $1,000,000, but I know it exists. There are plenty of threads and videos that demonstrate the rattlesnake effect. But there are also many reasons why you have not experienced it yet, such as: the condition of your hearing, voltage setting, attachments used, ect. The fact remains that is does exist, and for those of us that can hear it, it clearly demonstrates that thermal inertia has no appreciable effect of stabilizing the coil temp.

However, in the interest of being a good sport ...

The thermal inertia of Kanthal A is 6014.898 J m⁻² K⁻¹ s^−1/2

Building the model to determine the frequency at which the thermal inertia does have an effect on stabilizing the coil temp is on you.

Can you share your source for the thermal inertia? That would be a good link to have. Although I don't have any idea as to how to apply it at this point, I am sure others could.

And yes, the attachments may have an effect on the "rattlesnake" effect. On my Aga-t, DUD, and other RBAs using 32-28 kanthal, it is not present with my vamo at any wattage setting. Even if it were present, you are making a huge assumption that the "rattlesnake" has anything to do with coil temp, and I don't believe it is a good assumption.

 

[denali_41]

I'm waiting for somebody to say the color is a factor

 

[Rader2146]

Kanthal Info: http://www.kanthal.com/Global/Downl...ting wire and strip/S-KA026-B-ENG-2012-01.pdf

It's not a huge assumption, it's an easy deduction. Juice makes noise as it's converted from liquid to vapor, it takes heat to vaporize the liquid, if there isnt enough heat to vaporize the liquid, there is no noise. So it stands to reason that if you can hear the cycle of noise/no noise, then at some point during the cycle, the coil temp falls below the temp required for vaporization. Meaning that the thermal inertia and latent heat of the wire is not great enough to keep the temp stable.

Since you have never heard the "rattlesnake", this might help...(@28:28 if it doesn't automatically skip to that time)

A PBusardo Review - Smoktech Z-Max V2 - YouTube

 

[Plumes.91]

so how can we sum this thread up in a sentence?

 

[junkman]

Kanthal Info: http://www.kanthal.com/Global/Downl...ting wire and strip/S-KA026-B-ENG-2012-01.pdf

It's not a huge assumption, it's an easy deduction. Juice makes noise as it's converted from liquid to vapor, it takes heat to vaporize the liquid, if there isnt enough heat to vaporize the liquid, there is no noise. So it stands to reason that if you can hear the cycle of noise/no noise, then at some point during the cycle, the coil temp falls below the temp required for vaporization. Meaning that the thermal inertia and latent heat of the wire is not great enough to keep the temp stable.

Since you have never heard the "rattlesnake", this might help...(@28:28 if it doesn't automatically skip to that time)

A PBusardo Review - Smoktech Z-Max V2 - YouTube

Wow, sounds like a Harley. No, I have never heard that from my vamo. Even he indicates that it he heard it on cartos, less so on viva novas, and I would guess nothing on RBA as that is my experience.

If my vamo did that on my RBA I would sell it. If I used cartos and my vamo did that I would sell it too. Since it doesn't on my RBAs, and that is the only thing I use on the VAMO, I am not worried about it at all.

That Kanthal document looks like a good resource - my initial look at it I couldn't find the thermal inertia equation - what page is it on?

 

[Rader2146]

That Kanthal document looks like a good resource - my initial look at it I couldn't find the thermal inertia equation - what page is it on?

The values for the equation are in the document, the equation is not.

Thermal Inertia Primer

Thermal inertia is synonymous with thermal effusivity.

Thermal effusivity - Wikipedia, the free encyclopedia

 

[PLANofMAN]

so how can we sum this thread up in a sentence?

I'll take a stab at it.

The ProVari makes juice taste better than the Vamo, but only at lower voltages; the closer one gets to 5v and above, the less noticeable the differences become.

How's that?

 

[sawlight]

I'll take a stab at it.

The ProVari makes juice taste better than the Vamo, but only at lower voltages; the closer one gets to 5v and above, the less noticeable the differences become.

How's that?

Nice to see you back, have a nice "vacation"? I missed all the fun, must have been a wild thread!

 

[hausmouse]

so how can we sum this thread up in a sentence?

We don't need a sentence we need a word and that word is "stupid." It's time to go make one comparing apples to oranges

 

[PLANofMAN]

Nice to see you back, have a nice "vacation"? I missed all the fun, must have been a wild thread!

It's good to be back.

We don't need a sentence we need a word and that word is "stupid." It's time to go make one comparing apples to oranges

I actually learned a lot about both the ProVari and the Vamo, and how those devices work they way they do through this thread, things I would have never known if this thread hadn't been started.