My thoughts about sub-ohm and latest VV/VW devices...

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dr g

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I'm now thinking about this dna 40 temp control thing. I seems to me that they have entered another variable (temperature) into their equation, which you can fix at your desired level (400 degrees or whatever). So it seems to me that now you can just set your wattage to the maximum 40W and forget it, relying on the chip to be the "cruise control".

Yup you can do exactly that. Depending on the specific build, sometimes you might consider coming down a bit, and also if you want a slower ramp to temperature for whatever reason.
 

Frocket

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This is such a great thread and thanks to RuSerious for taking the time to get it going and his and everyone's responses. Another dumb novice question. Does the Nickel 200 act like a governer? What are it's conductivity properties in regulating coil temperature?
Nickel 200 has an interesting property - as it heats up, the resistance increases. This happens with all resistance wire. Kanthal increases in resistance very slightly as it gets hotter (something like 2% increase at 500 degrees or so). Nickel 200 increases in resistance significantly more (~33% per 100 degrees) as it heats up.

The DNA 40 monitors coil resistance a few hundred times a second. When the resistance increases to a certain limit (whatever the increase for nickel 200 is at the set temp), it reduces power to keep the resistance from going higher.

For example, let's say that a 70 degree temp nickel 200 coil is at 0.15 ohms. Nickel 200 increases in resistance about 33-34% every 100 degrees. That means a 470 degree coil's resistance would be around 0.34 ohms. As soon as the coil hits that resistance, the DNA 40 cuts back on power (wattage) to keep the resistance from going any higher.

So, basically, the nickel 200 itself isn't controlling the temperature, it just becomes more resistive the hotter it gets. Without regulation, it would still continue to get hotter and hotter, same as kanthal. It's just much easier to tell how hot the coil actually is by measuring the resistance. The DNA 40 does this and reduces power (wattage) accordingly.

The big benefit is this - when using temperature control, the DNA 40 will throw maximum power to heat the coil as quickly as possible to the temperature limit, and then keep it there. Cotton begins to scorch around 410-420 degrees, so with max temp set at 400, you could fire a bone dry cotton wick as long as you like, without it burning. As the wick gets dry, you'll get weaker hits, but no dry hits.
 

awsum140

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I still maintain that the DN40 is actually controlling temperature, which is a byproduct of power by controlling power applied. It does sense the resistance, temperature, of the wire to accomplish that. IF the coil remains wet the temperature can be maintained and the power can be ramped up without exceeding the set temperature limit. The problem becomes keeping the coil wet with liquid and is also dependent on air flow. Now that may be "easy" in an RDA or RTA, but we all know that devices other than rebuildables that may not be able to wick well enough will be used on it by people who are not "detail oriented". IF the coil begins to dry out the power will get limited to prevent the coil from going over the set limit. This, to me, is taking VW vaping to a whole new level
 

Katya

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Katya

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VW was like a traditional cruise control; you set a speed and your car goes that speed, but it will still happily crash into the car in front of you.

Temperature control is like adaptive cruise control. You set a speed, but if there's a car in front of you that's going slower than the speed you've set, your car will slow down to match that car's speed.

Now this I understand. :D
 

Katya

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Thanks Katya :thumb:. It's been so long since I read that I had forgotten it was there.

;)

Oh, and Happy Belated! :blush: I hope you had a nice one!

head.gif
 

Ryedan

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;)

Oh, and Happy Belated! :blush: I hope you had a nice one!

head.gif

Thank you! The kids were going to come down with the twins (grandchildren, or 'critters' as I call them ;)) for the weekend but they cancelled so it was just my wife and I. Nice relaxing weekend. We're now stocked up on turkey for a good while too :)
 

Ian444

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As far as I understand, having never used one, the DNA40 behaves like a closed-loop system, in that you can set a target temp and it will adjust the power to maintain that temp. The current VV/VW systems are open loop, and the only way to compare them to a cruise control is a very crude one, like pushing the accelerator down a certain amount and then locking it in place. It won't account for undulations in the road, headwinds or tailwinds, and has no idea if the vehicle goes faster or slower, it is running blind. The DNA40 though is very much like a cruise control because it puts power into the coil and then measures the coil temp and adjusts the power to reach and maintain the target temp. That is what sets it apart from the others and could change the whole vaping game IMO.

It has surprised me how some people don't seem to "get it", I reckon the kids next door, if they started vaping tomorrow, would have no trouble learning to adjust the temperature to get the flavor they liked, and if they wanted more vapor quantity, would start asking questions about how to do it. They probably wouldn't question any of the theory, they would just eventually do what is required to "get that vape".

To me, if this system works as advertised, its a no-brainer. The worst that can happen is you end up with a fully functional DNA40 running kanthal. As a tool to learn the effect of temperature on flavor, and to avoid dry hits, to deliver a consistent vape on a slow draw or a heavy draw, and for fast coil heat-up, I'm really looking forward to it, nothing to lose and lots to gain.
 

rusirius

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Actually... Have you read through those .pdfs?

In the #4 point where he states the most complete result shows approximately 66% water. This one report is... well... compared to the others? It's almost like someone did it in their basement as a high school science project.

First off, the other 3 reports... they all VERY CLEARLY indicate that PG vapor is the largest constituent found in all the tests. These were very controlled and very well done tests... The "vapor" was passed through a charcoal blank and then a solvent was used to extract the components to analyze. That gives a VERY clear picture of what was or wasn't in the vapor and how much of it was there.

On the other hand, this forth report... The 16-3.pdf. Aside from the fact that the original juice they were testing contained both alcohol and water right in the juice itself, look at how they "collected" their sample. If you can't make sense of it, let me explain. Basically they took a test tube with a rubber membrane on top. They then created a hole to stick the ecig in and poked a syringe in there with it. They then continued over and over for 30 minutes to "pump" the syringe. Basically drawing in vapor (AND AIR FROM THE ROOM) into the test tube which was submerged in an ice water bath... This caused the air (and vapor) that was being pumped in and out of this setup to condensate. It was this condensate that was tested for it's contents...

Wait... say what?

So let's think about this... If you go home tonight and repeated this same test... only instead of an ecig sticking in the hole, you put just a plain old tube... repeat the same pumping of the syringe for 30 minutes... What do you think is going to happen? You're going to get a test tube full of WATER... why? Because you're sucking in room temperature air which contains, you guessed it... water... this water is going to condensate...

So as I hope you can see, this test was VERY clearly not intended in ANY way to show the amount of water vapor produced from an ecig. I believe it was more focused on the other contents and realized that the water was simply a by-product of their process.

The other 3 reports were much more controlled and as you can see found almost NO water in their tests.
 
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Aal_

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As far as I understand, having never used one, the DNA40 behaves like a closed-loop system, in that you can set a target temp and it will adjust the power to maintain that temp. The current VV/VW systems are open loop, and the only way to compare them to a cruise control is a very crude one, like pushing the accelerator down a certain amount and then locking it in place. It won't account for undulations in the road, headwinds or tailwinds, and has no idea if the vehicle goes faster or slower, it is running blind. The DNA40 though is very much like a cruise control because it puts power into the coil and then measures the coil temp and adjusts the power to reach and maintain the target temp. That is what sets it apart from the others and could change the whole vaping game IMO.

It has surprised me how some people don't seem to "get it", I reckon the kids next door, if they started vaping tomorrow, would have no trouble learning to adjust the temperature to get the flavor they liked, and if they wanted more vapor quantity, would start asking questions about how to do it. They probably wouldn't question any of the theory, they would just eventually do what is required to "get that vape".

To me, if this system works as advertised, its a no-brainer. The worst that can happen is you end up with a fully functional DNA40 running kanthal. As a tool to learn the effect of temperature on flavor, and to avoid dry hits, to deliver a consistent vape on a slow draw or a heavy draw, and for fast coil heat-up, I'm really looking forward to it, nothing to lose and lots to gain.
This is very true. It will open our eyes to how to use wicking mediums, and how to wick the coil to have the beat coverage. Also airhole placements and size. A lot of things.
 

skoony

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Actually... Have you read through those .pdfs?

In the #4 point where he states the most complete result shows approximately 66% water. This one report is... well... compared to the others? It's almost like someone did it in their basement as a high school science project.

First off, the other 3 reports... they all VERY CLEARLY indicate that PG vapor is the largest constituent found in all the tests. These were very controlled and very well done tests... The "vapor" was passed through a charcoal blank and then a solvent was used to extract the components to analyze. That gives a VERY clear picture of what was or wasn't in the vapor and how much of it was there.

On the other hand, this forth report... The 16-3.pdf. Aside from the fact that the original juice they were testing contained both alcohol and water right in the juice itself, look at how they "collected" their sample. If you can't make sense of it, let me explain. Basically they took a test tube with a rubber membrane on top. They then created a hole to stick the ecig in and poked a syringe in there with it. They then continued over and over for 30 minutes to "pump" the syringe. Basically drawing in vapor (AND AIR FROM THE ROOM) into the test tube which was submerged in an ice water bath... This caused the air (and vapor) that was being pumped in and out of this setup to condensate. It was this condensate that was tested for it's contents...

Wait... say what?

So let's think about this... If you go home tonight and repeated this same test... only instead of an ecig sticking in the hole, you put just a plain old tube... repeat the same pumping of the syringe for 30 minutes... What do you think is going to happen? You're going to get a test tube full of WATER... why? Because you're sucking in room temperature air which contains, you guessed it... water... this water is going to condensate...

So as I hope you can see, this test was VERY clearly not intended in ANY way to show the amount of water vapor produced from an ecig. I believe it was more focused on the other contents and realized that the water was simply a by-product of their process.

The other 3 reports were much more controlled and as you can see found almost NO water in their tests.
there's no real conflict between the the 4 pdf's as any water would have evaporated in the 3 you mention especially
if the solvent had a large evaporation rate relative to water.
 

skoony

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Actually... Have you read through those .pdfs?

In the #4 point where he states the most complete result shows approximately 66% water. This one report is... well... compared to the others? It's almost like someone did it in their basement as a high school science project.

First off, the other 3 reports... they all VERY CLEARLY indicate that PG vapor is the largest constituent found in all the tests. These were very controlled and very well done tests... The "vapor" was passed through a charcoal blank and then a solvent was used to extract the components to analyze. That gives a VERY clear picture of what was or wasn't in the vapor and how much of it was there.

On the other hand, this forth report... The 16-3.pdf. Aside from the fact that the original juice they were testing contained both alcohol and water right in the juice itself, look at how they "collected" their sample. If you can't make sense of it, let me explain. Basically they took a test tube with a rubber membrane on top. They then created a hole to stick the ecig in and poked a syringe in there with it. They then continued over and over for 30 minutes to "pump" the syringe. Basically drawing in vapor (AND AIR FROM THE ROOM) into the test tube which was submerged in an ice water bath... This caused the air (and vapor) that was being pumped in and out of this setup to condensate. It was this condensate that was tested for it's contents...

Wait... say what?

So let's think about this... If you go home tonight and repeated this same test... only instead of an ecig sticking in the hole, you put just a plain old tube... repeat the same pumping of the syringe for 30 minutes... What do you think is going to happen? You're going to get a test tube full of WATER... why? Because you're sucking in room temperature air which contains, you guessed it... water... this water is going to condensate...

So as I hope you can see, this test was VERY clearly not intended in ANY way to show the amount of water vapor produced from an ecig. I believe it was more focused on the other contents and realized that the water was simply a by-product of their process.

The other 3 reports were much more controlled and as you can see found almost NO water in their tests.
there's no real conflict between the the 4 pdf's as any water would have evaporated in the 3 you mention especially
if the solvent had a large evaporation rate relative to water.

moderator,double post.could you remove one/
 
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