What parameters influence the coil temp?

[VapinSweetZ]

From an article about DNA40:
"some people have assumed that your adjusting the temperature on this chip but that’s not true. You set a temperature limit and then adjust the wattage like normal. With this new chip it’s important to understand that more temperature will not produce more vapor. Temperature plays into how much flavor you get from your e-juice but higher temperature won’t produce more clouds. Vapor production comes from power, the more power you send to the coil the more vapor will be produces. Basically temperature = taste and power = volume."

I'm kinda confused right now, I always thought the only way for us to control the coil temp is by adjusting the wattage.
I'd love to hear a technical explanation.


EDIT: I think I understand it a little bit better thanks to PBusardo's video with Evolv's rep (https://www.youtube.com/watch?v=K8j_Za5RaTU), they show the new DNA40 and it's basically a Temp Limit, so I can only guess that the chip still controls the temp by adjusting the wattage, just lower the wattage when it sense you reached the temp limit.
For some reason Evolv's rep insist to separate wattage from temp like its completely 2 different things, I'm still not really sure about that, it's not like the chip can adjust the airflow on my atty :X

Also, if someone understand why is it necessary to use Nickel wire to measure the temp and why it will not work with Kanthal, it would be great to know.
AFAIK, Nickel heats up and cools down much faster, but I don't see why it's a requirement for the temp limit....


THANKS!

 

[DoubleEwe]

It does not sound right to me.
Whom is the quote from?

The heat is caused by the current flowing through the coils (which is a component of Power), thicker wire needs more current flowing through it to heat up (due to more flow area meaning less collisions). So I do agree with you that adjusting the wattage is how we control temperature. Obviously different wire thicknesses require different amounts of power to 'get hot', hence why the old ohms vs voltage power charts were only useful when using high AWG coils and are totally useless with thicker wire.

Higher temperature will produce more vapour, so I don't have a clue where they are getting their information from. Anyone who has ever cooked anything would realize this, if you turn up the heat then you get more steam (vapour). More heat = more energy available to transfer.

The other factors that do affect coil temp will be airflow (obviously blowing on things cools them) and liquid saturation (heat gets transferred to the liquid).

 

[93gc40]

Higher temps may result in more vapor. True.... BUT from what I have seen more vapor doers not always mean more flavor. Even when Cooking it is possible to COOK the flavor out of foods.

 

[DoubleEwe]

Higher temps may result in more vapor. True.... BUT from what I have seen more vapor doers not always mean more flavor. Even when Cooking it is possible to COOK the flavor out of foods.

Yes, I agree and some flavours seem to 'burn' at higher temperatures. The answer I gave was about vapour production and not anything to do with flavour (as per the OP).

As for the use of Nickel wire rather than Kanthal, I will speculate that it has something to do with either the temperature vs wattage relationship being easier to discern (in agreement with your heats up and cools down quicker) and therefore predict, or it could be that they have mapped the temperature characteristics of Nickel coils at given resistances and they can use that data to apply the correct wattage to create the desired temperatures. Kanthal may be harder to predict?

 

[skoony]

the chips have an amp limit. when wattage is set the chip monitors the temp,and resistance to insure
the chip doesn't go over its rated amperage.
thats the way i understand it.
regards
mike

 

[zoiDman]

Higher temps may result in more vapor. True.... BUT from what I have seen more vapor doers not always mean more flavor. Even when Cooking it is possible to COOK the flavor out of foods.

Don't forget that "Burnt to a Crisp" is a Flavor Also.

And that the Maximum Temperature that a atomizer coil can achieve will Exceed what Most People consider to be a "Good Hit".

 

[readeuler]

As far as why Nickel is necessary for temp control:

All metals change in resistance as their temperature changes. I believe that nickel's resistance changes far more readily than Kanthal. So a 100 degree change in the temp of a nickel wire will change the resistance much more than a 100 degree change in Kanthal wire.

I believe the DNA40 measures the resistance many times each second, and can make a very good guess at the temperature of the wire based on this data.

This is all possible with Kanthal, but it would require a much more precise measurement of the resistance. So precise that it's not feasible at this time.

That's what I've gathered, anyway.

 

[zoiDman]

As far as why Nickel is necessary for temp control:

All metals change in resistance as their temperature changes. I believe that nickel's resistance changes far more readily than Kanthal. So a 100 degree change in the temp of a nickel wire will change the resistance much more than a 100 degree change in Kanthal wire.

I believe the DNA40 measures the resistance many times each second, and can make a very good guess at the temperature of the wire based on this data.

This is all possible with Kanthal, but it would require a much more precise measurement of the resistance. So precise that it's not feasible at this time.

That's what I've gathered, anyway.

That is what I have gathered.

That the DNA40 Doesn't do any Actual Temperature Measurements. It does Temperature Calculations based on a Wires Coefficient of Resistance and the Wattage that the User Chooses.

Here is an Online Calculator that is Fun to Play around with.

Temperature Coefficient of Resistance

 

[K_Tech]

That is what I have gathered.

That the DNA40 Doesn't do any Actual Temperature Measurements. It does Temperature Calculations based on a Wires Coefficient of Resistance and the Wattage that the User Chooses.

Here is an Online Calculator that is Fun to Play around with.

Temperature Coefficient of Resistance

If I understand correctly, that's exactly what the DNA40 does. It reads the change in resistance as power is being applied and starts to throttle back on power to keep resistance at a certain value. That resistance corresponds to your set temperature +/- 10 degrees.

To the OP, I'll rephrase a possibly poor explanation I posted in your other thread.

Think of it like a car with cruise control.

You set the cruise control (temperature limit) for 70 mph (400 degrees). As you go up and down hills, the gas flow to the engine decreases and increases, making power output go up and down to maintain that speed (temperature). Even if your engine is capable of producing 300 horsepower, it's only going to use enough power to maintain the speed. Pretty much the same with the DNA40. It's going to ramp up power initially to get to your set temperature, but once it's there, power output will fluctuate as you vape to maintain temperature.

 

[edyle]

From an article about DNA40:
"some people have assumed that your adjusting the temperature on this chip but that’s not true. You set a temperature limit and then adjust the wattage like normal. With this new chip it’s important to understand that more temperature will not produce more vapor. Temperature plays into how much flavor you get from your e-juice but higher temperature won’t produce more clouds. Vapor production comes from power, the more power you send to the coil the more vapor will be produces. Basically temperature = taste and power = volume."

I'm kinda confused right now, I always thought the only way for us to control the coil temp is by adjusting the wattage.
I'd love to hear a technical explanation.


EDIT: I think I understand it a little bit better thanks to PBusardo's video with Evolv's rep (https://www.youtube.com/watch?v=K8j_Za5RaTU), they show the new DNA40 and it's basically a Temp Limit, so I can only guess that the chip still controls the temp by adjusting the wattage, just lower the wattage when it sense you reached the temp limit.
For some reason Evolv's rep insist to separate wattage from temp like its completely 2 different things, I'm still not really sure about that, it's not like the chip can adjust the airflow on my atty :X

Also, if someone understand why is it necessary to use Nickel wire to measure the temp and why it will not work with Kanthal, it would be great to know.
AFAIK, Nickel heats up and cools down much faster, but I don't see why it's a requirement for the temp limit....


THANKS!

They were able to develop a way to measure the temperature of the nickel wire.
They were not able to develop a way to measure the temperature of kanthal wire.

 

[zoiDman]

They were able to develop a way to measure the temperature of the nickel wire.
They were not able to develop a way to measure the temperature of kanthal wire.

Evolv Didn't develop a way to Measure Resistance Wire Temperature. That has been known for a Long Time. Evolv just implemented it into one of their Boards for Ni200.

They just have well could have Set their Boards to Measure NiChrome 60 or Kanthal A1.

See post #8 if you would like to do Your Own wire temp Calculations.

 

[Alien Traveler]

Good time to start a new thread “Does temperature really important?”
A lot of posts about wicks, length/thickness/diameter of coil, viscosity of juice, etc. will follow.

 

[edyle]

Evolv Didn't develop a way to Measure Resistance Wire Temperature. That has been known for a Long Time. Evolv just implemented it into one of their Boards for Ni200.

They just have well could have Set their Boards to Measure NiChrome 60 or Kanthal A1.

See post #8 if you would like to do Your Own wire temp Calculations.

If it's easy to develop/implement temperature limit for Kanthal A1, I'm sure somebody else will do it and make evolv's dna40 obsolete.

 

[zoiDman]

If it's easy to develop/implement temperature limit for Kanthal A1, I'm sure somebody else will do it and make evolv's dna40 obsolete.

I think what we will see down the road are Boards that have Coil Material Coefficients built into them. So a User can Select what Material they are Using.

A Forward Thinking design would Sample the Coil wire for Different Voltages and then make a Educated Decision about what Parameters should be used to Satisfy a Temperature/Resistance Equation.

 

[edyle]

I think what we will see down the road are Boards that have Coil Material Coefficients built into them. So a User can Select what Material they are Using.

A Forward Thinking design would Sample the Coil wire for Different Voltages and then make a Educated Decision about what Parameters should be used to Satisfy a Temperature/Resistance Equation.

That's all well and good, but you still need a material that has a high enough coeficient of resistivity in order to be usefully measureable.

the temperature coeficient of resistivity for nichrome seems to be 0.0004 (from the link in post#8) which is about 10 times lower than silver, copper, aluminum, tungsten and iron.

 

[zoiDman]

That's all well and good, but you still need a material that has a high enough coeficient of resistivity in order to be usefully measureable.

the coef of res for nichrome seems to be 0.0004 (from the link in post#8) which is about 10 times lower than silver, copper, aluminum, tungsten and iron.

What does it Matter what the Coefficient of Resistance is?

 

[edyle]

What does it Matter what the Coefficient of Resistance is?

Sorry; fixed.
I meant the Temperature Coeficient of Resistivity.
You want something with a high enough Temperature Coeficient of Resistivity.

Presumably, the Nickel that they chose has a much higher Temperature coeficient of resistivity than Kanthal.

 

[Alien Traveler]

I think what we will see down the road are Boards that have Coil Material Coefficients built into them. So a User can Select what Material they are Using.

Temperature coefficient of resistivity of nickel is 15 times higher than that of nichrome, and I think for kanthal it is even lower (compared with nichrome). So I do not think something could be done for kanthal in near future.

 

[zoiDman]

Sorry; fixed.
I meant the Temperature Coeficient of Resistivity.
You want something with a high enough Temperature Coeficient of Resistivity.

Presumably, the Nickel that they chose has a much higher Temperature coeficient of resistivity than Kanthal.

Now that sounds Reasonable.

The Long and the Short of it is a Coil Wire Gets Hot when Electricity goes thru it. Else it Can't Turn an e-Liquid into a Vapor. I Don't see it as a Huge Hurdle to set a Limit to how Hot a Coil Wire can get. Any Coil Wire Material.

And the Concept has been around for a Long Time. I think the Ever Increasing Watts Race to Higher and Higher Levels though has made it more Viable.

 

[zoiDman]

Temperature coefficient of resistivity of nickel is 15 times higher than that of nichrome, and I think for kanthal it is even lower (compared with nichrome). So I do not think something could be done for kanthal in near future.

Could be .