DNA40 vs SX350j

[Marc411]

I also own both the dna and the SX.

I use them equally but prefer the SX chip, for me it is more stable and has less "issues". Each chip has it's own quarks. I use them both in TP since I have other mods I vape kanthal on which don't have TP.

The SX consistently picks up a new atty and coil build and has very little refinement. Personally I have never had to press two buttons to find or even lock the resistance in on any topper. There are times when the dna will take a couple times to recognize the TP atty. The dna will also sometimes switch out of TP for no apparent reason, the SX has not had that issue.

I use both Ni200 and Ti G1, both seem to perform better and without problems when I use TI. When using Ti on the DNA the refinement is very similar to the SX, it has very little drift. I am using the early release of both chips and the SX firmware has not been updated on the SX. While I haven't needed to upgrade the firmware that is a positive to the chip.

Bottom line is they both have a valued space in the market and like anything else each person will have a personal preference. Seems a little odd that folks need to be hostile to one another because of their preference.

 

[dr g]

The SX consisitently picks up a new atty and coil build and has very little refinement. Personally I have never had to press two buttons to find or even lock the resistance in on any topper.

This, friends, is case in point about the engineering error.

 

[Yozhik]

Which is "better"? Well which "style" of user interface do you prefer? I don't use either as a laboratory instrument so I did not review error % before buying. I knew what I was getting into when I bought them (basically first gen mass market temp control) and a year from now when version 17.5 or whatever is out there, the whole discussion will be very different. Right now they both work much better for me than what I had before. So I'm satisfied I got my money's worth when buying each of them.

Within a year from now, we may be looking at a thermoresistor (e.g., Nickel) in the atomizer that is coupled to a heating element (e.g., Kanthal) to form a thermocouple (a device that exhibits voltage under the influence of a temperature difference). Or maybe someone will get even more exotic (e.g., a PTC ceramic). At that point, we'll then get to be arguing is it better than the method we use now? Can we still build our own coils somehow with that approach? What type of connector is best (backward-compatible 510 or a different approach)? And so on.

 

[retird]

Don't know much about a thermocouple (thermoresitor) so do they make them that can measure accurate temperature quickly as the temperature will rise several hundred degrees within a second or two? And the cost of such thermocouple (thermoresistor)?

 

[Yozhik]

Don't know much about a thermocouple (thermoresitor) so do they make them that can measure accurate temperature quickly as the temperature will rise several hundred degrees within a second or two? And the cost of such thermocouple (thermoresistor)?

A thermocouple is where two different conductors are coupled to measure a temperature difference. If the temperature at there connection point (e.g., coil) is T1 and the temperature at the base (e.g., 510 connector) is T0, then a measurable voltage (due to the Seebeck effect) can be recorded and temperature accurately estimated.

Thermocouples can measure heat in ms if designed that way. They can also be accurate enough for vaping (up to 1C is the limit on thermocouples generally). Obviously, there is a cost to manufacture an atomizer that will properly connect and isolate the the coil of one conductor from the other conductor. At the base you need an amplifier to measure the voltage arising from the Seebeck effect (it's small). You also need to have a chip or such for temperature measurement at the base as well. Finally, you'll need a good design to switch between heating and measurement (or you could do a kanthal coil with an insulated nickel/kanthal thermocouple running through - this approach makes the atomizer design easier too, but your "510 connector" or whatever now needs to support 4 connections).

Another nice thing about using a thermocouple is that resistance (i.e., length of the conductors) isn't an issue. The formula for the voltage generated by the Seebeck effect is α(T1−T0)−β(T1−T0), where alpha and beta are the Seebeck coefficients of the two different conductors. Nickel and Copper have Seebeck coefficients of -20 microVolts/C and 1.5 microVolts/C, respectively. So at 200 C with a Nickel/Copper thermocouple in a 20 C environment, that would generate about a voltage of -20 (180) - 1.5 (180) = 3.87mV. So if your temp at base is 20 C and you're measuring 3.87 mV there, then you know that the thermocouple is at 200 C. No more worries about refinement or locking resistance.

 

[Mad Scientist]

The SX consistently picks up a new atty and coil build and has very little refinement. Personally I have never had to press two buttons to find or even lock the resistance in on any topper.

Maybe I need to RTFM on the M-class lol. I always press the up/down buttons on the M-class simultaneously until it records the "cold" resistance when swapping attys. Is there some way to get it to recognize an atty swap without doing that?

One thing I really like about the DNA 40 is not having to remember to do that -- it asks me if its a new atty.

 

[Mad Scientist]

Don't know much about a thermocouple (thermoresitor) so do they make them that can measure accurate temperature quickly as the temperature will rise several hundred degrees within a second or two? And the cost of such thermocouple (thermoresistor)?

Any dissimilar metal junction will generate a small voltage if there is a temperature differential with another junction. I did some experiments with this on a coiled wick, must have been over a year or maybe two ago. I'll see if I can find the old thread and post a link.

 

[Mad Scientist]

Don't know much about a thermocouple (thermoresitor) so do they make them that can measure accurate temperature quickly as the temperature will rise several hundred degrees within a second or two? And the cost of such thermocouple (thermoresistor)?

Here it is from 2013:

Temp / Time curve inside an atomizer | E-Cigarette Forum

I used Kanthal twisted to nichrome for the heated junction (cheap, on hand and enought voltage to measure relative temp -- calibrated? Ha ha ha ha . . .). Yup, not too tough to measure temp at the wick.

The experiment was to prove that a well made wick/coil won't get hotter than the phase change temp of eliquid until the wick starts to dry (yeah, in 2013 I had to prove it). But anyway, thermocouple works great for this application.

 

[dr g]

Here it is from 2013:

Temp / Time curve inside an atomizer | E-Cigarette Forum

I used Kanthal twisted to nichrome for the heated junction (cheap, on hand and enought voltage to measure relative temp -- calibrated? Ha ha ha ha . . .). Yup, not too tough to measure temp at the wick.

The experiment was to prove that a well made wick/coil won't get hotter than the phase change temp of eliquid until the wick starts to dry (yeah, in 2013 I had to prove that to folks who refused to believe it). But anyway, thermocouple works great for this application.

I remember these discussions

Though in practice, it is fairly easy and common to overdrive the ability of the wick and liquid to transfer energy away from the coil. One of the first things I tested and learned from TC ...

 

[Mad Scientist]

I remember these discussions

Though in practice, it is fairly easy and common to overdrive the ability of the wick and liquid to transfer energy away from the coil. One of the first things I tested and learned from TC ...

Yes, I remember too -- I learned a lot by discussing with you -- really made me think hard most of the time lol. The experiment was a lot of fun -- I'll have to post up some others at some point.

This old experiment didn't take a lot of factors into account but the concepts greatly improved how I build stuff as one objective method of generating a dataset for evaluating various ideas. In the end, what it tastes like is still the ultimate test lol. I have a good sense of what burnt stuff tastes like -- a lot of experience there lol.

 

[Mad Scientist]

Within a year from now, we may be looking at a thermoresistor (e.g., Nickel) in the atomizer that is coupled to a heating element (e.g., Kanthal) to form a thermocouple (a device that exhibits voltage under the influence of a temperature difference). Or maybe someone will get even more exotic (e.g., a PTC ceramic). At that point, we'll then get to be arguing is it better than the method we use now? Can we still build our own coils somehow with that approach? What type of connector is best (backward-compatible 510 or a different approach)? And so on.

It will be a lot sooner than a year if there is demand. I can sell you one now, if you want

Yup, a different connector is a necessity and rebuilding will require additional skills and materials. The whole concept has a chicken and egg problem -- would you chuck almost all of your existing gear to buy some expensive new "thing" that basically nobody is yet using?

The DNA 40 is a genius idea by using the rtc of nickel so all the old gear still works once you buy a $6 spool of nickel wire. It's not perfect but it's good enough.

 

[Yozhik]

It will be a lot sooner than a year if there is demand. I can sell you one now, if you want

Yup, a different connector is a necessity and rebuilding will require additional skills and materials. The whole concept has a chicken and egg problem -- would you chuck almost all of your existing gear to buy some expensive new "thing" that basically nobody is yet using?

The DNA 40 is a genius idea by using the rtc of nickel so all the old gear still works once you buy a $6 spool of nickel wire. It's not perfect but it's good enough.

The general idea has been around for a long time, just like using nickel by itself for temperature control. Given the industry's growth, we're likely going to see a lot more of these ideas finally become commercialized. The Innokin ITC is an upcoming device that allegedly supports Kanthal in TC. The accompanying iSub TC tank that will come out with the mod has a very thick base and they've not shown anything about its 510 interface, so that could mean that it is a thermocouple-based design.

 

[Mad Scientist]

The general idea has been around for a long time, just like using nickel by itself for temperature control. Given the industry's growth, we're likely going to see a lot more of these ideas finally become commercialized. The Innokin ITC is an upcoming device that allegedly supports Kanthal in TC. The accompanying iSub TC tank that will come out with the mod has a very thick base and they've not shown anything about its 510 interface, so that could mean that it is a thermocouple-based design.

The general idea of using the rtc of a wire coil to measure temperature has been around for a long time but it's implementation in a functional mass produced device had some pretty major bugs worked out like a month ago and people are still complaining about the minor ones.

The mention of a 510 connector and Kanthal highlights the problem. 510 is a long obsolete connector based on the old 510 cigalikes but everyone still uses it. Mention of TC with Kanthal is on a drawing board so all the folks who make and buy Kanthal coiled attys can get in on the new TC wave -- it's not really spectacularly new or innovative; it's to support the old existing.

It's really, really hard to change something that makes the old gear into paper weights.

For thermocouple temp control done right the connector needs 4 contacts, strong enough to support a typical big RTA, simple, reliable , long cycle life, etc. Of course I could be wrong but I don't think that is on anyone's horizon right now. It's not on the horizon because it's different but it's not different enough to motivate the masses to chuck all the existing stuff.

The "next big thing" will be completely disruptive of what we have now. It won't have Kanthal or nickel or titanium or cotton or function like anything most are familiar with. It won't be an incremental improvement because not enough users will toss all their old stuff for incremental improvement.

 

[Jazzman]

It will be a lot sooner than a year if there is demand. I can sell you one now, if you want
QUOTE]

OK. I'll bite. Send me pics, specs, and you're PP invoice. But just to be clear, it needs to be smaller than a Volvo. And if you have a belt holster that would be a nice add on. I know it's a preorder, but I assume I can have this within a couple of weeks right?

 

[Mad Scientist]

You can take delivery within a week. I need a non-disclosure agreement and $100,000. Where do you want it delivered?

 

[Jazzman]

You can take delivery within a week. I need a non-disclosure agreement and $100,000. Where do you want it delivered?

Send the NDA please. And then we'll get to the specs

 

[Quantum Mech]

I also own both the DNA and the SX.

I use them equally but prefer the SX chip, for me it is more stable and has less "issues". Each chip has it's own quarks. I use them both in TP since I have other mods I vape kanthal on which don't have TP.

The SX consistently picks up a new atty and coil build and has very little refinement. Personally I have never had to press two buttons to find or even lock the resistance in on any topper. There are times when the DNA will take a couple times to recognize the TP atty. The DNA will also sometimes switch out of TP for no apparent reason, the SX has not had that issue.

I use both Ni200 and Ti G1, both seem to perform better and without problems when I use TI. When using Ti on the DNA the refinement is very similar to the SX, it has very little drift. I am using the early release of both chips and the SX firmware has not been updated on the SX. While I haven't needed to upgrade the firmware that is a positive to the chip.

Bottom line is they both have a valued space in the market and like anything else each person will have a personal preference. Seems a little odd that folks need to be hostile to one another because of their preference.

Mine don't have any refinement or auto atty recognition

Have to lock in each new coil when its at the same temp as the SX

I need to contact Yihi & see why their upgrade has left this out & my manual is missing that page

Am not happy, I may even have bought a clone

 

[Mad Scientist]

Send the NDA please. And then we'll get to the specs

Here's a photo of an early prototype which I dug out this morning. Your deliverable will be the atomizer of your choice with the drip tip milled at its base so your won't have wires in your mouth in use, coupled with one custom VW mod that controls temp via thermocouple to within an average of 3 degrees C. You'll get the draft NDA upon advice of a letter of credit in my favor from a reputable international bank in the amount of $100,000 payable upon delivery of the mod/atomizer combination (we'd have to work out the details of NDA and L/C conditions but I'm not doing your monkey dance knowing no stranger on an Internet board is likely to pay me that kind of money). If you really are or work for a mod manufacturer and you are actually serious, PM me your phone number and we'll talk. I'd be happy to consult on bringing a practical device to market and yeah, I won't need $100 k up front.

The point remaining, making a temp controlled device that includes accurate thermocouple temp control is not a year out, it's over a year ago. Making a mass produced device that the masses will adopt and is not compatible with any existing stuff is, in my opinion, never.

 

[Mad Scientist]

And now, back to (at least tangentially) the topic of this thread. I know I'm behind the curve with this question but here's what I noticed about the M-class behavior. I forgot (for the thousandth time) to press the two buttons on the M-class to set resistance when changing atomizers. The power it delivered throughout the vape was obviously based on the resistance of the prior atomizer from the last time I set resistance. So it would seem that, at least for the M-class, it does not use real time resistance data to calculate its delivered power. As a result, not only is the temp not accurate on the device, neither is delivered power. Atomizer resistance rises as the coil heats at each vape, so delivered power falls over the course of each vape.

For those "in the know," is this how the M-class works? Does the DNA 40 use the real time resistance data in its power calculation?

 

[Quantum Mech]

And now, back to (at least tangentially) the topic of this thread. I know I'm behind the curve with this question but here's what I noticed about the M-class behavior. I forgot (for the thousandth time) to press the two buttons on the M-class to set resistance when changing atomizers. The power it delivered throughout the vape was obviously based on the resistance of the prior atomizer from the last time I set resistance. So it would seem that, at least for the M-class, it does not use real time resistance data to calculate its delivered power. As a result, not only is the temp not accurate on the device, neither is delivered power. Atomizer resistance rises as the coil heats at each vape, so delivered power falls over the course of each vape.

For those "in the know," is this how the M-class works? Does the DNA 40 use the real time resistance data in its power calculation?

The M class I believe does follow a power curve against the resistance rise

With the wrong starting locked resistance if too low power delivery would be lower & end temp compared to setting

Too high a dry hit may be on its way with more power being sent to the coil & exceeding the TP setting

Something I have not checked is once the atomiser has been locked in does it fire a dead short or below its 0.05 limit

Need to get myself a dna40 to compare still