Wire surface area calculator
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Can you edit the ohms that the mod thinks it has? On my SMOK, I can tell the mod it is seeing more ohms than it really is.
This can only be done within a narrow range (I can't fool the SMOK that a .01 ohm build is a 3 ohm build) but it has the effect of increasing the relative voltage, even though this is not actually a VC mod.
Then I turn down the watts.
I am speculating that your build may need more volts than it is getting?
Sent from my R1 HD using Tapatalk
Hi @-KT-
I mentioned that the DNA250 is well within specification to provide 250watts to this coil in TC mode.
To my limited understanding it is the power (watts) that get the coil vaping. Yes they are a result of a combination of volts and amps, but I don't see volts being a significant factor here.
My belief is that the DNA250 had plenty of power available to provide well over the 140watts I had set the TC at - but the limiting factor was airflow.
In other words I didn't have enough airflow to the coils to allow for extra power provision and still limit the coil temperature to 430F.
The only other significant factor I'm aware of is the juice flow / evaporation / atomisation (is that a word). In this case I was very happy with the wicking and saturisation, so I refer back to the airflow.
To your second point, no, you can't manually adjust the Ohms register on DNA devices. You can lock the Ohms, but I don't know how you could get the false reading prior to locking the Ohms.
To be honest I can't see why you'd want to.
Earlier you mentioned that your mod is running in series mode.
Series means that you are limited to the amperage rating of each your batteries. Three 30 amp batteries in series is still a 30 amp circuit.
In parallel it would be a 90 amp circuit.
Your build takes over 27 amps at .09 ohms at 70 watts. That's just about exactly the actual amperage of a 30 amp battery (10 to 15 percent less than rating).
See:
Ohm's Law calculator
Is it possible that this could be the issue?
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Earlier you mentioned that your mod is running in series mode.
Series means that you are limited to the amperage rating of each your batteries. Three 30 amp batteries in series is still a 30 amp circuit.
In parallel it would be a 90 amp circuit.
Your build takes over 27 amps at .09 ohms at 70 watts. That's just about exactly the actual amperage of a 30 amp battery (10 to 15 percent less than rating).
See:
Ohm's Law calculator
Is it possible that this could be the issue?
Sent from my R1 HD using Tapatalk
The only thing that matters on a regulated mod is keeping within the amp limit of your batteries.
Power \ number of batteries \ minimum voltage of batteries.
The 140watts I had set:
140watts \ 3 batteries \ 3.4v cell cut off = less than 14 amps
ETA - I read the specifications on your mod - they are claiming 50 amp output from 28 amp input. I'm not an EE, but it would be interesting to understand how they did this (capacitors?)
If this is the case, then I agree that you are totally within the capacity of your mod.
Dumb question:
Have you tried a hard reset of the device?
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A buck/boost converter on the board lowers or raises the voltage being delivered on the output from a set voltage entering the circuit on the input side.
Many mods are going to read the resistance of the coil slightly differently, my steampunk consistently reads a bit high, as do a couple of my other mods. I don't manually change the resistance, since as long as it's consistent, the mod can read my coil however it likes to, and then I can adjust using wattage if needed. Even in temp control it's not a huge deal, as since the mod is doing the calculations consistently, I can just adjust ramp up and temperature while still getting a satisfying vape and allowing the mod to read the coil how it wants to. Seems to me doing the reverse process would be much more difficult, and not really worth it, since I'd then have to adjust everything else.
Slight mod differences aren't a big deal. If you are talking about totally wild swings, then it's something else. Also depends on the wire you are using... My SS builds may start out at my target, cold, but as they warm up and anneal, the resistance usually diminishes slightly. But pre-fire for the first time, I'm going to be getting a different resistance once my coil is broken in so I actually build slightly high... But, I think some fluctuation in SS resistance is normal and a property of the wire, though I don't know why I think that, I seem to be the only person talking about it. Perhaps I am doing something wrong...??
To the OP, I don't understand why you are so sure it's the airflow, but if it's not enough I'd imagine you could drill out the holes some, making airflow work better... ??
Good luck,
Anna
Slight mod differences aren't a big deal. If you are talking about totally wild swings, then it's something else. Also depends on the wire you are using... My SS builds may start out at my target, cold, but as they warm up and anneal, the resistance usually diminishes slightly. But pre-fire for the first time, I'm going to be getting a different resistance once my coil is broken in so I actually build slightly high... But, I think some fluctuation in SS resistance is normal and a property of the wire, though I don't know why I think that, I seem to be the only person talking about it. Perhaps I am doing something wrong...??
To the OP, I don't understand why you are so sure it's the airflow, but if it's not enough I'd imagine you could drill out the holes some, making airflow work better... ??
Good luck,
Anna
I thought I had gone to some lengths to explain why I believe the power limiting to be a product of insufficient airflow for the 22g build.
Here's a picture of a Dotmod RDA - it might help explain what I'm talking about.
I could be wrong. If someone provides a better explanation I'm open to hearing it.
I've gone back to my 24g build and I'm very happy with it, so I won't be doing any drilling into the DotMod 's (which I'd consider sacrilege).
If I ever want to try the 22g build again I'll buy a big airflow RDA, there are plenty to choose from.
To your comments on resistance changes to SS coils, I've only got DNA devices so can't speak for others, but I've not seen any resistance movement whatsoever on any of my SS builds.
I used to get a bit of movement with kanthal coils, but I put that down to them being contact coils - are you using spaced coils when building with SS?
I don't glow of dry burn my SS coils and only use them in TC mode, which might also be a factor - I know some people also use SS coils in Power Mode.
Have you looked at your temp, wattage, voltage, resistance, and lots more with Device Monitor in eScribe for the DNA mods. You will have real time data graphed as you vape. Seeing the relationships between wattage, temp set, and voltage can go a long way to helping you understand how they all interact. While it may be true that in a tank with low airflow you can reach a set temp of say 400F without the mod firing to 250W you're referring to. It's the nature of the design of all TC boards.
If you want to use it based on your own wattage selection you can do it in wattage mode. In wattage mode the mod couldn't care less about temp and will deliver the maximum wattage within the boards capabilities. Here's a graph of power output to resistance to help there. It's from the spec paper from Evolv.
If you want to use it based on your own wattage selection you can do it in wattage mode. In wattage mode the mod couldn't care less about temp and will deliver the maximum wattage within the boards capabilities. Here's a graph of power output to resistance to help there. It's from the spec paper from Evolv.
OK - fine, I'll do it if it will make you'll happy, I'm off to vape the 22g in Power Mode..
... I'll be back
... I'll be back
... It hits like a freight train at 90 watts but it's too hot a vape for me.
At 100watts it was popping like a Tommy gun. Didn't taste good at all.
At 120watts it tasted of burnt sugar - horrible - that's as far as I'm prepared to take it.
There was no point at which it tasted as good as the 24g in TC mode - and it gave me an immediate sore throat.
Back to TC mode for me.
At 100watts it was popping like a Tommy gun. Didn't taste good at all.
At 120watts it tasted of burnt sugar - horrible - that's as far as I'm prepared to take it.
There was no point at which it tasted as good as the 24g in TC mode - and it gave me an immediate sore throat.
Back to TC mode for me.
Good to know!
@Caterpillar - I am not familiar with your RBA, but I have seen people take off their drip tips to increase air flow. Just hit from the top of the atty.
If your device draws more watts then you know that's the issue.
Sent from my R1 HD using Tapatalk
Unless I'm completely misunderstanding you, it has nothing to do with airflow. Unless evolv changed their chips, your mod has no idea what kind of atty you're running....nor does it care. Insufficient airflow with cause it to go into temp protection faster but it won't limit your wattage. Your build will. You can drill all the holes you want in that topcap but it'll still limit your wattage based on your build.
Occam's Razor:
Maybe the mod only needs 70 watts to get the coil up to 420 degrees?
Have you tried to see if it draws more watts at 450, 500 degrees, etc?
Maybe the mod only needs 70 watts to get the coil up to 420 degrees?
Have you tried to see if it draws more watts at 450, 500 degrees, etc?
I'm not trying to start arguments or anything.
I legitimately want to help you determine what might be happening here.
I found the formula to determine how many watts are needed to heat steel to a given temperature.
Watts = 0.05 x Lbs of Steel x ΔT (in °F) / Heat-Up Time (in hrs)
The example here is for a .2 ohm build that we want to heat up to 420 degrees in five seconds.
.05 is the first number.
85mm of 22awg is about 220mg
A pound is 453592mg
Thus, 85mm of 22awg weighs .0048 pounds (220/45392)
.0048 is the second part.
Relative temperature increase to 420 from 70 is 350.
350 is the third part.
We will assume the third part is 5 seconds. This works out to .00138 hours.
.00138 is the fourth part.
Watts therefore = (.05 * .0048 * 350 / .00138)
That's = 60.86 watts.
This matches up with the coil calculator for a heat flux of 360.
For four seconds, it would be (.05 * .0048 * 350 / .00111)
That's = 75.6 watts
This matches up with the coil calculator for a heat flux of 360.
Given the above - I don't think the mod is letting you exceed 70 watts. It simply does not need to use that much energy to get your coil to 420 degrees.
LOL - please don't flame me!
;-)
ETA: edited for better math.
I legitimately want to help you determine what might be happening here.
I found the formula to determine how many watts are needed to heat steel to a given temperature.
Watts = 0.05 x Lbs of Steel x ΔT (in °F) / Heat-Up Time (in hrs)
The example here is for a .2 ohm build that we want to heat up to 420 degrees in five seconds.
.05 is the first number.
85mm of 22awg is about 220mg
A pound is 453592mg
Thus, 85mm of 22awg weighs .0048 pounds (220/45392)
.0048 is the second part.
Relative temperature increase to 420 from 70 is 350.
350 is the third part.
We will assume the third part is 5 seconds. This works out to .00138 hours.
.00138 is the fourth part.
Watts therefore = (.05 * .0048 * 350 / .00138)
That's = 60.86 watts.
This matches up with the coil calculator for a heat flux of 360.
For four seconds, it would be (.05 * .0048 * 350 / .00111)
That's = 75.6 watts
This matches up with the coil calculator for a heat flux of 360.
Given the above - I don't think the mod is letting you exceed 70 watts. It simply does not need to use that much energy to get your coil to 420 degrees.
LOL - please don't flame me!
;-)
ETA: edited for better math.
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Yes you are missing the point, but don't worry you seem to be in good company.
With the watts set to 140watts and the TC set to 430F this build was teaching 430F in about half a second and TC was kicking in and reducing the watts to the 60w to 70w range - IF I HAD MORE AIRFLOW THE COILS WOULD COOL MORE EFFICIENTLY AND TC COULD DELIVER MORE POWER
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