TC help (again!)

[Deleted member 54254]

My Odin Mini

 

[Simebaby]

Ohms definitely locked, replay turned on and active - let's see how this goes!

 

[Simebaby]

Right. So I had the mod set to 220C, cold ohms were 0.238 and locked, power at 30W. Got a good draw and turned on replay.
Coil is spaced.
All good. The mod was putting out around 15-17W to hit the target temp. Suddenly, power goes up to 26-27W to apparently hit the same temp - though clearly in reality it was much, much hotter. Nothing on the mod had changed, it was literally from one puff to the next.
Let the coil cool for a good 20 minutes and resampled the coil - 0.222 ohms. So I'm guessing that's why the mod suddenly dialled up the power.
Now, the mod is putting out 5-7W to hit 220C. Again, now much colder than the initial setup.
What I don't get is what am I doing wrong? This has happened on all the tanks I've tried it on, and both my DNA mods, with both SS and NiFe30 wire.
I'm guessing this isn't how TC is supposed to work? As it's far more hassle than just running in wattage mode.

 

[Squidgy]

Stumped me, happens on multiple tanks and on different DNA mods! Do you dry burn your coils before wicking? Are the coil legs secured tight? Can you post a picture of your build?

 

[hack400]

It's not surprising that the temperature is colder. This is because the cold ohms has dropped significantly. It is probably more accurate now. The mod doesn't have a clue what temperature the coil is really getting to, it calculates it.

I don't know if it's because the caked on juice reduces the resistance, or if there is something going on with the material, but like I said, I get this same behaviour. If the true resistance drops, it's going to change the TC behaviour.

I do have some SS316L coils. Next build on the coil RTA I'm going to try SS and see if it happens with coils vs. mesh.

 

[Deleted member 54254]

Which mod and what atomiser is it?

 

[Squidgy]

Is 0.016ohm really that significant? It seems to me that the coil/material is not behaving inline with the TCR values when it gets hot. Could be a sus wrap or connection on the coil, maybe.

 

[Simebaby]

Thanks all. I’m inclined to go with @hack400 here - I think the properties of the coil are changing as it’s vaped which is screwing up the TFR values the mod is expecting. Just for info, this attempt was in a (clone) Dvarw MTL FL on a DovPo Top Gear.
It *could* be a sus wrap but this has happened every time I’ve tried TC, all on different attys and with SS316 and NeFi30.
I have very few virtues and patience isn’t one of them , so I’ve binned it off and put a standard build back in for now.
Might have another play at the weekend. It might just be that TC isn’t for me - hardly the worst thing in the world in the grand scheme of things

 

[Deleted member 54254]

Could be down to wicking, you wick TC looser.

 

[hack400]

Thanks all. I’m inclined to go with @hack400 here - I think the properties of the coil are changing as it’s vaped which is screwing up the TFR values the mod is expecting. Just for info, this attempt was in a (clone) Dvarw MTL FL on a DovPo Top Gear.
It *could* be a sus wrap but this has happened every time I’ve tried TC, all on different attys and with SS316 and NeFi30.
I have very few virtues and patience isn’t one of them , so I’ve binned it off and put a standard build back in for now.
Might have another play at the weekend. It might just be that TC isn’t for me - hardly the worst thing in the world in the grand scheme of things

Last night I made a dual coil SS316L build and I have experienced exactly the same behaviour. The cold ohms were reading somewhere in the mid 0.175 area when initially built. After a tank or so the cold ohms had dropped down yo 0.165. By this morning when I did a cold read they had dropped down to 0.160 ohms.

So I have now seen this with mesh and Twisted Clapton (3-28/38) coils.

As I have said before, now that I have sorted the cold ohm, it's working just fine in TC. Just took a while to settle in.