The whole (?) truth about TEMPERATURE CONTROL

There are more and more mods with temp control. How does it work? Is it worth to consider? Let's see...

Generally the issue is not easy. Why? Among other things, because:

a) resistance of the temperature wire "floats" along with the temperature. And this is regardless of whether the wire is annealed or not. The changes are quite big - see the diagram taken from NiFe30 wire data sheet:

As you can see we shall forget about once set voltage to get the expected power - electronics have to control and "pump" the voltage all the time.

b) the temperature control system working DRASTICALLY DEPENDS ON WETNESS OF THE WICK. There is no way to measure "dry" wick - the coil will be immediately broken, or the controller immediately will drop the voltage to almost zero. So, the measurements must be done taking into account the saturation of the wick, which raises another problem:

c) smoke detectors :-) most of you probably know what tens of watts can do with a well saturated wick...

Now let's go to the first measurements...

UPDATE: 18.11.2015

IMPORTANT!

Thread starts to be a little illegible, so since now the results will be published on a dedicated website:

TC mods charts
It is in polish but the charts should be understandable.

The PROFESSOR: DICODES Extreme v2 UPDATE: 05.06.2015

Setup was made as microcoil with NiFe30 wire, 0.7 ohm, 30W and 250*C, the oscilloscope was set for longer acquisition time and GO..

Of course on Ni200 wire is same:

 So, here we can see how the temperature control should look like!

And that's it ... actually no, because:

NOTE: as I know, at this moment Extreme v2 is the ONLY mod with regulated temperature coefficient. We can change it within the range 100-650*C and it mens we can use different temperature wires (NiFe, Ni, Titanium, Wolfram, etc.)

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eVic VTC Mini 60W TC 24.09.2015

At first puff:

we can see that is VERY GOOD - no modulation, no oscillations, nice, actually BETTER than DICODES.
Also third puff:

with no comments - quite stable, smooth voltage. Only during 5th puff:

we have a pulse at the beginning, but then is smoothly again. Of course the wick is almost dry.

Generally very handy mod with good TC and very "smooth" voltage shape at VW.

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KOOPOR mini 60W TC 16.09.2015

At first puff:

we can see that is VERY GOOD - no modulation, no oscillations, nice.
Also third puff:

with no comments - quite stable voltage. Only during 5th puff:

chip begins to fight ;-) for keeping the proper temperature. Of course the wick is almost dry. 
Finally, with dry wick, the voltage is cut off:

NOTE: in TC KOOPOR mini has mysterious ;-) work modes: SOFT, NORM, HARD. Below you can see how do they look like:

In my opinion the only difference is in amplitude of first peak...

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iPV 3 Li 05.09.2015

As we can expect in case of Pioneer4you mod:

we have the PWM modulation. But don't panic ;-)  if we look more accurately:

we can see that the voltage generally "keep the level" - interruptions are very short. Then:

the interrupt time extends:

And finally with almost dry wick we have:

  200ms interruption and barely 20 ms of firing - there is no cloud. Of course so it should be :-)


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Cloupor GT 80W TC 19.08.2015

First puff, and at sight we can see:

it is VERY NICE. Voltage waveform is "calm", with very small oscillations and no modulation.

Next it is the same:

And when the wick gets dry:

Cloupor GT cut-off the voltage with no much hesitation.

And that's it! It's probably the shortest test which I've done :-) VERY GOOD!

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Sigelei 75W TC 12.08.2015

It's time to Sigelei, very handy and very solid mod. Let's see what about TC...

As we can see there is quite good: no modulation, only small oscillations unnoticeable during regular vaping. 
At third puff oscillations are a little bigger:

But during fifth one fluctuations return to initial state:

Only at the seventh puff greater battle begins ;-)
 

Interestingly, Sigelei does not give up like most mods at about 1V - there is no cut-off when the voltage drops below 1V. TC still works even though the voltage must drop to the about 0.5V:

 

So we have another very well-made mod with good TC feature.

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Eleaf iStick TC40W 23.07.2015

What can be expected from mod for 30$?? Surely not much... Really? Let's see:

Since first puff we can see that is VERY GOOD! Voltage is regulated smoothly, with no oscillation.
The same is during third puff:

And during fifth puff (and increased observation time) we can see the voltage cut-off after about 10s and dry wick (at ~1V level).

These peaks after cutting off voltage is a standby mode of iStick - it checks every few seconds what is going on with coil:

Thanks to this there is no way to burn dry wick. In some other TC mods it takes some time to cut off the voltage on dry wick, so the wick often burns a little.

So, very cool and neat mod allows to play with the TC for small money.

 (full review soon)

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DNA 40 23.07.2015

 The Progenitor of TC. How it works?

No comments at the beginning with wet wick. Then oscillations appear:

Which fortunately disappear after about 1-2 seconds:

When we look at the voltage in the longer run:

DNA takes about a second to examine what happens to the coil, and then starts to descend smoothly with voltage, and at the time when it comes to 1V cut them completely.

NICE

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iPV 4 10.07.2015

Knowing that the YiHi chip is inside we know what to expect:

 Right, the PWM modulation. Fortunately if we look more accurately:

we can see that with wet wick the PWM is barely noticeable - 20:1. The voltage interrupt is about 1ms every 20ms - unnoticeable.

Of course with drying the wick the interrupt time extends:

 

Now we have 1:5 - the voltage is fired for about 20ms, then we have ~100ms interruption. Of course it is fifth puff and wick is almost dry.

At 7th puff and dry wick we have:

 300ms interruption and barely 20 ms of firing - there is no cloud. So it should be :-)


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SX mini M-class

The first setup was made with 20 joules and 200*C, the oscilloscope was set for longer acquisition time and GO...

What the hack is going on? Let's expand the range and look at the beginning:

It seems that from the very beginning we have the modulation, and unfortunately it lasts:

Hmmm, not so good ...

Well, let's see more accurate. This time I set the temp. to 150*C, to easier observe the regulation. And the wick HASN'T BEEN SATURATING between successive puffs.

Beginning of the first puff:

 
And further:

You can see that with drying of the wick the modulation frequency is getting down, in other words the chip decreases the RMS (effective voltage) to keep the temperature in check - and this is  OK.
The voltage in a little longer time:

You can see that the intervals between pulses are getting longer with the wick drying.

Well, I checked it in many setups and must say: IT WORKS!

But ... WHY THEY USED THE PWM ?? I expected the voltage will be smoothly changed rather than "jumping" like Vamo ...
And this is the fundamental question - how the others do it?

Soon I will test another mods with temperature regulation and will see.

I also have a measurement NiFe30 wire, I'll put them later however there is no big changes in relation to ni200.

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 Now we have The MONSTER ;-) SnowWOLF 200W:

 

 Let's see what is going on with temperature control...



During the first puff everything is OK, wick is wet so the voltage level is stable:

 Then the wick is getting dry but the Wolf copes with it quite well:

 

With the wick drying the modulation appears:
 

Increased when the wick is almost dry:

In my opinion the WOLF is doing better than the SX because it doesn't start so drastic modulation at the beginning.


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