Advanced Feature Request: Temperature Overshoot/Underrun in TC modes

Discussion in 'Suggestions' started by 3l3tric, Jan 15, 2022.

  1. 3l3tric

    3l3tric New Member

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    Hello!

    I'd like to suggest a feature that would be incredibly useful for those using AF devices for various ceramic heating element and convection atomizers. With these atomizers, temperature control modes often either require extended warmup periods or pulsing of the fire button to make sure the material to be vaporized doesn't get too hot. This could be largely solved, however, if there was a setting allowing a "temperature overshoot" at the beginning of a hit, or setting the target temperature of the ecig coil higher temporarily at the start of a hit.

    In essence, the problem with these atomizers is that the coil that we're temp controlling is having to then heat up another medium (the ceramic/air), whose temperature we can't measure. If we just set the heating coil to the desired temperature of the ceramic dish/air, it'll take a fair amount of time for the actual heating medium (ceramic/air) to actually reach that temp, meaning we'll have to deal with extended heat up times in excess of half a minute in some cases. If we instead set the heating coil to a higher temperature, we will reach our desired temp with the heating medium a lot faster, but the heating medium (ceramic/air) will then continue to heat beyond our desired temp, causing the user to have to pulse the fire button to prevent the material from combusting.

    The solution then would be a hybrid of these two options, where the device operates in temp control mode with a "starting temp", then after the coil has been held at the starting temp for some time, the power would be decreased significantly and the temperature setting will be lowered for the remainder of the hit. This would allow for the fast heat up times in the second example above, while also allowing users to take extended hits without concern for overheating the ceramic dish/convection air.

    Now, this would definitely take a lot of guesswork and experimentation to configure for each use case, and this would venture well into the territory of using the "temperature" value more as an arbitrary variable than an actual reflection of the ecig's coil temp. I fully admit this feature would likely have no value to those using their ArcticFox boxes solely for traditional cotton wick and coil vaporizers. However, for those of us using our AF boxes for atomizers where the metal coil is being used to then heat a ceramic dish or other heating medium, this additional feature will allow for even more fine tuning and customization, in the same way that the advanced preheat curves of AF allow for more fine tuning of traditional vaporizers than an absolute preheat.

    I will admit, this feature does already sort-of exist in a roundabout way, in the form of custom Preheat curves, although in that case through limiting the output power at various time points. While this does a good enough job of further diminishing the power later in the hit, the feature I suggest with a primary and secondary temperature would make it easier on the end user to configure this sort of setting, since they could use temperatures they get from testing in normal temp-control modes. For instance, the user could get their desired secondary temperature value by experimenting with the normal TC mode at low temps with extended heat up times, then find their primary temperature by finding the lowest temperature setting in normal TC mode that gives them the heat up times they desire. This process would be easier and clearer than having to set up the custom power curve currently required.

    TL;DR feature request, allow for setting target temp lower at a user-specified time during puff. Not intended for standard ecigs, more intended for ceramic and convection atomizers where there's a lot of delay between the coil heating up and the desired material to be vaporized heating up. Feature is technically already possible but only through workarounds


    EDIT: Quick update with an example of roughly what I mean simulated using the aforementioned curve setting of Preheat. In my case this was a custom curve set to 100% power for the first 6 seconds to account for the initial ramp up time, followed by a sharp drop to 65% power to account for the drop in power output after the coils reached temperature normally, followed by a slow rolloff to 54% power output throughout the remainder of the hit. (20 second timescale for the graph)
    temp curve - Copy.png
    Since this atomizer uses a ceramic heating dish under a titanium bucket, this temperature curve results in the bucket heating to the desired temp more rapidly, then being held there without overheating as the ceramic heating element has the heat backed off gradually. Implementing this using a custom temperature curve required fiddling with the curve 20+ times while taking hits and checking the results in device monitor to finally arrive at this rough desired curve, while trying to implement this same curve with the feature I requested in the above post would simply require setting the starting temp to 510, the final temp to 455, and the switchoff point at ~8 seconds. Note also that other atomizers will require the coil to be held at the starting target temp for much longer than seen in the example image.

    Another element I wanted to clarify: This "temperature overshoot" should have a short timed "relax" feature for when users press the button again after a hit to apply heat for longer, similar to standard preheat relax timers. In this case you wouldn't need an overly long relax timer, likely in the range of 10-20 seconds, since the heating medium in most of these atomizers rapidly heats to below 250 degrees fahrenheit after just a few seconds without heat being applied. If the user does wish to press the fire button again immediately after ending a puff, the new puff should start with the "finishing temperature" from the previous puff, to prevent a sudden spike in heat with the start of the new puff.
     
    #1 3l3tric, Jan 15, 2022
    Last edited: Jan 15, 2022
  2. zelenariba

    zelenariba New Member

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    Simple hack would be to set desired temperature 20% higher for first couple of seconds. This is easily manually set.
    Everything else would be guessing game as far as I understand. To me fiddling with curve is more stressful than setting temperature higher for couple of seconds.
     
  3. brokenforum

    brokenforum New Member

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    Hi! This is OP (Having to use an alternate account, as for some reason I cannot access the login screen despite trying on multiple browsers and devices)

    The "hack" you describe is, if I understand it right, basically the feature I'm requesting. As far as I'm aware, there's currently no way to change the temperature target after you start a puff, and trying to change this value in between puffs with the face buttons on the device would be far too slow and cumbersome to be useful for my purposes. To be clear, I'm using an Rx Mini running build 190624, so maybe this was changed in a later revision? But I haven't seen this change noted on any changelogs I've seen for the mainline or nightly builds.

    If you can actually "easily manually set" the desired temperature higher for a short interval, I'd really appreciate a short guide on how, as the absolute closest I can find to that feature is the hacky workaround use of the preheat curve feature I described in my original post. As described there, that workaround fundamentally pushes the unit into wattage mode for the later duration of the hit, which isn't really ideal. All I really want is the ability to change the temperature target partway through a puff. I think in some other mods this would be called a "temperature curve" but I'm not entirely certain.

    Thanks for your reply, and I really appreciate if you are able to provide instructions for how to set up this feature if it does happen to already be present. Also, to the forum owner, I apologize for having to create a second account just to reply.
     
    #3 brokenforum, Jan 26, 2022
    Last edited: Jan 26, 2022
  4. zelenariba

    zelenariba New Member

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    Im sorry for misleading you. When I say hack I mean "hack". Manually setting temperature higher via mod buttons. Those boards are all lacking temperature sensor that's why this is a guessing game. Afaik those features are rarely implemented.
    Let's just wait for developers answer
     
  5. brokenforum

    brokenforum New Member

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    Ah, I see what you mean now. Unfortunately even with a mod with frontal face buttons that would be too slow for my purposes, as the bucket would cool pretty significantly by the time I managed to set the temp where I'd want it.

    I do hope the developer is able to implement a feature like this. I saw a couple old threads where developers seemed actively against this type of feature due to "defeating the purpose of temperature control", but I don't think anyone's ever brought up this feature in regard to atomizers with ceramic heating elements where "temperature accuracy" is a much more nebulous concept anyway. If implemented, we'd probably be able to cut a few seconds off of heat-up times at the start of cold puffs. Especially with quartz buckets, the current situation where the coil is restricted to only one accurate temp forces you have to choose between 15-20+ second heat ups or absolutely scorching your material with longer puffs.
     
  6. FearAndLawyering

    FearAndLawyering New Member

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    two profiles? a preheat profile and then a regular one
     
  7. widyahong

    widyahong New Member

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    Hi guys,
    1. You can still using preheat (using higher watt in some milli second) when in temperature control mode, set PI range to 100% ~ 1% but dont 0%, 0% will disable preheat and fully drive by PI, Watt, and temperature, when it set to 100% PI only work when target temp reaches.
    2. Or you can using max wattage of your mode, set PI range to 0%, and tuning P and I when connected to pc and use monitoring software in nfetool (harder).
    Please guys correct me if im wrong or out of topic because i dont read all, i used method 2 by the way hehe i love hard way.
     
  8. 3l3tric

    3l3tric New Member

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    As inconvenient as this would be, it sounds like this is honestly my best bet. This wouldn't work too well on my current mod since the +/- buttons are on the bottom and not easy to press mid-puff, but on front panel mods I imagine this method wouldn't work too badly.


    I may be misunderstanding, but it doesn't sound like these methods will get the behavior I want either. It sounds like method 1 would just let me set a higher wattage at the start of the hit, while method 2 I think would cause further issues if I were to get the overshoot working. I've never used PI mode, but as I understand it, the variables you have control over roughly control how sensitively the unit responds to temperature fluctuations and how strongly the unit applies/reduces heat to reach the target temp. It sounds like, then, whatever profile I use to try to set up an initial overshoot would end up having issues bouncing around between higher and lower temps, which isn't really what I want either. For instance, if I set the Integral term in a way that allows the temperature to overshoot its target at the start of the hit, this would invariably result in the temperature overshooting the target multiple times throughout the hit. It seems like method 2 might get me a bit closer to what I want than not using PI reg at all, but I don't think it would be ideal. As I said, I haven't used PI mode before though, so please feel free to correct me if I'm not understanding its behavior right. With how slow replies can be on this forum, I may just mess with it myself and update my findings later.

    Let me explain again the behavior I'm after, this time with a practical example. The "atomizer" I'm trying to use utilizes a metal coil embedded in ceramic as its main heating element, with this ceramic disc heating a bucket made of titanium/quartz which serves as the actual vaporizing surface. As such, although I can get fairly accurate temperature control of the ceramic disc itself, the bucket inherently "lags behind" the temperature of the disc, leading to me either having to choose between slow heatup times or taking short hits to prevent burns on higher temp settings.

    Due to the nature of the ceramic disc design, I can't just push a higher preheat wattage to solve the slow heatup problem. One the bucket has reached the desired temperature, it won't require anywhere near as much heat to maintain that temperature, so I also need the wattage to be able to drop down to a lower value after some time to prevent burning, which makes just setting the temp higher not ideal either. What I want ideally is a way to push the "max" wattage of the temp control profile (in my case, set to 40W) for a short duration of time after the intended target temperature is reached, then after a user-set interval, fall back into standard temperature control behavior. Whatever method the user would have to control this behavior (whether it's setting a time interval to delay active wattage throttling after hitting target temp, or an "overshoot temperature" setting like described in the OP) wouldn't really matter.

    To put it in even shorter terms, imagine that in the normal temp control profile, my mod will take 3.7 seconds using 40W for my coil to hit my desired target temp before throttling the wattage down to around 22W for the duration of the hit to sustain the temperature. The feature I'm asking for would cause the mod to use 40W output for about 5 seconds, then throttle the wattage down until the actual target temperature is reached again, then continue on using around 22W to sustain the set coil temperature.

    Basically, take the point in time where the mod would normally react to the target temperature being reached, and delay the reaction by an amount of time set by the user.

    I'll go mess around with the PI settings a bit and see if I'm able to get this behavior that way