Arizer portable heater tech discussion

Madri-Gal

Child Of The Revolution
FYI all pics have been restored in this thread. I have moved them all to a different image host to make the thread more understandable to read through.

:peace:
Thank you for taking the time to restore the pix. It made reading this thread so much easier and more enjoyable. I feel like I learned a great deal. Thank you again, @Stu .
 

triiosl

New Member
50F? Interesting, I'd always meant to ask...... So that temperature difference is because there's resistance to the heat flow. When designing heat sinks for electronics gear this is a 'degrees C per Watt' number. That is a value of 4 means one Watt causes the device to be four degrees hotter than the HS. If we run 15 Watts we have 60C to deal with and potential issues on standard 70C parts.
 
triiosl,
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OF

Well-Known Member
50F? Interesting, I'd always meant to ask...... So that temperature difference is because there's resistance to the heat flow. When designing heat sinks for electronics gear this is a 'degrees C per Watt' number.

Absolutely heat is flowing in conduction (not convection). As you point out if we measure an 8 degree 'delta' (difference in temperature) across that 'four degrees C per Watt' junction we know automatically that there is 8 Watts (Joules per second) flowing without directly measuring it. Same as Ohm's law gives us a current flow value if we know the voltage and resistance in play.

We measure, with thermocouples, such temperature drops so we know there is heat flow. Heat flow (conduction) is the only way to have a difference in temperature in such cases. If we knew the thermal constant, we'd be able to calculate the magnitude of that flow in Joules per second.

Solo works by conduction, not convection or radiation. It's what the rules of Physics tell us is happening. Much as we might wish it was otherwise?

Regards to all.

OF
 
OF,

Dan B

Active Member
This post was enough for me.

What would you prefer that we call heat energy moving through a fluid from one place to another? Guacamole?:shrug:

To keep semantics at bay, let me ask a simple question that all this really boils down to for me:

During a draw, does the temperature of the herb in the bowl either:

A) Increase?
B) Decrease?

I can show you examples of both. First, the Haze V3, a popular vape here in FCland.
23a.jpg


As you can see, the answer to the question I posed in this case is "B". The incoming air is not hotter than the load, thus cooling it during the draw.

Now contrast that to the Solo:
4.jpg


Clearly the answer to my proposed question is "A" for the Solo. The incoming air is hotter than the load, thus heating it further. This clearly shows guacamole is in play here.

Hey, I just made an entire post without invoking a single "C" word!

:peace:
 

deadlytoaster

Canadian lost in Europe
Yes I'd like to contribute to this hybrid heating discussion, nearly a year since the last post.

Seblamtics semantics, if a vaporizer transfers heat to the load by both means - conduction and convection, then it is in my eyes hybrid.

If for example a bowl temperature is 140c heated via conductive heating and simultaneously a second heating element provides hot air at say 180c, then is it not hybrid as both forms of tech transfer energy to the system?
 
deadlytoaster,
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OF

Well-Known Member
Yes I'd like to contribute to this hybrid heating discussion, nearly a year since the last post.

Seblamtics semantics, if a vaporizer transfers heat to the load by both means - conduction and convection, then it is in my eyes hybrid.

If for example a bowl temperature is 140c heated via conductive heating and simultaneously a second heating element provides hot air at say 180c, then is it not hybrid as both forms of tech transfer energy to the system?

Yes, I think that would qualify, although such convection contribution would be minor indeed. Practical convection vapes heat air much much hotter than that since heated air has very little mass so needs to be quite a lot hotter to contribute much.

Can you point to such a device now available for sale? TIA

OF
 
OF,

nms

Well-Known Member
While it doesn't have a lot of mass, given the heater location on devices like the solo 2(air path), and in other kinds of hybrid heaters particularly in between the time where a draw finishes and the heater shuts off(when it does), there's always a volume of air that gets heated above the oven temperature near heater temp(because the heater always has a bigger temperature than the oven). When you pull this air into the oven air passes through the herb and easily vaporizes(through what is commonly called convection here) the compounds on top of the green matter, which generally have a lot of surface area making heat transfer easier.

On some devices the heater is capable of consistently heating the air in the chamber while on(for example solo 2 heater like showed before has a temperature above 300 ºC and its placement forces air to share a lot of surface area with it, giving it some convection power), giving them the convection like experience. The more time a specific volume of air remains near the heater, the closer it'll get to the heater temperature, meaning slower draws on heaters that are not regulated by flow result in higher temperature air passing through the plant. Some devices the heater only heats the herb chamber, by heating the walls, meaning there is no additional air being heated as you suck the heated air out. Air can never heat beyond the chamber's temperature, because it comes fresh from the outside directly to the chamber. This results in a classic conduction experience, where you need to let the system reach stability before drawing again.

Some heaters on some hybrid devices are not very powerful or very responsive. So these devices rely a lot more on conduction, because either the heater is not hot enough, has enough surface area with the air around it, or takes too long to activate when you start drawing. If the heater cannot consistently heat the air around it above(or near) oven temperature the hot air won't be enough to fully vaporize the compounds.

The ideal safe, while still providing consistent usability, scenario, which the solo 2 excels at, is having the chamber temperature very close to the ideal vaporization temperature, and bring slightly hot air in to vaporize the compounds. Since like said above air's density is small, and as a result so is the heat power it carries, it generally cannot transfer too much heat to the herb. On hybrid devices, since it only needs to slightly increase the temperature, which is already at near vaporization stable temp in the oven, the lack of heating power resulting from the lack of density is compensated by the need to transfer a smaller amount of energy for vaporization.

Full convection devices, usually have MUCH more powerful heaters, and need to heat the air far above vaporization temperature. This has some consequences. The first one is that even heating is impossible, and minor combustion is always likely to happen(I've tried to find the research that I read that backed this up, but I can't, so if someone has seen it please post it, if not, well take it as an unbacked argument because that's what it is because I may have just dreamed of it), as some parts of the plants will absorb most of the heat, particularly the ones closer to the air flux.

Each technology has it's advantages, but convection will generally have a far more targeted effect, while conduction will generally affect the overall mass inside the chamber. I would say that since air flows around the herb, while heating it, it has a higher effect on the surface compounds of the plant, which are mostly terpenes and cannabinoids, giving it the sensation of better flavor, while conduction always heats the whole plant, mixing in different compounds that do not taste as well.

For convection to reach these same compounds, it needs to heat the surface of the plant as air passes through, and then the center of the plant matter by conduction from the outside of it to the inside. Since the oven doesn't get to a stable temperature, this doesn't happen as much, so I assume most of the substances inside the green matter, remain there, as they won't reach the same temperature as a oven does.

I would assume full conduction to be the safest method, as you have guarantees that the temperature never goes above what you need it to go. Hybrids next, and convection vapes safety will be the worst of the bunch, mostly at higher temperatures as I BELIEVE small points will take enough heat to combust, even if it's not noticeable.

I believe the solo 2 has a great balance as shown in the previous graphs, the oven temperature seems perfectly stable, particularly the convection effect of it seems to be highly regulated to the point where it's effective and safe. I wish we could test this on more vapes.

PS: Important to notice, that the density of air is an effect that must be taken into account when taking a measure of heat through a thermistor, and while the relative temperature within the measured values will be correct, a thermistor not meant for measuring air temperatures needs adjutment to deliver the actual temperature at a given point(https://www.researchgate.net/public...low_measuring_devices_for_detecting_hypopneas). Different thermistors/thermocouples also have different uncertainties in different medias.
 
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invertedisdead

PHASE3
Manufacturer
Full convection devices, usually have MUCH more powerful heaters, and need to heat the air far above vaporization temperature. This has some consequences. The first one is that even heating is impossible, and minor combustion is always likely to happen(I've tried to find the research that I read that backed this up, but I can't, so if someone has seen it please post it, if not, well take it as an unbacked argument because that's what it is because I may have just dreamed of it), as some parts of the plants will absorb most of the heat, particularly the ones closer to the air flux.

A convection heater which is inefficient and poorly designed will require much hotter temperatures to heat the air adequately for vaporization. But a good one will not.

Even my homemade vaporizer can vaporize an entire bowl in one inhalation with the heating coil set to 550-600 degrees, that's the absolute hottest part on the entire vaporizer, isolated entirely from the air and vapor path, conducting through glass of all materials: so we know the internal air temperature being produced during a draw is quite a ways below that thermocouple coil reading. This is radically different heating quality from, say, a chinese convection vape that has to heat metal to glowing temperatures to generate a phase change.

For convection to reach these same compounds, it needs to heat the surface of the plant as air passes through, and then the center of the plant matter by conduction from the outside of it to the inside. Since the oven doesn't get to a stable temperature, this doesn't happen as much, so I assume most of the substances inside the green matter, remain there, as they won't reach the same temperature as a oven does.

I find that unlikely as baking temperatures for household goods in a convection oven are always faster than a standard oven. The brownies are done even sooner with convection because heat transfer is improved, not removed.
 

nms

Well-Known Member
A convection oven is a oven regardless, in the same way you'd qualify the solo 2 oven as a convection oven. I'm talking about products where the air is the only thing that heats up during the draw. Once the draw is over so is the source of heat. In this scenario, as soon as the draw stops, so does the heat, meaning that conduction happening in the plant matter from the heat acquired from the hot air happens for a much shorter timespan than say a stable oven where the system's temperature is stable(a convection oven as you describe will even the heating, but the system's temperature is stable).

You are right about design, the more surface area and preferably the more power you can store in a given media, in your case glass, the more heat you can transfer to the air around it. The solo 2 is also a good system, where it forces the air through small area forcing most of the air volume that enters the device to get really close to the ceramic element and as you see both have similar temperatures of operation(and much higher than needed for a pure conduction system, even if you boost the temperature initially to increase heat up time, you don't need to persist it for long periods particularly when not drawing)

I BELIEVE most devices compensate the decreased surface area and thermal capacity(lack of heat 'mass') with increased temperatures.
 
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nms,
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DrJynx86

Well-Known Member
Subbing!

I fried my first SOLO trying to convert it to tabletop while using a spare 12v battery.

Back then I started to replace everything with Arduino + OLED screen, even before the SOLO II, and I always think of coming back to this project, since then having other two SOLOs and an ArGo.

Tomorrow I will scavenge hunt my garage and seek for the missing pieces. I definitely know where the SOLO is, the heater and everything, but the Arduino + OLED might be difficult to find.

Anyway. I hope to post some progress soon!
 

nms

Well-Known Member
Arduinos go around $2-3 nowadays, but without a working device it may be hard to reverse engineer. Connecting a live device to an oscilloscope to see how it heats whatever heater it has(or how it interacts with the heater controller if there is one, same for thermocouple/thermistor) would be a major help and ensure you don't burn the heater as well. Would be fun to actually make a custom low temp(200ºC) in house vaporizer with a 3D printer, ultem and some cheap glass core, plus the cheapo chinese electronics well isolated from the air path.
 
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DrJynx86

Well-Known Member
Arduinos go around $2-3 nowadays, but without a working device it may be hard to reverse engineer. Connecting a live device to an oscilloscope to see how it heats whatever heater it has(or how it interacts with the heater controller if there is one, same for thermocouple/thermistor) would be a major help and ensure you don't burn the heater as well. Would be fun to actually make a custom low temp(200ºC) in house vaporizer with a 3D printer, ultem and some cheap glass core, plus the cheapo chinese electronics well isolated from the air path.

There is nothing to do with the original board on my case because that's fried up, but I had excellent success by using PWM and 9 or 12 volts on the heating element, while probing the temperature with a termocuple and a good tester.

It's really easy to drive the heater, but I'm powering it with a separate 12 v power supply. Reverse engineering the board to keep all the circuitry to charge and use the batteries is extremely well above my skills, and even decapping the SoC and seeing under a microscope it will be impossible without many brains and lots of time, unless some help from Arizer.

Arduino is perfect because as you mention is really cheap and many parts compatible, I'm using a 12v controller board to power up the heater without frying the arduino (different circuits between 3-5v (arduino+OLED) and 12v (heater), and a OLED that's 2x the size of the ArGo, meaning lots more of data for geeks.

For me the best things would be easy of use, easy of getting the components and assembling, cheapness, and also easy of sharing "Custom Firmwares" with different settings (session, duration, power, oled graphics, etc)...
 
DrJynx86,

OF

Well-Known Member
You might consider as a starting point Solo I which I think uses the same heater/sensor.

First thing I'd do is drop the heater voltage back to what happens from a nominal 7.4 Volt battery. Running it at higher voltage also runs up the current meaning the power (product of current and voltage) is even higher still by an alarming amount. By the numbers if it was 18.5 Watts before (based on 2.25 Amps times 7.4 Volts for 18.4 Watts) it becomes 3.65 Amps times 12 Volts for 43.8 Watts, more than twice normal? That can't help things last.....

IIRC the sense is done by a 'thermistor' who is about 10,000 Ohms at room temperature (you can easily find it probing the four leads from the oven), I think this is a PTC (Positive Temperature Coefficient) device, it's resistance goes up with temperature. You can easily test this, monitor the resistance while you apply 7.4 Volts for ten seconds or so. To adapt to Arduino you need only put a current source (resistor in simple applications) in series and sense the voltage across the Thermistor with an analog input. Scale the resistor (current) so the cold and hot voltages are in range.

Solo I and I suspect Solo II are nothing fancy in the control department. A simple setpoint control (full on or off, like your home heater, not proportional) with some hysteresis built in to prevent 'chattering'. I recall measuring a few degrees with Solo I. That is you might switch on when the temperature drops to 388F and off again at 992 seeking 390. Whether it's on or off at 390 exactly depends on if it's heating or cooling. Standard stuff, just like your home thermostat does with the heater for your house. Or the one in your water heater for that matter. There the offset is put in mechanically, with Arduino we might do it in software but more likely by feeding a bit of current to or from the sensor when the heater is on.

We know from experience 'close is good enough', a few degrees is not really important.

The same idea happens in most other conduction vapes, of course. No need for elegant PID or similar systems, we can let it hunt a bit for temperature control.

Regards to all.

OF
 

nms

Well-Known Member
Nevermind
Edit #2: I removed my unbacked claim, but I would think a voltage boost converter to be necessary for the heater to work consistently as the battery degrades, making the judgement on what kind of the heater is there kinda hard to decipher. You can deliver the same amount of 'power' with 12V power supply and 4-2V battery as sources, just not for the same amount of time.
 
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DrJynx86

Well-Known Member
The way I did it back then with the Arduino was using PWM (Pulse Width Modulation) to control a separate 12 v source (to avoid frying the arduino) connected directly to the heater, bypassing all the original SOLO motherboard and components.

PWM lets you fine tune the pulses and duration, for example setting the pulses to 50% of the time will provide 6v if measured with an analog control or scope.

IIRC I think I tried to match the 7.4v back then. In terms of wattage, voltage or amperage, in the end I always measured the temps and cut everything at 200 or 210 trying to match the original settings, as the PWM control makes thing easier, it's all about not abusing the heater and best way is not drive much current as OF recommended, and best way to do it is keep the temps, very cicly, lol.

For me one of the best uses of a slightly bigger OLED screen would be showing a chart of the temperature, battery or session estimated durations, or heck, even a tiny mini game for extra vaping enjoyment.
 

OF

Well-Known Member
Nevermind
Edit #2: I removed my unbacked claim, but I would think a voltage boost converter to be necessary for the heater to work consistently as the battery degrades, making the judgement on what kind of the heater is there kinda hard to decipher. You can deliver the same amount of 'power' with 12V power supply and 4-2V battery as sources, just not for the same amount of time.

It's obviously not necessary to compensate for a degrading battery voltage if the original doesn't? All that happens is the duty cycle changes (the heater is on more seconds per minute as the battery, and therefore power, degrades). If you want to make it stable, it's easy enough to do. Just buffer one of your PWM outputs to deliver the desired voltage (sense that voltage with an analog input with a simple filter). Just don't deliver an average voltage over what it sees 'worst case' (two times 4.2 Volts, 8.4 total). Remember the heater is on for a minute or so heating from cold, but the time it gets the load up to temperature the heater itself could well be toast. It works just fine as designed?

Regards to all.

OF
 

DrJynx86

Well-Known Member
It's obviously not necessary to compensate for a degrading battery voltage if the original doesn't? All that happens is the duty cycle changes (the heater is on more seconds per minute as the battery, and therefore power, degrades). If you want to make it stable, it's easy enough to do. Just buffer one of your PWM outputs to deliver the desired voltage (sense that voltage with an analog input with a simple filter). Just don't deliver an average voltage over what it sees 'worst case' (two times 4.2 Volts, 8.4 total). Remember the heater is on for a minute or so heating from cold, but the time it gets the load up to temperature the heater itself could well be toast. It works just fine as designed?

Regards to all.

OF

On my ArGo, if I put it very close to my ear, I can actually listen a very fast "clicking" sound the PWM makes when heating. The SOLO shows the heating led on and off and I think that one is one second or so per cycle, but I'm sure it's doing a very fast PWM too.

Edit: totally right about not compensating about voltage, it's a tree member ecuation, volts, ampere and wattage. To keep up with the voltage degrading, just rise the amperes, with PWM it's just a matter of more time ON than OFF, a simple solution for something so "random" as heating (each one usage, not physics).
 

Hippie Dickie

The Herbal Cube
Manufacturer
PWM lets you fine tune the pulses and duration, for example setting the pulses to 50% of the time will provide 6v if measured with an analog control or scope.

interesting … i never tried to measure my PWM output, however i think of it as gating the current - the full supply voltage is there at the heater coil, the heater resistance doesn't change, so the PWM is controlling the amps. And, from what i have read online, the temperature generated by the nichrome80 coil is determined by the amps going through the wire (or, ribbon in my case).
 

OF

Well-Known Member
interesting … i never tried to measure my PWM output, however i think of it as gating the current - the full supply voltage is there at the heater coil, the heater resistance doesn't change, so the PWM is controlling the amps. And, from what i have read online, the temperature generated by the nichrome80 coil is determined by the amps going through the wire (or, ribbon in my case).

True enough, but a bit awkward? Since PWM does indeed reduce the current (basically 'full blast' times the percentage of on time) and the resistance doesn't change that means the effective voltage is lower......Ohm's law is a law, always in effect. To find the actual power (in Watts) you need to multiply the current (in Amps) times the Voltage (in Volts). If you're chopping the current, you need to use the resulting 'average' values not max possible voltage or current.

The Watts delivered are heat energy at one Joule per second per Watt. How hot things get depend on how fast that energy leaks away by conduction or is used to make vapor (oh, joy!). The remaining energy can then heat the load. How many Joules it takes to raise the temperature a given amount (say a degree) is a function of the material and can vary ten or more to one.

IIRC it takes about four Joules (four Watts for a second, or two for two.....) to deliver a calorie of heat. One calorie raises a gram of water one degree C.

But it's Watts (Volts times Amps) that produces the heat, not either Voltage or Current alone. But their product. Less current at higher voltage will do the same work, which is why we use very high voltages to distribute power (lower currents, smaller wires needed). It's also why we changed cars from 6 to 12 Volts as I recall the story it takes a bit over 2.5 pounds of copper out of every car. Which can add up when you sell a LOT of cars......

Regards to all.

OF
 

Hippie Dickie

The Herbal Cube
Manufacturer
the effective voltage is lower......Ohm's law is a law

yes, and that's relativity … the actual voltage stays the same, but the current definitely stops for the off part of the duty cycle.

in the beginning, the charts i saw of nichrome heat were indexed on current, not voltage, which gave me the flexibility, in the early days of the Bud Toaster, to pick a 5v power supply. i have since gone to 2S battery supply (6.4 for LiFePO4 cells) to get enough gate voltage (4.5v) to drive the MOSFET at a very low Rds ohms.

not to argue, just to offer my viewpoint - i don't find it awkward … really helped clarify the whole PWM control aspect.
 

OF

Well-Known Member
in the beginning, the charts i saw of nichrome heat were indexed on current, not voltage, which gave me the flexibility, in the early days of the Bud Toaster, to pick a 5v power supply.

not to argue, just to offer my viewpoint - i don't find it awkward … really helped clarify the whole PWM control aspect.

If you go back and check, you'll find that chart was for a specific gauge (size) of wire? In such cases the power is often graphed against current (in defference to materials with 'funny' temperature/resistance changes) but that, in turn is based on the power equation from Ohm's law. That is the voltage is calculated against the known resistance and then multiplied by the current, same as ever. Watts is Volts times Amps, there really isn't another definition only different ways of expressing things around the idea that the power is a function of the pressure (voltage) and flow rate of electrons (current) same as you calculate the power of moving water or horsepower by force (voltage) and distance traveled (current). Current alone doesn't cover it since a large diameter wire will produce less power for the same current because it's resistance being lower it will 'develop less voltage' for that same current.

You need both current and voltage, but you can calculate either if you have the resistance? BTW, you can use the modified formula "Power equals I squared R" That is current in Amps squared times the resistance since current times resistance is itself voltage by Ohm's law. So, it's really current times voltage still, just without the extra step. Yes, you can regulate by changing current, but you will also be changing voltage and power will always be the product of those two. Using just current change will indeed give you more power if you go up, but an accurate answer to how much depends on voltage as well. Double the current and you raise power by four not two since the voltage also doubles?

Fun stuff. Always follows the same rules.

Regards to all.

OF
 

OF

Well-Known Member
But are we even sure the Arizer heater element is Nichrome?

Not AFAIK, but then again why does that matter? It's a heater, you put current through it, it gets hot.

It has resistance, so it heats. If it changes resistance a bit (1/4% per degree C is typical of common metals), that doesn't really matter either as that will simply be compensated for by changing duty cycle automatically.

The metal itself, whatever it is (and it could be carbon film or similar) is buried in a ceramic body isolated from the airpath, load and everything.......not that that matters in the end either?

OF
 

nms

Well-Known Member
The ceramic body is isolated from the air path? I believe this is not right according to the pictures shown previously. This would also make it impossible for hotter air(than oven air) to enter the oven which is obviously happening. I think you have a personal deal against solo being convection :lol: :lol:. It matters to understand the limitations of the system and decypher the components in it, because the resistance will determine the needed voltages to be supplied given limitations on battery's maximum current supplied.

EDIT: I don't want to start a pointless discussion on what the solo is, while I have one it works fine and I don't want to break it appart. I'd be more curious in discussing a possible easy to build DIY vape than taking apart something that is working fine, while fun it is not productive to make an assumption based discussion.
 
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