I'd like a definitive answer once and for all: do amps matter?

[AzPlumber]

Sure. As long as you're saying "they ALL matter, since they are not separable (they are interrelated) and you can't view amps in isolation and then ask a question like that."

Absolutely they all are part of the equation. I never said amp didn't play its part, I only tried to convey that wattage was the key not amps.

 

[Dampmaskin]

Steam Engine calculates up to four parallel coils.

That is for twisted wire. With parallel non-twisted strands you can have billions.

I just tested it with a bunch of zeros, and it showed me a coil more than six billion light years wide.

 

[PapaSloth]

I don't know much about heating coils, but I do know a lot about stepper motors, and it's definitely true that high-voltage, low-amperage vs. low-voltage, high-amperage has a completely different effect on stepper coils even when the total wattage is exactly the same. High-voltage, low-amperage coils cause the motor to turn faster because the coils charge faster, but have low torque. Low-voltage, high-amperage coils turn more slowly but have high torque. This is the exact same set of coils, mind you, just charged in different ways, but it behaves completely differently. If I generalize this to heating coils, I would imagine that with a high-voltage, low-amperage power source, the coil come up to maximum temperature quickly, but would have a lower top-end. On the other hand, a low-voltage, high-amperage power source would cause the coil to increase in temperature more slowly, but would attain a higher final temperature. But, I'm speculating about the heating coils, because I only really know about motors.

As a thought experiment, imagine a 1000 Ohm coil that was charged with 100 volts at .1 amps, resulting in 10 watts. It only get warm in spite of the high voltage. Now imagine a 1000 Ohm coil at .1 volts but 100 amps. It would flame out almost instantly, even though it's still only 10 watts.

 

[Dampmaskin]

With heating coils, the heat flux is proportional to the power (wattage). With electromagnetic coils, I believe the magnetic flux is proportional to the current. (ref) I don't know much about electromagnetic coils, but it seems to be completely different effect, so you need to use a different set of equations.

A heating wire powered with DC does not care (electrically speaking) whether it's coiled up or straight. In an electromagnetic coil, the geometry of the coil has a large effect on its electrical properties. In a DC powered heating coil, it does not.

 

[PapaSloth]

I like turtles.

 

[Midniteoyl]

In power lines, you up the voltage way high to reduce the current. This reduces the losses and heating of the wire. Also means they can use a smaller wire. As the voltage is stepped down, the current rises, requiring thicker wire.

If you are the only house on your block using electricity, the power you are using will be the same power across the whole system, say you are using the whole 48kw available from the panel (most are 200amp). Which set of wires have to deal with more heat? The mains from the transformer to the house, or the main lines feeding the transformer? Remember, the power is the same in both sets...

 

[ValkyrieCT]

hehehe spying IDK what's going onView attachment 370183

 

[Midniteoyl]

I just looked up 20 gauge copper wire, and it's about .101 Ohms per 10 feet. So, you're saying that 100 feet of 20 gauge copper wire wrapped into a coil with resistance of 1 Ohm will heat the same as 5cm of 30 gauge kanthal wrapped into a micro coil? Surely not.

No.. because of the emissivity of the wire.. (The emissivity a material is its effectiveness in emitting energy as thermal radiation).

 

[PapaSloth]

No.. because of the emissivity of the wire.. (The emissivity a material is its effectiveness in emitting energy as thermal radiation).

You obviously know more about this than I do, so I'm yielding the floor to you

 

[Midniteoyl]

You obviously know more about this than I do, so I'm yielding the floor to you

Maybe, maybe not... You were correct after all

 

[PapaSloth]

Maybe, maybe not... You were correct after all

Even a blind squirrel has to find an acorn some days!

 

[Dampmaskin]

Good point Midniteoyl, the electrical efficiency of a conductor increases with voltage. However, for all practical purposes, a heating coil is 100% efficient to begin with.

 

[rondasherrill]

I like turtles.

They would probably make great atomizers...

 

[rurwin]

?
How can you have VA by itself? You'd have to have a varying load or something. Or you're just varying voltage, similar to what VW does.

A (bipolar) transistor is a variable current source. There is nothing more complex about building a variable current source than building a variable voltage source. It is variable power that requires you to measure the load and control one of the others to produce the right power.

There is a VA device out there right now, the Talifun Eye.

The answer to the OP's question was given on the third page. It is possible, although unusual to create a high resistance build that vapes the same as a low resistance build when fed the same power. But in order to truly understand it, you need more than ohms law. You need Kirchhoff's circuit laws - Wikipedia, the free encyclopedia as well.

Let's build three identical one ohm coils. Let's also say we have an accommodating dripper where we can wire these coils into either series or parallel configurations without changing the wicking or airflow. That's not impossible, but it might be a challenge.

When we wire them in parallel and feed them with 3V, all the coils have 3 volts across them. We can do ohms law for each in turn and find that they each take 3 amps. By Kirchhoff''s current law, we can see that the mod is having to produce 9 amps, and 9 x 3 = 27W. However each of the coils is seeing 3 x 3 = 9W. There are three coils, so 9W+9W+9W = 27W.

Now let's wire the coils in series. In this case the same current is going through all the coils. There's nowhere else for it to go. Let's say that that current is 3 amps. By ohms law, we know that the voltage across one coil will be 3 volts. Kirfchhoff's voltage law tells us that if all the three coils have 3V across them, then the mod must be putting out 3V+3V+3V = 9V. So the total power is 9V x 3A = 27W. However each coil is still seeing 3V and 3A and is still producing 9W.

So whether they are in series or parallel, each coil always sees the same voltage and the same current. If the individual coils are all seeing exactly the same voltage and current in both situations and if, as we stated earlier, the wicking and airflow is the same, then the vape will be identical between the two situations.

------------------------------------------------------------

Variable Current control has one major advantage. If you are building coils with the same type and gauge of wire, then the same current setting will give you the same power per millimetre, the same power per mm2 (of surface area) and the same power per mm3 (of wire).

If your wicking and airflow are efficient, then you can use the same current setting no matter how big or small you build your coil.

Most people, I think, use only a small handful of different sizes of wire, mostly of the same type. It would be simple to remember that for 28AWG Kanthal I like, say, three amps, but for 30AWG I prefer two amps.

 

[dr g]

Look. I can't make it any simpler. If you know 2 variables, you know them all (of watts, ohms, volts, amps). You don't know the full heat characteristics unless you know more about the wire. But aside from that for the moment:

You've held power constant. That's one variable that's known. You'd also have to vary one of the other variables accordingly. You don't get to vary amps. You can vary ohms. You can vary voltage. You don't get to vary amps. Amps are a result (really so are watts, as dependent on volts and ohms).

This is meaningless and was already covered:

The question was whether AMPS per se affect vape. Amps only, he specified the same power (watts). Yes that does mean the same thing as whether resistance or voltage affects vape per se.

The answer to all three is no. They only affect vape in the way the builds differ. And they may not differ, so it's really the build that is the determinant.

The OP's question is NOT "does 'the build' determine anything.
Let me say that again. He wasn't asking about 'the build'.

The build was not his question but it is the answer. The build determines the relative vaping characteristics of any two coils fired at the same wattage. They can be the same or different, entirely because of the build, and not because of the amperage/power passing through the build.

 

[AttyPops]

A (bipolar) transistor is a variable current source. There is nothing more complex about building a variable current source than building a variable voltage source. It is variable power that requires you to measure the load and control one of the others to produce the right power.

There is a VA device out there right now, the Talifun Eye.

The answer to the OP's question was given on the third page. It is possible, although unusual to create a high resistance build that vapes the same as a low resistance build when fed the same power. But in order to truly understand it, you need more than ohms law. You need Kirchhoff's circuit laws - Wikipedia, the free encyclopedia as well.

Let's build three identical one ohm coils. Let's also say we have an accommodating dripper where we can wire these coils into either series or parallel configurations without changing the wicking or airflow. That's not impossible, but it might be a challenge.

When we wire them in parallel and feed them with 3V, all the coils have 3 volts across them. We can do ohms law for each in turn and find that they each take 3 amps. By Kirchhoff''s current law, we can see that the mod is having to produce 9 amps, and 9 x 3 = 27W. However each of the coils is seeing 3 x 3 = 9W. There are three coils, so 9W+9W+9W = 27W.

Now let's wire the coils in series. In this case the same current is going through all the coils. There's nowhere else for it to go. Let's say that that current is 3 amps. By ohms law, we know that the voltage across one coil will be 3 volts. Kirfchhoff's voltage law tells us that if all the three coils have 3V across them, then the mod must be putting out 3V+3V+3V = 9V. So the total power is 9V x 3A = 27W. However each coil is still seeing 3V and 3A and is still producing 9W.

So whether they are in series or parallel, each coil always sees the same voltage and the same current. If the individual coils are all seeing exactly the same voltage and current in both situations and if, as we stated earlier, the wicking and airflow is the same, then the vape will be identical between the two situations.

------------------------------------------------------------

Variable Current control has one major advantage. If you are building coils with the same type and gauge of wire, then the same current setting will give you the same power per millimetre, the same power per mm2 (of surface area) and the same power per mm3 (of wire).

If your wicking and airflow are efficient, then you can use the same current setting no matter how big or small you build your coil.

Most people, I think, use only a small handful of different sizes of wire, mostly of the same type. It would be simple to remember that for 28AWG Kanthal I like, say, three amps, but for 30AWG I prefer two amps.

Yeah, sure, but only theoretically. And since I'm not versed in thermodynamics theory, I'm not even sure your example is correct theoretically. You're basically saying that there's no variability to the wire heating between the two configurations. I think, in this example, the thermodynamics are different, not ohm's or Kirchhoff's laws.

Bet'cha they don't behave identically in series and in parallel. I admit it's a hunch. But I'd stand by my original statement that different is different.

Take the series example, the heat distribution across the coil from one end to the other (all 3 ohms worth) is probably going to be different compared to the 3 parallel coils. So it will vape differently.

Anyway, the whole thing is moot. As I've repeatedly stated, amps can't be viewed in isolation. And although I know of variable-amp circuits, my original statement included things like responding to another variable (like a variable load). Or you're changing voltage too. You can't view amps in isolation. You just can't.

Besides, your answer is then basically "Yes, amps matter". So we all (well, most of us) agree on that. They are part of the equation. You can't say amps don't matter.

 

[AttyPops]

This is meaningless and was already covered:





The build was not his question but it is the answer. The build determines the relative vaping characteristics of any two coils fired at the same wattage. They can be the same or different, entirely because of the build, and not because of the amperage/power passing through the build.

No one, in this entire thread, is saying the build doesn't determine stuff.

Where are you coming from?

 

[rurwin]

Bet'cha they don't behave identically in series and in parallel. I admit it's a hunch. But I'd stand by my original statement that different is different.

Take the series example, the heat distribution across the coil from one end to the other (all 3 ohms worth) is probably going to be different compared to the 3 parallel coils. So it will vape differently.

If all the coils have exactly the same resistance, exactly the same voltage across them, exactly the same current flowing through them, and they all have the same wicking and the same airflow, what is different?

I will even design the atty for you. You have a dripper with six posts. Under the build-bed there are exchangeable plates which wire the posts either for parallel coils or for series coils, so you can reconfigure the build between the two options without even touching the coils.

 

[AttyPops]

lol.

I understand the example. My point is that just because you have potential difference X across a resistance wire of some given length, doesn't mean that it heats uniformly across the length of the wire. So if you build parallel vs serial where the sum total of the lengths are the same, you end up with different thermodynamics. You'd have to find thermodynamic theory texts and dig in. It just isn't worth it to me. I'm still going with "different is different" in that regard. A simple example may be that having 6 connection points vs 2 changes the equation...since heat sinks change temp, and temp changes resistance.....

Also, look back at the recent discussion Midniteoyl and PapaSloth were having to see other variations on "different is different".

Besides, it's moot. This thread is NOT debating if you can build identical performing setups two different ways. What we're really discussing is "do amps matter?".

 

[rurwin]

This thread is NOT debating if you can build identical performing setups two different ways. What we're really discussing is "do amps matter?".

The OP asked:

The question is, if you have a low ohm build like .25 with a standard amount of voltage, let's call that 4 volts compared to a build with a relatively high resistance like 3 ohms at 13.85 volts would they vary at all in the Vape experience (ie flavor, vapor production, throat hit, and vapor density)?

If you put three one ohm coils in series, you have 3 ohms. If you put them in parallel, you have 0.33 ohms. That is a very close match to the original question.

My point is that just because you have potential difference X across a resistance wire of some given length, doesn't mean that it heats uniformly across the length of the wire. So if you build parallel vs serial where the sum total of the lengths are the same, you end up with different thermodynamics. You'd have to find thermodynamic theory texts and dig in. It just isn't worth it to me. I'm still going with "different is different" in that regard.

It is not different; there is no difference. Each coil has 3 amps going through it, each coil has 3 volts across it, and each coil outputs 9 watts of heat.

Two lengths of resistance wire passing the same current and with the same voltage across them, given the same conditions of wicking and air flow, will heat up the same. Each tiny part of the wire can be thought of as an individual resistor with it's own voltage drop. The voltage drops will be evenly distributed over the length of the wire, and so the power output will be evenly spread over the whole of the wire.

Some of that power output may go into producing vapour, and that part of the coil may remain cool, and other parts of the coil may not be in contact with liquid and so that part may get hotter. Some parts of the coils may be touching other hot parts of the coil and so warm up faster. But every tiny bit of the wire is producing the same amount of heat energy as every other tiny part.

If some parts of the coils are glowing, you've got a bad build, but it would still have a negligible effect. An orange glow means about 1100C, and Kanthal is only 4% more resistive at that temperature. A 4% increase over at most 10% of the wire only increases the resistance by 0.4%, which is a good deal smaller than the inaccuracy of any build. If you use 3 inches of wire, you would have to cut it to an accuracy of 12 thousandths of an inch to make that orange glow matter. Nichrome increases by around 6% at 1100C, but that's still negligible.