Most Common Coil Building Misinformation I've Received

[skoony]

inductive resistance occurs in AC circuits... the flow of electrons need to be reversed and then sent back in the opposite direction. the faster the reversing cycle, the higher the inductive resistance will become
in pulsed DC there isnt a reversal of electron flow to deal with

its the magnetic field that causes inductance not the direction
of current flow.
its actually the increase and decrease in voltage and current that
creates the expansion and contraction of the magnetic field. it doesn't
necessarily have to be AC. AC will maintain a constant inductive
reactance by it very nature. a pulsed DC at a short enough time period
and high enough frequency should do the same. my question should be do these devices
produce pulsed DC at a rate that would matter.
regards
mike

 

[RamseyAD]

This is brilliant. Well said!

 

[BlkWolfMidnight]

Huzzzaaaa

I got this concept a long while ago, this is why I have Ohm per foot and per inch broken down in a table on my volt meter. I'd assume that your resistance (force required to push electrons through the wire results in heating) comes from the density of the material being used. Higher gauge results in a lower density (no bottle neck).

I've seen this concept at work with patch cables in the A/V industry, stranded works better then solid for a simple reason, more pathways equates to less density overall, but this doesn't decrease the heating of them depending on the gauge of the strands (rarely this happens as most patch cables are a unified directional pass, no opposing forces at work and no termination point). Maybe I'm a bit off kilter here trying to compare apples to grapes but this is how my mind breaks it down to logical and digestible blocks of information.

Though some thoughts, I don't mean to railroad the topic but using what is known about this now, would it be even possible to create an ideal coil build (coil spacing and size) to maximize heating efficacy and reduce the amount of cold spots by using inductive heating zones to the optimum. I once pondered that though a micro-coil is great, your missing out the spaces that vapor can escape from (solid tube will act as a solid tube). Though spacing the coils out will lead to cold spots, this is where induction heating zones come to play. That is the maximum radiated heat zone falling dead center in the space for each coil to not overlap but rather create a space where everything is being heated at once.

Just a thought though.

 

[tj99959]

Huzzzaaaa

I got this concept a long while ago, this is why I have Ohm per foot and per inch broken down in a table on my volt meter. I'd assume that your resistance (force required to push electrons through the wire results in heating) comes from the density of the material being used. Higher gauge results in a lower density (no bottle neck).

I've seen this concept at work with patch cables in the A/V industry, stranded works better then solid for a simple reason, more pathways equates to less density overall, but this doesn't decrease the heating of them depending on the gauge of the strands (rarely this happens as most patch cables are a unified directional pass, no opposing forces at work and no termination point). Maybe I'm a bit off kilter here trying to compare apples to grapes but this is how my mind breaks it down to logical and digestible blocks of information.

Though some thoughts, I don't mean to railroad the topic but using what is known about this now, would it be even possible to create an ideal coil build (coil spacing and size) to maximize heating efficacy and reduce the amount of cold spots by using inductive heating zones to the optimum. I once pondered that though a micro-coil is great, your missing out the spaces that vapor can escape from (solid tube will act as a solid tube). Though spacing the coils out will lead to cold spots, this is where induction heating zones come to play. That is the maximum radiated heat zone falling dead center in the space for each coil to not overlap but rather create a space where everything is being heated at once.

Just a thought though.

No-No-No

Resistance is what is holding the force back. Resistance "impedes" the flow of electrons.
Volts = force
Amps = flow of your electrons
Resistance = prevents (slows) the flow of electrons

 

[chickennuggets]

good info me thinks

 

[mcclintock]

Yeah, most vapers don't really understand electricity. They may still be able to get what they're shooting for with experimentation.

Impedance vs. Resistance: I certainly started with resistance before moving on into impedance, it's simpler. The term impedance is used 2 ways. Fully, it is used for AC calculations and has magnitude and phase (a vector containing resistive and reactive terms), as does the voltages and currents. Less scientifically, it is only a magnitude and since it is a "nominal" value applies to the circuits' passband where it is often mostly resistive -- calling it "impedance" rather than resistance is merely an acknowledgement it's not a simple resistance.

Resistance is a better term for it in vaping since there usually is no AC component and even if there is we're ignoring it.

inductive resistance occurs in AC circuits... the flow of electrons need to be reversed and then sent back in the opposite direction. the faster the reversing cycle, the higher the inductive resistance will become
in pulsed DC there isnt a reversal of electron flow to deal with

It becomes a DC voltage plus an AC term. Reactances respond to change: capacitors oppose change of voltage across them, inductors to change of current.

 

[victoryt71]

That is why the "language barrier" was confusing to me. You are the first to point out,

as long as the wraps' diameter and the wire gauge remain constant.

That would have made sense to me. Not everyone that vapes understands electronic components or terms associated with a basic circuit. They just experiment with wire until they find a gauge they can build fairly easy with and experiment some more with the number of wraps until they get the production they are looking for...works great if you never change builds or devices. Confuses the heck out of a newbie like me when I'm told to decrease the gauge of the wire to get more surface area on my coil and get blank stares when I ask, "wouldn't that make the coil too wide to fit the deck if I wrapped it enough to get the same resistance?"

 

[Treborsmug]

Okay,,,this is great. I have a couple questions. Test meters have the 'ohm' symbol. Not one for impedance. Look at any circuit board. All those tiny ceramic, multi color striped (color codes) for different resistors. Never heard of an 'Impeder". Not trying to be a wise guy......it's really just popped into my head. Sometimes the simple stupid things that mess me up.

 

[victoryt71]

Think of it this way. voltage=water pressure, impedance=the diameter of the hose you are using, and amps=how fast the water is actually coming out of the hose.

Let's say a fully charged 18650 battery is your outside water spigot and you connect your everyday water hose to it to fill a bucket. The shorter the hose is the quicker the water gets to the bucket and it does not matter if the hose is stretched out or coiled up, the water still has to travel the same distance. If you increase the length of the hose it will take longer for the hose to transport the water to the bucket...again, does not matter if the hose is coiled up or stretched out.

If you put a splitter on the spigot and use two hoses (parallel coil) you will half the pressure (resistance/impedance) that you were getting out of just one hose but double the amount of hose you are using (heating surface) and the same amount of water will reach the bucket faster. By the way, if you use a smaller diameter sized hose it will take longer for the same amount of water to reach the bucket...so you would have to use a much shorter piece of that hose for the same amount of water to reach the bucket in the same amount of time it would take to reach it through the garden hose. Makes sense in my head anyway...lol. After reading this I almost hate to post it. Hopefully it will make sense and help you somehow.

 

[victoryt71]

The reason kanthal is a good wire to use is because it is very heat resistive and gets hot very fast. All a coil is, in reference to vaping, is a wire wound resistor without the ceramic covering. The ceramic dissipates the heat to keep your circuit cooler. Without the ceramic, you basically have a heat inductor instead of a resistor.

 

[Treborsmug]

Ahhhh...more obvious......once someone points it out......thanks...

 

[Signmaker]

I once pondered that though a micro-coil is great, your missing out the spaces that vapor can escape from (solid tube will act as a solid tube).

A contact coil, even a tensioned contact coil, is far from being a solid tube. Vapor particles pass through the tiny imperfections in the wire's surface, which under a microscope resembles a tree trunk with rough bark. In fact, if you picture two logs with very rough bark laid on top of each other, and then shining a bright light along the seam from the far side, you can visualize how vapor escapes a contact coil.

As for the topic of wire gauge and it's relative performance, also keep in mind how the changes in mass relate to the speed of thermal change through the vape cycle. In simple terms, more mass equals slower changes. This is easily noted by the "lag" in coils using low gauge wire. This lag also comes into play when the coil is cooled by airflow, where greater mass actually works in our favor, as it gives more consistency.

In experience, coils made with high gauge wire are more airflow sensitive. Draw a little too hard, and the coil cools below it's most efficient vaporizing temperature. This results in a cool, "dry" tasting vape. Draw a little too gently, and the coil gets hotter, causing a hot vape, with a "burnt" or ashy taste.

 

[Ryedan]

I am new to building and have been trying lots of different builds. What I am looking for is a high surface area low resistance build which equally has a low enough heat capacity to fire quickly.

Any suggestions would be appreciated?

Get to know the Steam Engine coil design calculator. I use it any time I want to make a coil configuration I've never done before. It outputs heat flux and heat capacity. I pay a lot more attention to heat flux because my builds are usually at power levels where heat capacity doesn't matter much (I don't really care if my build starts making vapor in 0.15 second or 0.25).

If you need any help with it feel free to PM me.

 

[victoryt71]

Thanks for the link Ryedan!

 

[Ryedan]

Thanks for the link Ryedan!

You're welcome victoryt71

 

[MacTechVpr]

A contact coil, even a tensioned contact coil, is far from being a solid tube. Vapor particles pass through the tiny imperfections in the wire's surface, which under a microscope resembles a tree trunk with rough bark. In fact, if you picture two logs with very rough bark laid on top of each other, and then shining a bright light along the seam from the far side, you can visualize how vapor escapes a contact coil.

As for the topic of wire gauge and it's relative performance, also keep in mind how the changes in mass relate to the speed of thermal change through the vape cycle. In simple terms, more mass equals slower changes. This is easily noted by the "lag" in coils using low gauge wire. This lag also comes into play when the coil is cooled by airflow, where greater mass actually works in our favor, as it gives more consistency.

In experience, coils made with high gauge wire are more airflow sensitive. Draw a little too hard, and the coil cools below it's most efficient vaporizing temperature. This results in a cool, "dry" tasting vape. Draw a little too gently, and the coil gets hotter, causing a hot vape, with a "burnt" or ashy taste.

Excellent observation and why a t.m.c. in part yields the explosive vapor density it does. A uniform application of strain only encourages the consistency you describe in turn contact and this is what drives the impressive efficient transfer of energy to the wick. In my informal scientific survey of many hundreds of users and builders of t.m.c.'s the most common used adjective is "cold" irrespective of target temperature resistance evidencing an impressive improved efficiency over comparable conventional winds.

Thanks for the feedback here sign. Wish I could find a way to get even more new users trying this. Particularly with such an aggressive emphasis lately on jigs facilitating (formed, compressed) close contact coils which don't share these efficiency advantages. Baffles me. I can't believe these realities are so difficult to appreciate that those selling these devices aren't aware of them. Especially those I've directly provided consulting to.

'Nough said.

Good luck.