Next new thing: Variable resistance?

[Wakefulpanda]

Me and a friend were talking about this today. Is variable resistance possible? Could you make a 3.0 ohm coil and have the ability to dial it down to your desired resistance?

I was reading a page about dimmer switches and thought about e cigarettes.
http://home.howstuffworks.com/dimmer-switch1.htm


I'm not a scientist but I think maybe at some point someone can figure out how to do this. Any thoughts?

 

[BigDvon91]

To affect Resistance you would have to be able to control Voltage and Current, so youd probably have to be able to alter the viscosity of your liquid.... i aint no engineer by the way LOL

 

[Bunnykiller]

its easier to change the voltage than change the resistor..... to change the resistance, you would need to change the size of the coil....

 

[bcalvanese]

Interesting.

Off the top of my head, one way would be to put a rheostat in series with the coil.

Hmmmm...

 

[Bunnykiller]

Interesting.

Off the top of my head, one way would be to put a rheostat in series with the coil.

Hmmmm...

the rheostat would have to be able to handle as much or more current than the coil.... making it a bit on the large size and the lost energy used in diverting it away from the coil would play hell on battery life....

 

[bussdriver]

Theory for the inventors out there:

Could you power the coil with AC and then vary the inductance of the coil?

 

[Thrasher]

While not the same exactly, I would think the ability to dial in a set temp with temp control is pretty much already doing this As changing the resistance on the fly would just be adjusting how hot the coil gets at a set voltage


The AC powered mod came and went. The inductance is a magnetic field within the center of the coil and wouldnt heat the coil itself ,that has to interact with a core which would be a wick. And the wick being inert doesnt react to the magnet resonance

This is how inductance furnaces work in metal foundries the furnace doesnt get hot until you actually start dumping metals/alloys into the magnetic field Then they react.

 

[WattWick]

Didn't work too well the last time



Question is... why would you want to vary the resistance?

 

[Bunnykiller]

Thrasher" data-source="post: 15380503" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch">

While not the same exactly, I would think the ability to dial in a set temp with temp control is pretty much already doing this As changing the resistance on the fly would just be adjusting how hot the coil gets at a set voltage


The AC powered mod came and went. The inductance is a magnetic field within the center of the coil and wouldnt heat the coil itself ,that has to interact with a core which would be a wick. And the wick being inert doesnt react to the magnet resonance

This is how inductance furnaces work in metal foundries the furnace doesnt get hot until you actually start dumping metals/alloys into the magnetic field Then they react.

well you are kinda sorta correct.... but any coil that is supplied with AC has inductance core or not... the inductance( AC resistance) can be changed a tad via frequency... increase the frequency, it increases the inductance ( AC resistance) but not by much. and considering the nature of the small coils we use as heating elements, the Heneries are in the milli, micro, nano range ....

 

[Nada Nix]

Short answer: No.

Resistance is a physical property of the wire, so the only way you can adjust it is mechanically.

You could put a variable resistor in series with the coil, but that's a bad idea because as Bunnykiller says, it would just waste a lot of power as excess heat. Much better to vary the power electronically by changing the voltage etc.

On the link you gave, the first page "the old way" shows a coil with a moving contact, called a rheostat. It mechanically adjusts the length of the coil. You can only adjust it in steps of one full coil wrap. What would prevent it from working, is that the kanthal wire develops a coating of oxidization on it when it's heated, that prevents it from conducting electricity. So the moving contact arm wouldn't make a proper electrical contact to the coil.

The "new and improved way" described is a form of pulse width modulation (PWM), that is, turning the electricity on and off very quickly, and varying the proportion of time that it's on versus off. It doesn't change the resistance of the light bulb / coil. That kind of circuit has already been used very commonly in e-cigarettes.

 

[Nada Nix]

Could you power the coil with AC and then vary the inductance of the coil?

You could vary the frequency of the AC to change the amount of power to the coil. Basically you'd need a 10-watt broadband radio transmitter. There are much easier ways of doing things.

Great that you all are curious about electronics, but just keep in mind that lots of very smart engineers (which I don't claim to be) have thought about all these things already. Take a look at the DNA 40 temperature-control board for example, it works on the principle that wire changes its resistance as it's heated. It measures the resistance many time per second, calculates the average temperature, then adjusts the power level to keep it from over-heating and burning your wick. There's a tiny computer on board to coordinate everything... pretty cool.

 

[mcclintock]

That would be like trying to turn a car by bending the tires, rather than just turning the whole wheel.

Didn't work too well the last time



Question is... why would you want to vary the resistance?

That thing's a monstrosity! But not a totally bad idea, if simplified. As it is, a prototype that should have taught the problems with the basic concept. What could be good is just something like switchable dual coils for different vapor, and/or coils for battery aging, for example 6 and 7 wrap coils otherwise the same. If that atty was better designed in the first place, one could take out most of the coils and ignore that resistance markings as meaning much anything, although I'm not sure what the switching setup is. You could have a "regular" and "cloud" setting where those resistances are more like 2 and .2 .

 

[tj99959]

"Pots" have been around forever (think changing stations on an old radio). The only problem is the size.

Basically this is what it would look like.

 

[JMarca]

By doing variable resistance which isn't that easy all you really achieve is the same thing we've already done with VV/VW, by that I mean another way to alter the potency of the vape. If companies want to be innovative remove the coil and wick all together, make an atomizer that actually heats up the juice just hot enough to vaporize it without the need to use a coil or wick.

That would be amazing, but honestly not going to happen.

 

[Dampmaskin]

Could you make a 3.0 ohm coil and have the ability to dial it down to your desired resistance?

Yes you could, but it would not be worthwhile.

Could you power the coil with AC and then vary the inductance of the coil?

See above.

 

[edyle]

Me and a friend were talking about this today. Is variable resistance possible? Could you make a 3.0 ohm coil and have the ability to dial it down to your desired resistance?

I was reading a page about dimmer switches and thought about e cigarettes.
The Old Way - How Dimmer Switches Work


I'm not a scientist but I think maybe at some point someone can figure out how to do this. Any thoughts?

The next thing is temperature control; with kanthal.

 

[RandyF]

By doing variable resistance which isn't that easy all you really achieve is the same thing we've already done with VV/VW, by that I mean another way to alter the potency of the vape. If companies want to be innovative remove the coil and wick all together, make an atomizer that actually heats up the juice just hot enough to vaporize it without the need to use a coil or wick.

That would be amazing, but honestly not going to happen.

Never say never. It is a safe bet there is someone working on a way to move away from coil/wick vaping to something else, which will likely be much easier to control. It will happen, it is just a matter of how long before we see it.

 

[NancyR]

I really don't see the point, we can already change the resistance by what wire we use, how many wraps ect. Being able to change the voltage/wattage on a device already allows us to change the heat the coil is putting out, and now we have the temp control coming out that will allow us to keep wicks from burning.

 

[T4T3Z0R]

Never say never. It is a safe bet there is someone working on a way to move away from coil/wick vaping to something else, which will likely be much easier to control. It will happen, it is just a matter of how long before we see it.

ive been thinking about this fr a while. try to use the same principle used in a humidifier.

 

[philoshop]

K.I.S.S. No offense intended by the last 'S'.

ETA: Making things over-complicated is best left to Governmental entities. They're very good at it.