Varable voltage?

[surbitonPete]

A question for the electronics guru's out there.
Would it be possible to make a mod with a variable voltage controller?

I have noticed that variations of between 1 to 3 volts over the standard 3.7 volts can make quite a difference to the vapours flavour and throat hit. It would be great if you could set your own desired voltage. The slight variations in voltage between all the different e-cigs may have a lot to do with the variations in people's experience with them.

oh I can't edit the spelling in the title!

 

[breakfastchef]

I have been working on this, but have not found a suitable potentiometer for this purpose. My concern is a seeing a eduction in current when the voltage is reduced. It would be pretty cool to have a small desktop box where you could dial in a voltage and link it to a manual switch.

 

[exogenesis]

Suspect there's as much variation in atomizer coil-wire length/resistance
from a single manufacturer, than between manufacturers
(except Dura/510/Titan maybe, these may be a bit different anyway).

Makes it even more desirable to be able to control the current,
via voltage.

 

[tinear]

I have been working on this, but have not found a suitable potentiometer for this purpose. My concern is a seeing a eduction in current when the voltage is reduced. It would be pretty cool to have a small desktop box where you could dial in a voltage and link it to a manual switch.

a Variac, maybe?

 

[fenez]

Look up attenuation that is how guitar amps change voltage they make what is called a power break or a hot plate that does precisely what you are looking to do, but be aware many many people have killed their equipment making homemade attenuators

 

[tinear]

Look up attenuation that is how guitar amps change voltage they make what is called a power break or a hot plate that does precisely what you are looking to do, but be aware many many people have killed their equipment making homemade attenuators

A HA! a fellow string bender! actually, i had EVH in mind when i proposed the Variac

 

[fenez]

yes I am a string bender love EVH

 

[Fox3]

Or just get a variable voltage power supply. I have a couple for microcontroller development work, they go from nothing to instant poof of an atomizer coil .

 

[surbitonPete]

The ideal thing I am thinking would be tiny, like a little volume control that could fit into the mod and have just a small voltage range that could be turned up or down. I just don't know if it's possible. .....but it's great to hear some of you are already working on the idea.....I am looking forward to hearing about the first mod with variable voltage control.

 

[kinabaloo]

Pete - I posted a circuit for this somewhere before. Should be space enough in the box (for example, MoonMan's).

Potentiometer controls a power transistor or voltage regulator. An alternative would be a multi-pole switch that introduces a variable number of power diodes into the atty supply path (about 0.35v drop across an IN4001 power diode with virtually no heat loss; 0.7v with 2 in series, etc.).

 

[labrat]

I started modding this weekend and looked up to see my model train throttle. It is actually a very high end transistor setup. I did make a battery pack but ran out of time to start a passthru. Later this week I should get around to it. I got 2 tire valve stems for $2.99 and need to use up the other one. I will say, with a better power supply I have found I need to put down the PV or get rather light headed over doing the nic intake. You folks and your ideas rock.

 

[kender]

Something like this would work. Adjust the pot for the temp that you want the atomizer to work at and it will adjust the power automatically to maintain the temp.

Ive built a couple of these to automatlically control the temps in my computer. Hook the atomizer on the fan connection and use a PTC temp sensor. All parts are very small and would fit in the battery box mods.

 

[surbitonPete]

Keep at it fella's .....Once you guys work out exactly how to make it ....I can copy it....lol.

 

[breakfastchef]

But, what happens to the current when the pot is turned down? The perfect solution, beyond my abilities, would be to have a constant durrent, variable voltage circuit.

Something like this would work. Adjust the pot for the temp that you want the atomizer to work at and it will adjust the power automatically to maintain the temp.

Ive built a couple of these to automatlically control the temps in my computer. Hook the atomizer on the fan connection and use a PTC temp sensor. All parts are very small and would fit in the battery box mods.

 

[kinabaloo]

My original post. A mosfet would be smaller than the chunky one shown. The transistor is behaving like a high power pot, controlled by the smaller base current altereded by a real pot.

http://www.e-cigarette-forum.com/forum/battery-mods/10969-volts-amps-6.html#post215253

A 4k7 res on the negative arm of the pot will allow variation over the top half of the voltage range rather than from zero.

breakfastchef - some confusion i think. The idea is to vary the power (IxIxR) by varying the current by varying the voltage.

 

[surbitonPete]

But, what happens to the current when the pot is turned down? The perfect solution, beyond my abilities, would be to have a constant durrent, variable voltage circuit.

Yes that would be good but wouldn't you need to know exactly what is the ideal operating current first with that method??

 

[surbitonPete]

My original post. A mosfet would be smaller.

http://www.e-cigarette-forum.com/forum/battery-mods/10969-volts-amps-6.html#post215253

Hey hi there Kinaba ....haven't you actually made it yet? ..I see you have worked hard on a design!

 

[kinabaloo]

I used to be heavily into electronics. Isawhim and Kender seem to be also. I have no time Pete The circuit is from elsewhere; it's a basic design pattern but the pic was handy and shows the two views. The link in the original post has a good intro to transistors.

It strkes me that what we really need to control as a user-adjustable power knob is the juice flow moreso than the heater coil current. But at prsent there's no way to do that; would be quite eay with a piezo atty though.

I think a piezo-coil hybrid would be best; piezo for the flavorings+nic+minimal base, coil for distilled water + VG/PG/PEG-400. I first suggested this a week or two back. Not a simple thing, but a manufacturer could do something with it; get the best of both worlds, at the cost of more complexity.

Dry deposits would not get burnt and VG would not be decomposed; and a simple water or vodka clean would be sufficient.

 

[kender]

breakfastchef the problem is the only constant is the atomizer resistance. So by changing the voltage the current will also change.

 

[kender]

kinabaloo time is my problem also, too much work and not enough time for fun.