NEXT challenge to master the "sweet spot"

[warp1900]

I know i saw something about this long ago in the forum, i can't find it anymore for some reason.

potentiometers

I already did a few attempts at this but since i was basically shooting in the dark.

So...Has anyone tried to use a potentiometer to regulate the power fed to the atomizer?

Is it possible at all? (i would think so)

I think it would be amazing to make subtle changes to the power in order to hit our own "sweet spot" for vaping.

 

[surbitonPete]

It was something I suggested might be a good idea quite a while back....and I think a few of the modders that have that kind of expertise have had some success making some variable voltage type devices but I haven't really been keeping up with all the modding lately.

 

[framitz]

If you could find a wire wound rheostat with a range of 0 to about 3 ohms it might be very useful in finding the sweet spot.
Fileot1.jpg - Wikipedia, the free encyclopedia
Photo is actually a pot, but if you use center and one end it's a rheostat.
I'm not sure such a component is available though.
Otherwise we would need a variable regulator to do the job.

 

[breakfastchef]

A potentiometer will vary voltage, but would also vary current flow. A variable voltage/constant current circuit would be ideal.

 

[warp1900]

ok... 2 different scenarios,

one would be vaping form a 4.5v 1600Ah power supply and the second from a 2 x 3.0v batteries.

I'm guessing the setup for a variable control would be different in each case?

 

[framitz]

Anything that varies voltage will change current if the resistance of the load remains the same...

So if you were to use a simple unregulated power supply with an output of around 6VDC with high current potential connected to a variable AC transformer (variac) you could vary the voltage at will while still providing all the current demanded by the load (atty).
When you find the 'sweet' spot just record the voltage and you have it.

 

[warp1900]

Anything that varies voltage will change current if the resistance of the load remains the same...

So if you were to use a simple unregulated power supply with an output of around 6VDC with high current potential connected to a variable AC transformer (variac) you could vary the voltage at will while still providing all the current demanded by the load (atty).
When you find the 'sweet' spot just record the voltage and you have it.

I'm looking for something that is not fixed, but i can change whenever i want/need.

This is my "project" box for this experiment, (please don't laugh too much), i started by pure logic (my own logic lol) and with no real knowledge of electronics.

As you can see it has RCA jack on each end so i can connect my special pass-through or any battery pack or power supply i want to test with it.
The pot i used here is one that was scavenged form a crappy soldering gun with temperature control.
I only used the pot, no other electronics.
While it does move the range shown on my multimeter when set to continuity, it only acts as a on/off switch when applied to the battery/pass-through setup
I tried one other cheap pot that had a spring system to reduce/increase. same results.

I know i am far off from what is needed, anyone up to do the real testing to try finding a working version of it?

 

[mnealtx]

A potentiometer will vary voltage, but would also vary current flow. A variable voltage/constant current circuit would be ideal.

So, put it in parallel - that's the only way you could get constant current, anyway

 

[framitz]

I'm looking for something that is not fixed, but i can change whenever i want/need.

This is my "project" box for this experiment, (please don't laugh too much), i started by pure logic (my own logic lol) and with no real knowledge of electronics.



As you can see it has RCA jack on each end so i can connect my special pass-through or any battery pack or power supply i want to test with it.
The pot i used here is one that was scavenged form a crappy soldering gun with temperature control.
I only used the pot, no other electronics.
While it does move the range shown on my multimeter when set to continuity, it only acts as a on/off switch when applied to the battery/pass-through setup
I tried one other cheap pot that had a spring system to reduce/increase. same results.

I know i am far off from what is needed, anyone up to do the real testing to try finding a working version of it?

I don't think you're so far off at all, but I think you need a high power, low resistance pot. The small ones are usually carbon film and can't handle current, that's why I suggested a wire wound earlier.

The difficulty is finding one with low enough resistance:
http://www.potentiometers.com/SeriesM.cfm?session_num=2009080804484654
No prices shown, but maybe a request for quote would result in a free sample

BTW may be too big for the box shown.

 

[warp1900]

I don't think you're so far off at all, but I think you need a high power, low resistance pot. The small ones are usually carbon film and can't handle current, that's why I suggested a wire wound earlier.

The difficulty is finding one with low enough resistance:
Series M Wirewound Potentiometer
No prices shown, but maybe a request for quote would result in a free sample

BTW may be too big for the box shown.

Awesome, any suggestion as for what ratings i should go for?

 

[framitz]

I'm thinking 4 watts or so to be safe. They might be pricey.

 

[warp1900]

I'm thinking 4 watts or so to be safe. They might be pricey.

I saw some for as much as $40 8-o

how about this for $4?

VW24F-10-19.5K-B1K

 

[framitz]

Then there is the question of series VS parallel.
I think if you connect the center tap of the pot to +V in, one end to ground, and the other end to the atty you will have a voltage divider. Turning the knob will change how much current goes to the atty VS how much goes to ground. I think that's about as good as you can do with simple analog electronics.

You could then connect a volt meter to the atty input to monitor it's voltage when you find the 'spot'.

 

[warp1900]

Then there is the question of series VS parallel.
I think if you connect the center tap of the pot to +V in, one end to ground, and the other end to the atty you will have a voltage divider. Turning the knob will change how much current goes to the atty VS how much goes to ground. I think that's about as good as you can do with simple analog electronics.

You could then connect a volt meter to the atty input to monitor it's voltage when you find the 'spot'.

Great, i will do some testing and update on the results.

 

[framitz]

I saw some for as much as $40 8-o

how about this for $4?

VW24F-10-19.5K-B1K

1K ohm is way to much resistance, you really need something that will vary between about 1 and 5 ohms. Even with 1k it will be difficult to get changes around the 1 to 5 ohm range that you need.

Something at 10 ohms should be ideal.
VW24F-10-19.5K-B10
This stuff doesn't come cheap that's for sure.
You will have to be careful not to turn it to the extremes because at one end you will effectively be shorting the power source to ground if wired as I described earlier.

Something to remember is that if the atty is 3.5 ohms and has 6V applied then setting the added series resistance to 3.5 ohms will result in 3V across the atty and 3V dropped across the resister.

 

[framitz]

Thinking on this more and on how I would do it if I still had the proper equipment...
I would use a variable DC power supply.
Something like this:
Bench AC/DC Power Supply Kit
or
Power Supply HY152A Power Supply for Tatto
or
Variable Power Supply Kit

Of course the expense of any of these probably isn't warranted, but if you could borrow one somewhere . . . They're standard equipment in many electronics shops.

 

[warp1900]

ok, i see where you're going, not a bad idea.

That last one looks like it would be worth spending the $11 just to try it out.
Thanks

 

[framitz]

ok, i see where you're going, not a bad idea.

That last one looks like it would be worth spending the $11 just to try it out.
Thanks

I agree, not sure of the current rating though, the 300mS may be a typo for 300ma.

 

[Nuck]

In the past, I looked everywhere for a simple pot that was small and could handle the load of high voltage vaping. I was never able to find one. After speaking with RjG he mentioned using a variable voltage regulator. The regulator itself is controlled by the ratio of 2 resistors. By making one of the resistors a small pot you can then control the voltage between any low and high voltage mark you desire.

I built a battery box mod that works quite well but I used a regulator with a high drop out (LM317) making the unit inefficient. The pricer LDO model (UCC283-ADJ) from TI is an excellent solution.

Linear Regulators - Single Channel LDO - UCC283-ADJ - TI.com

To calculate the resistances you will need to set your preferred min and max voltage you can use:

LM 317 Calculator

 

[warp1900]

In the past, I looked everywhere for a simple pot that was small and could handle the load of high voltage vaping. I was never able to find one. After speaking with RjG he mentioned using a variable voltage regulator. The regulator itself is controlled by the ratio of 2 resistors. By making one of the resistors a small pot you can then control the voltage between any low and high voltage mark you desire.

I built a battery box mod that works quite well but I used a regulator with a high drop out (LM317) making the unit inefficient. The pricer LDO model (UCC283-ADJ) from TI is an excellent solution.

Linear Regulators - Single Channel LDO - UCC283-ADJ - TI.com

To calculate the resistances you will need to set your preferred min and max voltage you can use:

LM 317 Calculator

That sounds very interesting Nuck,

At this point, i don't even care much for size, I'm just starting to believe that a solution might take more money than expected.

Yes I would think the logical approach to min and max would be 3.7v up to 6.6v.

TI already helped solve one that had ben floating around for long in the forum. (5v regulator)
Hopefully it will help with this one as well.

Thank you for the info and the tips.