Quest to find the perfect voltage.....

[AriM]

Rather than building multiple mods, with limited adjustment, I have taken the plunge and built a mod box based on a variable (regulated) DC power supply. The supply has a range of 0-13v and a max load at 3A. I have purchased virtually every brand and impedance atty/carto/tank etc on the market....including all adapters and possible variations (I am sure I am missing some). I will probably swap the PSU for a switching supply (with fine adjustment) in the next few weeks, but this one is good enough to do preliminary testing. I might throw a scope and some proper analysis tools into the mix, but DC ripple hardly seems relevant in a constant current PSU. I mean we aren';t building power amps. For now I am just using a basic meter to confirm the regulated supply numbers.

I have already found the max on a few atty's (standard 510's give up the ghost at around 7 volts), I am also discovering the exact voltage/current draw that leads to the best combo of flavor and throat hit.

Interestingly I have found that not one single atty/carto/tank etc... pulls more than about 2.12 amps. If I could find one that handled more than 7v, I might be able to hit the PSU's max load. So far I am operating with quite a bit of headroom though.

I will begin to build a comprehensive list of all atty/carto/tank electrical specs. in this thread. This can hopefully help some folks design better/optimized battery and VR mods.

Tomorrow I will try to get an exact parts list and the electrical specs for the switch and the resistance of the components (I have a 20 foot, give or take, lead that connects the PSU to the mod box). I doubt the resistance of the lead (wire) and switch are much. The lead wire is 18ga pure stranded copper. If it tests out to be significant, I will replace it with heavier solid core leads and see if I can get it's resistance down.

Also the switch is a high quality, low resistance (super simple) momentary switch. The goal here is to test the optimum voltage/draw for each specific atty. (not to optimize the test jig). I think it would be simple enough to just subtract the total load of the wire and switch when implementing in another design.

I have gone out of my way to keep the design SUPER SIMPLE, and minimize components. Here is a list of the signal path.

1. Tripp-Lite surge protected outlet.
2. Kill-a-watt electrical meter (to measure draw of the PSU at the outlet)
3. Standard 15A NEMA to IEC power cable
4. EXtech 382202 DC PSU (constant current 0-13v, 0-3A)
5. banana plugs, with screw down terminals
6. 18ga stranded copper leads (screwed down to bananas and silver soldered at all other points)
7. 3A-250v momentary switch
8. battery connector from ego/riva (accepts ego and 510 threads...switch and circuitry removed)
9. various atty's and tanks

only had a chance to do a few minutes of actual testing (and pop a few atty's), but so far the results are fascinating....like I said the current draw is much lower than I expected (even at higher voltage).

my ultimate goal is to build a 12v coil/atty with direct injection (servo driven). Possibly a micro controlled regulator, that is programmable via USB and a simple software interface. Overkill? you betcha'

 

[Gummy Bear]

,,,,,,,,,,,,,,,,,,,,,,,,,,,

 

[Java_Az]

mind if i join you gummy...... ......

 

[Gummy Bear]

cool,,, you brought beer.

 

[breaktru]

Just pulled up my recliner to my monitor screen... okay I'm nice and comfy now...

 

[Gummy Bear]

Java, watch my chair, I gotta go to the bathroom,,, I'll be right back.

 

[Java_Az]

Your chair is safe but i swear outa the corner of my eye i seen breaktru take a sip off your beer.

 

[Gummy Bear]

He ain't got cooties does he?

 

[breaktru]

Ya caught me Java.. didn't think anyone would notice

 

[breaktru]

Not to worry gummy, da doctor said it's only cold sores

 

[Gummy Bear]

Shhh, I just saw AriM. quick, hide the beer.

 

[AriM]

beer, popcorn, recliner....pv's....sounds like a party....mind if I stop the experiment and have a seat?

ok....got to the bottom of the lower than expected current draw....turns out my test leads (from bananas to anode/cathode on the business end) measure out at 0.2 ohm. So much for my delusions of grandeur, thinking that somehow the laws of physics had changed for me.

decided that the PSU being used wasn't up to snuff. Swapping it for the switching supply today. I just didn't have consistent enough control over the specs. Hopefully a $300 PSU will best the cheap $129 guy in the picture. We'll see.

goal for today is to build a new set of leads and use a better switch. I have some high end components in storage. I will swap the 18ga for some 10ga. Considering building a balancing network on the end of the wire leads to bring them down to null. That is a hell of a lot more complicated than I had envisioned, but as long as we are driving this ship to mars.....

I can clone the network used in some of my audiophool speaker cables....hahaha finally a use for a balancing network....I know it is possible to use certain types of diodes to accomplish this task as well, but that is beyond my scope....and I don't want to launch into a project with-in a project (that never goes well)

I imagine using welding cable would be the ideal, with a corrective network on the business end to null the load....but how the hell you would connect welding cable to a ego/510 connector is another effort in futility (unless the laws of physics want to change for me again)

The real goal here is to test the attys/carts/tanks with the purest possible voltage source...to see if anything on the market is even appropriate for what I have in mind down the road....again if I have to start measuring switching noise and what not, then forget it....I would be better off building some high dollar power amp....

Since my test lead is an utter failure, I can only report that....

I am, of course, open to suggestion.....I would consider a fluctuation in load of a few 10th's of an ohm to be acceptable tolerance (taking into account ringing and PSU oscillation)....but a swing of much more tells me something is wrong with my testing methodology....that or most attys/carts/etc on the market are utter junk (I am leaning that direction, why else would I want to engineer something "better")

I would ultimately like to have a pre-atomizing spray nozzle directed on a high quality heating element....the pump could be actuated via servo or microcontrolled motor....yeah yeah yeah ok, I know first build a set of test leads that aren't utterly pathetic....

you know you guys are allowed to play ball in the street with me, my dad says it's ok....I am obviously going to need some suggestions and help along the way here....

if anyone has any ideas on how to build a set of leads that are close to null....then please save me some head scratching....I honestly kind of feel like having a cigg after this embarrassing first attempt....

oh if it's any consolation, CE2's 3.2ohm (plus .2 ohm for the jig) seem to vape the best (IMO) with 100% vg (24mg/ml) at 4 volts even.....and ego-tank with the same mixture seems to hit it's sweet spot at a hair under 5v....standard 510's (same mix) seem to work best with dripping at around 6 volts (and release magic blue smoke above that)

P.S. I test all atty's and carto's with a delrin drip tip....and no secondary seal....I digress...I'll save those tid-bits for something more than a half ... test rig....

hopefully that will be later tonight....pulling the switching PSU out of the box as this is typed

 

[AriM]

Shhh, I just saw AriM. quick, hide the beer.

now see here young man....have you young ruffians been having one of those ...... parties in my house....you kids and your wheelie boards and hippity hop devil music

 

[AriM]

......by the way, just looking for an excuse to buy that $1500 b&k PSU I have had my eye on all these years....give me a reason not to....(yeah that means I am disappointed with the performance of the switching PSU i just un-boxed)....if I go get that b&k I might just have the most overbuilt PV in the history of all that is PV's....give me a reason not to go get it

I'm begging here.....imagine the futility and grandure of being able to vape at exactly 4.125 volts

 

[perlionsmitnick]

Ok I'll go first. My guess for the perfect voltage is somewhere between 4.2 and 5.1 volts, or between this and that.
P.M. me for my address so that I can receive my prize.

 

[Java_Az]

......by the way, just looking for an excuse to buy that $1500 b&k PSU I have had my eye on all these years....give me a reason not to....(yeah that means I am disappointed with the performance of the switching PSU i just un-boxed)....if I go get that b&k I might just have the most overbuilt PV in the history of all that is PV's....give me a reason not to go get it

I'm begging here.....imagine the futility and grandure of being able to vape at exactly 4.125 volts

Might want to look at your circuit. What is the total resistance with and with out the atomizer. Just am idea before you go out and buy a $1500 PSU.

 

[AriM]

Ok I'll go first. My guess for the perfect voltage is somewhere between 4.2 and 5.1 volts, or between this and that.
P.M. me for my address so that I can receive my prize.

so far that doesn't seem to be the case....it looks like the effect is all over the map....depending on the variables....but then again I never asked the question....

EC2's at 3ohm and up are awful above 4 volts (burnt metallic taste) and standard 510's (dripped) seem to be best at 6v and up (until they fail)....the real goal of this experiment is to find a good range to build a DVRM. I mean if nothing works well at 3 volts and everything fries at 7 then why bother to include anything outside those ranges (it would just equal extra resources in the program). Also having conclusive numbers (not guesses) can equal a more streamlined program. Since my goal is a digital VRM I have to choose stepped/fixed output values. Sure maybe between 4 and 5 volts is optimum, but there are infinite points between there in the analog domain....therefore I need specific numbers....maybe it's all a waste of time, but then again so is every mod....the most basic "e-cigg" that delivers vapor containing nicotine is all ANYONE really "needs"....

all of this hopefully leads to a simple program that can be modified when I move to phase 2 (a custom built, direct inject atty/vaporizer). Like I said earlier it's totally rediculous and overkill, but that's exactly why I want to do it.....

not looking for guesses on what the "perfect voltages" are....hell if anything the title of the thread was/is a joke.....it's just a diary/log I am keeping (so I can remember what I was talking about a week from now)....and if some experienced EE's want to step in and give me some tips that equal an actual result....then I would be very appreciative.....can't make any promises beyond that....only that I will do my best until I determine it's not fun anymore....

 

[AriM]

Might want to look at your circuit. What is the total resistance with and with out the atomizer. Just am idea before you go out and buy a $1500 PSU.

mentioned that in the earlier post....the total resistance of the leads (from bananas that plug into the PSU, to the anode/cathode of the ego batt connector) is 0.2 ohm.....that's enough (IMO) to change the performance of the atty connected to the rig....I am talking off the PSU jumpers, of course.....I just ripped it apart again and measured the bare wire....and then a 100ft. length of the same wire....resistance at 100ft. was over 1ohm...I think I found the culprit....I will employ more appropriate wire throughout....about to test the switch and see what it specs. out at....

I know I won't ever get to null (without a balancing network) but I would be happy with 0.09 ohm (because the ambient fluctuation of all attys I have tested is above that)

I want the better PSU, because I want to have more accurate control over the output values....the 2 I have worked with over the last day or so are totally unacceptable....the first one was off by 0.4 volts....the new unit is within 0.1....i would be happy to have control beyond that (it will be necessary when designing the final legs of the concept)

It's kind of difficult to suss out the exact characteristics of the atty's when your reference is off....I would consider drift of .01 volts acceptable, and a test jig with a load of .09 ohm or less acceptable....I think anything else and I am just kind of pissing in the wind and hoping none blows back....maybe it's unrealistic and pointless....won't stop me from trying....most hobbies are pointless and unrealistic....

 

[Java_Az]

For sure will effect it. My PT is .3 but i am using a USB cord with 24gauge wire in it. 24 gauge is .02567 ohms per a foot. Other then making the cord shorter going to a lower gauge wire is about the only option beside switching to silver braided aircraft wire and thats only going to give you a 7% decrease in ohms for the same gauge wire.

 

[AriM]

For sure will effect it. My PT is .3 but i am using a USB cord with 24gauge wire in it. 24 gauge is .02567 ohms per a foot. Other then making the cord shorter going to a lower gauge wire is about the only option beside switching to silver braided aircraft wire and thats only going to give you a 7% decrease in ohms for the same gauge wire.

there is also the option of building a balancing network (resonant tunneling diode)....it's a negative feedback diode based circuit (it's used on lot's of snake oil audiophile products).....it does in fact null a cable run (well not perfect null, of course)....which is totally pointless for a speaker/amp, but could be really useful here.....

I do have some nice ltz silver braid (cotton dielectric) for my reference rig (I'm an audio.acoustics engineer), but I can't justify tearing apart $2000 worth of cabling to build a PV....or can I??

I think my only option is to go to some welding cable and figure out how to extend the anode of the battery connector to accept that....again hardly seems worth it....

let me dig up the schematic for that balancing network, and maybe you would be so kind as to look at it....it';s a fascinating circuit.....you might find it useful someday....it truly does provide negative resistence (but imposes certain current limitations)

thanks for the suggestions....will start returning some exact specs. to the forum as soon as I get the load of the jig as low as possible....

I have yet to see a detailed chart outlining the electrical characteristics of the popular atty assemblies

at least i think it would be valuable, and it's something I have to do anyhow for the next leg of my project....so why not share it



P.S. I am fascinated by your avatar....is that a wire wound pot you are using for the adjustment leg?? If so, would you mind telling me the value?