voltage vs ohms

[AlmityPunx]

ok so newbie question here...

my old apollo vtube (may she rest in peace) i used vivi nova tanks with 2.4 ohm heads generally at between 3.6-4.2ish volts.

buddy hooked me up with a Lambo tube which is basically the lavatube 2.0...

so firing it up it burns a lot hotter at lower volts. seems like it is dumping out about twice the power! i cant bring it over 3.5 without feeling like im at about 5.2 on the old one.

so my question is... what voltage ranges for different ohm ratings.
like 2.4 ohms = 3.5-4.2

thoughts?

 

[PhreakySTS9]

That's hard to answer since it's such a broad question and everybody has different preferences but a V-Tube to a Lambo should not make 3.5 volts feel like 5.2. Or at least, not between two devices that are pretty much the same anyways. Are you using the Vivi Nova still?

 

[1337paintbal]

ok so newbie question here...

my old apollo vtube (may she rest in peace) i used vivi nova tanks with 2.4 ohm heads generally at between 3.6-4.2ish volts.

buddy hooked me up with a Lambo tube which is basically the lavatube 2.0...

so firing it up it burns a lot hotter at lower volts. seems like it is dumping out about twice the power! i cant bring it over 3.5 without feeling like im at about 5.2 on the old one.

so my question is... what voltage ranges for different ohm ratings.
like 2.4 ohms = 3.5-4.2

thoughts?

there's an ohm/voltage graph that shows a good range to be in. it shows what volt would be to high for the ohm (could risk destroying the atty) and what volt to ohm would be to low (wouldn't produce much vapor if at all)... but after a lot of vids and scrolling around the forums it seems that some devices "say" its at 4 volts but fires much higher or much lower, it seems like a common issue with a lot of vv with menus to set the power... also it seems that -- for example-- 1.5ohm dual coil attys are really two 3ohm coils, so if you switched attys from a dual coil to a single coil it could do the same effect.

 

[AlmityPunx]

ya got the same novas and everything... exact same tank actually... i just took it off my vtube when i broke it and put it on this lambo.

i didnt think it would be any different but idk... ill check around for some charts.

but just your personal prefrence... i like a cooler vape generally.

 

[LucentShadow]

Dial it to where it performs how you like it.

Chances are probably good that the Lambo does not show a true representation of the output voltage. There are some PWM VV devices that have been found to read the average voltage instead of RMS voltage, which causes them to read lower than what they are delivering.

Other than that, it depends upon how warm you like your vape. Wattage is simple to figure, and there are calculators on the net that are quite handy:

Ohm's Law Calculator

So, with your midrange voltage:

2.4 ohms @ 3.9v = 3.9 * 3.9 / 2.4 = 6.34 watts

To get the same heat with a 3 ohm atty, you can plug a few voltages in the above, or use this:

sqrt( 6.34 watts * 3 ohms ) = 4.36v

 

[haiqu]

Chances are probably good that the Lambo does not show a true representation of the output voltage. There are some PWM VV devices that have been found to read the average voltage instead of RMS voltage, which causes them to read lower than what they are delivering.

You might want to clarify that. RMS refers to AC voltages, and all e-cigs that I'm aware of run DC through the coil. Thus an "average voltage" would merely get rid of jittery readings, not show any major difference over all.

 

[AttyPops]

You might want to clarify that. RMS refers to AC voltages, and all e-cigs that I'm aware of run DC through the coil. Thus an "average voltage" would merely get rid of jittery readings, not show any major difference over all.

Think of the PWM stuff as A/C...rectified. It still conforms more closely to RMS voltage than average voltage as I understand it. Another way to say it...it could be A/C since the coil doesn't care about direction of the current. It's the peaks of the PWM square wave (and % duty cycle) that counts. So you could draw every other peak as a negative voltage with appropriate gaps (since it's not a smooth sine wave) and do the RMS calc if that helps visualize the problem. The net result is that it conforms mostly to RMS calculations for output voltage. At least that's how the discussions have been going here.

 

[LucentShadow]

You might want to clarify that. RMS refers to AC voltages, and all e-cigs that I'm aware of run DC through the coil. Thus an "average voltage" would merely get rid of jittery readings, not show any major difference over all.

Some devices (I believe the Lambo is one of them) use pulse-width modulation to vary the fixed dc voltage that they are powered from. This converts the DC voltage into a form of AC voltage, where the duty cycle determines the effective voltage that the load will 'see'. That's a very basic clarification, but there is more info around:

Pulse-width modulation - Wikipedia, the free encyclopedia

I won't go into the differences between average and true rms, but there is a recent thread about this very issue that I think explains it fairly well:

http://www.e-cigarette-forum.com/fo...on-reviewers-pulse-width-modulation-mods.html

Ninja'd!

 

[PhreakySTS9]

pbusardo actually just made a great video going into all of these issues yesterday. I highly suggest anybody curious about this problem checking it out. The Vmax is the device i've heard this problem the most about. I've heard people saying they have it dialed down to 3volts and they are still getting what feels like 5.5 volts or something equally way too strong for them. I've heard of at least 1 or 2 people saying they can't even use the Vmax since even at the lowest settings it is outputting far too much power for them to even have a comfortable vape.

 

[MorpheusPA]

I notice it myself. My Vision Spinner at 3.8 seems to hit somewhat harder than my Volt X2 at 3.7 (far more than the 0.1 volt difference would account for).

I tend, as Mr. Busardo says, to use my tongue as the guide as to whether I'm happy. That Spinner could, at the 4.3 setting where I tend to use it, be outputting 3.2 or 6.8 and I wouldn't care. It works for me at that setting.