http://www.e-cigarette-forum.com/fo...able-voltage-mods-pulse-width-modulation.html
Deja vu (as posted earlier in this thread).
Deja vu (as posted earlier in this thread).
Eleaf Istick
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But there are people her claiming it does....
????
Last night was the last straw for me. Battery indicated < 1/3 charge left, and my coumarin pipe liquid was tasting burnt. Put it on my MVP @ 3.7 volts, and wonderful, smooth vape was had by me.
Personally, I would like to know, once and for all if it bucks or not. Then, if it doesn't, we can wonder how people were getting low intensity vapes on a fresh battery at a setting of 3 volts. If it does, then mine were defective.
vape on ECFers.
If you feel the units are defective, try opening a claim through eBay's money back guarantee. It's a process through the resolution center, but if ebay decides the units appear defective, they will require the seller to either refund you or replace the units at no charge. Better than taking a loss or passing on potentially defective units to someone else. Even though sellers may not offer returns or try and discourage them by large restocking fees, eBay buyer protection subverts that process. It only takes a few days for resolution.
Sellers will usually rather go ahead and please the buyer rather than have to deal with eBay's resolution process.
Unfortunately, I bough mine through vapenw.com, so I don't have eBay protection. I did send a request to vapenw.com, and will post here if I hear anything back. A coworker may be interested in buying them from me for $60 (for the pair). I'll take the $16 loss.....
My previous two posts (and the last one, a link to a 2012 ECF thread) were very enlightening to me. It may explain exactly what I and others have been experiencing.
Bottom line, the istick doesn't work for me, and it's disappointing. It would have ben a hell-of-a-deal if it had.
Oh well....
BTW, I still want to see actual testing done on the istick to confirm what it is actually doing.
I purchased mine from the vapenw eBay site not their website. I did notice they have a 14 day return policy on the website. I hope mine works ok, I vape my Hana clone around 13+ watts.
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As long as your Build is at or above 1.35 Ohms, you Shouldn't have any problems hitting at 13 Watts even if the Voltage Output can't go below 4.2 Volts on a Freshly Charged Battery.
4.2v = (13w x Ohms)^1/2 => Ohms = 1.35
Thanks for that link dude.
Read a few articles that attempted to 'splain PWM, having read this one I think I'm almost there. Mebbe sorta kinda, but closer!
http://www.e-cigarette-forum.com/fo...able-voltage-mods-pulse-width-modulation.html
Deja vu (as posted earlier in this thread).
A lot of good posts in there from some old modders that were building 5 volt analog buck mods, and were involved in the first experiments with PWM regulation being built into homemade mods. Much of what we buy today was started in the Modders Foruim.
Nope. If you got it from the Eleafus site I'd contact them and let them know about it. Maybe you can send it back under warranty
Hehe - I do not have mine in my hands yet. All of my worry is from the reading in this fine fact filled forum
Found more:
http://www.e-cigarette-forum.com/fo...on-reviewers-pulse-width-modulation-mods.html
Phil discusses:
Taste Your Juice | THE VAPEBRAIN ECD METER
Basically, this problem has reared it's head before, and the istick is doing what it was designed to do. It just isn't accurate in what it is calling voltage (as it relates to LOW WATTAGE vaping).
So, a measured voltage using anything but a meter capable of measuring PWM correctly, will read lower than the "true" voltage as it relates to the amount of heat generated AT THE COIL. Max voltage vs Average voltage. You see, the coil simply doesn't cool off enough between high voltage pulses to make the effective voltage less than the max applied voltage in terms of the amount of HEAT generated.
Of course, I can't confirm this, but apparently it is measurable.
The ECF threads I linked to describe exactly what happened to me with the istick.
Vave vs. Vmax and which is reported on the display.
From the thread linked in this post, is an example taken to the extremes for clarity:
quote (post #52):
i will answer the question i asked previously about a 300v battery ..
at 1% duty cycle the Vaverage will be 3v, if you use the average into a 2Ω atty, the power calculation (v^2)/r gives 4.5W
now .. in reality .. you are applying 300v to a 2Ω atty for 1% of the time.
when it is on .. the atty power is 45000W .. 1% of that is 450W.
so you can see an error of 10000% has crept in from using Vavg.
rms for a pulsed waveform is calculated by Vrms = Vpeak * √duty
so for the example
=300 * √0.01
= 300 * 0.1
= 30Vrms
using that in the power calculation means you get 450W for the calculation.
using rms becomes more important as the battery voltage rises.
it was never a problem with an ego but it is important to get right with dual batterys.
You can derive the error from ..
Vave = Vpeak * duty
Vrms = Vpeak * √duty
Solve for duty in both equations
duty = Vave / Vpeak
duty = (Vrms / Vpeak)²
so Vrms = Vpeak * √(Vave / Vpeak)
as Vpeak increases, Vrms increases further and further from Vavg.
http://www.e-cigarette-forum.com/fo...on-reviewers-pulse-width-modulation-mods.html
Phil discusses:
Taste Your Juice | THE VAPEBRAIN ECD METER
Basically, this problem has reared it's head before, and the istick is doing what it was designed to do. It just isn't accurate in what it is calling voltage (as it relates to LOW WATTAGE vaping).
So, a measured voltage using anything but a meter capable of measuring PWM correctly, will read lower than the "true" voltage as it relates to the amount of heat generated AT THE COIL. Max voltage vs Average voltage. You see, the coil simply doesn't cool off enough between high voltage pulses to make the effective voltage less than the max applied voltage in terms of the amount of HEAT generated.
Of course, I can't confirm this, but apparently it is measurable.
The ECF threads I linked to describe exactly what happened to me with the istick.
Vave vs. Vmax and which is reported on the display.
From the thread linked in this post, is an example taken to the extremes for clarity:
quote (post #52):
i will answer the question i asked previously about a 300v battery ..
at 1% duty cycle the Vaverage will be 3v, if you use the average into a 2Ω atty, the power calculation (v^2)/r gives 4.5W
now .. in reality .. you are applying 300v to a 2Ω atty for 1% of the time.
when it is on .. the atty power is 45000W .. 1% of that is 450W.
so you can see an error of 10000% has crept in from using Vavg.
rms for a pulsed waveform is calculated by Vrms = Vpeak * √duty
so for the example
=300 * √0.01
= 300 * 0.1
= 30Vrms
using that in the power calculation means you get 450W for the calculation.
using rms becomes more important as the battery voltage rises.
it was never a problem with an ego but it is important to get right with dual batterys.
You can derive the error from ..
Vave = Vpeak * duty
Vrms = Vpeak * √duty
Solve for duty in both equations
duty = Vave / Vpeak
duty = (Vrms / Vpeak)²
so Vrms = Vpeak * √(Vave / Vpeak)
as Vpeak increases, Vrms increases further and further from Vavg.
Got mine yesterday - working great so far, seems to hit a little harder on watts than my Sigelei 30w*. I have to dial it down a watt or two, but so far I dig it! Lasts about a day with moderate chain vaping with 2-3 sec drags.
Edit: I've been using it with a Aerotank Mega with a 2.1 ohm coil @ 10 watts.
Edit 2: *Meant hits harder than my MVP 2.0, not Sigelei 30w.
Edit: I've been using it with a Aerotank Mega with a 2.1 ohm coil @ 10 watts.
Edit 2: *Meant hits harder than my MVP 2.0, not Sigelei 30w.
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I think if more people would run the istick in Wattage mode,they would be a lot happier with it!I can't understand why anyone would want to use variable voltage as their main setting,on this small mod?
If it only had variable voltage,it wouldn't be as popular as it is. In fact it would be a Ego Winder,only shorter and square.
It's not square!
The science (an ohms law calculator) will easily show that there is no difference between setting at VV or VW. If the vape is different, it's the PCB, not the science.
A 2.0 ohm coil set at 6.8 watts is 3.7 volts. A 2.0 ohm coil set a 3.7 volts is 6.8watts.
I have observed no differences switching between vv and vw in the iStick. In fact, it is really easy to use either one as the display shows both the Watts and Volts or the Volts and Watts . It could even be considered a learning tool.
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The Istick--like the MVP2--has a fixed 510 connector pin.
Here are 5 "fixes" for problems with the MVP2's pin:
http://www.e-cigarette-forum.com/forum/blogs/capt-shay/6338-fixing-mvp-vv3-contact-issues-guide.html
You didn't mention which Nautilus coil you're using.
For me the Aspire BDC's are OK (but not great) at 6-7.5 Watts and start to taste burnt at 8 Watts and above.
On the other hand...the Aspire BVC's are pretty good at 9-10 Watts but really start to shine at 13-14 Watts.
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...
I know it seems really complicated.... Sorry about that.
Basically, I THINK the voltage displayed on the istick is less than what it actually is putting out (when compared to the true DC voltage from, say a Provari).
Furthermore, I think it's worse at lower voltages than at higher ones. Which, makes it burn too hot for me even at the lowest setting.
Apparently, Vrms is what the istick should display, but it is displaying Vave (IMHO).
Therefore 3v indicated is higher than 3 V DC equivalent.
The root mean square (abbreviated RMS or rms), also known as the quadratic mean, is a statistical measure of the magnitude of a varying quantity
Vrms for a sine wave will be different from
Vrms for a square wave will be different from
Vrms for a trapazoid wave will be different from
Vrms for a triangle wave will be different from
Vrms for a sawtooth wave will be different from
Any of these if the waveforms are smoothed and filtered with circuitry after the regulator chip produces them.
Which Vrms would be the correct voltage to display?
MasteringElectronicsDesign.com : How to Derive the RMS Value of Pulse and Square Waveforms
Well I'll be using 1.8 ohm BVC coils in my arsenal of nauty minis so we shall see.
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