PWM, possibly the cause of burnt flavor?

[UncleChuck]

So I hate clearos, I hate vivi Novas, I'm a carto tank kind of guy. Every single clearo I've tried has given me a burnt flavor quite frequently. This is my main gripe with them, and this is why I don't use them.

II had tinkered and modded all the clearos and vivi novas I had to increase their wicking ability, assuming the burn taste was just from inadequate juice. This helped, but still didn't get rid of the problem.

The first time I tried some clearos, I like them. I was using them on an eGo battery at the time, then when I got home I switched to my Zmax and after awhile couldn't stand them. Tried many different kinds, still didn't like them.

I'm starting to think that the low frequency PWM of many devices out there could be the cause of this burning flavor, which would also explain the huge difference of opinion people have about clearos and vivi novas. Some love them, some hate them. Maybe the people that hate them are all using PWM devices, like me?

I had considered this for awhile, and then recently threw some bottom coil cartos on my vamo, and on anything other than extremely low power settings, they taste burnt to me, off and on, kind of like clearos and vivi novas.

Anyone think this is possible? I suspect the design of a wick inside of a coil, like with clearos, novas, bottom coil cartos, etc cannot deal with the spikes in voltage seen with PWM as well as a standard carto can, which is totally surrounded by juice soaked filler at all times. The voltage spikes may be absorbed without issue by cartos, but with the coil being totally exposed, and only fed by a wick inside of the coil, the coil reacts quicker to higher voltage, so can burn for extremely short periods of time during the high voltage spike of PWM devices.

So to test this I used a Vivi Nova, an old Kanger (T2 I believe) and a few different styles of clearos on an eGo battery, and on a non-PWM mod (ST Bolt) I experienced no burning flavor, overall the devices performed well.

Then I put them on my Vamo and ZMax, both of which use low frequency (33.33 or whatever it is) PWM. I put them into voltage mode and set the voltage at 3.6 volts, to compare to the voltage that the eGo and Bolt were probably delivering. As I suspected, every one gave off a burnt flavor somewhat frequently. Swapped back and forth between the Bolt and the Vamo and there was always a burnt flavor that would appear when using the Vamo (and Zmax)

That was with a rather standard voltage setting. The nova had a 1.8 head, the kanger metered to 2.1 and the clearos were all around 2.1-2.3ohm. So there is no excuse for this burnt flavor, 3.6v on a 2.1 ohm coil is by no means high power vaping.

I've long suspected that the PWM had an affect on how the device vaped. The Provari's flat signal would be ideal. Maybe when people are saying their Provari hits better than any of their other devices, they aren't kidding.

Thoughts? Any mistake in the comparison I made, or any faulty logic I was using? I figured if this was truly the case, it would be much more well known, and addressed by manufacturers (no more 6v spikes, for instance)

 

[Thrasher]

I've long suspected that the PWM had an affect on how the device vaped. The Provari's flat signal would be ideal. Maybe when people are saying their Provari hits better than any of their other devices, they aren't kidding.

only problem is the PV is PWM also but a higher rate.

most times the burned taste is just that - from too much voltage.
the one thing to remember is most of the battery mods while the same voltage the voltage to the atty is stronger and more steady as it is a bit more regulated, i used to notice with my old twist as the battery wore on i had to bump it up a bit on voltage for the same vape.

has to be asked - are you sure the z and vamo are set to rms mode? as avg hits harder.

when vaping with a nova on my prov or vamo i had to constantly keep it tilted and flooding the head during a hit or i got the burned taste also. while it wasnt as bad with the twist i still ended up doing it when chain vaping.

 

[RichardV]

Most of the VV/VW units seem to be using pwm now. I think that your Vamo may be set to "NO1" which is the AVG or average voltage setting. This setting will give much higher voltage than the volts you have set.
Power your Vamo on and press the right(+) button down for at least 10 seconds, if it shows "NO2" (RMS mode) then you were in NO1. Leave it set at NO2 and the voltage will be very close to the volts you have set and the burned flavor may be a thing of the past.
I had the same problem with burned flavors with the VV Gripper that also uses pwm but only uses the AVG mode and the only decent vape I was able to get from it was on an RBA with a 3ohm coil.
You can get some good info from the Vamo section of ECF.
VAMO

 

[UncleChuck]

Both the Zmax and Vamo are set to RMS mode.

The Provari does use PWM, but the output signal is flat, compared to the huge voltage spikes seen in many other devices.

With the large voltage spikes there are times when the coil is getting a full 6v, and other times not. The ides is that is averages out to be the desired voltage. With something like a motor, it works fine, as the speed of the motor will stay fairly steady. But with something like a tiny coil, it seems perfectly possible that the 6v spikes are not "averaged out" by the coil, but instead overload the coil with too much voltage during the spike, and giving off burnt flavor.

You can even hear this with the rattlesnake sound these make on some settings with certain devices. If you can easily hear it, odds are the coil is getting far too hot, although only for short periods of time.

Think of it this way. Say you are using a PV that can adjust voltage while you are taking a vape. It has a little dial, and you can turn the power up and down. Say you have it set for 4 volts, which works perfectly fine. Then in the middle of taking a vape, you turn the voltage up to 6 volts for a split second and then back down to 4. Overall the vape felt like a 4 volt vape. Same vapor production, throat hit, etc. But because of that short burst of too much voltage, there is also a tiny burnt taste introduced.

Not exactly a perfect comparison to what we are talking about here, but close enough to hopefully illustrate my point.

EDIT:

I just wanted to point out that that I'm not bashing the Vamo or Zmax, nor am I praising the Provari. I like my Vamo and Zmax quite a bit, and don't own a Provari, so don't take this as some pro-provari thread, or anti-anything else thread. It has nothing to do with the devices themselves, just the specific tech and how it affects vape quality.

 

[kiwivap]

Only thing is I vape using both a Vamo and a Zmax and don't experience what you've described. I use vivi novas a lot with these devices and don't get burnt flavor. The only time I get a dry hit is when the tank is almost empty and I forget to tilt it.
I've used both devices in watts and voltage modes and haven't experienced spikes in power. I mainly use watts, but have used voltage sometimes. I've also noticed both devices are consistent in output with each other - they give the same output when on the same setting.

The rattlesnake sound is more easily heard when I use cartomizers than when I use vivi novas, which contradicts your idea that if its more easily heard then the coil is getting too hot, and your hypothesis that this occurs more with vivi novas.

The biggest reason I've seen for people loving or hating vivi novas has been the poor performing knock offs, and with clearos the same issue. Also differing QC on different batches - more so with some clearos - the Vision vivi novas have been pretty consistent. if the issue was PWM then it would be an issue with any attachment - a cartomizer coil would not be extra immune.

 

[tc1]

How long has it been since you dry burned your coil?

Vivi Novas (and other devices) require a dry burn after a couple of refills minimum or else you get gunk build up on the coils which burn when firing... thus the taste.

You said you tried cartos too though so I'm not sure. I honestly have no issues with flavor on my pwm devices using different atomizers.

 

[crxess]

Recheck your Vamo. If you pull the battery in Volts setting it will Default - 3.0v Avg. - and run High spikes.
Rattlesnake effect is a product of 3.7 battery power and stops when using (2) 18350 batteries. Also gets minimal in RMS mode.

As to Frequency mode - logic would dictate that lower frequency works better overall. Less cycling and longer low cycles for wick to bring cool liquid to the coil.

PWM in and of itself is not the issue. It has been used in audio systems for years with smooth/true reproduction of sound. The issue arises in regulation after modulation - proper filtering of excess energy.

One note from reading up on device testing - It seems all of the PWM devices running avg. do a run away at low voltage settings. i.e. 3.3v setting yields over 4.5v. My Y.J. Lavatube exhibits this characteristic yet works extremely well at 4.2v setting. I always use 2.4ohm or higher coils to avoid issued on that unit.

Simple proof PWM works - <the difference in production between avg and rms at the same settings> again all in regulation

ETA- Watch a coil in action on a pwm device - IGO-L Dripper is a good one - and you will see a smooth ramp up to full glow when fairly dry. When properly saturated you see constant evaporation - no pumping effect.

You may need to restart your Vaping habit on PWM lower and work up rather than accept that you must vape at (X) volts. It may be that you are simply over cooking certain juices.

 

[fourthrok]

Okay...I'm trying to understand this. I usually use 2ohm single coil cartomizers in tanks when I vape. I have mechanicals and eGo T mods and a VV Gripper and Ovale V8. On the latter two, I've been setting my voltage at around 3v for the 2ohm and 3.3v or higher for the 3 ohm. It doesn't taste "burnt", really, but I wish I could tone it down a bit. Seems to run a little hotter than is ideal for me. I like the strong hit...that's great. But it just seems like there's a LOT more voltage going on than I'm setting it for!

Are you saying that if I turn the voltage up that it will even up somehow? For example...on all my other APVs I generally like a setting of around 3.7 with the 2ohm cartomzers on mechanicals. I was told, when I got the Gripper to start at 3v and work my way up...but I never really ventured past 3.3 because it didn't make sense to me that higher might actually vape cooler. So...I'm a bit confused.

I should set the voltage higher on the Gripper and V8 then...because of the AVG PWM? Will that ease things up a bit with my vape?

 

[tc1]

The gripper and V8 both use vavg and not rms ... that is why they feel hotter than what you have set.

 

[fourthrok]

The gripper and V8 both use vavg and not rms ... that is why they feel hotter than what you have set.

Right...I got that. But a post above was saying

One note from reading up on device testing - It seems all of the PWM devices running avg. do a run away at low voltage settings. i.e. 3.3v setting yields over 4.5v. My Y.J. Lavatube exhibits this characteristic yet works extremely well at 4.2v setting.

So...I was wondering if I set the voltage up a bit on the V8 and the Gripper (my first instinct was to set it at 3.3 volts for my single coil 2ohms since that is approximately what the eGo T Mod runs in regulated mode, and I like that) That seemed hot to me, so based on what someone had told me...I went DOWN with the volts all the way to 3volts. Now that was okay...but MUCH hotter than I would have thought that lower voltage should be. Now I hear that at low voltages that the VVG and the V8 are running hotter...that leads me to think maybe by setting the voltage up HIGHER than "logic" tells me might help. I'm trying it now...3.7 volts with a 2 ohm. Seems okay. Not too hot really, but not that much different from 3volts. Thoughts?

 

[tc1]

That is most likely due to your voltage setting being closer to the actual voltage output of your battery. When that happens, you are lowering the voltage curve and outputting a more consistent load voltage.

At higher voltage settings the curve is once again increased which in theory should increase "hotness' however at this point you might be limited by amp threshold.

 

[crxess]

Right...I got that. But a post above was saying


So...I was wondering if I set the voltage up a bit on the V8 and the Gripper (my first instinct was to set it at 3.3 volts for my single coil 2ohms since that is approximately what the eGo T Mod runs in regulated mode, and I like that) That seemed hot to me, so based on what someone had told me...I went DOWN with the volts all the way to 3volts. Now that was okay...but MUCH hotter than I would have thought that lower voltage should be. Now I hear that at low voltages that the VVG and the V8 are running hotter...that leads me to think maybe by setting the voltage up HIGHER than "logic" tells me might help. I'm trying it now...3.7 volts with a 2 ohm. Seems okay. Not too hot really, but not that much different from 3volts. Thoughts?

Well, you have made 1/2 the step. You probably need more like 3.8 - 4.2. However the second half also comes into play. You need to up the resistance some. Probably in the range of 2.5-2.8.
The problem is in the low voltage setting on these devices, not the actual resistance. They tend to swing wildly at low voltage and even at the top end several exceed the 6v, some as high as 7v.
The higher resistance is only to keep the coil at a setting that will give you a comfortable vape at these voltages. i.e. a 2.0ohm would be very hot while a 4.0ohm would be rather cool.

 

[fourthrok]

Interestingly...the thing about the voltage veering wildly at lower voltage makes some sense. I really do like the 2ohms...so I'm going to try to keep using them because they go well with my mechanicals and eGo T Mod. I do have some SR 3ohm, but they were pre-punched and I don't like how manufacturers put the holes so low on the cartomizer. They just gurgle too much and run too hot. I'll get some and punch my own...but that won't be until sometime the week after next. Meanwhile...the 3.7volts and the 2ohm single coil carto in the carto tank seem to be playing well together. I don't feel the hit is too hot at all...I'm getting masses of vapor and TH...and the taste is good. The device isn't getting really warm like it was...it's just better all 'round.

I think this is a break through for me...and will enhance my experience with the VVG and the V8 greatly. I liked them a LOT...but was a bit frustrated too. Now I'm much happier. I'll have to play around with what voltage to use for the 3ohms...not sure, but probably will end up around 4 to 4.2.

 

[tc1]

I'm actually kinda surprised that no one has released a newer gripper style mod with RMS. I know the groove is coming out but I actually prefer the vv gripper form factor.

 

[dBm0]

Interesting read here. Thanks for the insight into how PWM mods operate at their upper and lower thresholds. Had no idea. Looking to get a new VW mods soon. Waiting for the right one and catching all this great cross talk is really helpful. Thanks.

 

[Thrasher]

Interestingly...the thing about the voltage veering wildly at lower voltage makes some sense.

i think this will improve over time as the regulation circuits get better made, or until a chinese company finally tears open a provari and copies the accuset chips.

 

[tc1]

i think this will improve over time as the regulation circuits get better made, or until a chinese company finally tears open a provari and copies the accuset chips.

It's not really the hardware but the software. China is great at hardware and engineering ... terrrible at software. That's why they pirate everything. lol

 

[UncleChuck]

Recheck your Vamo. If you pull the battery in Volts setting it will Default - 3.0v Avg. - and run High spikes.
Rattlesnake effect is a product of 3.7 battery power and stops when using (2) 18350 batteries. Also gets minimal in RMS mode.

As to Frequency mode - logic would dictate that lower frequency works better overall. Less cycling and longer low cycles for wick to bring cool liquid to the coil.

PWM in and of itself is not the issue. It has been used in audio systems for years with smooth/true reproduction of sound. The issue arises in regulation after modulation - proper filtering of excess energy.

One note from reading up on device testing - It seems all of the PWM devices running avg. do a run away at low voltage settings. i.e. 3.3v setting yields over 4.5v. My Y.J. Lavatube exhibits this characteristic yet works extremely well at 4.2v setting. I always use 2.4ohm or higher coils to avoid issued on that unit.

Simple proof PWM works - <the difference in production between avg and rms at the same settings> again all in regulation

ETA- Watch a coil in action on a pwm device - IGO-L Dripper is a good one - and you will see a smooth ramp up to full glow when fairly dry. When properly saturated you see constant evaporation - no pumping effect.

You may need to restart your Vaping habit on PWM lower and work up rather than accept that you must vape at (X) volts. It may be that you are simply over cooking certain juices.

Good point, it's not the PWM that's the issue, it's the regulation.

There are also other factors that could be at play here, such as the juice being used, but the large voltage spikes seem like they would have some effect, and with my person experience of burning flavor with certain atty designs, but not others, and only on specific PVs, it seemed like the electronics were the issue here, as it was the only constant while switching things around looking for the cause of the burnt flavor.

I've put my Vamo and Zmax (both V2s with RMS) through a lot of use and am very familiar with how they perform. Set to the same voltage as my mechanical or non-regulated mods they perform just about the same, and perform well. Except with some atty designs.

I wonder if it's just the wick material. It's all silica, and all the cartos I used generally are vertical coils with only filler and no wick, and they never have this issue. Some RBAs I've used had silica wick and never produced off flavors, but were drippers so were always constantly saturated in juice. Traditional attys I used also had silica wick, but again were used as dripping attys and were always well saturated.


I don't really know to be honest, with vaping there are so many tiny little variables that can effect vape quality, but all I can say is that to me the only connection I can make that matches my experience is devices that have (badly regulated) PWM and certain atty designs are the cause of the burnt flavor.

I cannot say why others have not had this same issue or noticed the same thing. Perhaps others have noticed it without realizing it, and just attributed it to clearos and vivi novas being bad products, instead of the combination of high voltage spikes and the atty design are the real cause (if this is actually true, of course)

So basically nobody thinks this is possible? That full 6volt spikes isn't going to have any effect to the coil or the quality of the vape it's producing? I'm not trying to be argumentative simply trying to figure out where others stand on the idea.

Awhile ago I read that PWM shouldn't be used if the voltage spikes are higher than what the device being powered can take. I'd consider certain resistance attys unable to take 6volts, so it would seem that under certain conditions the voltage spikes of certain devices could cause issues.

 

[kiwivap]

So basically nobody thinks this is possible? That full 6volt spikes isn't going to have any effect to the coil or the quality of the vape it's producing? I'm not trying to be argumentative simply trying to figure out where others stand on the idea.

I don't think its the reason Chuck. I would notice if I was getting burnt hits. The clue for me in what you say is that this doesn't happen with your cartos. I can definitely tell if I have a burnt hit on a carto - I accidentally vaped one at too high watts one day and oh boy - not nice. A carto coil is going to be just as susceptible as a vivi coil.