question for other vtr owners

[CHUCKmfnNORRIS]

I did some searching and didnt find what i was looking for. i just got the vtr and when i press the power button it sounds like there the power is arcing. its a steady, quick sound and is coming from inside the mod, not the tank connection. it happens with all tanks ive put in it. the iclear30s, 2 protank 2, dct tanks with the adapter. is this something normal that i shouldnt worry about or should i bring it back to where i got it?

Thanks

 

[CHUCKmfnNORRIS]

its more of a buzz coming from inside the mod. i contacted innokin and have not gotten any responses, i also tried 3 different batteries, all imr batteries. i tried it at all wattages and voltages and still no difference between the two.

 

[CHUCKmfnNORRIS]

there is no vtr owner who could say that they hear it too?

 

[KjAthena]

I have heard others including PBusaro on his reveiw complain of a "rattlesnake" sound due to the chip used in the VTR...I have one and love it but here no sound...;if in doubt return and get a new one that you check while in the shop...better safe than sorry

 

[CHUCKmfnNORRIS]

thanks, thats another way to describe it.

 

[WidowsSon]

I'm thinking you are hearing the rattlesnake effect caused by the method used to regulate voltage...

Voltage is not something that can be turned up and down easily with dissipating the extra energy which can be done in a number of different ways... instead of trying to dump the energy, most mods use a method called PDM or pulse duration modulation / PWM or pulse width modulation, similar principle, most members would say PWM, but that is usually used for encoding information in electronic systems. PDM is the same essentially and used for controlling the duration of an electrical pulse for controlling the speed of motors or the voltage to a device.

essentially there is a chip that quickly turns the power on and off at a specific rate really fast... if full on power was 4.0 volts, then if you turn the mod on for .01 seconds and off for .01 seconds continuously you would have the equivalent to 2.0 volts. On for .015 seconds and off for .005 seconds is 3 volts etc....

the rate at which this switching occurs can cause a rattlesnake effect that you can audibly hear if it is too slow... you don't hear it on a provari because the rate at wich it pulses is much higher and not noticeable. Same principle though.

You probably hear this, I hear this on my VTR.

 

[CHUCKmfnNORRIS]

but nothing to worry about?

 

[WidowsSon]

nope... nothing to worry about...

nothing to fear but fear itself...... and bears.

 

[CHUCKmfnNORRIS]

thanks, i contacted the shop i got it from a few minutes ago and they just told me the same thing. they said it isnt gonna cause the unit to have other problems and not change the life of the mod.

 

[WidowsSon]

Just for your information, you will experience this effect on a lot of VV/VW mods. This is one of the many reasons provari owners site the unit as being superior. It works under the same principle, but at a much higher frequency negating the effect.

 

[00gt1]

Awesome post!! I was wondering why my VTR sounded like that. Thanks WindowSon

 

[Glenn_K]

Greetings; I think WidowsSon nailed the explanation, but you might find it worthwhile checking out some PBusardo vape vids -- he shows computer bar charts of the power profiles for various APVs. Can't remember exactly which ones in which he talks about the 'rattlesnake' sound, but i'm pretty sure it was in some of the recent ones I watched, which included the Vamo, the iTaste VV and the iTaste MVP.

Scroll through the final third of the review vid, that's where the analyses are shown.

Regards
Glenn

 

[WidowsSon]

Another note,

many members here will refer to units that have Direct Current compared to PWM....

other then mechanical units that just deliver battery power all Variable Voltage Mods are using PWM to control their voltage (please correct me if I'm wrong). Some people see a 100% duty cycle on their oscilloscope's because of the resolution of their scope is too low...

e.g. PWM/PDM is switching on/off real fast like mentioned previously... the measurement of this is called it's duty cycle and it's cycled with a specific frequency. In many cheaper VV mods, this frequency is 33hz (btw, I'm not saying that 33hz is bad or good) which is easily shown on even the cheapest oscilloscope's

When you get into mods that have faster (does not necessarily mean better) frequencies like the provari (I've heard it runs at 800hz, although I cannot confirm this), it takes an oscilloscope with a better resolution to see the duty cycle. If you don't have such an oscilloscope, it may look like a solid line on the scope and you may feel that it is somehow running at 100% duty cycle or direct current.

That's not true, it's still PWM, the person reviewing just doesn't have an oscilloscope with a high enough resolution to see that.

PWM/PDM is used EVERYWHERE... in fact the power companies limit the massive amounts of power coming from Power Plants by Alternating the Current at 240hz over the power lines which is stepped down again at your house to 120hz giving us Alternating Current or AC Power... The lights in your home are constantly being turned on/off at the rate of 120hz, the element just doesn't react fast enough to notice, although you can notice this flicker in fluorescent lights.

DC Power is already low enough Voltage that it's not dangerous so can be supplied without stepping it down unless you want to control the voltage in which case you need to do 1 of 2 things.... PWM, or get rid of the extra energy in some other form (usually heat)... I can't see a mod wasting that extra battery power on heat and still being efficient hence why they always use PWM.

When you control the brightness of your monitor from 100% (which would be 100% duty cycle) it uses PWM to dim it, flipping the backlight on/off at different duty cycles.

Low duty cycle means that the power is off more than on, a high duty cycle means the opposite.

There will obviously be a point at which using a higher frequency is of no value to an e-cig... e.g. 4000hz is probably no better than 1000.

I'm not sure where that line is with an e-cig, but once someone figures out at what point the heating elements can't react to the difference, anything after that is just specs for marketing. (which is usually what drives these types of numbers)

I would assume that a heating element is not fast to react to these types of cycles as it takes many thousands of micro seconds (or a second or two) to watch a coil go from hot (glowing) to cold... If the coil was fast to react to these changes you wouldn't just hear the rattlesnake, but would see it flickering.

I'm not sure if 800hz is better than 33hz, but when you get into 100hz or more it is probably safe to assume there's no difference.

Hope that helps

 

[Myk]

My SVD makes that sound.

After reading this thread I just checked my Vamo and it makes it very quietly. I feel better now. I thought the same as you, a loose connection arching power. I always thought the rattlesnake sound was at the coil not the chip, I've heard that sometimes.