Chip Questions?

[Tintreach]

So I'm about to jump into the world of making a VV mod. I figured if I can restore a motorcycle or repair a 40 year old ham radio this will be a walk in the park as long as my imagination doesn't run dry.

I have been looking at both the Nivel's and dna's. The one thing I can't dig up is the PWM frequency of any of these, I haven't even seen a photo or youtube with these on a scope.

So how do these stack up against the China mods DC/DC converters or is this along the lines Provari when it comes to the PWM frequency?

Any feedback our suggestions would be great.

 

[Mstr Mashnst]

I'm not sure, it is a factor in a dead short devices, ie; the coil. There may be some readable frequency as noise, out side of that, voltage and amp draw is what you are looking for. If I was trying to start a motor at a lower voltage then it was rated at, that would be my first question of the power supply. It might be fun to do a high voltage pulse into the coil to see if it would keep it clean.

 

[Tintreach]

The main thing what does it look like on a scope? The Provari's seem to look more constant vs the china mods hence the "rattle snake" since the chip isn't switching voltages at full duty cycle.

 

[Mstr Mashnst]

I can't tell you. I could pull out my scope and find out but, I'm not. Maybe someone will come along and let you know. Good luck.

 

[Bestillsoicanshootyou]

I am in no way an elictrimagicalengineer but I wouldn't sweat it too much, go for the chip that
looks to suit your style and build preferences the only place I've seen an oscilloscope come into play are
in Prov forums. I think if you build a board from scratch- then you may need a 'scope.

 

[Tintreach]

Hell, I've already started drafting a real tube mod... no solid state crap.

 

[Iusedtoanalog]

Hi Tintreach. i do know that the okr-t6 and the ptn04050c chip have a switching speed of ~5.3khz versus the chinese mods of ~33hz. I do use the okr-t6 and t10 in my everyday mods. I have a few ptn04050 chips waiting for me to get off my duff and get them in something. Life has been getting in the way of my fun lately....lol... as far as the nivel and dna chips I would think that they are high speed switching chips onboard those platforms. And more likely they are based from the ptn chip design, I have heard that the Provari uses the same chiptype that is in the ptno4050(its a texas instruments chip) but I have never had a Provari apart on my bench to confirm this heresay.....Hope you find something to power your new mod that you are happy with. Good Luck. Happy Vaping.

 

[DrMA]

I don't have a scope, but I do use my DNA 20 mod regularly. The vape is perfectly smooth, no rattlesnake effect, so the PWM frequency has to be pretty high, possible in the hundreds of kHz range. BTW, the OKR-t/6 has a switching frequency of 600kHz and is the smoothest vape I ever had.

 

[rolf]

I used a 04050 c and even edged a board for it , woks great!
but ...would I use it again ? not at about 35.00 or so ! I am with you on solid state ,just give me a 4-1000 tube and oil filled capacitors in powersupply and my old heathcit vtvm and I be happy !! lol
analog forever rolf ( kk7lx )

 

[retird]

On the dna20d here is a bit of info from Pbusardo video....fast forward to 14:10..

A PBusardo Review - The Opus D & The DNA-20 - YouTube

 

[dr g]

I don't have a scope, but I do use my DNA 20 mod regularly. The vape is perfectly smooth, no rattlesnake effect, so the PWM frequency has to be pretty high, possible in the hundreds of kHz range. BTW, the OKR-t/6 has a switching frequency of 600kHz and is the smoothest vape I ever had.

Sorry to resurrect this post from the dead, but just to get the info on record: brandon says the DNA20 switches at 225kHz.

 

[DrSeuss]

I believe, although cannot be certain, that the Provari operates with a step up converter, running in the >100's of kHz, with a couple of mosfets on the output to 'chop up' the output into PWM. This fits with my interpretation of the various attempts on this forum to reverse engineer the board.

The benefits of this approach are that you get to run the boost converter at a fixed voltage, with no complicated feedback loop and chop up the output using an MCU controlling some mosfets. The downside is, to fit within the step-up converters frequency response, you have to chop up the output at a low frequency creating the 'rattle'.

The alternative approach is what I believe Evolv use, which is to actively control the feedback loop of the voltage converter, this has a benefit of increased granularity and no 'rattle snake'. Potentially this also has the lower BOM cost, but higher development time required

But in actuality either would work, I'd say the Evolv was probably the superior piece of engineering, but doesn't necessarily add enormous value to the end user.