Help with undertsnading shorts and IPV2

[paulb787]

I am trying to have a better understanding of shorts that occur. I recently made the switch from a dna30 to a ipv2. The dna30 had better short protection in my eyes.

While operating the ipv2 with a magma in dual coil mode I saw the leads leading to the terminals glow while pressing the fire button. at the same time my ohms went from 1 ohm to 3.3. I am guesing this is a short but the ipv2 still fired? I think the leads got crossed inside the terminal. Does anyone else have a ipv2? what does it say when it shorts?

Also, is there any documentation that relates to shorts that's geared more toward vaping?

Thnx
Paul

 

[0dBu]

I am trying to have a better understanding of shorts that occur. I recently made the switch from a dna30 to a ipv2. The dna30 had better short protection in my eyes.

While operating the ipv2 with a magma in dual coil mode I saw the leads leading to the terminals glow while pressing the fire button. at the same time my ohms went from 1 ohm to 3.3. I am guesing this is a short but the ipv2 still fired? I think the leads got crossed inside the terminal. Does anyone else have a ipv2? what does it say when it shorts?

Also, is there any documentation that relates to shorts that's geared more toward vaping?

Thnx
Paul

You got any pics?

 

[AzPlumber]

A short is zero ohms. A loose connection would increase resistance (ohms).

 

[realsis]

I have a ipv2 50 as well. I've never fired a short or had a issue with them so I'm not going to be much help. However I was under the assumption it would NOT fire a short being a regulated mod. That said, it WILL however fire a resistance down to .2 sub ohm. You probably knew all this already. A true short on a ohm reader will NOT have a consistent reading but will jump all over with its reading. So when you put it on the ohm reader, what exactly happened? Does sound like a loose connection.

 

[paulb787]

Thanks that makes sense!

 

[joesquid]

I don't have an IPV2 but would be surprised if it measures ohms while firing. Are you sure you're not reading volts when you fire it? A short would read 0 ohms. Having leads crossed under the terminals will have no effect as they are already shorted together by the terminal.

 

[Kaezziel]

Joe is right, I personally do not know of any device that will read resistance while power is applied... this tends to blow fuses in multimeters and generally just breaks things.

 

[AzPlumber]

I have a Smok Vmax that will display ohms while it's being fired. Not sure if it's real time or stored info, I'll have to keep on eye on it and see if the display changes during a hit and the ohms happen to change. Probably a better chance of that happening on a new coil.

 

[Kaezziel]

That would be interesting to know, Plumber... I know that as a general rule in electronics, we never, ever read resistance with power applied to the circuit.

 

[InTheShade]

I have a Smok Vmax that will display ohms while it's being fired. Not sure if it's real time or stored info, I'll have to keep on eye on it and see if the display changes during a hit and the ohms happen to change. Probably a better chance of that happening on a new coil.

I've speculated about this due to a question from a member asking if his resistance chances in the middle of a vape, would the device know and adjust his wattage. Nobody seemed to know the definitive answer. It makes sense though that the device would not be reading the resistance during the firing and would in fact be using stored info.

I have a Zmax, maybe I need to come up with a way of testing it. I've never seen the resistance change during a fire but then again, I've never really tried to look for it changing.

 

[AzPlumber]

That would be interesting to know, Plumber... I know that as a general rule in electronics, we never, ever read resistance with power applied to the circuit.

Yep I'm curious myself. I just wonder if it's easier to design protection in the resistance circuit or include some sort of memory for stored info.

 

[Kaezziel]

Probably easier to include a memory... I've blown fuses in Fluke meters by having it set to read resistance when I meant to read voltage...

 

[joesquid]

Ohm meter use a highly regulated known voltage to determine resistance. If you apply voltage to the circuit you are testing it would certainly throw off the reading and in most cases blow the meter. If you can still read resistance, I'm sure it's stored info.

 

[Kaezziel]

Hmmm... gonna go out on a limb here, Joe
NAS Oceana or the Norfolk station?

 

[joesquid]

LOL.....but neither. NSA Norfolk. Retired Navy ET but still work for the Canoe Club.

 

[Kaezziel]

Cool! AT2 at Oceana for a while... got out after 9 years and kinda wish I had stuck around for retirement... the benefits woulda been good to have, but young and dumb trumped looking into the future for me... lol

 

[rusirius]

True, sort of... You can't use a multi-meter to read resistance in a circuit while it's live because the meter is trying to read a very low current that it's supplying and any sort of live circuit typically has enough current to blow it's fuses... Even if it didn't, you still wouldn't get an accurate reading...

However, it IS possible to know the resistance of a coil while it's being fired... Using the same equations used to make our coils in the first place...

A mod (micro controller based) can take a resistance reading milliseconds before firing... With known resistance, we now have a known voltage drop... And since it obviously knows how much voltage it's putting into the circuit it can then measure the current and reverse the calcs... Resistance = Voltage^2 / Wattage

I don't know for sure that this is how it's done, but it's certainly easy enough to do... In fact, I have a Sigelei that ONLY shows the resistance while firing... there's no other way to get it to display it... and it does change while being fired... I've watched a brand new coil change resistance as it cooks off and settles in...