Calculating Ohms Based on Number of Coils

[SingedVapor]

This is a relatively quick question but I am trying to calculate before I measure so I don't waste wire.

I know that twelve wraps on 30 gauge will equal about 2.0 ohms.

So if I wrapped dual coils with that I would simply half it and be at 1.0 ohms.

What do I do for three coils? Four coils an so on?

All I'm simply asking is for the equation for determining ohms as I move up the number of coils.

 

[mvroman]

It depends on the diameter of the coils as well, not just how many wraps.

Editing for a better response:

If you know that 2 ohms is 12 wraps and you wrap around the same thing everytime, just divide. So 6 wraps SHOULD be 1 ohm. 4 wraps would be .66 ohms and so on.


Sent from my SAMSUNG-SGH-I337 using Tapatalk

 

[steved5600]

I'm sure there is but i'd use these. I trust these apps. Coil wrapping | Steam Engine | free vaping calculators
https://play.google.com/store/apps/details?id=com.valsoft.vaperstoolbox&hl=en

 

[SingedVapor]

I apologies for the miscommunication what I mean is.

Ok say that every coil I wrap is exactly the same.

1 coil = 2.0 ohm

As I add another coil to the atomiser it changes the ohms. So two coils I the exact number of wraps would make it

2 coils = 1 ohm

What do I do for three or four coils? Divide by the number of coils?

So three coils would equal?

 

[GMayberry]

If we are assuming that both are exactly 2Ω, then yes, 2 coils would be combined at 1Ω, 4 coils at .5Ω and so on. Be careful subohming. Know your batteries, equipment, etc....

 

[steved5600]

Oh wraps are affected by diameter of the coil and how tight they are the sure fire way to know is by length. In case you are new or somewhat new in rebuilding here is my speech on the matter
Learn ohms laws, Use an ohm meter, use good batteries ( no battery with the fire in the name) and designed for e-cigs, use a good smart charger, do not over drain ( below 3.4v) or over charge a battery, use the locking ring on mechs. I recommend you don't go below the resistance of your mech when you build a coil system.

 

[SingedVapor]

Guys I know ohms and sub ohms, I have a reader and the only reason I asked this is because I have a limited amount of Kanthal left and was considering putting a three coil build on a kayfun but keeping it above one ohm due to my segelie 20w being finicky and not firing sub ohms. I appreciate your concern but I'm well acquainted with all this, I'm simply trying to understand it mathematically. It's easy for me to put an atomizer on an ohm reader, but I want to understand why that number that is there is there. I appreciate the concern though

(It wastes too much wire having to rebuild constantly and by the time I read the ohms it's usually to late to unwrap it so I have to throw it all away and start over which is wastefull )

 

[Seanchai]

For each coil you wrap, you divide by that number to find your total resistance. So if you wrap 3 two ohm coils, your total resistance will be 0.66. (two ohms divided by three coils.) Four 2 ohm coils will be 0.5, etc. Always check it with a multimeter/ohm meter, obviously... not just because of shorts, but because leg length can affect your resistance too.

 

[crxess]

It is the length, diameter and resistive quality of the Wire.

2" of Kanthal A1 26 Ga. will always be the same resistance regardless of wraps/diameter of the coil

 

[Dampmaskin]

Formula for determining total resistance of several coils in parallel:

R_total = 1 / (1/R₁ + 1/R₂ + 1/R₃ + 1/R₄ etc.)

Simplified formula - only works when all coils have identical resistances:

R_total = R_coil / NumberOfCoils

 

[SingedVapor]

Formula for determining total resistance of several coils in parallel:

R_total = 1 / (1/R₁ + 1/R₂ + 1/R₃ + 1/R₄ etc.)

Simplified formula - only works when all coils have identical resistances:

R_total = R_coil / NumberOfCoils

Thank you very much

 

[Bunnykiller]

View attachment vapecoils.xlsx


if you have Excel on your computer... try this sheet I made to determine coil stats

 

[DaveP]

I have enough trouble getting the exact value out of a single coil on the Kayfun, but it doesn't have multiple positive poles, just a negative and a positive.

Taking the reciprocal of all the resistances and then taking the reciprocal of the total is the way to do it, as others have already posted. Good luck!

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