RDA Parallel coil ohms question

[UniversalVapes]

Question is simple, how do you calculate the ohms of a parallel coil build? I know duals halve the ohms of each coil, do parallels work similar?

Say I build a single coil, 24g @ 2mm with 5-6 wraps. According to steam Calc, that's in the range of .4 ohms, give or take. What will that same exact build come to with two strands of wire, same diameter wire?

I've heard that parallels produce similar vapor to duals, with less the juice consumption. I'm really thinking about building parallels>>>duals. I just need to know how to safely wrap them first. Thanks in advance for the answers!

 

[mr.fabe]

Question is simple, how do you calculate the ohms of a parallel coil build? I know duals halve the ohms of each coil, do parallels work similar?

Say I build a single coil, 24g @ 2mm with 5-6 wraps. According to steam Calc, that's in the range of .4 ohms, give or take. What will that same exact build come to with two strands of wire, same diameter wire?

I've heard that parallels produce similar vapor to duals, with less the juice consumption. I'm really thinking about building parallels>>>duals. I just need to know how to safely wrap them first. Thanks in advance for the answers!

I like twisted coils and I measure them as dual coils on steam calc. I simply halve the readings.. i.e., if it quotes .4 ohms, my dual coil build (2 wires/coil) will be .2 ohms. I would imagine it will be the same with parallel coils too.

 

[suprtrkr]

Steam Engine calculates parallels. It figures them as twists with no actual twists in them. Theoretically, the resistance is calculated by the cross sectional area of the involved wires. You can look all that up, if you like, as the data is posted and standardized for AWG gauges. Or you can multiply the wire diameter by pi (3.14 etc.) to get the area yourself and apply the resistance factor.

 

[coilburner]

What the difference between dual coils and parallel coils? isn't two coils, two coils?

 

[SomeTexan]

Dual coils is two seperate coils in the atty. Parallel coils are 2 wires wrapped side by side around the same mandrel. Kind of 2 in 1. If it's a kanthal build, you pinch them together like you would a normal coil you just have 2 wires at each end.

 

[coilburner]

so the mod will read them the same whether they are wrapped together or two separate coils.

 

[SomeTexan]

I believe so, but I haven't built and tried any yet. All my Kanthal is too big. I need to order a bunch more in smaller sizes so I can play.

 

[suprtrkr]

What the difference between dual coils and parallel coils? isn't two coils, two coils?

Duals are two separate coils on the posts, usually on opposite sides. Parallels are one coil twisted with two pieces of wire lying side-by-side around the mandrel. This is confusing, I will admit, because dual coils are technically in a "parallel" circuit in electrical terms. Dual parallel coils are also possible; that just means 2 parallel coils installed on opposite sides of the posts.

 

[suprtrkr]

so the mod will read them the same whether they are wrapped together or two separate coils.

No. The resistance is technically calculated by cross sectional area. This will not be identical, albeit probably close, because leg length will not be identical. Moreover, there is some cross-leakage between coil wraps in a contact coil, and this factor will also vary somewhat between 1 and 2 wires per coil. In a parallel coil, the leakage occurs to the other wire, not to a different location in the same one. The difference is small, but it exists.

 

[93gc40]

Steam Engine calculates parallels. It figures them as twists with no actual twists in them. Theoretically, the resistance is calculated by the cross sectional area of the involved wires. You can look all that up, if you like, as the data is posted and standardized for AWG gauges. Or you can multiply the wire diameter by pi (3.14 etc.) to get the area yourself and apply the resistance factor.

Steamengine does account for twist or pitch if you enter the value. Resistance changes as you twist wire.

 

[suprtrkr]

Steamengine does account for twist or pitch if you enter the value. Resistance changes as you twist wire.

Quite right; my post is infelicitously phrased. Steam Engine does count twists in twisted wires, and this does change the resistance. The calculator asks you to enter the peak-to-peak distance and further suggests you measure the length of 10 twists and divide to get better accuracy. However, if you enter 0 as the distance factor, it will calculate parallels.

 

[93gc40]

A zero pitch Twist, by definition, is parallel.

 

[UniversalVapes]

So, I entered all the info. For my target resistance of .25 ohms, (dual parallel) it says I would need 14 wraps per coil. This is /2 due to the fact that there are X2 strands, correct?

Edit: So I would only wrap 7 times with the coil technically coming to 14 wraps.

 

[EverPresentNoob]

IF you have Steam engine set to tell you about parallel coils and it says 14 wraps, you need 14 wraps. My favorite setup is dual parallel 28G on 3mm mandrel. with both at 7 wraps it is around .35 ohms.

 

[93gc40]

2 or more wires twisted together or paralel are counted as 1 wire. So 14 wraps is 14 wraps.. Way too many IMO, so is you want to keep that OHM rate, you will want a larger ID on the coil to drop the wrap count down. I prefer to build coil with wrap counts of 5-10.

 

[shreduhsoreus]

Dual parallel coils are essentially quad coils that are wrapped in pairs. So the final resistance will be a quarter of what a single coil would be, and half of what a standard dual coil would be.

 

[93gc40]

Dual parallel coils are essentially quad coils that are wrapped in pairs. So the final resistance will be a quarter of what a single coil would be, and half of what a standard dual coil would be.

AND when twisted that resistance drops MORE.

 

[shreduhsoreus]

AND when twisted that resistance drops MORE.

You've got it backwards, it's actually a little higher resistance when you twist instead of running parallel. My preferred dual parallel build is 24g N80 with 3mm ID, 5 wraps. That's .09 ohms. Using Steam Engine and switching it to twisted, to achieve that same target resistance you need less wraps, ranging from 2 to 4 depending on how tight the twists are. That means each wrap has more resistance.

 

[93gc40]

^^^ Dang, i always seem to reverse that. Dyslexia sucks.