Formula for calculating ohms when recoiling dual coil heads

[toots]

Hehe, just found out the formula for calculating the ohms when recoiling dual coil heads, and it is easy peasy to work out

Ok, all you do is this:

Example: Using 2 x 2.50 ohm coils

Formula: 2.50 + 2.50 = 5 divided by 4 = 1.25 ohms

How easy is that. I had no idea how to work it out but now I do, and hopefully this will help anyone else out like me starting to rebuild their dual coils

I've got ready made ones coming from FT so I thought I'd better find out how to actually work it all out for myself, instead of relying on other people to tell me which ones to get. I also know a few of us on here have just started to buy these ready-made coils and some of us will be re-coiling dual coil heads.

[DiscoDes]

Mar 28, 2014 13:24:42 GMT toots said:

Hehe, just found out the formula for calculating the ohms when recoiling dual coil heads, and it is easy peasy to work out

Ok, all you do is this:

Example: Using 2 x 2.50 ohm coils

Formula: 2.50 + 2.50 = 5 divided by 4 = 1.25 ohms

How easy is that. I had no idea how to work it out but now I do, and hopefully this will help anyone else out like me starting to rebuild their dual coils

I've got ready made ones coming from FT so I thought I'd better find out how to actually work it all out for myself, instead of relying on other people to tell me which ones to get. I also know a few of us on here have just started to buy these ready-made coils and some of us will be re-coiling dual coil heads.

toots you are correct!

[Deleted]

I'm sorry toots but although you ended up with the correct answer in your example, your method is wrong.

The formula for total (Rt) of two resistances (R1 and R2) in parallel is Rt = (R1 x R2) / (R1 + R2)

[DiscoDes]

OOPS!

Yes Toot's answer was correct but I didn't check her method, I would make a CRAP teacher!

[dave]

Even easier is that when both coils have the same resistance (e.g. 2.5), the total resistance is just half the resistance of one of the coils.

[DiscoDes]

Or if you want to get complicated :





But I don't bother because after all "Resistance Is Futile"

[Deleted]

Mar 28, 2014 14:18:54 GMT DiscoDes said:

Or if you want to get complicated :





But I don't bother because after all "Resistance Is Futile"

No thanks DES  .. two in parallel is straightforward but three or more needs a calculator 

[Phoenix .]

Mar 28, 2014 14:17:24 GMT dave said:

Even easier is that when both coils have the same resistance (e.g. 2.5), the total resistance is just half the resistance of one of the coils.

I was just going to say that dave.

[erik514]

Mar 28, 2014 13:24:42 GMT toots said:

Hehe, just found out the formula for calculating the ohms when recoiling dual coil heads, and it is easy peasy to work out

Ok, all you do is this:

Example: Using 2 x 2.50 ohm coils

Formula: 2.50 + 2.50 = 5 divided by 4 = 1.25 ohms

How easy is that. I had no idea how to work it out but now I do, and hopefully this will help anyone else out like me starting to rebuild their dual coils

I've got ready made ones coming from FT so I thought I'd better find out how to actually work it all out for myself, instead of relying on other people to tell me which ones to get. I also know a few of us on here have just started to buy these ready-made coils and some of us will be re-coiling dual coil heads.

It's the right answer but just divide the resistance of the coil by 2. Each coil is 2.5 so 2.5/2=1.25

[Deleted]

Brilliant thread thanks.

[stonethecrows]

toots, I've got a load of them coming from ft, too. I can't be doing with all that twinding/bending/twisting all the time. Might as well some other bugger do it for me:).

[toots]

Mar 28, 2014 14:07:06 GMT @yinyang said:

I'm sorry toots but although you ended up with the correct answer in your example, your method is wrong.

The formula for total (Rt) of two resistances (R1 and R2) in parallel is Rt = (R1 x R2) / (R1 + R2)

Now I am confused

[toots]

Mar 28, 2014 14:16:33 GMT DiscoDes said:

OOPS!

Yes Toot's answer was correct but I didn't check her method, I would make a CRAP teacher!

[vigowomble]

Thanks for the thread toots. And everyone else for the added maths. I'd been wondering about this.

[toots]

Mar 28, 2014 14:18:54 GMT DiscoDes said:

Or if you want to get complicated :





But I don't bother because after all "Resistance Is Futile"

  Noooooo, don't want complicated - want eeeeeeezy please