COIL FORMULA

[strujas]

Does anybody can tell me how I can calculate frequency of coil if I know diameter and width of wire and turns of wire ,,I need a formula.

[Qiaozhi]

Does anybody can tell me how I can calculate frequency of coil if I know diameter and width of wire and turns of wire ,,I need a formula.

Try here -> http://www3.telus.net/chemelec/Calcu...alculators.htm

[strujas]

I have this formula,,but this is for calculating turns of wire ,,

[bbsailor]

Frequency of a coil

I assume you mean the coil self resonant frequency. This can be easily measured with a signal generator and scope. It is very difficult and complex to calculate the self resonant coil frequency as it is very dependent on the following variables.
1. Coil diameter
2. Number of turns
3. Wire insulation thickness
4. Wire insulation dielectric constant
5. How tightly the windings are bound together
6. Shield spacer thickness
7. Shield spacer dielectric
8. Surface area of the shield material

Once you know the coil inductance and the coil self resonant frequency, you can then easily calculate the coil capacitance. Higher self resonance frequencies mean lower coil capacitance and lower self resonant frequencies mean higher coil capacitance.

bbsailor

[strujas]

Hm

this is whites concentric coil
L1 - transmiting
L2-feedback
L3 - reciving

L1 inside diameter is 6.375inch with 85 windings of 0.36mm wire(width of windings is 0.188inch)

L2 inside diameter is 3.937 inch with 27 windings of 0.36mm wire

L3 inside diameter is 3.188 inch with 275 windings of 0.23mm wire(width of windings is 0.219 inch)
I need to know how much UH is every of the windings ,,then i will use Erics formula and calculate how much turns is needed for a coil of 32cm
(12.6 inch)

[Qiaozhi]

this is whites concentric coil
L1 - transmiting
L2-feedback
L3 - reciving

L1 inside diameter is 6.375inch with 85 windings of 0.36mm wire(width of windings is 0.188inch)

L2 inside diameter is 3.937 inch with 27 windings of 0.36mm wire

L3 inside diameter is 3.188 inch with 275 windings of 0.23mm wire(width of windings is 0.219 inch)
I need to know how much UH is every of the windings ,,then i will use Erics formula and calculate how much turns is needed for a coil of 32cm
(12.6 inch)

Hi Strujas,

Using my own coil calculator I get the following results:

L1 = 6.375" (162mm)
wire thickness = 0.36mm
turns = 85
inductance = 6.4mH

L2 = 3.937" (100mm)
wire thickness = 0.36mm
turns = 27
inductance = 406uH

L3 = 3.188" (81mm)
wire thickness = 0.23mm
turns = 275
inductance = 26.3mH

To wind a search coil with an L1 inside diameter of 320mm ->

L1 = 320mm
wire thickness = 0.36mm
turns = 55 / 56
inductance = 6.33mH / 6.5mH

L2 = 198mm
wire thickness = 0.36mm
turns = 17 / 18
inductance = 381uH / 425uH

L3 = 160mm
wire thickness = 0.23mm
turns = 176 / 177
inductance = 26.2mH / 26.5mH

The problem with a concentric configuration is that the coils affect each other when combined in the search head. So you'll probably need to add or subtract one or two windings from these figures, especially with the nulling coil.

Good luck!

[strujas]

For few days i will start with constructing,,I'l hope that i will be successful,,,on the original coil with diameter of 162mm are some capacitators U can see them ot the photo under text,,,is it possible to use same cap.. for coil of 320mm diameter?

[ivconic]

formulahhhhhhhh!!!!!


How about this?
I am using it from time to time...

[Qiaozhi]

For few days i will start with constructing,,I'l hope that i will be successful,,,on the original coil with diameter of 162mm are some capacitators U can see them ot the photo under text,,,is it possible to use same cap.. for coil of 320mm diameter?

If the inductance of the 320mm diameter coils is the same as the 162mm, then the answer is yes.
However, there seems to be something inconsistent about the values you have given. The resonant frequency for the receive coil (using L3 and C44) is 5.97KHz, but the TX frequency is either 3.36KHz (with C40 only) or 2.37KHz (with both C40 and C42).
Are you sure that the inductance values are correct?
The other possibility is that there are some additional capacitors on the control board. This is quite likely to be the case if the transmitter is a Colpitts type oscillator.

[Unregistered]

coils formula

Does anybody can tell me how I can calculate frequency of coil if I know diameter and width of wire and turns of wire ,,I need a formula.

http://www.carnets-tsf.fr/coils

[strujas]

Abouth the capacitors: That values is on the schematic of coil ,,I dont know is that ok,,but i will find soon

[rumensat]

see this

[strujas]

Qiaozhi can you send me instalation of your coil calculator?

[Qiaozhi]

Qiaozhi can you send me instalation of your coil calculator?

Hi Strujas,

Executable file attached.

[strujas]

Thanx my friend....