need multi-layer coil calculations formula ?
I need to constrct a 100uH coil work in 3 MHz oscillator
Inductance Considerations
The inductance of a wound core can be calculated from the core geometry using the following formula:
L=(0.4*pi*μ*N2*A*10-8)/l where:
L=inductance (henries)
μ=core permeability
N=number of turns
A=core across section (cm2)
l=magnetic path length(cm)
AL is the Inductance Factor of a core, and is expressed as nH/turn2 (or mH/1000 turns).
L(nH) = N2 * AL
where:
L = inductance in nH for N turns
AL is provided by the Manufacturer
but if you are not using any core
there will be about 1nH for each 1cm
hope this will help
AL = core inductance factor
when you say inductor do you mean
1} a cored inductor multilayer
2} a flat round coil of a certain dia
3} a small inductor as used in a radio for a tuned circuit etc
be more specific and descriptive a coil aint just a multilayer coil becouse by default any coil in multilayer... unless its an open loop
no wonder you found several formular
give us all more info so we can narrow the scope ... for the dirivitive function required to be more easily phathomed
thanks above for some maths
NOT this , I need the formula for a multi-layer work in freq. more than 3 MHz