I'm trying to wrap my own inductors (air coil) for an RF circuit that I am making and I am having a little trouble solving for the number of turns I need to reach the desired inductance.
\$L=\dfrac{D^2N^2}{18D+40l} \$
- L = inductance in uH
- D = coil diameter in inches
- l = length of the coil
- N = number of turns
I'm wondering if there is a way to negate l from the equation using the gauge of the wire. I'm using 32AWG magnet wire and have found that 113 turns is equivalent to 1 inch of l. Can I just replace l with N/113?
My goal is to be able to measure the diameter of the non ferrite core I am going to wrap around and plug in the desired inductance. It shouldn't matter how long the coil is in the end unless I reach the end of the core and wrap another layer on top.
If possible, is there an online calculator that will do this for me?