Air coil calculation

Approximate Air Coil Inductance Calculator

http://my.athenet.net/~multiplx/cgi-bin/airind.main.cgi



Single-Layer Air Coil Calculator

http://www.pronine.ca/coilcal.htm



Resistor-Inductor AC Behavior

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/rlimp.html



Inductance of a Coil

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/indcur.html#c2



Impedance

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/imped.html#c1