Single layer coil design
charts (aka nomographs) are a dime a dozen on the Internet. Here is RF Cafe's 0.083¢
contribution. A couple examples of usage are included. You're welcome.
Single Layer Coil Design Chart
This chart can be used to find inductance of a coil when dimensions and number of turns are known, or to find
specifications to give a desired Inductance. Draw a line between either T and L or d and
l/d, whichever are both known. Draw
a second line between remaining known quantity and point of intersection of first line and unmarked vertical line.
Extend second line to scale for unknown quantity and read answer.
EXAMPLE A: We have a coil 5" in diameter, 19 turns, 37 turns per inch, and wish to find the inductance.
l = 19/37" = .52";
l/d = .52/5 = .104.
Draw a line between d=5 and l/d = .104.
Draw a second line from T = 37
through the intersection point to the L scale. Read the answer, 100 microhenries.
EXAMPLE B: We require the number of turns of a coil 5" in diameter, wound 37 turns per inch, to give 100 microhenries.
Draw a line between T = 37
and L = 100.
Draw a second line from d = 5,
through the intersection point, to the l/d
scale, and read l/d = .104.
Then l = 5 x .104 = .52
Inches. The number of turns is .52 x 37 = 19,
approximately.
Single Layer Coil Design Chart
Posted April 16, 2013
