Multilayer air core inductor on a rectangular former:
The calculator allows calculating the number of windings of the multilayer air core coil on a rectangular former at the design stage. You can select measurement units - mm or inches, and also AWG or SWG wire number - the wire diameter will be determined automatically. This calculator based on Rosa's straight wire self-inductance formula (formula 9 on p.305) and formula for mutual-inductance between two unequal straight wires from American National Bureau of Standards circular C74 (formula 182 p.273 with error correction). The coil is represented as many parts of straight wires. Calculating the self-inductance of each part, and mutual inductance of each possible pair of straight wire parts and summing it all, we get a self-inductance of the multilayer coil. For audio system filters, a Brooks coil is used with an optimal winding geometry. Such coils are calculated by the separate module of the Coil64 program.
This is the "virtual winding numerical method" that is the same as in the calculation of multilayer coil with round former. The accuracy of the calculation is to 5%. At a very high value of inductance, it's possible the small hang. See more about source formulas. Many thanks to Robert Weaver for his great help.
Calculate number of turns
ENTER THE INPUT DATA:
| Select units: | AWG → | SWG → |
| L | = | – Required inductance | |
| a | – Width of former cross-section | ||
| b | – Height of former cross-section | ||
| l | – Length of winding (former) | ||
| d | – Diameter of wire without insulation | ||
| k | – Diameter of wire with insulation | Automatic |
| N | = | – Number of turns |
| n | = | – Number of Layers |
| c | – Winding thickness | |
| Lw | – Required length of wire | |
| Ω | = Ohm | – DC Resistance of coil |
Copyright ©2016 Valery Kustarev
Another useful calculator:
- Single-Layer Inductor on a rectangular former, calculator by Robert Weaver (more accurate for the rectangular single-layer inductors)
- Calculator of multilayer inductor on a round former
