Multi-turn Air Core Inductor & Mu(Cu)&Mu(ABS)
Multi-turn Air Core Inductor & Mu(Cu)&Mu(ABS)
(OP)
I seek a precise formula to predict an optimized radius for a fixed L value of 8uH +/-5% using 36AWG on an ABS (Acrilo Nitrile Butadiene) core (4T bottom layer, 5T top layer) with Q>50. I believe the formula must consider the three (u) Mu values for the copper wire, ABS(+ its brown colorant)and air. The u value for vacuum is a given. I can find no reference u value for Cu as I do know its value is temperature dependent from research. Operating environment Temp = 10-130 deg F. Need these 3 u-values also.
Know of a good reference book (or physicist-mathematician e-mail addy) to consult?
Know of a good reference book (or physicist-mathematician e-mail addy) to consult?





RE: Multi-turn Air Core Inductor & Mu(Cu)&Mu(ABS)
The Cu will REDUCE the inductance due to EDDY current what would be very cumbersome to calculate. Frequency dependent, too.
I don't think the temperature effect will be anywhere close
to your tolerance range, so I would just neglect it at first.
Simplest way : make one coil without ABS -- measure -- repeat. If no LC meter: Parallel with 300pF, measure resonance.
You wrote "Optimized..." .Optimized for WHAT ?
More ? <nbucska@pcperipherals.com>