Home > categories > Electrical Equipment & Supplies > Inductors > Finding total impendence of an inductor?
Question:

Finding total impendence of an inductor?

I want to find the total impendance of a coil. I think I know how to do it but I'm not sure.Z X + RX 2(pi)wLL (uAN^2)/lZ is impendance, R is resistance of the wire of the coil, X is the reactance, w is current frequency in hertz, L is inductance, u is permeability of the core, A is area of the coil loops, N is number of turns in coil, and l is the length of the coil.Together this would yieldZ (2(pi)wuAN^2)/l + RWould this be correct?

Answer:

All these formulas only apply to a sine wave single frequency. Z is from ohms law if you have measured V and I: Z + V/I Ideally Z is stated as a vector |Z|, which means a magnitude in ohms and a phase angle in degrees. If X and R are known: Z + sqrt(R^2 + X^2). This is using trigonometry to account for the resulting direction of the vector (phase angle) of the two components R and X. Some calculations involving power, voltage, impedance and current are easier using vectors and trigonometry, while others are easier using complex numbers (real and imaginary component). Complex numbers have a set of rules for arithmetic using them. Adding them as for two impedances in series is very straight forward. Z as a complex number is R + jX The following formulas allow for converting from one representation to the other. PF (Power factor) true power / apparent power cos(θ) from trig. θ arccos(PF) |Z| V / I with a phase angle (θ) Rseries |Z| cos(θ) Xseries |Z| sin(θ) Z R + jX |Z| sqrt(R^2 + X^2) where X is the net reactance of XL and Xc. θ arctan(Xs / Rs)

Share to: