# Calculate L in RL AC simple circuit

Discussion in 'General Electronics Chat' started by german, May 12, 2010.

1. ### german Thread Starter New Member

May 12, 2010
1
0
Hi everyone,

I need to make what I am sure is a very simple calculation, but I have never dealt with AC and RL circuits before. The situation is the following:

http://img512.imageshack.us/img512/3585/circuito.png

The aim was to determine L experimentally.

A voltage Vin = 4 [V] was applied at a range of frequencies (from 0.1 [kHz] to 3 [MHz]), and the respective Van for an antenna was measured as a function of the frequency (f).

R = 100 [Ohm]
Ran = 1.1 [Ohm] (the measured resistance of the antenna)

With this, and the table f vs Van, how can I determine the inductance L of the antenna?

I would appreciate it very much.

Kind regards

2. ### dsp_redux Active Member

Apr 11, 2009
182
5
How much do you know about freq. response? Does this means anything to you?
$
H(s)= \frac{V_a}{V_{in}} = \frac{R+ R_a +Ls}{R_a Ls} \text{ where } s=j\omega = j2\pi f
$