2022-03-15 19:59:12 +01:00
|
|
|
# Inductors
|
2022-03-20 18:30:04 +01:00
|
|
|
|
|
|
|
Inductors are similar to capacitors, but there are a few key differences:
|
|
|
|
|
|
|
|
1. **They store energy in their magnetic field**
|
|
|
|
2. **They resist to changes in current**
|
|
|
|
3.
|
|
|
|
|
2022-04-15 14:51:51 +02:00
|
|
|
![[inductor_schematic.png]]
|
2022-03-15 19:59:12 +01:00
|
|
|
|
|
|
|
**Inductance:**
|
2022-03-20 18:30:04 +01:00
|
|
|
$$
|
|
|
|
\begin{flalign}
|
|
|
|
&L = \frac{N^2 * A * \micro}{l} &\\\
|
|
|
|
\\
|
|
|
|
&L = Inductance \\
|
|
|
|
&N = \text{Coil Turns} \\
|
|
|
|
&A = \text{Area of the coild} \\
|
|
|
|
&\micro = \text{Permeability} \\
|
2022-06-05 18:53:01 +02:00
|
|
|
&\textit{How easily a magnetic field can be created in the medium of the inductor} \\
|
2022-03-20 18:30:04 +01:00
|
|
|
&l = \text{Length of coil} \\
|
|
|
|
|
|
|
|
\end{flalign}
|
|
|
|
$$
|
|
|
|
### Inductors in Parallel
|
|
|
|
$\displaystyle \frac{1}{L_{t}} =\frac{1}{L_{1}}+\frac{1}{L_{2}}+...+\frac{1}{L_{n}}$
|
|
|
|
|
|
|
|
### Inductive Reactance
|
|
|
|
Is the strength of opposition to alternating current in an inductor, measured in $\ohm$
|
2022-03-15 19:59:12 +01:00
|
|
|
|
|
|
|
$$
|
|
|
|
\begin{flalign}
|
|
|
|
&X_{L} = 2\pi fL&&\\\
|
2022-03-20 18:30:04 +01:00
|
|
|
&f = Frequency \\
|
2022-03-15 19:59:12 +01:00
|
|
|
&L = Inductance
|
2022-03-20 18:30:04 +01:00
|
|
|
\end{flalign}
|
|
|
|
$$
|
|
|
|
|
|
|
|
**Example:**
|
|
|
|
|
|
|
|
```circuitjs
|
|
|
|
$ 1 0.000005 30.13683688681966 45 5 43 5e-11
|
|
|
|
v 144 256 144 128 0 1 10000 5 0 0 0.5
|
|
|
|
l 240 128 240 256 0 0.03 -0.004925046545906014 0
|
|
|
|
w 144 128 240 128 0
|
|
|
|
w 240 256 144 256 0
|
|
|
|
o 1 64 0 4099 5 0.025 0 2 1 3
|
|
|
|
```
|
|
|
|
Calculate the Inductive Reactance in this circuit:
|
|
|
|
|
|
|
|
$$
|
|
|
|
\begin{flalign}
|
|
|
|
&X_{L} = 2\pi fL &\\\
|
|
|
|
&f = 10kHz = 10.000Hz\\
|
|
|
|
&L = 30mH = 0.03H\\
|
|
|
|
&X_{L} = 2\pi * 10.000 * 0.03 \\
|
|
|
|
&X_{L} \approx 1885\ohm
|
|
|
|
\end{flalign}
|
|
|
|
$$
|
|
|
|
|
|
|
|
|
|
|
|
**Example 2:**
|
|
|
|
|
|
|
|
```circuitjs
|
|
|
|
$ 1 0.000005 30.13683688681966 45 5 43 5e-11
|
|
|
|
v 96 256 96 128 0 1 200 5 0 0 0.5
|
|
|
|
l 240 128 240 256 0 0.4 0.00896251184146064 0
|
|
|
|
w 240 256 96 256 0
|
|
|
|
r 96 128 240 128 0 200
|
|
|
|
o 1 64 0 4099 5 0.025 0 2 1 3
|
|
|
|
```
|
|
|
|
|
2022-04-15 14:51:51 +02:00
|
|
|
Calculate the [[Resources/electricity/glossary#Impedance Z|Impedance]] in this Circuit:
|
2022-03-20 18:30:04 +01:00
|
|
|
|
|
|
|
$$
|
|
|
|
\begin{flalign}
|
|
|
|
Z = \sqrt{R^2 + X^2} \\
|
|
|
|
X = X_{L} - {X_{C}} \\
|
|
|
|
\\
|
|
|
|
X_{L} = 2\pi fL \\
|
|
|
|
X_{L} = 2\pi * 200Hz * 400mH \\
|
|
|
|
X_{L} = 2\pi*200*0.4H\\
|
|
|
|
X_{L} \approx 502.65\ohm\\
|
|
|
|
\\
|
|
|
|
Z = \sqrt{200^2+502.65^2}\\
|
|
|
|
Z \approx 540.97 \ohm \\
|
|
|
|
\\
|
|
|
|
I_{RMS} = \frac{I_{max}}{\sqrt{2}} \\
|
|
|
|
I_{RMS} = \frac{V_{rms}}{Z} \\
|
|
|
|
V_{RMS} = \frac{5}{\sqrt{2}} \\
|
|
|
|
V_{RMS} \approx 3.53V \\
|
|
|
|
I_{RMS} = \frac{3.53}{540.97} \\
|
|
|
|
I_{RMS} \approx 6.5mA\\
|
|
|
|
I_{max} = 0.0065 * \sqrt{2} \\
|
|
|
|
I_{max} \approx 9.12mA \\
|
|
|
|
|
2022-03-15 19:59:12 +01:00
|
|
|
\end{flalign}
|
|
|
|
$$
|