Derive equation for RLC circuit

In summary, to get the given equation, you can use the voltage divider formula and manipulate it by multiplying it with appropriate terms. The equation represents the relationship between output voltage and input voltage in an RLC circuit, where [omega][/2] stands for the resonant frequency. A picture of the RLC circuit being used is also requested.
  • #1
Ai En
2
0
how to get this equation:
Vout/Vin = [RL]/[-[ω][/2]+jω(R/L)+1/(LC)]
 
Physics news on Phys.org
  • #2
- Show us the picture of the RLC Circuit your using.
- Tell us how Vout is defined.
- Tell us what [omega][/2] stands for (use the boards LaTeX syntax).
 
  • #3
http://upload.wikimedia.org/wikipedia/en/1/14/RLC_series_band-pass.svg
 
  • #4
Hi Ai En,

as a solution you could use the voltage divider formula to get a first equation:
[tex]\frac{V_{out}}{V_{in}} = \frac{R_L}{R_L + j \omega L + \frac{1}{j \omega C}}[/tex]

afterwards if you think that's useful you can try to manipulate this formula until you get the one given to you. Since i can not interpret your given equation (as i said use the LaTeX encoding to be more clear about your formula) i can only guess and did for example multiply the whole formula with [itex]\frac{j \omega L}{j \omega L}[/itex] and the denominator again with [itex]\frac{L}{L}[/itex] that results in:
[tex]\frac{V_{out}}{V_{in}} = \frac{j \omega R_L}{L \cdot \left( - \omega^2 + j \omega \frac{R_L}{L} + \frac{1}{C L}\right)}[/tex]
 
  • #5


To derive the equation for an RLC circuit, we first need to understand the components involved and their properties. An RLC circuit consists of a resistor (R), an inductor (L), and a capacitor (C) connected in series. Each of these components has a specific impedance, which affects the overall behavior of the circuit.

The impedance of a resistor is given by Ohm's law: R = V/I, where V is the voltage across the resistor and I is the current flowing through it.

The impedance of an inductor is given by the equation: XL = jωL, where j is the imaginary unit, ω is the angular frequency, and L is the inductance.

The impedance of a capacitor is given by the equation: XC = -j/(ωC), where j is the imaginary unit, ω is the angular frequency, and C is the capacitance.

To find the overall impedance of the RLC circuit, we need to add the individual impedances of each component. This can be done using Kirchhoff's voltage law, which states that the sum of all voltages in a closed loop is equal to zero.

Applying Kirchhoff's voltage law to the RLC circuit, we get the following equation:

Vin - Vout - IR - IX - IC = 0

Where Vin is the input voltage, Vout is the output voltage, IR is the voltage across the resistor, IX is the voltage across the inductor, and IC is the voltage across the capacitor.

Substituting the impedance equations for each component, we get:

Vin - Vout - I(R + jωL) - I(-j/(ωC)) = 0

Rearranging the equation and dividing both sides by Vin, we get:

Vout/Vin = [RL]/[-[ω][/2]+jω(R/L)+1/(LC)]

This is the derived equation for an RLC circuit, which relates the output voltage to the input voltage and the circuit parameters of resistance, inductance, and capacitance. This equation can be used to analyze the behavior of an RLC circuit and determine its resonance frequency, bandwidth, and other important characteristics.
 

Related to Derive equation for RLC circuit

1. How do you derive the equation for an RLC circuit?

The equation for an RLC circuit can be derived using Kirchhoff's laws and the equations for voltage and current in each component (resistor, inductor, and capacitor). The final equation is a second-order differential equation that describes the behavior of the circuit.

2. What are the assumptions made when deriving the RLC circuit equation?

The derivation assumes that the circuit is in steady-state and that there are no external forces or sources affecting the circuit. It also assumes that the components are ideal and have no resistance, inductance, or capacitance.

3. How is the RLC circuit equation used in practical applications?

The RLC circuit equation is used to analyze and design circuits in various applications, such as power systems, filters, and resonance circuits. It helps determine the behavior and response of the circuit to different input signals and can be used to optimize the circuit for specific purposes.

4. Can the RLC circuit equation be solved analytically?

Yes, the RLC circuit equation can be solved analytically using techniques such as Laplace transforms or differential equations. However, in some cases, numerical methods may be needed to solve the equation due to its complexity.

5. What are the limitations of the RLC circuit equation?

The RLC circuit equation assumes ideal components and does not take into account any non-idealities such as resistance, capacitance, and inductance. It also does not consider any external factors that may affect the circuit, such as temperature or noise. Additionally, the equation may become more complex for circuits with multiple components or non-linear elements.

Similar threads

  • Engineering and Comp Sci Homework Help
Replies
5
Views
270
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Electromagnetism
Replies
22
Views
231
  • Introductory Physics Homework Help
Replies
12
Views
4K
  • Engineering and Comp Sci Homework Help
Replies
8
Views
2K
  • Introductory Physics Homework Help
Replies
6
Views
1K
  • Introductory Physics Homework Help
Replies
8
Views
275
  • Introductory Physics Homework Help
Replies
15
Views
4K
Replies
5
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
9
Views
10K
Back
Top