# Math Help - ODE forming from elcetrical circuit

1. ## ODE forming from elcetrical circuit

Hey guys,

I have been given a diagram of an electrical LCR circuit, containing a 200ohm resistor, 5000microF capacitor, 4H inductor with a 100V DC power source.

I need to find 2 differential equations, which are probably both second order:

The first is for the voltage across the capacitor over time(which is definitely 2nd order)

The second is for the current though the inductor over time.

Is there anyone out there that can help me?

2. Originally Posted by deragon999
Hey guys,

I have been given a diagram of an electrical LCR circuit, containing a 200ohm resistor, 5000microF capacitor, 4H inductor with a 100V DC power source.

I need to find 2 differential equations, which are probably both second order:

The first is for the voltage across the capacitor over time(which is definitely 2nd order)

The second is for the current though the inductor over time.

Is there anyone out there that can help me?

Dear deragon999,

I'll try to help, but can you please tell me about the diagram, the resistor, inductor and the capacitor; are they all parallel to each other??

3. Oh yea, sorry about that, its just a simple series circuit

4. Anyone got any advice?

5. Originally Posted by deragon999
Hey guys,

I have been given a diagram of an electrical LCR circuit, containing a 200ohm resistor, 5000microF capacitor, 4H inductor with a 100V DC power source.

I need to find 2 differential equations, which are probably both second order:

The first is for the voltage across the capacitor over time(which is definitely 2nd order)

The second is for the current though the inductor over time.

Is there anyone out there that can help me?

Please refer RLC circuit - Wikipedia, the free encyclopedia. It will give you some idea. I think by using equation, $L\frac{d^{2}q}{dt}+R\frac{dq}{dt}+\frac{1}{C}q(t)= v(t)$ you will be able to answer the questions. I have'nt done LRC circuits in the university therefore I may not be able to answer your questions regarding this matter (the reason why my answer took so long to appear). But I hope the given suggestion along will help you.