/sci/ - Science & Math

>>11605799
Have you not taken differential equations, OP? All that is happening here is that linear ODE is being solved. Something called "method of undetermined coefficients" is being used where the forcing function for voltage is plugged in and current is guessed.

>>11605799
>>11605827
Btw, to solve for A and φ you straight up just plug I(t) into the ODE and do differential calculus.

ODE.. you need step by step solution? Just google RLC ODE derivation.

Do you understand periodic functions of V(t) and I(t)?

>>11605847
>Do you understand periodic functions of V(t) and I(t)?

No, I guess that's the hardest part for me in the differential equation.
I have taken diff equations but not electromagnetism or electronics.

>>11605910

Why is voltage E*sin(wt)?

From a practical point of view we consider a sine Wave beacuse we use AC current for electrical transmission. Also this result can be generalized for other kind of signals using Fourier analysis.

>>11605975
This is just normally how alternating current power is transmitted, in a sinusoidal waveform. It has to do with how AC is generated.

Can you explain this?

>>11605975

Because the voltage is alternating current at an amplitude and a frequency.

If you applied a DC voltage, there are only certain configurations of the RLC circuit that would oscillate. That is the characteristic state of the circuit or the unforced differential equation.

With an AC voltage source, this circuit act as a filter for certain frequencies....

>>11606045
It is a trig. prop.
Cos(A+B)=Cos(A)Cos(B)-sin(A)sin(B)

A=wt-phi
B=phi

Man you are fucked up, no offence.

>>11606061

Do u think I sit at home memorizing this shit bro?

Can you do 100 pushups?

Apparently this is what A should finally look like when solved.

I tried to do my own graph using this result but it doesn't look like it should. Will post it next.

>>11606109

Here's what happens when I plug in some constants from an actual RLC circuit and give w some values and plot it.
It doesn't look right at all.

I asked around and people said the formula for A is wrong, but how could it be?

>>11606080
I didn't remebered it exactly, I googled it.

And pushups don't have anything to do with this, poor defence. Don't use "comparisons" like that in your homework or you will fail.

>>11606113
Plot it for the Interval (0,5000) and you will see the expected response.

>>11606127

There are two kinds of people in this world. Those who can do pushups and those who can solve diff equations.
This sounds like a joke but take a look around, that generalization applies really well.

>>11606165

It's still wrong.

>>11606113
>>11606109
play with https://www.desmos.com/calculator/h4ripl23eh

>>11606172

Weird it looks just fine there.

>>11606113

L might be wrong. The number seems awfully small for Henry's.

>>11606109
>>11605799
Lol, we took this shit in highschool in Africa.

Do Americans really ?

>>11606113
What you have there resembles the curve you would get with DC, are you sure your circuit is correct ?

>>11605827
This guesing shit is stupid, is there no other way to solve this ?

>>11606501

No, I didn't know the inductance of the coil so I calculated it. Probably wrong.

>>11606561

Changed L to 0,103 and the graph makes sense now..