Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs

Dashboard
Notifications
Mark all as read
Q&A

Current and voltage in AC circuits without impedance

+1
−1

How can we find the equation of current and voltage of a capacitor circuit if the input voltage is AC without using the impedance formula Xc = -jωC?.

SeeMe

We have for homework to find the equation of current of the circuit and the equation of voltage of the capacitor assuming we just connected the voltage source to the circuit

We can say that Ic = C1*dV/dt and Vc = Vo(0)+∫I(t)dt and from Ohm's law we can say that dV/dt = d/dt(V1-IR1) but what is the value of I?

Why does this post require moderator attention?
You might want to add some details to your flag.
Why should this post be closed?

0 comment threads

1 answer

+2
−0

Since this is homework, I'm not just going to give you the answer.

When all else fails, go back to first principles. That's what handy shortcuts, like using impedance, were derived from.

In this case, you'll end up with a system of differential equations. You have already written the equation for the capacitor current as a function of its voltage. Note that the capacitor and resistor currents are the same. You should be able to write the equation for the resistor current.

The voltage across the two components are also related, in that their sum must equal the driving voltage.

After you write the various individual equations, you solve the set of equations to get the capacitor voltage as a function of the driving voltage. Note that this assumes you've already had your differential equations course.

Why does this post require moderator attention?
You might want to add some details to your flag.

1 comment thread

General comments (2 comments)

Sign up to answer this question »

This community is part of the Codidact network. We have other communities too — take a look!

You can also join us in chat!

Want to advertise this community? Use our templates!