- #1
n00bcake22
- 21
- 0
Electrical Engineering-- Capacitor Resistor Circuit
Hello all. First time posting so excuse any fourm faux pas I may make. I was wondering if anyone could lend some help with the circuit below (ignore the *, they are just space holders to prevent reformatting of the circuit):
|------) |-----) |--------\/\/\/\/\----------|
|*****C*****C*********R********** |
|********************************|
|--------------------/*** -----------------|
****************Switch
Here are the details of my question:
C1=C2=C (value unknown, used as the energy source, and both charged to 2.5V initially)
R=500 Ohms
Question: Find the minimum value of capacitance such that when the switch is closed at t0 = 0 to t=1ms, the voltage across the resistor (R) does not drop below 4.9 Volts. Please show/explain equations and work.
Below is what I have (let me know if any of it is wrong):
Kirchhoff Voltage Law
- v_c - v_c = v_r
2 * v_c = v_r
Inserting voltage equations for v_c and v_r
2 * ( 1/C * Integrate( i_c(t) dt, t0, t) + v_c0 ) = i_r(t) * R
Series circuit so i_c(t) = i_r(t) = i(t)
2 * ( 1/C * Integrate( i(t) dt, t0, t) + v_c0 ) = i(t) * R
Now I'm stuck; how can I express i(t) as a function of knowns and/or C.
Thanks again for all the help!
Homework Statement
Hello all. First time posting so excuse any fourm faux pas I may make. I was wondering if anyone could lend some help with the circuit below (ignore the *, they are just space holders to prevent reformatting of the circuit):
|------) |-----) |--------\/\/\/\/\----------|
|*****C*****C*********R********** |
|********************************|
|--------------------/*** -----------------|
****************Switch
Here are the details of my question:
C1=C2=C (value unknown, used as the energy source, and both charged to 2.5V initially)
R=500 Ohms
Question: Find the minimum value of capacitance such that when the switch is closed at t0 = 0 to t=1ms, the voltage across the resistor (R) does not drop below 4.9 Volts. Please show/explain equations and work.
Homework Equations
The Attempt at a Solution
Below is what I have (let me know if any of it is wrong):
Kirchhoff Voltage Law
- v_c - v_c = v_r
2 * v_c = v_r
Inserting voltage equations for v_c and v_r
2 * ( 1/C * Integrate( i_c(t) dt, t0, t) + v_c0 ) = i_r(t) * R
Series circuit so i_c(t) = i_r(t) = i(t)
2 * ( 1/C * Integrate( i(t) dt, t0, t) + v_c0 ) = i(t) * R
Now I'm stuck; how can I express i(t) as a function of knowns and/or C.
Thanks again for all the help!