Timeline for Determining an equation for the current after the switches close
Current License: CC BY-SA 4.0
15 events
| when toggle format | what | by | license | comment | |
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| Nov 26, 2020 at 20:38 | answer | added | Jan Eerland | timeline score: 1 | |
| Nov 26, 2020 at 18:17 | answer | added | Chu | timeline score: 1 | |
| Nov 26, 2020 at 16:20 | comment | added | DKNguyen | You can use Falstead simulator to verify. Note you never gave us LC either. Warning: don't use degrees inside sine, especially if there is more than one term in there since the units of 10000t must match up with degrees and it gets all weird and nonstandard. Stick with radians. | |
| Nov 26, 2020 at 16:16 | comment | added | alex |
is i(t) = -0.125Sin(10000t - 5.74(degrees)) correct?
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| Nov 26, 2020 at 16:13 | comment | added | alex | kk thnx for the help, ill see if i can calculate it now. | |
| Nov 26, 2020 at 16:11 | comment | added | AJN | In short, there are three unknowns. We need three equations. Two of them are \$i_L(0+)=\dots\$ and \$L\cdot di_L(0+)/dt= v_C(0+)=\dots\$. You need one more equation. | |
| Nov 26, 2020 at 16:08 | review | First posts | |||
| Dec 10, 2020 at 12:32 | |||||
| Nov 26, 2020 at 16:08 | comment | added | alex | I am pretty sure the one i found was incorrect, but here it is symbolab.com/solver/vector-cross-product-calculator/…, im not sure how do do the fancy math markup stuff | |
| Nov 26, 2020 at 16:07 | comment | added | AJN | \$di/dt = A\omega cos(\cdot)\$. For this circuit, after switches change over, \$L di_L(t=0+)/dt = v_C(t=0+)\$. So, you can solve for A and \$\phi\$ from two equations and two unknowns. \$\omega\$ is the standard formula for LC circuits for this circuit also. | |
| Nov 26, 2020 at 16:06 | comment | added | DKNguyen | Now that you have initial conditions, you need a differential equation of the circuit after it switches. Or you can use shortcuts since you know the form of the solution. | |
| Nov 26, 2020 at 16:05 | comment | added | alex | oh my bad yeah that was a typo | |
| Nov 26, 2020 at 16:04 | comment | added | alex | Il(0-) must be 0.0125A and Vc(0-) should be 5V due to how they behave in a DC circuit iirc. | |
| Nov 26, 2020 at 16:03 | comment | added | alex |
so the caps are open circuits and the inductors are short circuits, so the initial current as they close will be 5 / (200 + 200)A, and since the current cant change instantly because there will be an infinite voltage then as they close it will stay the same, that's pretty all I'm pretty sure i have done correctly
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| Nov 26, 2020 at 16:01 | comment | added | DKNguyen | Assuming infinite time before the switch switches, that means it starts in steady state. Since it is a DC source, what is a cap and inductor at DC? Also "switch closes" doesn't mean much for DPST switches. | |
| Nov 26, 2020 at 15:56 | history | asked | alex | CC BY-SA 4.0 |