Recent content by alexmath

Homework Statement I've been trying for a week to understand root locus and how it works but what i got is a big confusion that's why I'm asking here for help. Why do we only look at open loop transfer function of the system when we are supposed to know the stability of the closed loop system...

Thank you!

I connect them in series like this: V ------- R ------- C ------- gnd, where V is the input, and Vc is the output. http://en.wikipedia.org/wiki/RC_circuit#Transfer_functions What i want is to get back from s-domain to time-domain.

Homework Statement R = C = 1; Homework Equations G(S) = 1/(s+1) The Attempt at a Solution Suppose R = C = 1 then the transfer function from the input voltage to the voltage across the capacitor is 1/ (s+1). So Vc(S) / V(S) = 1/(s+1). Getting back to time-domain: Vc(t) = V(t) * e^-t. What's...

Hi, I've been struggling to find the answer to this questions, which are probably simple ones. Does it matter what order a resistor and LED ( or any component ) are in. For example: Vcc -----resistor------Led------gnd or Vcc ------led-------resistor------gnd Are they the same...

You are right. My mistake!

Homework Statement Problem is in the pic. uploaded. Homework Equations The Attempt at a Solution Also in the pic. The right answer is -3, where is the fault? Thank you!

So by using transformers we lose half of power in the primary? In which conditions do we use resistors in favor of transformers and vice versa? Which of them is more efficient? I understand how they work but i really want to see which of them is more efficient? Thank you!

Hello! I'm still not clear on a few things: For example: Let's say a manufacturer creates a device which runs at 120W (let's say a lightbulb). Does this mean that i can use which combination of voltage and current such that V*I=120W i want? Another example: Let's say that the maximum...

only two first components added up give 40j+100 ( i did not even check the calculation) , wolframalpha was wrong haha... the correct answer is: 123.47<17.53 right? so the final impedance is 123.47 over sqrt 2 or not here? (1000t + 17.53 degrees converted in radians)

checked it on wolframalpha... what's wrong? :(

Homework Statement Hello everyone! I have the following circuit to solve, and my result is a bit wrong... can you tell me please where's the mistake? E=10sin(1000t) Find the current delivered to the circuit. Find the equivalent impedance of the circuit. Find the equation of the current and...

transformers -- Don't understand VpIp = VsIs Homework Statement If the equation below of any transformer is true, therefore it does not matter if i connect a lightbulb or anything else either to the primary or the secundary, it should be working the same, right? I have a 220v-3v step down...

Ok, sorry for that. Can you also tell me how the equation 1 and 3 should look like, in 3 days a have a test and I'm really really struggling understanding this.

I tried solving the following circuit using nodal analysis, but the answer I've got is wrong. Can you tell me please which one of these 3 equation is wrong? Thank you!