Could someone please help.
i need to connect a 12vdc motor which can draw 16 amps
to a switch that has an led on it. the led is rated at 3v 20mA.
The power supply i am using is rated to put out 12vdc at 30A
I thought of the possibility of adding a resistor to the positive pole of the led.
In...
For the following circuit I need to find the output waveform.
A. Conceptually I am at sea here but I will have a stab at it. My though process is as follows :
At a given instant, the AC voltage is at a fixed value and this value drops (##V_drop##) across the resistor ##R##.
The voltage...
I am close to graduating as an EE major but I have never been able to organize a step by step method on analyzing a circuit. It seems to me that every time I am trying to analize a circuit I end up with a bunch of equations and nothing more. I know that I should:
1. Know what im solving for...
I'm trying to understand the physical reason why when you drive an ideal inductor (no series resistance) with an ideal voltage step input (no series resistance), e.g. some Vin(t) = V0u(t), the output current will be a linear ramp. I can see how to derive this from the inductor equation, v = L...
Here, at voltage source zero crossing,
cos(2to + pi/4) =0.
So, 2to+pi/4 = pi/2
This gives to=pi/8 = 0.3926s.
But the given answer is twice the answer I got i.e. 0.7852s.
Have I missed anything here?
Hi.
Let's say we have a circuit like that, and we want to find the Thevenin/Norton circuit from a and b points.
So for Vth, we calculate the Voc, in which we remove the 2K ohm resistor and calculate the Voc. I calculated it correctly. But I have problem in calculating the Norton current. So in...
I am given that all the BJTs are the same.
First of all, when finding node voltages like Vref should I make the node voltage a voltage source first and then do circuit analysis? If so then I would use KVL but that does not give me Vref = 2Vbe.
I do know that Vref = Vb1 = Vb2. What am I doing...
Equivalent capacitance before and after remains the same.
Now the 10F capacitor (which was initially connected in parallel with 20F) would have 30 C charge. Hence an additional 20C must have been supplied to it. The only path which may supply the charge is through battery. However this leads...
I tried to conserve the charge on the left plates of both the capacitors as intially the total charge on both is 48 and at t=t0 the total charge is 36(on c1) +4V(V is the potential across c2) so i got V=3 and then i conserved the energy
Initial energy on both capacitor = final energy on both +...
Summary:: Trying to find Rth but I do not get the same value as the one from the solution.
[moderator: moved from a technical forum. No template.]
I am trying to find Rth to solve this problem, however once I simplified it, I get a value of 700.745 Ω while in the solution, the answer is...
I built a guitar (fuzz) effect, and analysed the sine wave from a tone generator through an oscilloscope. Wondering what the wave means and how it got to be the way it is. I will attach a picture of the oscilloscope screen + the circuit I used for the Fuzz effect. My question is what the cause...
I have to solve a problem related with an 'invented' (non-real) MOSFET working in its saturation region (amplifier). I have solved all the questions, but I'm unable to get the last one. Basically, I need to determine the output resistance of the amplifier as a function of other given 4...
I really don't have any clue why the total voltage is equal to the voltage drop over the 3 Ω and 2 Ω resistors and independent of the 4 Ω resistor . Does it have to do with parallel circuits?
To solve this question first I calculated the potential energy the capacitor A stored. It's equal a: Ca.V²/2. Ok, so when switch S1 is open and S2 is closed I calculated the equivalent capacitance as if they were in series --> 1/Ceq = 1/Ca + 1/Cb --> Ceq = (Ca.Cb)/(Ca+Cb). So I used the formula...
I honestly don't know how to quite even begin this problem.
Looking at Fig 3-2, the slopes of the graphs are 1/R, and hence where the slopes are 0, we have infinite resistance, in which case current wouldn't flow through that resistor and hence simplify the circuit. So I was trying to find...
From the circuit I have:
##-v_b + v_a + V = 0##
##v_b - V = v_a##
##i_1 = (v_b - V)/R_1##
##I + i_2 = i_1##
##(v_b - V)/R_1 = I + v_b/R_2##
From this last equation I get ##v_b = 10.8## and hence ##v_a = 5.8##.
However, apparently that is wrong. (And hence my answers to #2 were all wrong as...
I don't get this. Since we have analyzed the circuit separately for each source, adding them should give me the final values of I1, V2, I2, V1 etc. However, that's not quite true—from cases 1 and 2, I should have I1 = 4 + 5 = 9 mA, but it's 8mA. Hence, I thought that the black box consumes 1mA...
I am having a hard time solving this. Letting \$i\$ be the current flowing into ##R_3##, ##i_1## the current flowing through ##R_1## and ##i_2## the current through ##R_1##—and the node between R3 and R1 be e_1;
Using KVL and KCL, I've managed to find that
##i + I = i_1 + i_2##
Hence...
I am going through "Circuit Analysis for Dummies". On pg 18, it says, "If you calculate the power dissipated as 0.1 watts, then a 0.25-watt resistor can handle this amount of power. A 0.125-watt resistor should be able to handle that amount as well, but when it comes to power ratings, err on the...
Hi,
after calculations I end up in the circuit below¨ (Thevenin equivalent)
So now I have to say Rth=RL and I will find Rx ?
The initial circuit is this:
Thanks
Hi,
I'm trying to solve this but it becomes difficult. I'm using KCL and I repalce ZL = j0,1ω (Ω) , ZC=... etc.
Finding 3 equations with 3 unknown variables (plus the ω).
And now is the time for Cramer's rule.
I'm not sure if I should move on.
What do you say ? I'm on track ?
Thanks.
..
Hi all,
I was trying to solve this but I'm stuck as you can see in my notes below:
Using simulator the I1=3.125 A | I2=-1,857 A | I3=4,375 A and Power of the dependent current source = -46.875 W
Any idea, what could be wrong ?
Thanks.
I know the following equations for if the damping ratio is less than 1:
$$\sigma = -\zeta \omega_n$$
$$\omega = \sqrt{(1 - \zeta ^2)\omega^2_n}$$
I am given the following circuit that I built on LTSpice:
Measuring the voltage between node 2 and ground (blue), and the voltage Vc4(t) (green) I...
Hi all !
I want a confirmation for this exercise please.
The circuit:
This is my try: https://www.docdroid.net/EFuTDMp/new-doc-2019-10-03-234340-1-converted.pdf
--
Thanks
Summary: Perform nodal analysis on a circuit to find voltages.
For a laboratory I am trying to find the nodal voltages for a circuit we built using hand calculations. I have the answer as we ran the simulation which shows all the nodal voltages, however my nodal analysis seems to be wrong as I...
Hi all,
I tried to solve this, but I can't find the R(equal). I use the following method.
The circuit:
For t<0 the switch is closed so the iL(0-)=4 A
For t>0 it opens and the iL(∞)=0 A
Now, I want to find the value τ=L/R(equal)
Then I will use the: iL(t) = iL(∞) + ( iL(0-) - iL(∞) )* (...