Circuit Definition and 1000 Threads

  1. I

    Cutoff frequency for this RLC circuit

    How would i find the cut of frequency of this RLC circuit .I have used LTspice to find it but what is the equation for finding it
  2. deskochan

    Finding the voltage of the circuit (resistor ladder)

    The answer is B. My question: (a) What is the basic approach to start to think about this problem: Equivalent resistance? ohm's law? (b) What is the purpose of gamma = R2/(R1+R3) because I have no idea how it uses? (c) Why the answer is an exponential drop of voltage?
  3. I

    Current in RLC Series Circuit: Need Help

    So am trying to find the current in the RLC series circuit ,but i think i have done something wrong ,if anyone could tell me where i went wrong ,it would be great ,thank you Resistor-100ohms Capacitor-0.01uF Inductor-25mH Voltage Source-50v a.c 1kHz
  4. A

    Metering a Single Phase 208 VAC Circuit

    Good day, I hope to understand how to use a 3 phase energy meter to measure single phase 208 VAC circuit. The basic idea seems simple, yet, complex meters don't seem to have this ability. Would anyone be able to describe what kind of information one would need from a digital 3 phase meter...
  5. J

    Electronics Will this electronic circuit work? (back-to-back polar capacitors)

    All I need is for someone to look at my schematic and tell me if this circuit will work. Thanks.
  6. U

    Electrical circuit problem (resistors, capacitors, inductors )

    I did try redrawing the circuit at steady state , but I'm not really sure. I have attached the circuit that I tried drawing, I assumed the branch with the capacitors to be absent at steady state since current won't flow through them anyway. With this diagram I get the correct answer for Q 19 ...
  7. cemtu

    Engineering Shunt Resistor, Grain Boundaries & Solar Cell Circuit

    In the circuit equivalent of a solar cell, shunt resistor is described as "The irregular polycrystalline lattice grain boundaries that resist to the flow of electrical current in the silicon material." If this explanation is correct, shouldn't it be "lower shunt resistance increases the current...
  8. Wrichik Basu

    Gain limiter circuit in LTspice - current flowing in wrong direction

    This is one more thread in my quest to learn simulations in LTspice. I am trying to simulate the gain limiter network shown in this video. A snapshot of the video is available for quick reference: My schematic in LTspice is shown below: For the simulation, I am using DC sweep on voltage...
  9. LarryS

    EM Waves Generated by an LC Circuit?

    I am not an electrical or electronic engineer. I am trying to understand how a simple, series LC circuit running at it's resonant frequency can generate EM waves. I believe, based on what I have read, that the frequency of the generated EM waves will be the resonant frequency of the circuit...
  10. Wrichik Basu

    What's wrong in my LTspice simulation of an Op-Amp integrator circuit?

    I am doing an online course on op-amps. The specific video I am talking about is this one (skip to 24:25). Here, the professor has derived the expression of the op-amp integrator circuit, and in the next slide, he tells that we can create a triangular wave from a square wave using this...
  11. Pouyan

    Complex circuit and its resistance

    The true answer is : The voltage between P and Q is 1.5 V. I got stuck finding the total resistance. My question is: Is B parallel to both A and C? Is C parallel to D ? I tried many ways to find the total R but failed! My first attempt: I say the system ABD is in serie with C...
  12. Xiao Xiao

    Engineering Finding V and I in a simple circuit

    So I know I have to use kirchhoff's Voltage Law so when I apply it's: -12+4i+2Vo-4-Vo=0 and Vo=6i so --> -16+4i+2(6i)-(6i)=0 but apparently that's wrong and Vo should be =-6i and so when I substitute it in the equation it should be -16+4i+2(-6i)-(-6i)=0 and I don't understand why.
  13. X

    Engineering How to Determine Voltage and Current in an RLC Circuit?

    Hi i want to know just how to approach this question. i know the omega=100 then should i find XL and XC? and then find the voltage in points c and d? also how do i find the current that enters point c? thanks a lot.
  14. cianfa72

    When to Use a Two-Port Representation for a Quadripole in External Circuits?

    Hello, I'm struggling with the conditions under which makes sense employ a two-port 'external' representation of a quadripole (four-terminal electrical network) when interconnected to an external circuit (to take it simple assume a linear + permanent electrical network). Starting from circuit...
  15. J

    B RC Low Pass Circuit Sine Wave Response

    Hey Everyone, I am trying to gain a level of fundamental understanding of an RC circuit sine wave response through the mathematics and was wondering if someone could help me work it out. Fundamentally a sine wave is represented by the equation y=-ky'' . When a sine wave is used as the input...
  16. Pouyan

    Which lamp is dimmed in the circuit?

    The true answer is B. But I don't understand why! I know: Kirchhoff's circuit laws : ∑In=0 If we assume that a current that goes from plus to minus, before it passes through lamp B, I know that according to Kirchhof's laws, part of the current will pass through the bottom path where there is...
  17. Osnel Jr

    What factors affect the induced voltage in an induction circuit?

    I'm thinking it would stay the same. Any answers?
  18. Vossi

    Verifying a circuit design with voltage regulators

    Need help verifying if this circuit design and use of elements is correct. The goal here is to run a 3v motor, hence I need to make the use of voltage regulators for a constant 3v energy to transfer.
  19. Wrichik Basu

    How do you calculate the series resistance for this Triac control circuit?

    Disclaimer: Some of you might easily recognize that the components and circuit I am talking about are related to one of my projects, on which I had posted some months ago. Actually, the circuit is the same as the one in my project, but the one I am posting in this thread actually uses high...
  20. PRITAM the cat of Ne

    Engineering Op-Amp circuit output analysis trouble

    THE ANSWER IS GIVEN: 6V, but according to me as the positive terminal is grounded the negative terminal will be virtually grounded (0V), from ohm's law (applying to the two series resistance) it is expected that Vo is 0V! I don't know where I am getting wrong!
  21. qh4305

    Why is the energy of a circuit in a magnetic field at infinity zero?

    Why is the energy of a circuit placed in a magnetic field at infinity zero?
  22. Xiao Xiao

    Engineering Electric Circuit Analysis of this First Order R-L Circuit

  23. hugo_faurand

    Amplifier for piezoelectric sensor, OP Amp circuit

    Hello everyone ! I'm working with a piezoelectric cell and I need to retrieve the variation of the charge of the cell as a voltage signal. I found this circuit (a charge amplifier) with an OP Amp ( here the piezo cell is represented as the current source with the capacitor and the resistor on...
  24. Andrei0408

    How do you calculate the impedance of the primary circuit?

    I'm not sure if it helps for what I'm looking, but I've calculated the mutual inductance, M, using the equation: M=U2/(ω*I1) = 106.3μH. I don't need the numerical value in particular, I just want to find a way to deduce the formula in order to calculate Z1. Thank you!
  25. T

    How Does Project 122 Snap Circuit AM Transmitter Work?

    Hi, guys! Could anyone provide an explanation about how the following AM transmitter works? It is similar to the AM transmitter for project 122 of the Snap Circuit kit by Elenco. Does it work as a switching modulator?
  26. E

    A query about this electrical circuit symbol

  27. Istiak

    Is My Delta to Wye Conversion Calculation Correct?

    I was following these [steps](https://www.allaboutcircuits.com/textbook/direct-current/chpt-10/delta-y-and-y-conversions/). I was calculating resistance for left side circuit. $$R_1=\frac{2 × 2}{2+2+4}=0.5\Omega$$ $$R_2=\frac{2 × 4}{2+2+4}=1\Omega$$ $$R_3=\frac{2 × 4}{2+2+4}=1\Omega$$ Then...
  28. Xiao Xiao

    Engineering Finding Vc for two circuits, Electric Circuit Analysis question

  29. B

    Induced EMF in a small square loop of wire at center of an AC Circuit

    I used the voltage of the power supply and resistance to solve for the current in the larger circuit (20V/5ohms=4 amps). I am not sure if the equation listed above is the correct one I should be using, but I tried it using the following numbers. For omega, I used 2*pi*frequency. N should...
  30. Z

    Don't know how to make an ultrasonic sensor circuit....

    Hello everyone, I am studying abroad and I am working on a speedometer project. I am preparing to use an ultrasonic transmitter and receiver to make an ultrasonic sensor circuit, and then connect it with the single-chip microcomputer msp430 to realize the functions of speed measurement and...
  31. Anubhav

    Oscillations in an LC circuit (Question from Irodov)

    https://www.physicsforums.com/attachments/282131
  32. brainbaby

    LT spice result analysis, Capacitance Multiplier vs RC filter circuit

    Hi friends, I have simulated two circuits, one is an RC filter and other is a Capacitance multiplier. My aim of experiment is to validate a decrease in Iout (load current) of CM circuit as compared to load current in RC filter circuit. Theoretically, Iout (CM circuit) < Iout (RC filter) Vp-p...
  33. Tim86

    DC current through a resistor circuit

    Summary:: Current through a certain resistor in a mixed dc circuit. Hi, Sorry if this is the wrong forum. I'm trying to work out the current through R1.The answer I need is 2 Amp, which I have confirmed with a simulation software. I have calculated the source current as 8A, the current past...
  34. J

    Calculate the impedance in this RC circuit

    So Z = sqrt[ R^2 + (1/wc )^2] and V=Ecos(wt) so I= Ecos(wt) / sqrt[ R^2 + (1/jwc )^2] but how do I use this to find the amplitude and phase of the current?
  35. R

    Circuit Analysis Theorem For the Number of Independent Equations

    I attached a screenshot of the book (sorry no pdf available for this book). Right above the somewhat central line they give the theorem that if there are m currents and n nodes, then there will be n - 1 independent equations from the current law and m - n - 1 from the voltage law. I count 4...
  36. M

    I Checking for negative feedback in a circuit

    This is the circuit in question. During lecture, when checking whether this was negative feedback, my instructor said that if the v_out increases, then v- increases as well, which would lead to the next v_out decreasing because v_out = A(v+ - v-). I get how if v- increases the next v_out would...
  37. M

    Some questions about capacitor discharging

    why does the voltage of the capacitor eventually go to 0 when discharging the capacitor? I heard that's because "current starts flowing when discharging", but how exactly does that lead to V going down? I know that I = C * dV/dt, but that doesn't seem to help me understand why V goes down (which...
  38. Xiao Xiao

    Electric Circuit Analysis, Nodal Analysis and finding Voltage.

    Summary:: The image shows two circuits, in the first one, using Nodal Analysis we find that V1=4.8V, but in the second circuit V1=10 because using KCL - 10+V1=0. I understand what happened in the first circuit, but I don't understand what happened in the second one, they look the same to me...
  39. Xiao Xiao

    Engineering Help in Electric Circuit Analysis -- One current source and a resistor network

    o9
  40. Z

    PWM signal generating circuit based on LM393

    This is a PWM signal generating circuit based on LM393. When I was running this LM393 circuit, I found that this circuit only consumes about 10 milliwatts of power at a voltage of 5V. Not only that, this circuit can work normally at 3.3V, 12V and 18V. But later I found that this circuit...
  41. C

    Current flow in a semiconductor circuit

    N/A
  42. Xiao Xiao

    Help finding Thevenim Equivalent - Circuit Analysis

    Summary:: So I found Vth=1.19 using Nodal analysis and I'm not sure if that's right, I'm trying to find Rth now but I'm confused as to what to do, any tip that tells me at least from where to start is appreciated. Edit: so I did 12||60 so Rth=10 ohm, is that correct? Is Vth correct too?
  43. Frigus

    Equal Peak Voltages in a Circuit: Is It Always True?

    In highlighted statement they are saying that vector sum of peak voltages of all components in circuit is equal to peak voltage of battery,I think they are saying this due to the fact that vertical components of both b and c diagrams are equal but what if their horizontal components are not equal?
  44. wcjy

    Circuits - Transfer function of this LRC circuit

    Got B = 9. My school doesn't provide answers, hence could someone double check if my answers is right? Thanks!
  45. hquang001

    Which Formula Should I Use for Calculating Power in an AC Circuit?

    Should i use P = V.I or P = Vrms.Irms.cosφ ?
  46. icesalmon

    Engineering What is the output for the following logic circuit?

    I obtained the following result: ([(A xor B) xor 0]* AC)' ([(A'B + AB') xor (0)]*AC)' [([A'B + AB']*(0)' + 0)*AC)]' [(A'B + AB')*(1)*(AC)]' [A'ABC + AB'AC]' [AB'C]' A'+B+C' the solution to this problem is getting a different answer, I don't know why this solution isn't inverting the output AB'C
  47. M

    Question about re-drawing circuit

    Hi, I was attempting this problem where the aim is to find the output current as a function of the voltage difference ## P_{in} - P_{out} ##. I just have two quick questions about this circuit: 1. If the 'reference voltage' (which I assume is how the ground voltage is referred to) is the same...
  48. S

    Engineering Can a voltage test source help solve for Rth in a complex Thevenin's circuit?

    So I've been absolutely stumped on this one. I've tried about a million different things but none of them have seemed right. A combination of the odd layout of the circuit, and a combined voltage/current source are making things really complicated for me. I'm somewhat sure the RTh is 15kΩ due to...
  49. patric44

    Is it illegal to reproduce someone circuit schematic in your paper ?

    hi guys i am trying to write a paper based on someone previous paper in which he discussed a simple electric circuit on some topic , my question is : is it illegal for me to reproduce the circuit schematic using multisim or something and properly cite them in my paper ? or i need their...
  50. L

    Transformers in a circuit, interpreting the label

    Hi hi, I was trying to use a transformer, that typical transformer that we have in house for a project, but then I notice something, well all this can be just a misunderstand from me. Actually a transformer have a voltage and a current, at least that is what it says the labels, "18V and 3A" for...
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