Circuit Definition and 1000 Threads

A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by excess current from an overload or short circuit. Its basic function is to interrupt current flow after a fault is detected. Unlike a fuse, which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation.
Circuit breakers are made in varying sizes, from small devices that protect low-current circuits or individual household appliance, up to large switchgear designed to protect high voltage circuits feeding an entire city. The generic function of a circuit breaker, or fuse, as an automatic means of removing power from a faulty system is often abbreviated as OCPD (Over Current Protection Device).

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  1. Kaushik

    Facing issues in understanding a Purely Inductive Circuit

    Consider a purely inductive circuit with an inductor of self-inductance ##L## and sinusoidally varying AC source of peak voltage ##V_{m}##. First of all, Why is ##V_{ac} = ε_{ind}## (where ##ε_{ind}## is the back emf)? Now, at ## t=0 ##, voltage is increasing at a fast rate. Hence, due to the...
  2. R

    I Question about Grounding in this Circuit

    Click the attached file to see the figure and the book's explanation. The explanation for 27-7 (a) makes sense as the point a comes after the grounding point and before anything else. Therefore it should have a potential of zero. But, to me, 27-7 (b) doesn't make any sense. Why should the...
  3. J

    PCB Layout questions for my High Voltage circuit

    I am looking at using a few 2 kV film box capacitors in series and I'm trying to make the board as compact as reliably possible. Let's say that I have two equal valued series capacitors rated for 2 kV each in series across a 4 kV power supply. Each capacitor will then have a voltage at 2 kV...
  4. curiosissimo

    Using Kirchhoff's laws on this current division problem

    The main problem is the verse of the 2 currents ## i1 ## and ## i2 ## . I think they both go clockwise, so in the node A we should have ##i1+i2=20A##. Now let's apply the second law (going clockwise). So ##ΔV1-R1*i3 - R2*i4 + ΔV2=0##, where ##i3## and ##i4## are the currents which pass through...
  5. Anirudhhades

    LR Circuit: Answers to Common Questions

  6. A

    Are All 10 Ohm Resistors in Parallel?

  7. E

    Does the electrostatic force create current in the circuit?

    As I understand potential difference is the reason of current. Does it mean that the electrostatic force creates current?
  8. J

    Engineering Simplifying a series / parallel circuit and calculating unknown values

    Given the circuit above, I have to solve for the labelled currents, find V total and R total accordingly. 1A is flowing through the 5Ω resistor as shown. Assuming electron flow (negative terminal to positive) for circuit. The connector in the middle was somewhat confusing. Without it, this...
  9. R

    Directional actuator control circuit

    Hi there. I want to power and control a linear actuator that is considered heavy duty. I am contemplating either using an an existing control driver or building the circuitry with various components. i want to use these attractive control buttons which are led light up...
  10. ubergewehr273

    I Extraction of a particular quantum state from a quantum circuit

    Hello everyone! I'm trying to implement a quantum circuit that yields a superposition state $$\frac{1}{\sqrt{2}} (|01 \rangle + |10 \rangle)$$ I'm using parameterized gates to achieve this. I have been able to create the state $$\frac{1}{\sqrt{2}}(|01\rangle + e^{i\phi} |10 \rangle)$$ Is there...
  11. M

    Engineering Simplification of a digital circuit

    I am trying to solve this problem I have solved this myself in two different ways, but i am getting different results. Solution # 1 Solution # 2 Now to find : Please see output is different in solution#1 and solution#2. Which solution is correct ? Is there anything I am missing.
  12. K

    I AC circuit and non-conservative field

    *Please refer to the attached question file
  13. N

    Using Complex Impedances in these RLC Circuit Calculations

  14. cianfa72

    Circuit Theory - about the applicability of the substitution theorem

    Hi, I've a doubt about the applicability of the substitution theorem in circuit theory. Consider the following picture (sorry for the Italian inside it :frown: ) As far I can understand the substitution theorem can be applied to a given one-port element attached to a port (a port consists of...
  15. M

    Engineering Help understanding this asynchronous sequential circuit please

    I am finding difficulty in understanding the sequence transition graph My Book has given solution like this Question : I have marked red circle in the above table. ...book has given E but I think it should be F ...What is correct here E or F ? Here is the state diagram given in the book
  16. jisbon

    RLC Parallel Circuit: Analyzing Current & Voltage at t=0-

    These are my attempts at doing this question, and I was wondering if I am correct so far. At t= 0-, i(L) will be 0A, since the capacitor acts as a open circuit. However, I'm not sure why V(c) at t=0- will be -20V as given by the answers. Won't it be 0V? Moving on, since current in inductor and...
  17. E

    Could you check this Li-ion charging circuit?

    Can secondary cell can be described in circuit simulator?? With other symbols like capacitor. Also I wonder if there's a program that provide secondary cell(like Li-ion battery). Please help me
  18. jozefmak

    Grounding a circuit through a capacitor/parallel RC circuit

    Hi, I have two similar circuits. One of them is clear for me but I am not sure how the second one works. Let's start with the clear one: a parallel RC circuit, which is explained here: At time t = 0s there are zero volts across the resistor because the capacitor is fully uncharged. After...
  19. Kaushik

    Understanding the Phase Difference Between Voltage & Current in a Circuit

    Consider a circuit with a witch, capacitor and an AC voltage source. The sinusoidal AC voltage source is depicted in the following graph: We know that, ##Q = CV## ##\frac{dQ}{dt} = C \frac{dV}{dt}## ##i = C\frac{dV}{dt} \tag{1}## So from the graph, the voltage increases rapidly around ## t =...
  20. Samama Fahim

    Calculating the Thevenin's Resistance of a Breadboarded Circuit

    How would we calculate the Thevenin's resistance for the above circuit? The right answer for this circuit is 1.5 kOhm. $$R_{567} = R_7 + (R_5 \parallel R_6) = .5 + .67 = 1.2 k\Omega$$ $$R_{34567} = R_3 + (R_4 \parallel R_{567}) = 1 + .75 = 1.75 k\Omega$$ $$R_{TH} = R_1 + (R_2 \parallel...
  21. A

    Calculation with this electric circuit (battery and resistors)

    Hey, I am struggling a bit, als I try to solve this problem - I‘d say all five statements are correct, but it is said, that one must be incorrect
  22. T

    Another angle of "Why do you need a line 2 on a circuit?"

    I know that on an alternating current circuit, you have to have both a line 1 and a line 2 to have a circuit. Here is a pictorial diagram of an alternating current circuit: In a previous thread, I asked why would an AC circuit like in Diagram 2 not work? Here is a photograph of diagram 2...
  23. Helena Wells

    Voltage Substractor simple circuit

    I have created a voltage adder using this circuit where Va and Vb are the input voltages. And Vout is between the emitter and the resistor. How can I modify it to a voltage substractor?
  24. Kaushik

    Question about charged capacitors and inserting a dielectric into one

    First when it is connected to the battery, the capacitors start accumulating charges such that the potential difference equals that of the battery. Then the current stops flowing. ##Q_1 = CV## ##Q_2 = nCV## Where 1 and 2 represent the capacitor with capacitance C and nC respectively Then, when...
  25. M

    Engineering Calculating Power Lost in a Resistor (within Transformer Circuit)

    Hi, I have a simple question that I don't have a fundamental understanding of: do resistors dissipate reactive power (in addition to active power)? For context, when we are looking at a transformer (single phase) equivalent circuit (similar to the one in the image attached), we are asked to...
  26. E

    Help designing an electrical circuit for camper van

    Hi everyone Hopefully I am not out of line posting in this forum. I am looking for some advice planning the electrical system for my camper van. I know very little about electrical circuits and all related to it, and after 4 days of research I am still nervous to spend a lot of money and...
  27. Kaushik

    Does potential drop when a charge flows through a wire w/ 0 resistance?

    Let us connect a battery of potential difference V to a wire. There is no resistance. Nothing! Now the battery creates some potential difference and the charges in the conducting wire move due to the Electric field created in the conductor by the battery. So, as the charge moves, its potential...
  28. T

    A different angle of Why do you need a line 2 on an AC circuit?

    Preface to thread: I am darn well aware of the fact that on an AC circuit, there has to be a line 2 after the load to bring current back to the power source. This thread is about WHY does there have to be a line 2 after the load to bring current back to the power source. I hope that I don't...
  29. D

    How to calculate R1 and R2 in this RC circuit

    Using the Capacitor voltage vs. time graph, I calculated the time constant τ when the switch is closed (capacitor charging) and open (capacitor discharging). I calculated τclosed = 2.5s and τopen = 3.75s. Since the resistors are in parallel when the switch is closed, I assumed that 1/Req = 1/R1...
  30. Boltzman Oscillation

    Where is the demodulator in this AM receiver?

    I am trying my hands on building receivers and transmitters. For now I would like to build this receiver here: now I see that the 500pH inductor in parallel witht he 200uH capacitor are in charge of filtering the unwanted frequencies. The top-left NPN is in my guess an emitter follower to...
  31. Frigus

    How to simplify this capacitor circuit?

    I tried to find logic behind how do we simplified the circuit as given for 2 hours and I unable to find any clue. I can do it just by following rules but I am unable to get intuition. I tried to make sense of it but how can we even make two points as one.
  32. J

    Dr. Middlebrook's "Technical Therapy For Analog Circuit Designers"

    Dr. R. David Middlebrook was a very well known professor of analog engineering at Caltech. He was also a cofounder of the power supply design and analysis group "Teslaco". Dr. Middlebrook developed a program "Technical Therapy for Analog Circuit Designers". The dvd was available for several...
  33. Boltzman Oscillation

    What approach should be used when solving a circuit?

    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 I am solving for...
  34. naftacher

    Confused as to where I begin to solve this circuit branch problem

    I am thinking that this circuit needs to be simplified somehow? Finding an equivalent resistance and moving from there?
  35. naftacher

    Struggling to find the equivalent capacitance of this circuit

    I asserted C3, C4, and C5 to be in series. **I found the capacitance of "C3-4-5" to be 1.67x10-6 F. This I did by using 1/C = 1/C3 + 1/C4 + 1/C5 Then I noticed that I had another series circuit of "C3-4-5" and C1, and C2. Again, I used a similar formula. I obtained an equivalent capacitance of...
  36. Boltzman Oscillation

    Engineering How does this Bipolar RF Amplifier + Output Transformer circuit work?

    I am trying to create a receiver for a personal project I am working on. This is the RF amplifier that I was given by a book I am following. How does this circuit work? Usually for a BJT amplifier I find the DC bias point and then use the small signal model after I bias the circuit? I understand...
  37. Adesh

    Capacitors connected in series: Why is the voltage the same?

    Here is a circuit diagram: . We have three capacitors, with capacitances ##C_1##, ##C_2## and ##C_3##. Plates are labelled as ##A_1, A_2, A_3 ... A_6##. Point P is connected to the positive terminal of the battery and point N is connected to the negative terminal of the...
  38. cnh1995

    Engineering Why Does Doubling the Time Solve the AC Transient Equation in an RC Circuit?

    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?
  39. rachelmaddiee

    Voltage drops in a series circuit

    Known: V source = 30.0 V , R1 = 15.0 W, R2 = 15.0 W, R3 = 15.0 W To determine the current, first find the equivalent resistance. I = Vsource/R and R = RA + RB = Vsource/RA + RB 30.0 V/15.0 W + 15.0 W + 15.0 W = 1.5 A This is as far as I could do the work for this question. I’m having trouble..
  40. Boltzman Oscillation

    Engineering Variable Gain Amplifier Analysis help

    I need to find A_v, I want to relate Vin to Vout. To do this I did KVL on the major loop: $$V_{DD} = I_D*R_D + V_{SD1} - V_{SD2} - I_D*R_D$$ Since M1 = M2 then everything would cancel out and I would just get V_dd = 0 which is probably wrong. This is assuming V_sd1 = V_sd2, is that correct?
  41. Adesh

    How can electrons flow all the way through the circuit?

    Electric currents and the things within are generally explained through the help of intuitive water current examples, where potential difference is explained through the pressure difference and electric current is explained as the flow of water. But I like to think in terms of some driving force...
  42. jisbon

    Engineering Finding the transfer function for this circuit

    Transformed circuit: Using KVL, Now, I am unsure about the current to use KVL in this case. As far as equation goes: Vi(s) =(I1*R)+(I3*R)+Vc(s), where Vc(s) = V0(s)/u as shown in the circuit. How am I supposed to find the current I1 and I3 for the two resistors in this case? Thanks
  43. hmzi123

    Solve the circuit and find all the currents in the circuit

    Hello, i have this circuit as a homework. And i have to find all the I's, and Uef, i got stuck at writing Kirchhoff's laws in this circuit, do you think you can help me write them, and also can you explain how can i calculate Uef?
  44. hmzi123

    Engineering Solve RC Integrator Circuit Problem | Romania Student

    Hello, i am student from Romania ( first year) and my physics teacher told us to solve this problem. We know that C=150 nanofarad, R= 1000 ohms, and the frequency we should take is more then 1061 ( 10kHz, to be more exactly). My problem is that i don't know what to take as V1 ( i took it coswt...
  45. H

    Designing a DC Motor Torsional Spring Circuit with Arduino Uno

    I'm a relatively new entry into the world of electronics so my understanding of what is possible may not be an accurate one. In a nutshell, I would like to have a DC motor act as a torsional spring with some variable virtual spring constant (k). The motor, or "spring", would act against an...
  46. kyphysics

    Which Circuit Breaker Switch to Turn?

    My home water heater is messed up. If I want to reset the circuit breaker for it, which should I turn? There are three: 1.) garage (where the heater is located) 2.) water heater/dryer 3.) heat pump
  47. S

    Calculating Total Resistance in a Circuit: Delta - Y Formula or Simpler Method?

    To find total resistance between 22 Ω, 14 Ω and 4.5 Ω should I use delta - Y formula? Or there is other simpler way? Thanks
  48. evinda

    MHB Construct circuit that implements truth table

    Hello! (Wave) I want to construct a circuit that implements the following truth table:\begin{equation*} \begin{array}{c|c|c|c|c} P(Input) & Q(Input) & K(Output) & A(Output) \\ \hline 1 & 1 & 1 & 0 \\ 1 & 0 & 0 & 1 \\ 0 & 1 & 0 & 1 \\ 0 & 0 & 0 & 0 \end{array} \end{equation*}In...
  49. R

    I Hamilton path and circuit rounded path problem

    Here is a graph. I wonder if it has hamilton path or circuit. In hamilton path we have to cross once and only once at an edge, and the start and the finish must be different locations. In hamilton circuit we have to start and finish the same edge. So the circle which B is rounded, which kind of...
  50. jisbon

    Engineering Nodal Analysis of this Circuit using the Laplace Transform

    Was just practicing some problems on the Fundamentals of Electric Circuits, and came across this question. I understand I will have to transform to the s domain circuit, which looks something like this: Then doing nodal analysis, I will get the following for the first segement (10/s-V1)/1 =...
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