What is Circuit: Definition and 1000 Discussions

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. X

    Current flow in a two source circuit

    Hi guys, is the current flow in this picture correct? I'm trying to understand current flow in a two source circuit.
  2. E

    Can this circuit be solved? Please explain

    See the attached image. This circuit seems simple enough, but the fact that the voltage drop across each of the resistors is not the same means that equivalent resistance methods cannot be applied. Is more information required? Thanks for your help!
  3. E

    How to know if a certain number is a don't care in KMAP

    Homework Statement given the function $F(a,b,c,d)=Σ(0,1,2,4,5,10,12)$ how can i know for sure if 8 is a don't care? and is it possible for 6 and 14 to be don't cares? Homework Equations it's part of a bigger exercise, so the boolean expression i got from previous parts is a'c'+c'd'+b'd' The...
  4. R

    Calculate the RMS current of an ac circuit

    Homework Statement : [/B] calculate rms value of current i= 3+ 4 sin(ωt+π/3)Homework Equations : [/B] Irms2=(∫0T [I(t)]2dt)/TThe Attempt at a Solution: I tried to integrate but I'm getting a T term.
  5. Harshna

    Engineering Find Currents I1 and I2 in an Electric Circuit

    Homework Statement I need to find the currents I1 and I2 in the attached image, but am having some difficulties grasping the concepts. I am given E(t) = 338sin(t) as well as values for R, L and C. I think I know what I need to use but I am not sure how to put it all together Homework Equations...
  6. marsupial

    Valid and Invalid interconnections

    Homework Statement My question is about the following circuit: https://ibb.co/hWnb9v According to the answer, it is an invalid circuit as the voltage drop on the left totals 14V and on the right totals 16V, and they have to be the same between any two terminals. I understand that it has to be...
  7. ryanuser

    Can a simple metal detector be modified to detect pipes at a higher voltage?

    Hello, I am a civil engineering student undertaking a project to investigate the effect of pipes and pipelines beneath the ground on the urban city environment above. In order to proceed I am designating a simple metal detector. Due to low depth capability of all commercial metal detectors mine...
  8. G

    Engineering Voltages and current in a circuit: incorrect signal?

    Homework Statement Consider the circuit in the figure and calculate V1, V2 and IA. Notice that the symbols V and A represent, respectively, an ideal voltmeter and an ideal ammeter. Homework Equations Ohm's Law $$V=RI$$ KVL The sum of the voltages of a mesh in a circuit equals zero. We...
  9. T

    Circuit breaker using microcontroller project

    So I am trying to make a circuit breaker using a microcontroller. I managed to get as far as this So I have the CT with a peak detector running to the adc. I then calculate the rms by dividing by root 2, which I then compare with a reference in this case 10A and it trips via the mosfet/relay...
  10. M

    Need help with a mod-6 counter using JK flip flops w/ control bit

    Homework Statement [/B] I am currently working on an assignment in which I create a six-state up/down counter. The purpose is to understand the functionality of flip-flops within a circuit among other things. There are 3 input bits (Q2,Q1, Q0), and a 4th control bit (C) which determines the...
  11. C

    Potentiometer Circuit 1: Balancing the Current - Solving for Ix and Rx

    1. problem statement, all variables and given/known data 1) What is the relationship between Ix and Rx ? 2) Prove that on varying resistance Rx , Ix reduces to zero . Homework EquationsThe Attempt at a Solution Assume resistance of Galvanometer is ##r## . Total resistance in middle branch...
  12. S

    D-Flip-Flop Circuit: Understanding the Enable and Clock Input Functions

    So I have been watching his videos trying to get ready for second year engineering (electrical). However, I am very confused as to what exactly is going on when he is pressing the enable/pulse switch during the run-through at 14:45. He has the enable connected to a capacitor, and he calculates...
  13. J

    Find the value of resistance in the circuit

    Homework Statement Homework EquationsThe Attempt at a Solution [/B] I don't understand how can current in ammeter be zero .Why is 2V battery not sending current in the right loop ?
  14. C

    Calculating Currents & Voltages of an RLC Circuit

    Homework Statement An RLC circuit contains the following components in series: a 15Ω resistor, a 200μF capacitor, and a 12mH inductor. What are the currents and voltages through each component? It's known that the current through the resistor is 1.75A⋅cos(250πt) Homework Equations χL=ω*L...
  15. C

    Resistor and current in a circuit

    Hello , I have to teach a group of 9th grade students role of resistor in a circuit and how it affects the current in the circuit . This will be their first exposition to circuits .So I need a good and simple analogy so that students can grasp these concepts easily . This is what I plan to...
  16. prakhargupta3301

    Why isn't the Heat generated = Voltage*Charge carried?

    I found out that Power of an electrical circuit will be equal to the work done divided by the time T for which the power by the cell or battery is exerting to keep a potential difference V in the circuit for a charge Q. Hence, Power= Voltage*Charge/time Which then can be written as: Power=...
  17. B

    How Does Gauss' Law Apply to Currents in Electric Fields and Circuitry?

    I am designing a device, which will utilize an electric field. The question I have run into is whether or not the current is treated as the charge enclosed for Gauss' Law, or if there's another way I would calculate it. Also, am I correct that the voltage of the circuit would be different than...
  18. esha

    Potentiometer nulling voltages in a circuit

    this is the potentiometer and the emf of cell E2 is unknown. now to know the emf just finding the null point of the galvanometer is enough. its because at that given length the potentiometer has the same potential as the cell. but why are they equal at null point? Sent from my Micromax E311...
  19. S

    Short Circuit Current on 161kv line

    I work at a electric arc furnace. We measure a lot of items on our furnace and found that some weeks we preform well and other we do not (kwh/ton). With everything else being equal i believe that the utility's available short circuit current is affecting this. The utility feeds our substation...
  20. F

    RC circuit -- finding the charge on each capacitor

    Homework Statement I have to find the charge ##q## on the capacitors (all have capacity ##C= 4 \mu F##) and ##\mathscr{E} = 12 V##, ##R=50 \Omega##Homework EquationsThe Attempt at a Solution I wrote the nodes current equations ##\begin{cases} i_{1}+i_{2}=i_{3}\\ i_{3}=i_{4}+i_{5}+i_{6}\\ ...
  21. R

    Maxwell Ansoft and Circuit Editor

    Hi Guys, I'm simulating a SRM in Maxwell 2D transient solution and my wingdings are external but a group of them are not able to show in the maxwell circuit editor. I've got this error: Cannot find the matching inductor in the imported file. Can someone help me with this?
  22. S

    Electricity (charge on capacitor in circuit)

    Homework Statement A capacitor of is connected as shown in the circuit. The internal resistance of the battery is Amount of charge on capacitor plates will be : Homework Equations no relevant euqations given. The Attempt at a Solution I don't even know how to begin with the question:(...
  23. S

    Electricity (Potential difference between points in circuit)

    Homework Statement In the circuit shown, what is the potential difference VPQ? Homework Equations No relevant equations given in question The Attempt at a Solution Tried kirchhoffs law. Tried to find equivalent battery and resistance but that doesn't seem to be possible.
  24. A

    A circuit board to charge a LiPo battery?

    Hi guys I'm creating a prop that's probably going to have a 7,4V 5000 mah 45C RC Lipo battery in it, and I'm planning to keep it permanent in the prop with a charge circut to charge it up with usb perhaps. I've thought of using a tp4056 circuit I have laying around and it seems like the...
  25. evinda

    MHB All boolean functions are computed by a depth 2 circuit

    Hello! (Wave) I am looking at the following exercise (pg. 92, ex. 11.1 , book:Gems of Theoretical Computer Science by Uwe Schöning ) : Why can all boolean functions on $n$ variables be computed by a circuit with only 2 levels (a depth 2 circuit) ? What is the size ( number of gates ) of such a...
  26. R

    Calculating Heat Loss in a Series Circuit

    Homework Statement Determine the heat loss in the circuit that is connected in series with two batteries (12 V and 6V) and two resistors (6ohms and 4 ohms). Homework EquationsThe Attempt at a Solution I used the difference in P = V^2/R, the power dissipated in the circuit, to calculate the...
  27. F

    Complex Capacitor Circuit (for me)

    Homework Statement 1. V for C1 2. Let's Say "C" is Resistor then C1 = R1 etc. how to get Eq Resistance for this Circuit ?[/B]Homework Equations Faraday's Law, Kirchoff Law The Attempt at a Solution [/B] for no 1 :I just want to make sure. point A is transfering negative charge to C2 and...
  28. e0ne199

    Engineering Problem with series RLC circuit and dependent source

    Homework Statement here is my problem : Homework Equations like usual, the problem is related with RLC circuits and transients The Attempt at a Solution [/B] from here, the solution is obviously wrong because from the solution, its alpha should be -300 and not -0.4...and from the...
  29. evinda

    MHB Why isn't the circuit a combinatorial one?

    Hello! (Wave) I read the following about parity functions: Since I haven't heard of combinatorial circuits before, I have searched for them. I have found the following: http://http://www.math.northwestern.edu/~mlerma/courses/cs310-04w/notes/dm-combcirc.pdf I haven't understood how we deduce...
  30. H

    How to choose a fan for open circuit wind tunnel?

    Hi all, I am trying to design a open circuit wind tunnel, and I've got to the point where a fan should be selected. However, I am not familiar with fans at all, so I am wondering if you could help me! My understanding is that the fan selection process is quite similar to the pump selection...
  31. gimak

    Impedances in a 5 element circuit

    Homework Statement Just help me with 18 b. Homework Equations V1 = c1I1Z1. Same for V2,3,45. V = V1+V2+V3+V4+V5. V/I=Z=impedance. The Attempt at a Solution Maybe because of symmetry Z1=Z2 & Z3=Z4. Perhaps Z5 takes out one of the branches? Can I get a hint?
  32. P

    Logisim question -- Simulation of a small logic circuit is not working

    I am trying to implement the following circuit in Logisim, yet all I get is y=0. Any idea what might be the problem? First image is what I am trying to implement; second it my Logisim attempt which yields 0. I'd appreciate some feedback.
  33. M

    Solve RLC Circuit Problem Homework

    Homework Statement http://imgur.com/a/3xSYb Homework Equations RLC equations: q= Qmax e ^ -Rt/2L cos wd t wd = [ 1/LC - (R/2L)^2] ^ 1/2 The Attempt at a Solution So, I am trying using Kirchoff law, but not sure what the question asks. I thought it may be a trick and after a long...
  34. A

    How Does a Capacitor Charge to Negative Voltage in an RC Circuit?

    Homework Statement At initially, the switch is open meaning there is no current flowing. So how does the capacitor is initially charge to -5V? and what does a negative voltage capacitor means? I thought it is only when the switch is closed (t=0) that when the capacitor is being charged...
  35. Likith D

    Regarding volume gain circuit

    The above is a circuit i found on the net regarding amplification of volume. I needed to know if increasing the potentiometer resistance (between "cold" and "wiper"; terminal 1 and 2?) in the circuit would increase "volume" Also, i could use a potentiometer resistance ( between "cold" and...
  36. G

    Understanding Circuit Breaker Terminals: IN & OUT Explained

    Why does a circuit breaker not show which terminal is IN and OUT?
  37. gimak

    Finding the average energy in an RLC circuit

    Homework Statement Homework Equations Q(t) = Aei(wt+Φ); dQ/dt = i*w*Q(t); E = (L/2)(dQ/dt)2 + Q2/2C i = √-1 E above is average energy The Attempt at a Solution When I plug in Q(t) & dQ/dt into equation above (E) I get: A2L/2(w02-w2)cos[2(wt+Φ)] w02 = 1/LC After I plugged both of them in...
  38. M

    Powering an LED strip with a 12v battery

    Hi, I want to run a cheap 5 meter led strip along the inside of my boat for cool night lighting. It will be powered by a 12v deep cycle battery. I was hoping y'all could double check what I was thinking before I set something on fire... Here is the led strip...
  39. Asmaa Mohammad

    The rheostat and the brightness of the bulbs

    Homework Statement In the circuit shown in the figure, what will happen to the brightness of bulb A and bulb B when the wiper moves from point X to point Y? Homework EquationsThe Attempt at a Solution [/B] When the wiper moves towards Y we get smaller resistance, hence the current intensity...
  40. Asmaa Mohammad

    The reading of the ammeter and the reading of the voltmeter.

    Homework Statement In this circuit What will be the reading of the ammeter and that of the voltmeter when: 1. Key S1 and key S2 are open. 2. Key S1 and key S2 are closed. 3. Key S1 is closed and key S2 is open. (Neglect the internal resistance of the source) Homework EquationsThe Attempt at a...
  41. Asmaa Mohammad

    Using Kirchhof's laws to solve a circuit

    Homework Statement In the circuit shown in the figure (attached with the solution). Determine: 1. the reading of the ammeter when the key (K) is open. 2. The reading of the ammeter when the key (K) is closed. Homework EquationsThe Attempt at a Solution [/B] What confuses me in the circuit...
  42. D

    What happens in a parallel circuit when more resistances are added to it? And why?

    Hello. Something has been bothering me for a while now: Consider a circuit with one battery and only one light bulb, for example. We have a value for the resistance of the bulb (R) and there is also one value for voltage (U) and one for current (I). Now, let's imagine that we connect a new...
  43. M

    Electronic Circuit with 2 diodes

    Homework Statement I have to find Vo in every diode state possible. We know diode Vf = 0.7 Homework Equations Va-Vc < 0.7 = diode OFF Va-VC > 0.7 = diode ON The Attempt at a Solution State 1: if D1 OFF and D2 OFF Vo will be equal to Vi State 2: if D1 OFF and D2 ON Vo will be equal to...
  44. T

    AC Mains meter circuit design for energy sources....

    What circuit design is used to ensure that the renewable energy source does not begin to absorb energy from the grid (for instance, when its terminal voltage drops below the distribution line voltage)?
  45. unseeingdog

    Final charge on capacitor for an RC circuit

    Homework Statement Homework Equations ##q = CE(1 - e^{-t/RC})##The Attempt at a Solution I assumed that, since the problem specifies that sufficient time has passed, it meant to say that enough time passed. thus making the exponential term in the equation go down to 0, and the charge in the...
  46. C

    Power of resistors in parallel vs series circuit

    Homework Statement Two Ohm's resistors in parallel consume power of 76 W and 24 W. What power will each of them consume if transfer them to the serial circuit with the same voltage of source. Sorry for my bad english translations I m not use to writing questions in English.. So what confuses...
  47. R

    12V diode combiner circuit question

    Hello, I'm currently doing an electrical refit on a 29' Bristol. I have an anchor/steaming light for the top of the mast. I'm connecting them to two separate single pole single throw breakers. My problem is that I need the steaming light (fwd light) to be able to come on indipendantly from the...
  48. Arman777

    RLC Circuit DC Homework Solution

    Homework Statement Homework Equations The Attempt at a Solution I used the loop rule where ##ΣΔV=0## and junction rule. From here I get 4 equations ##i_3=i_1+i_2## ##ε-i_3R_3-i_1R_1-L(di\dt)=0## ##ε-i_3R_3-i_2R_2-Q\C=0##...
  49. H

    Solving the Parallel Circuit: R=25, X[c]=100, X[L]=25

    Homework Statement what is the value combined impedance of the parallel circuit ?when R=25 ,X[c]=100 and X[L]=25 Homework Equations I think we use this equation to solve parallel impedance .... The Attempt at a Solution...
  50. K

    Calculating total resistance of a combination circuit

    Homework Statement Find the total resistance of the circuit Homework Equations Parallel resistance: 1/Rtotal = 1/R1 + 1/R2 + 1/R3 + ..., Series resistance: R1 + R2 + R3... The Attempt at a Solution The 1470 ohm resistor is parallel to the 50 ohm resistor and the 1000 ohm resistor, but there is...
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