Circuit (Network) analysis is the process of finding the voltages across, and the currents through, every component in the network.

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RC High Pass Filter output drift problem

I am unable to find a proper explanation for this. When I create the passive RC circuit as shown and feed it 8 us pulses at 25KHz, The output of the RC circuit drifts for some time until it settles as ...
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1answer
12 views

Node analysis problem

trying to solve using Node method I have stuck. R1=6800 R2=5600 V1=5 V2=-7.2 I am stuck, is it: ((e-5)/6800 + (e- (-7.2))/5600=0 ((e-5)/6800 + (e+7.2))/5600=0 or ((e-5)/6800 + ...
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2answers
54 views

Diodes and fixed voltage source [on hold]

This came from my elementary physics lab practical. The piece which I am confused over is the language used so and I quote Note that the ideal fixed voltage source direction is in the opposite ...
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1answer
33 views

how to find equations for current of circuit with transistors?

using Ohm's law, i need to find the current for $$I_C , I_B$$ in terms of: $$V_B, V_C, V_{DC1},V_{DC2}$$ for the following ciruit. my solution is: $$V_{DC2}+{I_B}{R_B}={I_C}{R_C}+{V_{DC1}}+{V_E}$$ ...
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4answers
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What is the use of an op-amp whose output and inverting input are connected to ground?

I am in first year of Engineering school and I was given an assignment containing this circuit, which drives pressure sensors in a pitot tube : I am struggling to understand the whole circuit, and ...
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1answer
27 views

Need help understanding the concept of “Circuit model of a discharging RL circuit”

I don't understand the statements for t<0 and t>0. Why does this happen?
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2answers
40 views

Power calculation and Ohm's Law for Reactance

Hi I have the following question: V = 120V, I = 10 A, I lags V by 60degrees simulate this circuit – Schematic created using CircuitLab The load consists of a resistor and an inductor ...
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1answer
32 views

Automatic LED lamp with sound sensor

I have an auto light circuit with a sound sensor. The problem is when I try to simulate, this circuit does not work. Here is the circuit. I think the mistake is on the resistor is too large. then I ...
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0answers
35 views

Circuit confusion help

Can someone help me understand this circuit. I'm confused how both 5v and 12v are connected to same transistor Q63. Is 5/12v flowing through the same circuit when it's turned on? Or is Q63 simply ...
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1answer
33 views

Inductor's self-resonant frequency: Do we want it to be high or low?

Inductor selection always confuses me. There is a spec for inductors as self-resonant frequency. For example, on digikey, as SR frequency of inductors increase, the price may increase or decrease. But ...
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2answers
94 views

Why this circuit has a DC current?

Consider the circuit below: simulate this circuit – Schematic created using CircuitLab If I try to solve this circuit in the frequency domain, I get: $$X_C = \frac{1}{\omega C} = ...
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1answer
43 views

Node voltage analysis on circuit with a dependant voltage source

I am carrying out node voltage analysis on a circuit that has 2 voltage sources. One source is independent The other is dependent on a current through a resistor in the circuit After i carry out ...
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1answer
41 views

How to know the voltages between inductors? [on hold]

I've got a schematic as below, but I don't know what voltage is a output. simulate this circuit – Schematic created using CircuitLab
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23 views

working of operational amplifiers circuit [duplicate]

IN the Following Circuit, the opamp is neither working as buffer nor amplifier. kindly explain the working of the circuit. Its single supply opamp with 5 volt supply voltage.
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0answers
61 views

working of the opamp Circuit [on hold]

In the Following Circuit , how the opamp is working ? its not working as buffer. how the divider from 12 volts has stopped opamp from being a buffer ? thank you
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42 views

practical design of integrator circuit with Rogowski coil

I am designing a current sensing device, using a rogowski coil.To give a simple explanation of the Rogowski coil, if I were to disregard parasitic components L2, R1, C1 and R2 the output voltage would ...
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0answers
25 views

Emergency fpl circuit [on hold]

Recently I have seen a emergency led fpl which turned on just with my hand touching on two sides. When I used wattmeter,it was still on in case the wattmeter has turned on or off.so if we use it at ...
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1answer
39 views

Connect Two Transformer in Series

I have two transformers with a 220V primary and 12V secondary winding. What will happen if I apply 220V to the primary of the first transformer and connect the two secondary windings together? Will ...
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1answer
69 views

time it takes for the voltage to achieve 7 V

C1 = 56uF C2 = 12uF R = 12kohm E = 13 V I have this circuit and I want help to find out how long in takes for the voltage Uc2 to achieve the value 7 V? I have calculated the time constant to 117 ...
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2answers
38 views

Drive a capacitance load with a very large output resistance analog voltage source

I have a signal source with a very high output resistance. The output of this source is connected to the input of comparator. Actually the input capacitance of comparator is not large (about 20fF). ...
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46 views

How do I solve first-order circuits?

I'm having a lot of trouble understanding this topic in my circuits class for some reason. Take for example this circuit, I'm told that \$v_{1}(t)=10\$ and \$v_{2}(0^{+})=10\$ volts. I need to ...
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0answers
9 views

Free response / Forced response and Transfer function of RLC serial circuit

I need to find Free response / Forced response and Transfer function of RLC serial circuit using below sequence Step 1 : Mathematical model Step 2 : Get laplace transform for mathematical model Step ...
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2answers
20 views

Step Response RC Circuit: Current at Capacitor

I have a problem understanding why is that ic=0 at t<0 if the switch is closed for a long and only opened for t=0? My friend told me that at t<0, the ic will always be 0A regardless whether ...
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2answers
71 views

Calculating the capacitance

I have a problem that I would like to have help with. In the image above I need to calculate the capacitance. The values I was given in the beginning was: So I calculated U3, which was 17.3 V ...
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2answers
38 views

Thevenin Equivalent does not seem equivalent for me

The application of Thévenin theorem should give a equivalent circuit in terms of current and voltage of any linear circuit consisting of independent sources and resistances. Given this sample ...
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2answers
35 views

Calculating Vp in a half-wave rectified sine wave [closed]

If a half-wave rectified sine wave has an average voltage of 25V, how would I calculate the peak voltage?
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2answers
47 views

What kind of DC motor is this and what does the circuit do?

I've had this motor at least for 5 years (salvaged from something) and I remember it working then. However it doesn't work now (5 VDC mobile charger) and so I opened it up expecting to see just the ...
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2answers
50 views

Two batteries connected to a resistor

In the circuit shown here the conventional current direction is from V2 to V1 and is equal to 3 Amp. I understand the theory. But, if I make this circuit with two batteries, according to the schematic ...
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0answers
34 views

Designing an amplifier withBJT [closed]

Design the circuit shown in the figure by calculating the values of R1, R2, R3 and R4. 2N3904 NPN transistor is to be used. In this design the bias voltage between emitter and collecter should be 5V ...
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1answer
34 views

Relation between bels and decibles

Following is a sreenshot from "Fundamentals of electric circuits by Alexander and Sadiku". In 14.4 he defines "bels" and then in 14.5 the "decibels". I don't understand the line just above 14.5 that ...
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1answer
95 views

Help explain how this ac switch circuit works

Below is an ac switch circuit. COIL1_EN is used to enable or disable the switch. Does any one know how this ac switch work? I think it may be a standard design, can anyone give the related ...
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2answers
40 views

I need to be sure that these are right values for MOSFET 2N7000

I made A circuit for test mosfet in proteus But according to datashet the values are incorrects. I need your help : Is it normal these values ? For example : V(gs) in my circuit is 4 volts and ...
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1answer
25 views

Voltage applied to secondary is not matching calculation [duplicate]

Why is the RMS voltage applied to the secondary not 3.3 V in Multisim? 120/36 = 3.3 V
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43 views

Output voltage calculation for full wave bridge rectifier

What would be the calculation for the output voltage of this full wave bridge rectifier? Thank you.
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32 views

Usage of 2 x 6V rechargeable batteries in parallel

I need a rechargeable battery with 12V, can I use these two 6V batteries in a parallel circuit? 6V, 10Ah 6V, 3Ah If yes, what capacity would the combined battery have? Can I charge them also ...
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1answer
40 views

How to change the frequency of this sawtooth generator circuit?

I've found the circuit below in "The Art of Electronics" book. This circuit generates sawtooth signal. This is some of what is written about it: By using a current source to charge the timing ...
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1answer
59 views

I crossed two wires, and fried my circuit. How do I test for parts that need replacing? (I'm new to this, schematic included)

I built a metal detector with the Surf Pi 1.2 kit. This guide was a big help. This was my first project outside of soldering two wires together, definitely a learning experience. Probably a little ...
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2answers
54 views

MOSFET as a VCCS or an variable resistance

I am a bit confused. In saturation region, sometimes, an MOSFET is called voltage-controlled current source and sometimes it is called variable resistor where its resistance is controlled by the ...
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1answer
40 views

Adding a variable and DC voltage source LC circuit. How to the Voltage out?

I have the following I want to find out what the Voltage at the Node(\$V_{total}\$). I know that the capacitor and the inductor isolate the two sources from each other. This is what I get after ...
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2answers
50 views

Distortion in TDA2030 circuit

I looked at a friend's guitar amplifier which wasn't working, the problem was clearly (because it fell off) a broken IC (TDA2030AC). After replacing it, the amplifier started working again but when I ...
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1answer
50 views

will there be any difference between the output of a 555 oneshot and one made with a 74123?

I think there won't be any difference because the professor wants us to build both with 10 us pulse and with a duty cycle of 25%. I didn't have enough time to build both MMV, so that's why I am ...
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0answers
38 views

PSpice to HSpice conversion of a Transformer Rectifier Power Supply Circuit?

I was able to simulate the circuit in PSpice Student version, for the attached schematic. I am in the process of modifying the netlist generated in PSpice to HSpice , for which upon execution I get ...
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0answers
60 views

Are there simple ways to describe circuits containing resistors, capacitors, inductors, and memristors?

I am taking an introductory university physics course in electromagnetism, and we are currently going over RC, RL, and RLC circuits. Last semester in my computer architecture class, I did a paper on ...
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1answer
58 views

Finding inductor current at infinity

Can someone please explain how to go about solving this? I understand how we obtain Vc but when looking for the inductor current at infinity I get confused. Thanks!
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1answer
51 views

Regulating voltage so USB works with module

I recently purchased this GSM/GPS module. I would like to power this module via a USB cable but can see that it has varying input voltages. So bearing in mind that USB is 5V and that I'm an ...
0
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0answers
43 views

Why is the dependent current source ignored?

I need to find i1 / v1 when i2 = 0. According to the solution manual, the KVL is -V1 = 2kOhms*i1 + 1kOhms(i1 + i2), and since i2 = 0 they get -V1 = 3000i2. Are they forgetting the dependent ...
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1answer
36 views

Why does the output voltage of this bridge rectifier drop by 2VD?

Why does the output voltage drop by 2VD? Whats troubling me is the ground placed after the load resistor. If we were to remove that ground and measure Vout as shown in fig 4.25a, i understand that ...
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1answer
40 views

How to find the Thevenin resistance?

I am a bit confused with this circuit.I uploaded the circuit as you can see I already removed the resistance where I need to calculate the thevenin resistance. I know how to find the Thevenin voltage. ...
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2answers
36 views

How can I induce quality factor?

I'm trying to induce Quality factor of RLC circuit. In series, I did it with Frequency responce $$ H(s) = R/(R+sL+1/sC) = (something)/(s^2+2sw_0\zeta+w_0^2)$$ And $$Q=1/2\zeta$$ But I can't find how ...
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0answers
35 views

Li-ion protection circuit: MOSFET connection

I've checked a lithium ion protection circuit and found out that the D1 and D2 terminals from AO8810 are connected: But checking AO8810's datasheet I find that the MOSFET's drains are internally ...