Questions tagged [circuit-analysis]

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

Filter by
Sorted by
Tagged with
0 votes
0 answers
19 views

How do the 5 elementary two-port networks map to unbalanced networks with a common ground?

Background (questions below) I've been trying to understand how to use S/Y/Z/A-parameter matrixes to create circuits mathematically with 2-port components in series, parallel, and ground-shunt. For ...
  • 972
1 vote
1 answer
71 views

Charging of capacitor

Why Ca takes twice the time to charge as compare to Cx? In following diagram there are two capacitors Cx and Ca, which are going to be charged in steady state. Now I know the method to calculate pole ...
5 votes
4 answers
395 views

Slew rate of two stage OTA

I have learnt two stage opamp designing from books and yourtube videos, but have always failed to understand slew rate formula which is I5/Cc(I5 is bias current of M5 and Cc is compensation capacitor)....
3 votes
2 answers
137 views

Power factor problem

I need help solving this problem in my mind, so if anyone had a similar problem it would help me. In order to make a higher power factor on a receiver, we connect a capacitor of appropriate capacity ...
0 votes
0 answers
57 views

Different input voltages for IR LED and TSOP

I'm designing a circuit where I need to detect an obstacle in the front efficiently in ambient light at a distance not more than 3-4 cm. For that I'm planning to use IR sensor system, IR LED as ...
1 vote
2 answers
159 views

Howland current source for negative currents

I am currently in the process of utilizing the design of Howland in order to derive a source that is able to provide an \$I_{out}\$ between \$0A\$ and \$30A\$ at the output load \$R_L\$. As you can ...
  • 27
-2 votes
1 answer
59 views

RC circuit with a switch [closed]

The problem wants the value of R1, R2, and C. I have no idea to solve it. How can I use the output voltage to find the values of the resistances and the capacitance?
1 vote
1 answer
114 views

Why does KCL not work for this node?

Why does KCL not work at this node? From the DC operating point you can see that: IR2 + IL1 ≈ 1mA + 2.45uA is not equal to ID1 + IB1 ≈ 0.16mA + 8nA. So where does ...
  • 1,651
0 votes
1 answer
87 views

Tellegen's Theorem Question

In Irwin's textbook on Basic Circuit Analysis, there is the following exercise: Up to this point in the book, the concepts of dependent and independent sources have been discussed, and also the ...
-3 votes
1 answer
51 views

Why does adding a resistance in parallel decreases the circuit total resistance? [closed]

Why does adding a resistance in parallel decreases the circuit total resistance? Before you close the questions a duplicate, please read further: I know the classic explanation for this, and I think ...
  • 267
0 votes
1 answer
53 views

Crystal oscillator error due to ppm

In this link, the accepted answer states that there may be an error of 1 minute per month if the crystal ppm is 20ppm. Can someone help me with the math of how the error of 1 minute is arrived?
  • 2,864
-1 votes
1 answer
52 views

Is this circuit a series or parallel combination?

I’ve been confused on this aspect of my textbook. To me it appears that the answer is that it is both a series and parallel combination of elements, but I’m not sure if that is possible. Thank you.
0 votes
2 answers
70 views

How to find Thevenin's Equivalent Resistance

I am asked to find the thevenin equivalent of this circuit but I am having trouble. The solution says that: Rth=2(RxRy)/(Rx+Ry) Vth= (VxRy+VyRx)/(Rx+Ry) Can someone please explain to me how to arrive ...
0 votes
1 answer
92 views

RC 90 deg phase shift

What does 90 deg phase shift actually mean? Like, consider this below RC circuit. simulate this circuit – Schematic created using CircuitLab From what I understand, when I apply a sine wave at ...
  • 2,864
1 vote
4 answers
85 views

Using Power to Determine if Circuit Components are Compatible [duplicate]

When I am designing circuits, I usually look at the current and voltage specs of my source to determine if my source is sufficient for my circuit. For example, if I have a load that requires 500mA of ...
8 votes
2 answers
1k views

Why are these capacitors treated as if they are in series? Why must the incoming and outgoing current in a battery always be equal?

A circuit with three capacitors and an open end at A: I am a high school student. I am very confused by this example. The circuit is open at end "A" as shown but still there would be some ...
0 votes
3 answers
46 views

Distortion pedal volume and tone control messing up circuit

I have built a distortion pedal with 3 variable controls: gain, tone and volume. R8 is my gain control (it will be a potentiometer with 50k to 500k resistance.) R5 is the tone control, (low pass ...
3 votes
3 answers
164 views

Using complex impedance

Any help getting the answer shown here? I have tried adding the complex impedance of L and R in series and then adding that to C in parallel. I'm not super sure about that last step, and then ...
0 votes
1 answer
60 views

Active inductor

I am designing active inductor using OTAs (Transconductance amplifiers) and have a problem writing an equations. I wrote two equations for nodes V2+ and V2- and input current Iin. $$ 0=sCV^+_{2}+g_1(...
0 votes
1 answer
63 views

Grounding sensors to large bodies

I've attached a diagram of what I'm talking about. I have a large (600x300x10 mm) aluminum block in which I place thermistors to monitor the temperature distribution in the plate (in a standard ...
0 votes
2 answers
80 views

How many loads can I have on an open drain output?

So I am using this AND gate which has an open drain output. I am trying to determine how many loads that I can place on this output. I see in the datasheet, that the Iol is over 1mA, but I am unsure ...
  • 189
1 vote
1 answer
103 views

Thevenin's theorem for Voltage divider bias

I am calculating the base current of transistor Q1. To simplify the circuit equations, I applied the Thevenin's theorem and converter V1 and R1, R2 into Vth and Rth as shown in the image. Vth= V1x(R2/...
4 votes
2 answers
581 views

Confusion In RC circuit

I want to calculate voltage across the resistor. I divided the circuit into two parts: Charging=0<t<1, 2<t<3, 5<t<6(ms)... Discharging=1<t<2,4<t<5,7<t<8(ms)... $$...
  • 174
1 vote
1 answer
38 views

Series and Parallel Capacitors in Circuit Analysis

In the circuit below: I performed my calculations considering: $$\frac1{C_{eq}}=\sum_{k=1}^N C_k^{-1},$$ and $$C_{eq}=\sum_{k=1}^N C_k,$$ when the capacitors are in series and when they are in ...
1 vote
0 answers
60 views

Base resistor too low problematic?

I have recently designed and ordered some PCBs which can combine a horizontal and a vertical video sync signal into one composite sync signal (all are TTL signals). This is done using a BJT circuit ...
-1 votes
1 answer
93 views

How would you find the impedance of this circuit? [closed]

I am working on a project using C++ to find the impedance of a circuit. In implementing the program I have realised that the program cannot find the impedance for a circuit of this type. My intuitive ...
  • 67
0 votes
0 answers
33 views

How to derive effective transconductance versus oscillation amplitude in a oscillator?

In the page below in the lecture note shows a plot of effective transconductance versus oscillation amplitude. How is it derived? Or is there any source to derive effective transconductance versus ...
  • 1,651
1 vote
1 answer
80 views

Distortion Pedal Design

I am building a guitar pedal and came across a reference design here: https://www.wamplerpedals.com/blog/uncategorized/2020/05/how-to-design-a-basic-overdrive-pedal-circuit/ I'm not sure why the ...
0 votes
0 answers
42 views

How do I find the gain function for this circuit?

The cicuit shows a high order low pass filter, where the voltage is 240V RMS. I was told to use laplace to find v0/vi but i am still confused on how to get this and solve for the circuit as asked. I ...
0 votes
2 answers
109 views

Peak current of inrush limiting inductor?

I have this tricky question and I can't wrap my head around it. There is this inductor to limit the inrush current that will be charging up a capacitor. I'm questioning the design of it, but I don't ...
  • 274
0 votes
4 answers
201 views

Can this circuit with two resistors oscillate?

From this lecture note. Can this circuit oscillate as what the lecture said? I did simulate this circuit in LTspice but it doesn't work. The step from 1V to 0V does have many frequency components ...
  • 1,651
0 votes
1 answer
49 views

How to find noise sources from noise figure data?

An amplifier datasheet provides noise measurements that show it has a noise figure of 3dB for R_s = 100Ω and R_s = 10kΩ (same noise figure for both values of R_s) at T=300K and f=10kHz. I need to ...
1 vote
1 answer
40 views

Finding the "drop in potential" as current moves through a single resistor of a circuit with parallel resistors

I have four different resistors connected in parallel to a \$24.0 \ \text{V}\$ battery with internal resistance of \$0.500 \ \Omega\$. The resistor values are \$10.0 \ \Omega\$,\$15.0 \ \Omega\$, \$30....
  • 1,211
1 vote
2 answers
48 views

Finding the voltage available at the terminals of the battery in a circuit with parallel resistors

I have four different resistors connected in parallel to a \$24.0 \ \text{V}\$ battery with internal resistance of \$0.500 \ \Omega\$. The resistor values are \$10.0 \ \Omega\$,\$15.0 \ \Omega\$, \$30....
  • 1,211
2 votes
0 answers
86 views

Current Direction and Voltage Polarity in Capacitor/Inductor Circuits

I believe that this question may be simple for those with a little more experience, but it is still puzzling me. Studying capacitance/inductance, I understand that the capacitor in the DC case behaves ...
1 vote
1 answer
83 views

Finding resistance for parallel resistors: how is my reasoning incorrect, and what is the correct reasoning?

I have the following circuit: The voltmeter \$V_1\$ measures the voltage drop across the \$9.00 \ \Omega\$ resistor and has a reading of \$4.50 \ \text{V}\$. The reading on ammeter \$A_1\$ is \$I_1 =...
  • 1,211
0 votes
1 answer
82 views

Calculating the reading on ammeter \$A_1\$: why am I incorrect?

I have the following circuit: The voltmeter \$V_1\$ measures the voltage drop across the \$9.00 \ \Omega\$ resistor and has a reading of \$4.50 \ \text{V}\$. I am trying to calculate the reading on ...
  • 1,211
0 votes
2 answers
75 views

How do I find Vo in the circuit?

I1 + I2 = I3 I1 = Vi/Z1 ... Z1 = (1+sCR1)/sC I1= Vi(sC)/(1+sCR1) I2= Vi/R1 I3= -Vo/R1 I1 + I2 = I3 Vi[(sc)/(1+sCR1) + (1/R1)] =-Vo/R1 -Vi[(R1sC)/(1+sCR1) + 1] = Vo How do I change back to time domain?
  • 1
0 votes
1 answer
104 views

How to create 4-bit asynchronous counter?

I am new to Multimedia Logic and am trying to create a 4-bit asynchronous counter. I did something like this, but it doesn't work. I'm not sure if everything is properly connected and if I was using a ...
3 votes
0 answers
68 views

Why is each time constant in this transfer function equal to "open circuit" time constant not "short circuit" time constant?

From this lecture notes, the open circuit time constant approximation: How to prove the yellow part? The lecture note mentioned Richard Adler at MIT did prove this but I could not able to find his ...
  • 1,651
0 votes
1 answer
67 views

How to sketch the waveform of the voltage across capacitor and find equation that describes it? [closed]

Below DC voltage source, a switch, resistor and capacitor. At time \$t=0\$, \$C\$ has zero voltage across it and switch is closed. How do I sketch waveform of voltage across capacitor v/s time and ...
  • 103
0 votes
1 answer
117 views

Where are the transistor number 18 and 21 in op amp 741 according to Wikipedia?

I was trying to implement this op amp from Wikipedia in Proteus : Like this: But I could not find Q number 18 and 21. What is the reason that there are not Q number 18 and 21? Or if this image is ...
  • 1
1 vote
2 answers
113 views

Is my circuit analysis correct?

This is the circuit. It is assumed that beta is 99 and VBE=0.7 V for both transistors. Here is what I've done. Multisim confirms the first set of values I worked out regarding Q1. However it does ...
0 votes
1 answer
37 views

Find the voltage drop across the capacitor in the LRC circuit

I am having issues finding the voltage drop across this capacitor in the circuit attached. Attempt: The impedance of the inductor is 50j ohms, and the impedance of the capacitor is -j20 ohms. This ...
0 votes
1 answer
58 views

Help me to understand the output signal of this circuit

I want to understand the output voltage of this circuit. My analysis is: When we are in the positive half of the wave, the capacitor will charge and the current will flow through D1 after it goes to ...
  • 141
0 votes
0 answers
71 views

Is there any method to turn any PWM DC-DC converter to its small signal model at circuit level?

Is there any method to turn any PWM DC-DC converter to its small signal model at circuit level? As I know the PWM switch model does that well but it only applies to simple circuits and the switches ...
  • 135
0 votes
2 answers
82 views

Find the voltage across the dependent source

I was trying to do some first order circuits and there was this one that kind of confused me. Correct me if I'm wrong but if $$V_s=u(t)V$$ this means that for t<0 Vs=0 and for t>0 Vs=1 right? So ...
0 votes
2 answers
120 views

Does anyone know why this diff amp isn't working?

simulate this circuit – Schematic created using CircuitLab I'm new to electronics and I've been figuring out how a diff amp works. I followed a schematic I found on YouTube. Basically, as V3 ...
's user avatar
0 votes
3 answers
166 views

Resistance measured individually vs measured on PCB

I always wanted to ask this question. Suppose I have a 1 kΩ resistor. I measure its resistance by connecting a multimeter to both of its terminals (when it is not connected to any part of a circuit.) ...
  • 2,864
4 votes
1 answer
191 views

Is there any meaning attached to the Zener diode symbol?

Is there any meaning to the Zener diode symbol? The triangle is similar to a normal diode which originally indicated current flowing in one direction only. Is there any hidden meaning to the yellow ...
  • 135

1
3 4
5
6 7
115