Questions tagged [analysis]

Questions attempting to analyze the mathematical properties of a formula, the inner workings of a protocol, or the design of a given circuit.

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34
votes
2answers
3k views

Cross section of ceramic capacitors

I am trying to make a fault analysis of a bunch of ceramic capacitors. Short description of the application: 10 220 µF ceramic capacitors 1210 package are placed in parallel with a 3.6 V battery. A ...
26
votes
5answers
4k views

Puzzled by Nyquist frequency

Say I have a 1kHz sine, so no higher harmonics, then I need to sample it at least at 2kHz to be able to reconstruct it. But if I sample at 2kHz, but all my samples are on the zero-crossing, then my ...
16
votes
3answers
38k views

What's the difference between MOSFETs and BJTs (from a circuit analysis perspective)?

When analyzing circuits with transistors in them, when does it make a difference whether they are MOSFETs or BJTs?
11
votes
7answers
3k views

Differentiating between a square wave or sawtooth wave with a circuit…?

I want to build a simple sensor that takes a 100 kHz square or sawtooth wave with a known amplitude and outputs a high if it receives a square wave or a low for sawtooth. I'm pretty sure this ...
10
votes
1answer
196 views

What happened to all of the Dynamic Signal Analyzers?

Decades back there were at least half a dozen instrumentation companies offering Dynamic Signal Analyzers (DSA's). Not Spectrum Analyzers, but rather Dynamic Signal Analyzers. The main differences ...
9
votes
1answer
1k views

Why does this circuit oscillate?

The circuit below is an oscillator. When I simulate it with ltspice, it does indeed generate a waveform (although it doesn't seem to be a very pure sine wave). What I fail to understand is why it ...
8
votes
2answers
4k views

How to analyze this diode circuit?

I am trying to analyze this simple diode circuit by hand, but I can't seem to get too far. simulate this circuit – Schematic created using CircuitLab Using circuit lab, it is evident that ...
7
votes
8answers
2k views

Engineering Electronics: which approximation is usually good enough?

I have a strong computational background, so approximations with floating point precision depend on the type of computation. One thing is to know how to make an approximation and another one is when ...
7
votes
5answers
4k views

Predicting thermal equilibrium: what's wrong with my time constant?

I understand that this is arguably a peripheral electronics problem, but it seemed to fit here better than in physics. I've been doing some power electronics design work with large IGBTs mounted on ...
6
votes
6answers
559 views

Reading a circuit

Disclaimer: I am a beginner. I am reading a knol book on electronics, and I am faced with this schematics: How do I read a circuit to understand what it does ? Do I have to imagine the electrons ...
6
votes
1answer
2k views

Type 2 compensation network

I'm working through the excellent text on SMPS design "Switching Power Supplies A to Z", by Sanjaya Maniktala. Right now I'm reading the section on the feedback loop and stabilization. As a first-...
5
votes
3answers
427 views

Proper assignations of current directions

What is the best way to know the proper direction of current? Lets say we have this circuit below: The correct directions are given below: What are your techniques to know which is the proper way? ...
5
votes
2answers
686 views

Frequency response - finding transfer function

I have a this circuit: I am asked to find |H(\$\omega\$)| in its simplest form. I approached the problem by first recognizing that the first op am was a standard inverter. With that I basically ...
5
votes
1answer
246 views

What's wrong with my boost converter math?

I'm working some equations for a boost converter, and running into a contradiction I don't understand. Assume a steady state, perfect efficiency, and continuous conduction. Total instantaneous energy ...
5
votes
2answers
333 views

Voltage divider ambiguity

considering the following circuit : ...
5
votes
2answers
747 views

Analyzing the Protocol

I am trying to understand a protocol (shown in figure 1) . For now this I have understood that data is transferred at high to low clock. as shown in figure. and the sync is for every 8-bit. But then ...
4
votes
3answers
621 views

Time-series Statistical Analysis with FPGA

Suppose I have two time series, such as stock valuations or radioactive diagnosis, for which I need things such as covariances (QP -problem) among other things. Covariance calculations should be easy ...
4
votes
5answers
649 views

Assistance with CMOS simulation

It's been a very long time since I took intro level EE courses. I'm working on a hobby project and as a refresher I figured I would simulate a CMOS inverter. For the life of me I can't figure out why ...
4
votes
2answers
4k views

Why we use conjugate of current than the original phasor in the calculation of Complex Power i-e S=VI*

i have studied different books and sites for the above question but did not get the right concept that why the complex power encounter current conjugate not the original Phasor.if someone explain it ...
4
votes
3answers
177 views

Order of precedence for parallel operator

In electrical engineering the parallel operator || gives half the harmonic mean of two values. E.g.: \$R_1 \parallel R_2 \equiv \frac{1}{1/R_1+1/R_2} \$ But how should you compute \$kR_1 \...
4
votes
2answers
774 views

Problems with DC analysis of a PMOS circuit

I'm beginning with electronics and I've picked up the book from Donald. A. Neamen - Microelectronics. I'm stuck at a simple example of DC analysis for this PMOS circuit. simulate this circuit – ...
4
votes
4answers
919 views

Find impossible circuit resistance

What is the resistance Rx, in order to have Vo/Vs=1/2 Hi, my teacher asked us to solve this question, keep In mind that i'm not asking for you to do my homework, I think is just a impossible question,...
4
votes
4answers
10k views

How to get fundamental frequency of a signal using autocorrelation?

I am trying to get the fundamental frequency of a signal that only has a single pitch. I coded out the autocorrelation function using FFT and already got the autocorrelation result. Unfortunately, I ...
4
votes
1answer
5k views

Circuit analysis - software?

Surely there is some software that lets you draw a simple circuit diagram (DC voltage source and resistors) and then tell you the voltage, current, resistance, and power on R1, R2, R3, etc as well as ...
4
votes
1answer
280 views

Help with AC circuit theory problem

I need help with the following AC circuit problem: Given the circuit (attachment 1) with known data: $$\underline{Z_3}=200(3-j4)\Omega$$ $$\underline{Z_4}=100(3+j20)\Omega$$ $$\underline{Z_5}=100(3+...
4
votes
1answer
6k views

Questions about Thevenin's Theorem

I am reading up on Thevenin's Theorem and this has prompted a few questions that I hope somebody will be able to answer. This is the tutorial I am reading. The circuit below is then given as an ...
3
votes
4answers
22k views

How to change the frequency of AC supply?

Im using an inverter to convert Dc into Ac from battery. I want to control the frequency of the alternating current ie., increase and decrease gradually (eg: 1Hz 2Hz 3Hz... 60 Hz). Is it possible to ...
3
votes
2answers
517 views

What is this Op-Amp Configuration doing?

This Op-Amp Arrangement is part of an analog signal processing for a knock sensor of a combustion engine and I'm very curious about what this part actually does, as my google research didn't help me ...
3
votes
3answers
4k views

Simulation for a transmission loop using PowerWorld

I am now learning how to use PowerWorld Simulator. However, I faced some problems when I tried to enter the data given in the paper. I want to simulate the following transmission loop: First things ...
3
votes
2answers
3k views

Thevenin equivalent resistance of circuit with diagonal resistors

I'm trying to find the Thevenin equivalent for part A of this circuit: I begin by opening the circuit at the dotted line of part A. Then I try to find \$V_{oc}\$ across the two terminals that are ...
3
votes
2answers
24k views

Diode circuit analysis using ideal diodes exam problem

I've been reviewing some past exam and stumbled across this question So I need to find the current I through the middle diode and the voltage across the bottom left 10KΩ resistor. To try solve this ...
3
votes
2answers
230 views

Under what circumstances can impedances be simplified to simple resistances?

Consider the following circuit: This is a simple first-order low-pass RC filter. The cutoff frequency is: \$ f_c = \dfrac{1}{2 \pi (1k\Omega) (1\mu F)} \approx 159 Hz \$ The reactance of C1 at \$...
3
votes
2answers
521 views

Sniffing USB traffic at the hardware level

I've been looking to purchase a USB sniffer that will parse packets at the hardware level. I've used usbsnoopy and the like, but a filter driver solution is not my ...
3
votes
2answers
2k views

Calculating an R-RC circuit

This is not homework. I have this circuit, and I want to calculate V2. I know it is equal to V1 at t=0, and equal to \$V1 \cdot \frac{R2}{R1+R2}\$ at t=\$\infty\$, but I don't know how to calculate ...
3
votes
6answers
293 views

Calculating Voltage

I am trying to calculate the voltage \$Vw\$ of the following circuit: I have little experience with these kind of problems, so I tried to solve first a more simple circuit that did not include the R2-...
3
votes
2answers
881 views

Identifying an irreducible circuit?

How would you go about identifying an irreducible circuit? By irreducible, I mean combining resistors whether in series or in parallel to reduce the circuit.
3
votes
3answers
309 views

Thevenin analysis

I have a hard time understanding why Thevenin analysis works. I can see the math, and I can find the equivalent resistor, but I am not sure why it is a valid analysis from a practical point of view. ...
3
votes
1answer
1k views

How do I find out which current/voltage to use for an unlabelled LED panel?

I have a 600mm x 600mm LED panel with 576pcs 3014-type SMD LEDs in some unknown configuration/topology (edge-lit, similar to this one here: http://i01.i.aliimg.com/wsphoto/v0/1990066259_5/Wholesale-...
3
votes
3answers
2k views

Nodal analysis for current controlled current source

Okay here I go. I just started learning nodal analysis technique but I feel its difficult in solving the circuits consisting of dependent current and voltage sources. Im unable to solve this circuit. ...
3
votes
1answer
14k views

How do I decide which method to use in circuit analysis?

I'm an Electrical Engineering student, and circuit analysis can be really confusing to me. I sort of understand the concepts of solving circuits, but I don't really know when to use which method. Are ...
3
votes
1answer
1k views

How to calculate equivalent resistance?

This is not homework. Imagine an infinite resistor grid which the picture shows a part of. The question is what's the resistance measured across any of the 1k\$\Omega\$ resistors. I don't want you ...
3
votes
2answers
814 views

DC analysis of common source MOSFET circuits to find gate voltage using different power supplies

simulate this circuit – Schematic created using CircuitLab strong text I am solving problems on DC analysis of MOSFET circuits. We are supposed to find various parameters like Id(Drain Current)...
3
votes
3answers
2k views

Poles in electrical engineering

I'm currently an undergraduate electrical engineering student who recently took an elective mathematical course on complex analysis, where we learned about all kinds of singularities for complex ...
3
votes
2answers
6k views

How to solve a transient circuit

Given this circuit considering that before the switch closes the network is in a steady state. What steps should one follow to trace \$V_{L1}\$ before and after the closing of the circuit ? As far ...
3
votes
1answer
231 views

equivalent load resistance

I have the following circuit I am having some trouble determining the relationships between Iac, Io and Iacpk. I'm not quite seeing how the final equation for Iac was determined, specifically ...
3
votes
1answer
2k views

How do I treat a PMOS compared to an NMOS in small-signal analysis?

What exhaustive list can I use to determine the differences between NMOS and PMOS devices when doing small-signal analysis? Equivalently, what are the fundamental differences between NMOS and PMOS ...
3
votes
2answers
6k views

Supermesh Analysis of circuit of two loops

I have am having trouble moving forward with the following problem. The problem says that Find the value of Vs in the circuit below such that the power supplied by the current source is 0. The final ...
3
votes
2answers
1k views

Av for small signal analysis with BJT for unbypassed emitter and ro in place

My question is about another question on this site. On that question Z(in) for small signal analysis with BJT for unbypassed emitter and r0 in place Zin is asked for a common emitter configuration ...
3
votes
2answers
1k views

Common gate amplifier with load connected to negative DC bias

What's the difference between the following two circuits? Note that the capacitors are DC blocking, and the FET is on. I understand that usually, the load is connected to ground. But what would ...
2
votes
3answers
503 views

Thought Process on Designing Circuits

I'm currently in my second year of computer engineering. I've taken circuit analysis courses and have a good general understanding of components, and a little bit of digital design, however, I'm very ...