Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [nyquist-plot]

The tag has no usage guidance.

0
votes
2answers
53 views

Nyquist Stability Criteria

Find the stability where: Find the stability: \$ G(s)= \frac{(s+3)(s+5)}{(s-2)(s-4)}; \$ \$ H(s)= 1; \$ I run this code in matlab: ...
4
votes
2answers
2k views

Why isn't Nyquist taught like this?

When I learnt how to do a Nyquist plot I was taught a really long-winded method that I don't understand to this day. I realised by myself that if you are given a system like below where \$s=j\omega\$ $...
0
votes
1answer
42 views

Cole-cole plot curve collapses when trying to alter the valule of horisontal axis

I am a beginner and trying to simulate a cole-cole plot of a simple parallel circuit having two R, one coil and a capacitor. Image attaced, LTspice version is XVII, pc is windows7. I've read this Q-A;...
3
votes
3answers
733 views

Sampling rate understanding for ADC requirement

So I have this voltage plot. These are voltages corresponding to a current changes on a wire. I am trying to understand the rate of transmission for choosing a ADC to read these analog values. The ...
0
votes
0answers
99 views

How to plot a Nyquist Diagram in Simulink?

I can get the impedance in powergui,and I want to plot a Nyquist with this impedance
3
votes
4answers
322 views

Is the Nyquist plot useful in actual electrical engineering?

I am currently doing a course on linear control theory, and we are covering Nyquist Plot to study phase and gain margin. I find myself unable to appreciate this concept. One, the proof of the Nyquist ...
2
votes
2answers
101 views

What are the connection between bandwidth, Nyquist criteria and quantization?

I am trying to solve the below problem and I was not able to find the relation between bandwidth, Nyquist criteria and quantization. Can you please provide some hint? Imagine that the possible ...
2
votes
2answers
137 views

Why is this system stable?

I was given the system defined by the open-loop transfer function: \$L(s)=\frac{5(s^2+1.4s+1)}{(s-1)^2}\$ I was told to use the Nyquist criterion to determine stability. Examining the Nyquist plot ...
1
vote
1answer
113 views

Nyquist plot Phase Question

The above graph is pulled from the book "Automatic Control Systems" by Kuo. The subject loop transfer function is $$L(s)=\frac{K}{s(1+T_1s)}$$ or $$L(j\omega)=\frac{-jK(1-jT_1\omega)}{\omega(1+T_1^2\...
0
votes
1answer
117 views

Pure transport delay? (Nyquist plot)

How does pure transport delay affect the Nyquist plot, and how is it possible to find the maximum value of the delay, such that the system stays stable even after delay is introduced?
0
votes
0answers
297 views

sampling frequency for less duty cycle message signal?

I have a question regarding the sampling frequency ? Normally we will take 50% duty cycle square/ sine wave to explain about sampling frequecny/ nyquist theorem.. My doubt is what is he sampling ...
0
votes
1answer
279 views

How to find the nyquist rate

I have the following signals and their Fourier transforms: \$x(t)\$ and \$r(t)\$. The signals are limited such that \$X(e^{j\omega}) = 0\$ for \$|\omega| > \Omega\$ and \$R(e^{j\omega}) = 0\$ for \$...
0
votes
2answers
304 views

Doubt regarding Nyquist theorem for sampling analog signals [duplicate]

If for an arbitrary signal H(f) = 1 for 300-f-3700 Hz; 0 otherwise, what should be the minimum sampling rate? 7400 Hz or 6800 Hz and why?
3
votes
1answer
854 views

How to plot Nyquist Plots?

By using the open loop transfer function for a control system, how would you then sketch the Nyquist plot by hand? I'm aware you'd substitute any \$s\$ term for \$j\omega\$ and then rationalise the ...
15
votes
9answers
4k views

When is it required or permitted to sample below Nyquist rate

I have searched past questions and answers on this platform but none answers this question. A prof said it is possible to sample below Nyquist rate under certain conditions. I will like to know, first,...
0
votes
1answer
78 views

Problem about Nyquest signalling theorem?

A sinusoidal signal with amplitude 20 V and bandwidth 35 kHz is sampled at 2.5 times its Nyquist rate and then quantized using a 128-level quantizer. Determine: i) The resulting data bit rate? The ...
0
votes
2answers
205 views

Is the Nyquist plot a plot of Re(G(s)) v.s. Im(G(s) or Re(G(jω)) v.s. Im(G(jω))

It seems that people in control theory are divided over whether the Nyquist Plot/Diagram (that is the plot, not the contour!) is a plot of $$\text{Re}(G(s)) \text { v.s. } \text{Im}(G(s))$$ or $$\text{...