Engineering Stack Exchange
Engineering Stack Exchange

Questions tagged [signal-processing]

73 questions
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Why do color TVs make black and white snow?

If you let a color TV display something from an unplugged display port, it displays snow, right? Randomly varying black or white pixels on the whole screen. My guess was that the television was decoding the noise from the unplugged wires as a video…
Axel B
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Does a Faraday cage effectively act as a notch filter?

In reading about Faraday cages, I have found that most "real world" designs incorporate multiple layers of mesh. For example, this article from the National High Magnetic Field Lab discusses several different shielded rooms built of varying…
user16
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1 answer

Response of a system to a step function (Heaviside function)

I'd like to compute the response to a step function of a electrical/thermal system. Generally I can "easily" compute the transfer function $H$: $$H(\omega) = \frac{V_{out}(\omega)}{V_{in}(\omega)}$$ Since the Fourier transform ($\mathcal{F}$) of the…
Worldsheep
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How were the tones for DTMF chosen?

In my limited engineering knowledge, and limited research skills, I couldn't find a complete answer for the reasoning behind the chosen tones for DTMF. I did find a hint that said something about resonance/interference, but that's not enough details…
natebot13
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How can I filter out a signal while extracting only the desired one?

I know that my input signal contains a main sinusoidal signal, and I know its frequency but not its amplitude. Until now, I have been successfully using the least-squares method to generate a sinusoidal signal with the least difference from my…
chouaib
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Finding the sampling period to avoid loss of signal

We have: $$ s(t) = 4u(t)−u(t−1)−2u(t−2)−2u(t−3.5)+2u(t−4) $$ where $u$ is the Heaviside function. I had to draw the graph and find the minimum sampling period so we wont have loss of signal. I have drawn the graph. $t=kT$ where $T$ is the sampling…
sdfdsffsdf
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Pearson correlation of neural responses with it's linear estimation

I am trying to anderstand the following fact from this article (page 13): How can single neurons predict behavior Suppose I have a linear estimation of a stimulus: $ \hat{s} = \mathbf{w}^T(\mathbf{r} - \mathbf{f}(s_0)) + s_0$ where $\mathbf{w}$ is a…
user135172
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Spike in frequency domain in a dataset recorded using electromagnetic flow meter

I am trying to measure the water velocity of a stream along a channel using an electromagnetic flow meter at a specific location and depth. When I converted the data into frequency domain as power spectral density (PSD), there was a spike at the…
Nicholas
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Arduino DAC to Speaker

I'm working with an Arduino Due's two DAC pins. I want to output to a single 4W 5.7Ohm speaker to test my code, with the intent of eventually outputting to a set of speakers (woofer, mid-range, and tweeter) for better quality for frequencies between…
Richard Bernard
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What happens when very bright coherent light and weaker incoherent background light passes through doubly cascaded diffraction gratings?

Double diffraction is where a light beam passes through an grating with distance D1 between ridges and then passes through an grating with distance D2 The image after passing through diffraction gratings is a function of the product of two Fourier…
Frank
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Acoustical Design considerations for Active Noise Cancellation Project for Air vent

I am working on ''Active noise cancellation for air vent'' project. I am using NI myRIO1900 it has FPGA module(Xylinx Z-7010) , Audio Technica ATR 3350 omni directional microphones and Tevion Loudspeakers. I have done the programming using LabVIEW .…
charansai
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How do you generate an impulse signal in a mechatronic system?

Background: I have a piezoelectric force transducer that I am using to measure the force produced by a combustion reaction in a tube. The issue is that there is a lot of ringing that occurs during the reaction, leading to oscillatory "noise" going…
Ben
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What should be the sample frequency to test the response of a filter?

I am testing the frequency response as a filter as below, what should be the sample rate of the chirp signals, someone told me it should be at least 2 times of the input signals frequency, someone said it should be at least 10 times? Why?
LHX
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How do I study the frequency response of a physical system with Arduino?

I am a control engineering student and I am studying the frequency response of a system, so the Laplace domain, the Bode plot, poles, zeros,etc. ... I have clear grasp of their meaning, but if I think about the practice it is hard to grasp, at least…
dcr
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Adaptive downsampling of time-series data?

I’ve been tasked with developing software to (among other things) log temperature data from samples in a furnace. Generally the temperatures are very steady, but can, at times, experience dramatic changes. I’ll be storing the data in SQLite, which…
Rick
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