Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [random]

Use this tag when referring to systems that are random i.e are driven by stochastic processes.

49 questions
11
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1 answer

Are reverse biased transistors stable?

The usual circuit (found widely across the internet) for a true random number generator's (TRNG) entropy source is a reverse biased transistor like so: Q1 is typically a 2N3904 as it has been found to be quite noisy the wrong way round running in…
Paul Uszak
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9
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2 answers

How to generate different noise in LTspice from run to run

I'm trying to simulate noise in my circuit, and ideally want to get a histogram of a certain parameter affected by that noise over many runs. However, when I use the white() command in LTspice, or variations of rand(), I get the same result from…
Emily
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6
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4 answers

Simple low pass digital filter implementation for non-uniform sampling?

I have a system sampling an analog input and I want to filter that value using a simple, first order filter. EG something of the form: Yn = A*Xn + B*Yn-1 However I have no control over the underlying process and the sampling period is…
Peter M
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5
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Why does output of this reverse bias noise source not have normal distribution?

I am trying to build a noise source based on reverse biased PN junction (i am trying to replicate this project https://altusmetrum.org/ChaosKey/ ). At this point i tried multiple iterations but so far this is my best result achieved. The noise…
pigster
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4
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1 answer

Is the avalanche effect in Zener diodes a quantum mechanical process?

Firstly I would like to emphasise the word avalanche as it's fundamental to my question. I'm not concerned with shot noise, thermal noise or trash music. There is a video that explains the avalanche effect inside a Zener diode, from which the screen…
Paul Uszak
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4
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3 answers

A question on zero crossing versus random-fire SSRs

Figure 1. I have the above mechanism, where I control a single-phase fan motor's switch. I mean instead of a mechanical switch, an AC/DC SSR is switching ON or OFF from a remote place by a constant DC input (DC in in figure, 10V or zero). When the…
user16307
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4
votes
2 answers

$random in Verilog doesn't seem to be working

In Verilog, $random generates different random inputs but this doesn't seem to be working when I try. Each time I use $random for a reg or integer, I must be getting different different values but that is not so. I tried it even in Modelsim…
Abhi
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3
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2 answers

Unexpected patterns in Verilog $random

I have a Verilog test bench that monitors a 64-bit bus and should randomly schedule a flipped bit (packet corruption) to happen every 1-in-X packets. I was surprised to find it not injecting any corruption, and seemingly this is due to patterns in…
shuckc
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3
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1 answer

What is the purpose of masking the LFSR value in STM32's noise generation?

I read on section 14.3.8 of the STM32F4 reference manual that you can mask the LFSR output value partially or totally. At first I thought that it was used to change the pseudo random pattern (representative polynomial function) but I'm not really…
Florent
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2
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Randomize PCB trace generation with Altium Designer

We are trying to create a tamper mesh as a flex PCB. This tamper mesh will consist of around 10 signal traces in order to detect a tamper. One crucial point is that this tamper mesh should be different each time we generate it. This way it makes it…
Maurice Pannard
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2
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2 answers

Transaction randomization succeeds, yet values do not meet constraints

In the following code, I attempt to randomize the transaction which contains a dynamic array 'PhyRB', with the constraint that each element in the array is less than 'ResBlks' value. Please note that both 'PhyRB' array and 'ResBlks' are of unsigned…
أحمد المحمودي
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2
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3 answers

The distribution of phase angle between identical zero mean Gaussian random signals?

I am trying to solve the 2013 paper set by ISRO for electrical engineers. I was hoping to get some clues on how to approach this problem - No 22. random signals which have gaussian distributions will not be periodic and I can't understand what they…
Aditya P
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2
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2 answers

Random Error Waiting Time

Suppose that you have a design that has had an error after running 14, 18, and 20 hours. You're not exactly sure what is causing the error, but you make a change to the design that MIGHT fix it. How long do you have to run without seeing an error…
crj11
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2
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Old-school pseudorandom pulse generator (requesting assistance with hardware design)

I would like to design an old-school pseudorandom pulse generator to trigger various types of events (hardware suggestions only please - no programmable ICs). The events that I want to control need to happen, generally speaking, in the following…
Kelly Heaton
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2
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how do I make a solenoid operate after a random number of switch presses

New to the forum because I am stumped. Im building what I am calling the "water table" for my kids. It has a series of spigots, and channels that funnel into a kiddie pool. Then I got creative and added some solenoids to make some quirt guns that…
Ian Dunbar
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