Questions tagged [random]
Use this tag when referring to systems that are random i.e are driven by stochastic processes.
52 questions
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Why does adding a capacitor in parallel with an avalanche diode reduce the noise amplitude?
I'm trying to make a simple avalanche noise random number generator.
This is my circuit:
simulate this circuit – Schematic created using CircuitLab
Without C1 the "avalanche rate" is ...
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0
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2
answers
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random interval pulse for triggering sound effect [closed]
I am working on a small project using a cheap chinese MP3 player module, that can be triggered to play an mp3 by just sending it a pulse on one of its inputs.
The modules are of this type: https://nl....
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Switching regulator issues?
I'm trying to use a switching regulator (ptr08060w) to step 12V DC down to 2V DC, however it is not achieving this at all (even with no load connected), and is outputting a voltage that varies ...
- 111
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Avalanche effect of a Zener diode, or simulator bug?
On the Falstad simulator, I tried to illustrate the phenomenon of the avalanche effect of Zener diodes. I've added a capacitor to remove the DC component, too.
However, I'm not sure that the (very low)...
- 1
5
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0
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182
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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 ...
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1
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Effective resistance from a random resistance network
I am trying to calculate the equivalent resistance from a random resistance network formed by carbon nanotubes (CNTs.)
I have a MATLAB program where the CNTs are randomly distributed inside a volume. ...
6
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4
answers
2k
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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 ...
- 296
2
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0
answers
379
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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 ...
- 133
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84
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Random latch period of 555
I've designed a dice circuit, simulated it in Proteus (which worked) and got the PCBs manufactured. A problem I'm facing on the real thing is that if the button is pressed normally (e.g. for as long ...
- 110
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1
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Questions about strange behavior with 74194
I would like to use a shift register to control source-select in a pre-amplfier.
After watching this very nice video on https://www.youtube.com/watch?v=Y4djl3oYqDQ,
I made the same setup on my bread ...
- 19
1
vote
1
answer
672
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ngspice simulation : random signal source
I'm new at the ngspice simulator and I don't understand this line of a Netlist that I found
Vn 1 n1 dc 0V ac 1mV trrandom(1 5us 0s 125m 0m)
if the random signal ...
- 23
0
votes
1
answer
296
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Time Auto-correlation function for a polar reutrn-to-zero waveform
I used matlab to calculate the time Auto-correlation function for a polar return-to-zero waveform
to make sure that it has an ergodic property . I implemented the following formula as a function in ...
9
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2
answers
3k
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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 ...
- 91
1
vote
1
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318
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Generating unique values for multiple cyclic random variables
In the following code, I have 2 cyclic random variables in a class. One (an enumerated type) takes 3 possible values, and the other takes 288 possible values (due to a constraint).
So, I expect to get ...
2
votes
2
answers
110
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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 ...