All Questions
Tagged with signal-processing electrical-engineering
19
questions
2
votes
1
answer
48
views
How a switching mixer works in this example circuit?
I am reading about lock-in amplifiers and came across this example circuit of a mixer:
You have one sinusoidal input signal $e_1$ with a phase $\phi_1$ and the local oscillator has a square-wave ...
- 229
22
votes
12
answers
8k
views
How do computers store sound waves just by sampling the amplitude of a wave and not the frequency?
All of this just doesn’t make sense though.
I mean, doesn’t the amplitude represent the loudness and the frequency the pitch? Aren’t they completely independent from each other?
Is the book just ...
- 390
0
votes
1
answer
70
views
Doubt on time invariant system
Now I am delaying the output of a system (which takes $x \left( t \right)$ as input and gives $t \cdot x \left( t \right)$ as output) by $T$ then final output is:
Let's denote the output of the ...
- 1
7
votes
2
answers
555
views
What do I hear when listening to a computer-generated sine wave?
When I use a sine-wave generator (such as this one), I give credit to the software and my hardware that a pure sine wave is produced (as close as is technologically possible) — that is, no harmonics. ...
- 173
0
votes
1
answer
241
views
What happens during under-modulation?
I need clarification regarding what exactly happens to the information in amplitude modulation if it is under-modulated. I know that if it is over-modulated, some information will not reach the ...
- 15
0
votes
1
answer
391
views
Removing $1/f$ noise with lock-in-amplifiers
On the Wikipedia page for 1/f noise (at the bottom of the page) it suggests the noise can be reduced if the signal of interest is at DC. DC signals suffer from significant 1/f noise, so one method of ...
- 1,816
1
vote
2
answers
67
views
Wireless data transmission more than a bit at a time
I'm not that educated in wireless data transmission, but, the basics of frequency modulation and or amplitude modulation are quite basic. Is there any examples of transferring more than a bit at a ...
- 11
2
votes
1
answer
83
views
How LHC sensors work? [closed]
newbie here. I am here because after working with Raspberry Pi sensors and Analog to Digital converters, and computer processors, I wondered how exactly do sensors in large scale physics experiments ...
- 121
0
votes
2
answers
138
views
Multiple frequencies [closed]
could someone please inform me how it is possible to send multiple frequencies down one wire? I’m referring specifically to a communication protocol known as HART. It seems they send a 4-20mA signal ...
- 29
0
votes
1
answer
182
views
What does the phase discriminator portion of the Costas Receiver do mathematically?
What does the phase discriminator portion of the Costas Receiver do mathematically?
The output of the $I$-channel is $ \frac{1}{2}A_C \cos \phi \, m(t) $. Which means for small deviation of phase $ \...
- 33
0
votes
1
answer
20
views
What influences the variance of signal transmission speed?
I'm currently thinking about the various sources that influence time when it is synchronized with the NTP protocol. One of them is the physical layer (OSI-model).
When sending a bit over a cable, ...
- 913
1
vote
1
answer
123
views
How do scintillation detectors work, for gamma ray spectroscopy
So I understand what happens in the crystal with respect to the interactions and how the electrons in PMT are multiplied by hitting dynodes etc. But what I can't really seem to find any information on ...
- 579
0
votes
1
answer
45
views
Can the telephone signals be tapped by an intruder? [closed]
I have a doubt.
There are lots of telecommunication signals moving across the world, at the same time.
For example, take the case of mobile phone calls.
Millions of speech signals are propagating ...
- 12.5k
2
votes
1
answer
1k
views
Larsen effect and pitch of sound
Why Larsen effect produces always high pitched sounds, never low pitched?
- 1,343
0
votes
2
answers
218
views
Example of transfer function and driving signal equation
In a text I am using it states that for linear dynamical systems, there is a very simple relationship between the power spectrum of the driving signal and that of any one of the system variables. If ...
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