All Questions
Tagged with electric-circuits signal-processing
18
questions
14
votes
10
answers
8k
views
Why does a capacitor act as a frequency filter?
What is it about a capacitor which allows it to filter frequencies?
I understand the construction of a high-pass RC filter, and the mathematics behind it, but I'm struggling to find an explanation of ...
- 267
4
votes
2
answers
2k
views
What is the physical interpretation of the Fourier transform $(\mathcal{F}Z)(t)$ an impedance?
If I compose a impedances out of smaller ones in series and parallel configurations, e.g.
$$Z(\omega)=i\omega L_2+\tfrac{1}{\tfrac{1}{R_1}\ +\ i\omega C_1+\ \tfrac{1}{i\omega L_2}},$$
then I get a ...
- 8,523
2
votes
1
answer
428
views
What exactly happens in a low and a high pass filter?
I know the mathematics and equations behind the circuitry and how they tell us that the resistor blocks high frequency ac signals and allows low frequency ac signals to pass through with undiminished ...
- 4,954
2
votes
1
answer
94
views
Why don't we have heat circuits?
Common circuits use electricity to transmit power and signals.
I know we transfer heat power using things like HVAC (heating, ventilation, and air conditioning).
I don't know anything that encodes/...
- 347
2
votes
1
answer
49
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
1
vote
2
answers
539
views
Electrical equivalent of inverted pendulum
Background
I am working on a summer project to design labs for undergraduate students. One of the topics is feedback and there is already quite a lot of stuff about passive feedback, so we might add ...
- 11.6k
1
vote
1
answer
640
views
Fourier transform of power
In the notes I am reading they use the following. Let $U$ be the voltage (depends on time) and $I$ the current in a circuit with some resistor with resistance $R$. Then the power is given by:
$$P(t)=...
- 1,187
1
vote
1
answer
1k
views
Calculating decibel gain and loss
I'm doing a mobile/wireless networking subject and the physics aspect is giving me some trouble. I'm mainly confused about the conversion of dB, dBm and dBW and how to calculate the gain/loss from an ...
- 13
1
vote
3
answers
910
views
Electronic filter
Can you explain, please, step-by-step how an electronic filter does work?
For example, high pass filter. I know It's a trivial things, but I can't get it completely. Don't bring me formula and etc. ...
- 19
0
votes
1
answer
76
views
Proving a theorem about the average value of a function over a specific region
Let's say transient phenomenon in a function. A transient phenomenon is defined as:
"A transient event is a short-lived burst of energy in a system caused by a sudden change of state."
So, ...
- 291
0
votes
1
answer
170
views
Does phase of a signal (very low frequency, 0-100Hz) change due to pink noise?
One might experience pink noise when dealing with low frequency signals (0-100Hz). Curious to know whether pink noise has an effect on phase of the signal specially in lowest frequencies 0-10Hz.
- 235
0
votes
2
answers
150
views
Weird looking sine wave behavior in an electric circuit
while studying an RLC circuit I noticed some weird like sine waves at low frequencies (1-9 kHertz) on the inductor,
The amplitude behavior did not follow the theoretical model. Instead, suggested the ...
- 31
0
votes
1
answer
69
views
How to solve the transient response of a general $RLC$ network?
There is a $RLC$ network $\{V_i\}$ with a complex impedance $Z_{ij}$ on each edge. all vertices have initial voltage $V_i$ and all edges have initial current $I_{ij}$. Now, is there a general way to ...
- 151
0
votes
1
answer
34
views
RLC Bandpass Filter network
Can anybody tell me what the "s" in this equation is? I am looking for the transfer function of this circuit
0
votes
0
answers
35
views
Pulse to sine with the same frequency
I have a pulse signal with frequency f(t)
And i want to generate from it a sine signal with frequency f(t)
(f(t) doesn't vary a lot in time)
Is there a method to do it directly with a function ...
- 13