the analysis, interpretation and manipulation of signals
1
vote
1answer
46 views
Suggest FEC technique
I am a novice in signal processing so there may be a fundamental gap in my understanding of the concept. I am working on a link which has an error of 1 in 1000 bits which I have to improve to 1 in ...
0
votes
1answer
90 views
Capturing PWM Signal on an Oscilliscope
I have a stepper motor that is controlled by PWM. I am trying to analyze the signal coming out of the controller on an oscilloscope. Ideally, I would like to capture, maybe 2 seconds of wave form so ...
2
votes
1answer
96 views
Converting a tachometer signal into something a microprocessor can understand
I am attempting to build a digital dashboard for my car (a 1998 honda civic), I have run into a bit of trouble, wherein the tachometer signal is quite hairy. I was wondering if someone would lend me a ...
1
vote
2answers
67 views
Time domain and Frequency domain
what is the difference between time domain and frequency domain components? How do these domains differ from each other?
2
votes
2answers
128 views
Digital camera sensors and long exposures
Why do digital cameras need a long exposure time in low light conditions? Sometimes the exposures are 15-30 seconds or longer. Doesn't the electronic sensor achieve a steady state under 1 second or ...
1
vote
1answer
79 views
Fourier Transform
Does anyone have a mechanism to understand intuitively ( and automatically ) why the fourier transform of certain functions have certain shapes ( at least for some functions, not necessarily for all ...
0
votes
1answer
81 views
How are phase values able to capture motion from video?
I know that the phase spectrum contains most of the structural information about the image.
But I want to know more about importance of phase spectrum related to video signals.
I have read that ...
1
vote
1answer
37 views
What do you mean by cross range dimension of a radar's resolution cell?
I'm reading a book on radars and found this term. Any help is appreciated.
0
votes
1answer
51 views
Fourier Transform of an audio signal
How can we extract the frequency content of an audio signal given the histogram of beat energy versus beats per minutes?
1
vote
2answers
152 views
Peak detector and LM324 not working
Trying to make second circuit.
Here is my outputs
In1+ connected to ground, OUT1 blue and after diode red
In1+ signal red and Out2 blue
Why cap charges if there is no signal.. Capacitor is ...
1
vote
1answer
66 views
Detect a keep-alive signal
Reason/Background
I have a raspberry pi (garage) that's doing some security-related monitoring, and generates a "keep-alive" signal. I would like to have an alarm go off in a separate place (attic) ...
3
votes
2answers
327 views
How to make a peak detector circuit
I wasn't able to find a good guide on this and I only recently discover electronics for myself so have a little knowledge.
I was able to find something like what I need
Article
How does the ...
0
votes
1answer
113 views
Can I set thresholds for 74HC14N (6 NOT gates)? and use as schmitt trigger
I'm trying to convert sine-like wave from IR sensor(quadrature wheel encoder) into square one. Can I make it with 74HC14N(set some fancy RC configuration) or should I use op-amp configuration to be ...
1
vote
1answer
78 views
See if signal is amplified without an oscilloscope
I'm an electronics newbie, but I've had some experience with oscilloscopes in college lab. However, I need to design and wire a simple circuit that can read values from an electret mic. Since the ...
0
votes
1answer
73 views
The simplest circuit to translate from RJ11 to my PC [closed]
Assuming that you don't want to get a functionality, it doesn't need to be a DSL modem, you want to study some signals and you only need an input starting from an RJ11 and going to a PC; what is the ...
2
votes
1answer
37 views
Best method for trasmitting multiple video feeds at once via Bluetooth or WiFi?
If I want to transmit several video feeds via Bluetooth or WiFi what would be the best method to do so in order to save on bandwidth, increase speed, and maintain quality?
I wanted to know what is ...
0
votes
1answer
44 views
Digital Signal Analysis: Sinusoid and Filtering problem
I was wondering if someone could help me derive the answers for (ii) and (iii)? These are exam review problems, not homework, and I have no idea how to solve them. I have been trying to reference my ...
0
votes
3answers
52 views
Some confusion about impulse response
I'm a new learner in signal processing. I've got a problem in understanding impulse response.
For a LTI system, the output of the combination of impulses equals the combination of every individual ...
3
votes
1answer
75 views
Delta Sigma DAC-like switching of a mains AC load
I'm helping out in a project to convert an electric rice cooker into a sous vide cooker with a PID control. For those unaware, this is a precision-controlled water bath at "low" temperatures (setpoint ...
2
votes
2answers
136 views
GPS update rate
My thought process: I i'm am looking for a GPS that updates fast enough to actually read its position traveling 130 miles an hour ( I did some math and think 5 times a sec up date rate would get me 17 ...
2
votes
2answers
115 views
Down-Conversion of RF signal
I have a basic question about down-conversion of RF-signals.
The ideal scenario is described as follows.
Given a RF-signal (coming from an antenna), i.e., a real-valued function x(t), and given a ...
-1
votes
2answers
186 views
Connect DHT22 to serial connection
I'm trying to find a way to connect a temperature and humidity sensor DHT22 to an XBee's RX/TX pins without an additional microcontroller(Arduino or anything that needs software) or reprogramming the ...
0
votes
0answers
35 views
Aes/Ebu to Analog Converter IC
I will convert AES/EBU to analog, then monitor it and will convert it again to AES/EBU. Do you have any advice to convert AES/EBU to analog IC and analog to AES/EBU IC.
1
vote
2answers
68 views
What does “two signals aliasing to each other” mean?
So I just read something that two signals are aliasing to each other. I know what a single signal is being aliased - that is when sampling rate is not higher than or equal to the Nyquist rate. But I ...
-5
votes
1answer
43 views
Understanding the concepts of sounds analysis [closed]
I'm trying to understand many concepts behind sound analysis. Here's what I'm trying to understand:
What's sound & sound wave?
What's sampling and hertz? And how to do sampling? (starting from ...
1
vote
0answers
117 views
100kHz active filter design
I am designing a basic 100kHz active bandpass filter using opamps (LF353). I am only interested in receiving the 100kHz frequency (might drift a few kHz) from my input signal. I have used a basic ...
1
vote
1answer
42 views
DPD Auto and crosscorrelation
I am trying to learn signal processing and digital pre-distortion.
http://www.altera.com/end-markets/wireless/advanced-dsp/predistortion/wir-digital-predistortion.html
I am currently trying to auto ...
0
votes
2answers
65 views
How to get the phase response of an arbitrary LTI system?
If I have a frequency response (of a discrete-time system) composed of several complex exponentials such as $$H(e^{j\omega}) = A_0 + A_1 e^{-j\omega } + A_2 e^{-j\omega t 2} + A_3 e^{-j\omega 3} + ...
0
votes
0answers
70 views
Activating Triac, signal conditioning
I need help with the following circuitry.
Basically it is a correction of a bug in one of my company's products, an automatic glass door controller. What it is meant to do is when I give the lock ...
3
votes
1answer
103 views
Amplification circuit for a limited range of output signals
I have a sensor that puts out a signal between 0 and 25mV. Of that range, I am only interested in the 16mV to 22mV portion. The output should primarily be a DC signal, and the AC response, if any, ...
1
vote
2answers
459 views
STM32F4 - Digital Signal Processing ( DSP )
At this website, I have read that STM32F4 microcontrollers have DSP instructions. To quote:
It also implements a full set of DSP instructions
I am beginning to learn embedded C programming with ...
2
votes
3answers
155 views
RSSI to distance moving average
I'm calculating distance from an RSSI, and as it seems to have quite a high variation I want to take an exponential moving average.
My question is: Where in this calculation is it most applicable to ...
2
votes
2answers
127 views
Verifying design that uses guard ring
I had a colleague design a board for pH sensor amplification based on schematic (fig 1)and spec in a paper. The paper recommends using the spec noted in figure 3. It uses a guard ring to reduce ...
0
votes
1answer
182 views
How to connect a microphone to apply audio signal to electronic circuit?
I am working on a project where we have to design a band pass filter signals in audio frequency range. We have tested the filter design using Signal generator already, and now we want to see if it ...
0
votes
1answer
79 views
1
vote
1answer
70 views
MIMO with STBC example - How to derive SNR?
Conosider 2 x 2 MIMO system with the channel matrix H :
$$
H = \begin{bmatrix}
1&1/2\\
0&\sqrt{3}/2
\end{bmatrix},
$$
and transmit signal matrix S :
$$
S = \begin{bmatrix}
s_1&-s_2^*\\
...
5
votes
2answers
194 views
dimensional analysis of the Shannon-Hartley theorem
In the infamous Shannon-Hartley theorem the bandwidth of the channel is measured in Hz (Hertz) but the channel capacity is measured in bps (bits per second). So, either I'm missing something obvious ...
2
votes
3answers
228 views
Detect string plucking in electric bass guitar? [closed]
Anyone knows any idea of how can I detect plucking in a string of a guitar with an arduino (possibly using the pickup signal)?
Thanks in advance ! ;)
3
votes
2answers
147 views
Sampling Theorem
$$x(t) = \frac{sin(2000\pi t)}{\pi t}cos(1000\pi t)$$ is sampled with sampling period \$T_{s} = \frac{1}{8000}\$, to obtain the sampled signal \$x_{p}(t)=x(t)p(t)\$, where \$p(t)= \sum_{n = ...
0
votes
4answers
154 views
Is this a valid sinusoid?
The given image is from first edition of this book
To me the first sinusoid seems valid, in sense that values can be computed at different points.
However, in the case of second sinusoid I fail so ...
1
vote
1answer
71 views
Using ADC AD9057
I use AD9057 with fpga in my oscilloscope project. Here is the ADC pin-out
I use the following scheme to test ADC:
VREF OUT connected to VREF IN, this gives internal reference voltage +2.5V
Vd ...
2
votes
2answers
102 views
Analog to digital converter
I have very little electrical knowledge. So here is my question. I need to test some wiring harnesses if they grouped like it should be.
There is 70-80 points. differencing on the harness, these ...
4
votes
4answers
174 views
Why consider Linear Time-Invariant systems?
Okay this could be a very silly question but I am asking it anyway.
Why do we consider in most cases of signal processing that the system is Time-invariant?
Is it because most signals are linear and ...
1
vote
1answer
182 views
Why AD834+AD811 voltage controlled amplifier does not accept around ground signals?
I have setup a circuit according to page 15 of AD811 Op-Amp datasheet . The design receives 0.5-1.2 vpp sine wave between 1Hz-50MHz from AD9850 DDS and it also has around +0.7 to +1 v offset voltage.
...
1
vote
1answer
51 views
Variable voltage signal importing and procesing using computer in real time
I am working on a project where I need to import an analogue signal into a computer for real time processing. Signal strength is about 2-10V.
I found this solution where it is possible to use the ...
0
votes
1answer
179 views
AD9850 comparator problem. How to calculate is frequency?
I want to convert a sine wave produced from AD9850 (opens *.pdf) into square wave with its inbuilt comparator. AD9850 has a fast comparator with 3ns rise/fall time and propagation delay= 5.5ns.
...
2
votes
2answers
326 views
How to protect a signal from output short circuit?
I have made a signal generator based on DDS and amplified its output to 0-20 V pk-pk. Now I want to prepare the output side. My main concern is short circuit protection to prevent damage to my device. ...
2
votes
4answers
288 views
How to connect op-amps serially in high frequencies?
Assume I have a 50MHz signal with 300mV pk-pk amplitude and I want to amplify it to 8v pk-pk. For this purpose I selected AD8055. This is a 300MHz VFO that is suitable for this purpose. I selected ...
0
votes
1answer
152 views
Can Emitter Follower BJTs work with large signal?
Sorry for such elementary question.
As anyone knows emitter follower design of BJT has some specifications . For example they are suitable for driving low impedance loads and so. But because the ...
2
votes
2answers
77 views
Wireless signal reflection
When two devices are connected via wireless, one device sends a character using its TX line, and the character is received by the other device on its RX line, and vice versa.
My question is, RF ...
