# Questions tagged [signal-processing]

the analysis, interpretation and manipulation of signals

637 questions
Filter by
Sorted by
Tagged with
1k views

### Square wave autocorrelation integral

Given the following square wave signal g(t) : I'm trying to find the $R(\tau)$ of this signal, but I'm confused about how to solve the integral. In the signal above, the red square wave is the ...
408 views

### Dolby HX PRO implementation on existing tape recording deck

I'm experimenting the implementation of Dolby HX PRO's IC into an old stereo Fostex tape deck to improve high frequency and headroom capabilities. HX PRO works as a dynamic processor with the BIAS ...
73 views

### Pulse Train Sampling Rate

Assume I have a pulse train with frequency of F Hertz. A normal square wave has all odd harmonics. From Nyquist, if I want to "Reconstruct" the waveform, sampling frequency Fs should be at least 2*(...
3k views

### How does a car with keyless entry know where the key is?

If I hold the car key and touch the handle on the door, the car locks the doors. But if I leave the key inside the car, it won't lock itself. How does the car know where the key is located? What ...
71 views

### Find a sinusoid in a sensor data

I am collecting raw data from a radar sensor using source code from the manufacturing company to allow me to plot data. I am looking for a repetitive movement that would be considered sinusoidal. ...
46 views

### Are these two ways of doing equivalent?

I have two signals sampled at, say, 256 Hz. I want to make the difference between these two signals and downsample them, say until 32 Hz. Is it rigourously the same (in term of final result) to make ...
590 views

### PWM, PAM, PCM sine generation and usage confusion

I am confused about something fundamental regarding PWM, PAM and PCM. I am going to be using a speaker's driver analogy to explain my point. As far as I know motors use PWM for power input, I don't ...
6k views

### How can I determine the order of filter?

This is my first study about signal analysing. I'm very confused about filter order. My problem is how can I know whether its 4-th order, 12-th order, or 2nd order like the book says so? I'd like to ...
69 views

### How do single-phase inverters know if they're in sync with the grid after they're in parallel?

How can one inverter, once its output is already in parallel with the grid, measure the phase difference between the grid and itself? Any current or the variation in the current flowing on its output ...
189 views

### Phase Shift Keying: Is it ever actually used?

during my course in digital communications Phase Shift Keying is talked about where the modulation consisted of altering the phase of the carrier signal. This process takes up a lot of spectrum so I ...
149 views

### Amplifying signal with Darlington not working

I'm relatively new to electronics and this is not my usual field of work. For a bigger project I need to read a flow sensor's (Biotech FCH-C-PA-N) output. The output needs to be processed by an ...
64 views

### Mitigating unknown error in power analysis of ATMega328P microcontroller

Setup: Arduino Uno (ATMega328P Microcontroller) running inline assembly instructions using asm statements. Global interrupts disabled. Pin 13 (PORTB5), DDRB5 designated as output used for trigger ...
117 views

### I don't understand convolution, and I would love to see some worked examples

I'm trying to get ahead on my classes for the school year and decided to start with Alan Oppenheim's Signals and Systems course. I'm already very stuck on how to convolve two signals. I have some ...
527 views

### How does an electrical speaker determine amplitude and frequency? [closed]

So, I know that a DAC converts coded binary signals into analog signals, but what sort of thing determines the pitch and amplitude of the outgoing sound? Does the DAC use a clock for frequency and ...
2k views

### Edge detection circuit [duplicate]

I need to design an edge detection circuit to detect when a square wave signal goes from Low to High (rising edge) and when it goes from High to Low (falling edge). The circuit should preferably use ...
206 views

### Digital Audio Effects Design [closed]

I've recently graduated university with an MEng degree in Electrical and Electronic Engineering. As a third year project, I've used an ST-Microelectronics ARM Cortex-M4 based Nucleo microcontroller ...
122 views

### Help decoding line code

I have collected a burst signal from a radio device using an RTL-SDR and gnuradio and demodulated the FSK, but am having trouble deciphering what the line code is. Signal is at 151.3MHz Here is the ...
107 views

### Frequency locking for averaging resampling

Background I've done a long one-shot measurement of a periodic signal by an oscilloscope. Thus, I've captured around 250 periods of a signal. The signal itself is a pseudo-random binary sequence at ...
470 views

### Edge detection circuit (for rotary encoder)

I managed to decode a rotary encoder using an arduino to read the input signal but I noticed other than the interrupts, the code is mainly made up of lines similar to: "IF this AND that OR that AND ...
82 views

### RL filter output attenuation

I am designing high pass RL filter. R is 550 [Ohm], L is 220 [uH]. I calculated that time constant is therefore 0.0000004 [s] and -3 dB pulsation 2 500 000 and frequency 397 887 [Hz]. I put this on ...
75 views

### How to find number of poles from the unit sample response?

Below I'm attaching a snapshot of a problem and its solution. I do not get how they figured out system functional $\dfrac{Y}{X}$ from the given table. I'd really appreciate if you please help me ...
434 views

### Voltage regulator frequency range

I'm designing a new encoder pulses counter for my project, my encoder HE50B uses a 12-24 VDC Input, and it has 1,000 pulses per each revolution. also the maximum permissible speed is 5,000 RPM. Now I ...
48 views

### Index of frequency larger than power spectrum length

I am new in this community. So excuse me if it seems easy. I want to calculate the amplitude of a specific frequency in a signal. The frequency precision is (relevant question)  df = \frac{fs}{NP} \$...
216 views

### How do I reduce the frequency of electric current for part of a circuit that has variable frequencies?

I want to reduce the frequency of electrical current that is operating in the 220 to 240 khz range, to being a maximum of 20khz. I want it to still be variable though, and the magnitude of variation ...
325 views

### Is D flip flop equivalent to frequency mixer (difference frequency) for square waves?

I was trying to make a frequency mixer (only difference frequency) for two square waves (PWM1, PWM2, both 0.5-4KHz range) using ONLY Arduino due. I'm new to signal processing, and the only way I can ...
57 views

### Taylor approximation

Suppose we're given the position $x$ , velocity $\dot{x}$ , and acceleration $\ddot{x}$ at $t_1$. We need to approximate the position $x$ at $t_2$. In below picture, I understand ...
81 views

### Can the frequency of an electrical current be heard and distinguished from other frequencies just by connecting circuit to a speaker?

I have a circuit that I want to be able to detect the frequency of the current going on it (part of the circuit is AC, the power supply is going to be at least 3v, probably 5v, and 6v DC at most). I ...
119 views

### Sampling (reading) a digital data signal?

I'm currently working on a project, where I have an external device (POCSAG pager - POCSAG protocol) that is giving out a digital (5V - 0V) square-wave signal. I have an ATmega2560 (Arduino) ...
261 views

### Resolution enhancement for a 2wire PT100 setup with ADC and no external amplification

I'm working on a PT100 based temperature probe sensor to read temperature difference between two points inside a pipe with flowing water, the requierements are: 1mK resolution over 0-45C range. dual ...
395 views

### Matlab Phase Locked Loop Design : FM Demodulation

EDIT: It seems I've asked too much at once here. I'll do some more studying and come back if I have more specific questions. I'm trying to design an analog phase locked loop in Matlab. I've read ...
62 views

### How can I find charge from output signal of the Photo Mulitipier Tube?

Here I have a scintillator detector with PMT, It give a signal when a particle passing through it. I need to find the total charge from the signal. How can I find charge from the signal?
108 views

### What is rapid signal attenuation?

Attenuation describes the weakening of the signal as it travels from the transmitter to the receiver. However, this textbook describes a concept called "rapid signal attenuation" as a way to allow ...
602 views

### Interpretation of FFT FMCW Doppler radar results

After a lot of research and help from the users here, I managed to do some FFT and signal processing in my first time in my life :) I have got the following figure, which shows one peak frequency, ...
133 views

1k views

### Why the resultant period of two signals is the LCM of the individual period of that signal? [closed]

Suppose a signal is constructed using two independent signals(say S1 and S2)both S1 and S2 have two different individual frequencies.The resultant signal that has been constructed has a new frequency,...
975 views

### Octave pzmap: format poles and zeros

This question is linked to this one: Octave rlocus: format ploles and zero I am using the Octave command pzmap but the size of the markers of the poles and zeros ...
125 views

### Is there a specific preferred order of operation of signals?

Basic Signal Operations Performed on Dependent Variables-- The periodicity of the signal is varied by modifying the horizontal axis values, while the amplitude or the strength remains constant. These ...
108 views

### How do I create a subtractive or dffferential two channel audio mixer?

I have a desktop mixer made by Behringer (Xenyx X2222USB although I am not using its USB capabilities) which has a line level output that feeds 2 channels of a Behringer USB audio interface (U-Phoria ...
92 views

### op amp circuit functionality

what is the functionality of following circuit? It's a LM324 opamp and a sin or ramp signal get into it's inverting input and non-inverting input grounded. It's power is 12 and -12 and output of op ...
157 views

### Can we transmit a PSK modulated signal with YARD Stick One?

We are working on a project to produce a simple walkie talkie repeater. We have a RTL SDR, which we are using to reverse engineer our signal. Using this + URH, we think our signal is PSK modulated, ...
46 views

### lm13700 as Diode laser voltage to current converter

I generated two Signals, one using dac7611 (ramped signal with fre = 0.04hz ) and the other one, using AD9833 DDS (sin wave with fre = 32 KHz) then generated signals added using ad620an. Is this ...
150 views

In electronics engineering which is the better unit to work with radians or degrees?What are the advantages those 2 unit provides?
208 views

### Composition of a signal

Today in our signals and systems lecture we were going through a particular problem then our professor took a signal and broke into its constituent parts he drew this diagram------ Horribly out of ...
91 views

### How to improve AHRS algorithm

I'm currently working on a project with multiple IMUs mounted on moving vehicle estimating their pose. I've just read about AHRS algorithms. So I have two questions about them: Since my data is pre-...
99 views

### Transformer near signal lines

I am currently building an analog signal audio device and am designing a power supply to take mains in and convert it to +/-12VDC. I have experience designing power supply units but not in the same ...
39 views

### Mixed-Signal modular system grounding scheme

I'm attempting to create a sensitive, precise mixed signal system (more than 24bit) compose of a backplane and stacked modules on 2.54mm headers.It is multi-channel and channel's modules are well ...
194 views

### Getting rid of noises after RC low pass filter stage

I am outputting a 40kHz square wave from arduino and passing it through an RC circuit in order to get a clean 40kHz sinusoid out. However, the output wave I am getting is noisy.(see picture) Any ...
51 views

### Filter gyroscope's error from linear acceleration?

I need to use 3-axis angular velocity data for my application, but the gyroscope outputs angular velocity when under linear acceleration (not rotating). Is there a way to filter this error?