A signal is a stream of information in the form of a varying quantity. Usually in electronics, signals can be in the form of voltages, currents, or radiated electromagnetic fields.

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Enery and power when we have trigonometric functions (Fourier transform)

It is asked to evaluate the energy and power of the signal $$x(t)=10\cos(100t+30°)-5\sin(220t-50°)$$ Since it is periodic, I need to find $$\int _{-\infty}^\infty |x(t)|^2 dt \text{ and } ...
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63 views

can signal ground be carried in the connector shell?

I have a cable with 6 pins but I have 6 signals and I don't have space for the signal ground. If the shell is continuous from end to end, would it be fine to use that as the signal ground?
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1answer
56 views

Must this switch be turned on and off periodically?

Imagine that the AC1-2 is 170VAC at 150kHz~. I simply want to turn the MOSFETs on, and let the AC flow through a inductive-capacitive load. 1) If I can turn the MOSFETs on to saturation by ...
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1answer
81 views

Simple Power Line Communication

I'm working on a remote (wirless) door opener and I need to install a device (just in the opener) at the entrance of a building where there is an electric opener. The problem is i can not install ...
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1answer
36 views

noise signal passed thru Normal ( Gaussian Random variable) distribution system : exam problem?

I know that Fx(x)= F((x+a)/o) I don't know how to find Fx(x) that satisfy the p(y>=0) can someone clear this point to me ?!!
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0answers
25 views

Use of hpcompac desktop computer internal speaker for mobile phone audio output [closed]

My hpcompac desktop computer is dead but internal speaker is working I want to use this speaker to listen songs on my mobile phone, any suggestions?
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1answer
37 views

signal generator - circularly polarised

I am testing some hardware in lab that computes the four Stokes parameters. To test the hardware, I want to generate circularly polarised sine wave. Provided the frequency is high enough (above ~100 ...
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2answers
74 views

Looking for a simple way to inject a signal on 60Hz Mains line

Okay, so I'd like to be able to inject a really simple signal on top of the 60Hz AC Mains. It doesn't have to contain any data per se, just a simple signal to trigger a receiver on the same ...
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2answers
47 views

Change AC signal frequency without changing the voltage

I have a non constant -/+1 Volts to -/+7 Volts AC audio signal. I want to design a device that takes this input signal, doubles the frequency, without changing the voltage. So, the output voltage is ...
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3answers
71 views

Calculating the power of a signal

I'm trying to calculate the power of a signal and my tutor has given me this formula to do it. I've spent the past while building a program and now the foundations are there it's time to implement the ...
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2answers
44 views

how to determine the probability the two signals are equivalent

I am new to electronic engineering and DSP. I have this orignal signal matrix [X1,Y1] . . . . [Xn,Yn] and then it goes through series of transformation. It can be rotation/shift_bit/or whatever ...
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1answer
66 views

Proof: A strictly bandlimited signal must also be a signal of infinite time duration [duplicate]

How can I show that a bandlimited signal is also of infinite time duration? I know it has to do with Fourier transforms and convolution but I'm not sure how to actually prove it. I also know that the ...
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1answer
44 views

Detect the maximum of signal

I am trying to create a bloc with Xilinx system generator to detect the maximum of a sine wave. I used the strategy that: $$ x(n-1)-x(n-2)>0$$ and $$ x(n)-x(n-1)<0 $$ but I didn't find the ...
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3answers
118 views

How safely to send signal between logic and higher current pcb?

I'm designing a PCB with 4 FETs. These are driven in the same board by totem pole drivers, and their load are about 5A total. I am using PWM at 1000Hz. The signal comes from a logic IC in another ...
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1answer
47 views

lower and upper 3dB frequency from frequency response in Matlab

Is there any Matlab code available to find the lower and upper 3db frequency of a plot. If not what could be the easy way. I am aware of the theory but implementing is becoming difficult.
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1answer
48 views

Just need to check if this equation correspond to this block diagram

$$y(n)=y(n-1)-ax(n-1)$$ Is this correct? Thanks in advance.
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3answers
56 views

Is a multiplexed signal same as a composite signal?

Used to StackOverflow, this is my first question here. So please bear with me if the question is too simple and obvious to you as I am not good in Electrical Engineering stuff. I really need to ...
2
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1answer
63 views

Create a differential output signal

I need to supply the galvo driver with a signal "Voltage Range ±3.0V p-p or ±10.0V p-p (Differential Input)" - that's what it says in the datasheet. I have a 0-5V single ended DAC and differential ...
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1answer
53 views

Using a envelope detector to demodulate low voltage signal

I am currently working on a project in which I have a modulated RF signal at a carrier frequency of 400kHz. The signal itself is fairly low voltage, and I need to extract it from the RF carrier. I was ...
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0answers
68 views

How do Dualshock 4 pressure sensitive buttons work?

I'm doing a reverse engineering research about the PlayStation 4 controller. I want to know how do the analog buttons work (the triggers in the bottom, not the analog sticks). I've found a nice ...
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2answers
58 views

Does a regular signal booster with antenna work for cell phone?

I am not that much familiar with communication and antennas. I want to build a gsm repeater (gsm signal booster), but I am not sure if it works if I do it like the way we do for a radio. What I am ...
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2answers
60 views

Send data to an Arduino by using an audio cable

I want to send some Data to my Arduino by using the audio jack of my smartphone/computer. (USB is no option, since my smartphone does not support USB Host mode and I also don't want to go wireless or ...
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1answer
63 views

Find autocorrelation function of a signal

Find auto-correlation function of a signal $$g(t)=e^{-2t}\cdot u(t)$$ where \$u(t)\$ is the unit step function. I don't know how to start to solve this problem. My book list this equation only: ...
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2answers
93 views

Acquiring an accurate clock input for my computer

Building a timegrapher is quite straightforward, it is nothing more than a piezo transducer connected through to an amplifier. However, in order to actually utilize the results, one need an accurate ...
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1answer
52 views

FM signal example

Sorry if this question is too basic, but I'm a software engineer student who must study communication systems. I try to represent a FM signal in a graphing calculator, but I don't know why the result ...
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1answer
40 views

Confusion with output wiring and signal conditioning

I’m little confused about wiring and signal conditioning the following instrument: http://www.skypowerinternational.com/uploads/documents/4.3351.x0.140-161_WG-Geber-firstclass-advanced_analog_eng.pdf ...
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2answers
103 views

Optocouplers for purposes other than galvanic isolation?

In the diagram below there are two modules, A and B, which are separated by a physical distance of about 15m. Module A has a 12V DC power input. Module A powers module B (they share a common ground). ...
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3answers
72 views

Subtracting Audio Signal from Ambient Noise Signal

So I'm pretty well-versed in the software world, and my buddy and I decided to tackle a hack idea to get into hardware hacking but we're trying to figure out whether our implementation will actually ...
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2answers
83 views

differential amplifier will cancel DC present at input

In differential amplifier, it is written that "only AC signal will be amplified and DC part at the input will be canceled and hence there is no need of DC blocking capacitor". I am not getting this ...
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1answer
84 views

How can I boost/limit a signal to TTL levels?

I am researching a data acquisition system to measure the amplitude and frequency of a 4,100Hz 5v-25v AC square wave signal. Actually this is version 2 for me, in the previous version I analyzed the ...
0
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1answer
80 views

Ultra low current pulse generator (for BLE module interrupt)

At the moment I'm working on a project with at BLE-module. This module is based on the CC2541 from TI. I want the BLE-module to permanently transmit a signal. This module has two modes: a level- and ...
0
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1answer
83 views

Adding two signals and finding the RMS and Peak to peak value of the output signal

I would like to start by saying I have been solving exercise related to Op amps and how to find RMS values and Peak to peak values. But I got stuck on this exercise. Basically, two signals has to be ...
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1answer
75 views

How does a cable tone-and-probe kit work?

A useful tool for someone installing electrical cabling of any sort can be a Tone and Probe Tool: it allows one to find individual leads among a possibly hundreds in a cable trunk, without having to ...
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1answer
60 views

Maximum signal data rate

I have a frequency signal range from 25 Khz to 35 Khz. I know that the the minimum signal sampling to assure reconstruction of the signal from the samples is 70 Khz. Would it be correct to assume ...
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2answers
50 views

Which characteristics of a Radio signal are involved to be selected by radio receiver? [duplicate]

the radio antennas receives millions of signals. how our radio selects the appropriate signal as it's input? which characteristics of the signal are involved for this selection.
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2answers
57 views

Relationship between frequency and other signal characteristics

As a signal travels through the air it loses it's energy. When the energy of a signal gets low what happens to frequency, amplitude and other characteristics of that signal? Does frequency decrease ...
0
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1answer
81 views

Calculate transfer function given 3dB point?

I'm not sure the relationship between transfer function from the 3dB point. The transfer function should give the gain, and I suppose when we put in the frequency at the 3dB point, the transfer ...
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2answers
156 views

first Mini dsp Project using matlab and books

i have basic knowledge of matlab and took signal and system course. i want to do project like below. but dont know filter on matlab. are there any books i can learn fft commands etc.(dft, ...
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1answer
34 views

What is the LCCDE equation of this block diagram

I cant find the LCCDE equation of this system ı try to reduce but thing will get compliceted
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1answer
43 views

İs this system is a LTI or not ?

I have a F system and a input of this system is e x(n) = e^iπn/4 and output is y(n)=cos(πn/4) So is the F system is LTI or it would be ? I try to using addivity and Homogeneity but I cant do it
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49 views

What does it mean for a voltage to be attenuated by X dB [duplicate]

Say that a signal is passing through a medium, and in the middle of it, the amplitude of that signal drops by 90%, in this case I would just say that the media attenuates the amplitude by X factor. ...
0
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1answer
65 views

For a first order system, what type of response to a sine wave?

If I put a sine wave through a first order system and reconstruct it with some type of weighting (equal or not), how should the response come out? Should the response follow the original sine wave ...
1
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1answer
63 views

A circuit to prevent parasitic powering of FT232RL by MCU, will it work?

In a previous question I asked how to prevent the MCU TX pin (3.3V when idle) from powering an FT232RL Usb to Serial chip via the TX line: Preventing parasitic powering of FT232RL by ATMega328P I ...
2
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2answers
457 views

Split TV signal to make a video wall

I'm working on this project for University. We are generating visuals by sending audio signals from the computer to an old tv. Left channel to TV's Vertical, right channel to TV's horizontal. We send ...
0
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2answers
58 views

Find the power spectral density?

I don't understand how the graph of H(w) is used to find the equation for H(150) and H(200.)
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1answer
77 views

Limiting small signals to one direction (ideally with passive components)

My setup is as following: I use a Y-Cable for splitting an audio signal to two devices (boxes and earphones). The headphones have quite big speakers so they act also like a microphone - feeding back ...
1
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1answer
91 views

Why does USB signaling to microcontrollers need resistors

I'm currently trying to make a USB device with the ATMega16U2. On page 187 of the datasheet, there are unspecified resistors between the USB port and the pins of the microcontroller The Arduino Uno ...
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1answer
43 views

How can I combine my knowledge of signal processing with electromagnetic physics? [closed]

Now at University I've learnt both signal processing and electromagnetics, I am curious as to how these two areas can be combined into one. For example, in signal processing you are required to find ...
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1answer
79 views

When is a system's frequency response symmetric?

When is the frequency response of an LTI system symmetric, i.e. which property does it need to satisfy? Does it have to do with the system being causal (I believe this means that h(n) = 0 for n < ...
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1answer
47 views

DDC112 Analog to Digital converter

In DDC112 Analog to Digital converter, its mentioned that its suitable for Low-level current output devices, such as photosensors, and can be directly connected to its inputs. But to increase analog ...