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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49 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
25 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
41 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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1answer
40 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
38 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
46 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
79 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
45 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
35 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
98 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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108 views

Instrumented landing: why switching *everything* off [migrated]

Few days ago I took a flight to go back to my town. Towards the end of the journey, the captain demanded us to shut down any electronic device that we had on board, including iPods, CD players, phones ...
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3answers
62 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
76 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
69 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 ...
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1answer
50 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 ...
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1answer
72 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
59 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
45 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
44 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
44 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 ...
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1answer
52 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
64 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
21 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
41 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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0answers
46 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. ...
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1answer
54 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 ...
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1answer
49 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 ...
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2answers
413 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 ...
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2answers
50 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
66 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 ...
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1answer
78 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
42 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
64 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
36 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 ...
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1answer
40 views

Is there any repeater with power amplifier?

I installed sensor module connected with controller. Those are connected with 6-wire cable, and it consists of 2-wire power(5V & GND), 4-wire signals(0~5V analog). First time, I thought distance ...
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1answer
64 views

How electric signal is converted to more powerful electricity

First a little disclaimer: I've a newbie question which is simple, but somehow I can't explain it to myself. I'm interested in how electrical signals can trigger let's say a movement, which requires ...
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1answer
55 views

Line-of-Sight method of simple code transmitting for outdoors

I'm trying to determine the best way to do this. Basically I'm trying to design a system that would transmit a signal containing a simple code to allow the receiver to identify the source device. It ...
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2answers
41 views

RF Combiner Hardware

I have say, 4 170 MHz signals coming in on 4 BNC cables. I would like to add these signals together. Is there a name for a piece of hardware that does this? Are there any special considerations I ...
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2answers
88 views

How do I drop 19VDC from a 0-60VDC source to get an accurate linear 0-48VDC signal

I've been using the Stack Exchange website for years, but never asked or answered a question, so first I'd like to say thank you for all of the help over the years. On to the problem: I want to ...
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0answers
43 views

Voltage at some point on a transmission line (a power distribution line in this case)

I am interested in knowing the instantaneous DC voltage (ball park) at a capacitor bank on a power distribution line at the instant I interrupt the circuit some distance away. If I interrupt the ...
2
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5answers
127 views

Why do we need transforms (Fourier, Laplace, Z and wavelet etc.) for a signal to analyse?

Why do we need transforms (Fourier, Laplace, Z and wavelet etc.) for a signal to analyse? Is it necessary for practical calculations and analysis?
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1answer
41 views

Choosing the right sampling frequency for WLAN 802.11ac signal (BW : 80 MHz)?

I’ve got a WLAN 802.11ac signal & it’s bandwidth is 80MHz, now I would like to know the ideal sampling frequency for this signal. As per the nyquist theorem , the sampling frequency could be 160 ...
2
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2answers
302 views

Area under Dirac Delta function

What is the difference of the area calculation for the Dirac delta function when using different limits of integration? $$\int_{-\infty}^{\infty}\delta(x)dx = 1$$ but ...
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1answer
39 views

exam problem finding impulse response from a given system? [closed]

I search but i did't find useful way to answer it please how to get the impulse response from a given given system
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1answer
155 views

Why it has used BPSK modulation after OFDM?

I am quite new to OFDM modulation. I am reading this from a tutorial. In one of its parts, for showing amplitude variation of the OFDM signals, there is a graph that has used 8 sub-carriers and BPSK ...
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1answer
191 views

Comparison of Series and Parallel LC Filters for Noise Reduction

Since there are two basic types of LC circuits that can be used for passing/blocking signals, I'd like to know the differences when using series or parallel LC circuits for noise at a known frequency. ...
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1answer
98 views

When is impedance matching necessary? Isn't it much less efficient on all other aspects?

I understand that discontinuities of the physical properties of conductors create reflections much like dioptres reflect a bit of light, but : in which cases does impedance matching become ...
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0answers
33 views

How is 802.11 (Wifi) received signal strength (RSS) measured and reported to software?

I have looked around for a while now to find an answer to this question, but answers I find do not fully answer my question. I found this response interesting from another question on this site. ...
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2answers
61 views

Systems and signals - integration with dirac's function and step function

I'm taking the introductory course to systems and signals and the mathematics of integration using the step function and Dirac's function and For the first integral, I just don't know how to ...
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1answer
58 views

Replace Electret Microphone With Arduino Output

I have the following circuit for a simple FM transmitter. I want to replace the electret microphone with a simple tone generated by an Arduino (or equivalent) that will be broadcast over FM radio. ...