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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Making Device to Send Data to Smartphones: 100m range, 1kb/s bandwidth, low power

What I want to make: A device that immediately sends a notification if the device incurs a moment of high acceleration. The notification needs to denote the acceleration. There is no guarantee that ...
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0answers
20 views

mobile receiver [on hold]

I have a mobile phone it got wetted only by few drops of water and water contacted with signal receiver and it lost 3g signal receiving capacity but working on 2g part but how it is possible will ...
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6answers
88 views

Converting PWM to bidirectional square wave?

Is it possible to make bi-directional ( symmetrical) square waveform from PWM signal? Im talking about 40 kHz frequency and 0.5v /-0.5v peak to peak signal.
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1answer
75 views

Signal targeting a cell phone

I'm a computer scientist, in college I had a (basic) telecommunications course. I've found it interesting, but had afterwards no opportunity to use apply it professionally, which is of course not ...
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1answer
44 views

Digital filter implementation

Digital filters work on digital data. When we implement digital filters in hardware, does that data which was stored in the form of bits needs to be converted back to its quantized voltage level? If ...
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1answer
23 views

Connecting GPIO and SPI signals via cable

There is a requirement in one of our systems to transfer signals from one board to another board in the same system. The signals are GPIOs and SPI lines from I.MX6 processor and it is in 3.3V ...
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1answer
29 views

Hardware Implementation of Discrete time Systems

Discrete systems work on sampled signal values. Suppose if we want to implement such a system like a discrete amplifier (i.e., \$y[n] = A\cdot x[n]\$), how do we make sure that the input to this ...
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1answer
83 views

Radio signals blocked by red bricks / aluminum insulation

Do red bricks home/building and aluminum insulation diminish the strength of radio signals?
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1answer
39 views

Nyquist Sampling rate

We have \$z(t)=\cos(100πt)\cos^2(500πt)\$ . Find Nyquist sampling rate. Well, I know that \$f_s=2f_{max}\$. My main problem is that I am not entirely sure if I could re-write the above signal as: ...
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42 views

Simplest signal level/clip LED indicator?

I was looking to modify a circuit that would take a signal from a guitar, impedance-match, amplify and bias it so that it would be readable by the ADC of a micro-controller, effectively based off this ...
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1answer
64 views

Output resistance of Emitter Follower

I have to measure \$R_{in}\$, the input resistance seen by the signal. It was told me, that the quickest way is measuring the voltage gain using oscilloscope, insert a resistor before \$R_B\$, ...
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2answers
72 views

Internal resistance of signal source

It was told me that a signal sent to the circuit can be rapresented by \$V_{sig}\$ and \$R_{sig}\$, where \$R_{sig}\$ is the internal resistance of signal source. Now, let's consider that we have a ...
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2answers
59 views

Singnals, filters and power output

I have couple of questions: A square signal goes through a low pass filter and in the output of a circuit we get a sine. What happens there? Give a scheme? This is really weird, because, from what ...
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1answer
31 views

FM and phase/frequency deviation

I have a small understanding issue here, so I would be very glad if someone could help me a bit! We are given this FM modulated signal to volts; ...
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2answers
133 views

Double Side-band Amplitude for Radio Transmission & Single Side-band Reduce Carrier for Point-to-point Transmission

What are the reasons which lead to the use of double side-band amplitude for radio transmission, and single side-band reduce carrier working for point to point transmission? Thank you for your help.
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0answers
104 views

How to get fourier series of 8-bit character to be transmitted?

I have been reading this in a book, but can't understand how he used the 8-bit in fourier series equation to get the result below. The transmission of the ASCII character ‘‘b’’ encoded in an 8-bit ...
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29 views

Average signal power (signals and systems - discrete signal)

I am trying to find the average signal power of some discrete functions. For a finite interval, I can use the formula: ...
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2answers
229 views

Function generator outputs

A function generator has a 50 ohm and 600 ohm main outputs: http://www.ece.mtu.edu/labs/EElabs/EE2303/model_25.pdf What does it stand for? What is the difference? Is that about the load resistance?
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2answers
54 views

Multipath fading in mobile radio systems

Here is the problem that left me thinking: "In a mobile radio system (e.g., cell phones), there is one type of degradation that can be modeled easily with sinusoids. This is the case of multipath ...
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1answer
74 views

Drum machine circuit diagram

I'm having trouble understanding this circuit. Can someone help me get through it? I'm trying to understand what the signal is doing from start to end but keep running into electrical deadlocks.
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2answers
95 views

Which harmonics will be missing when duty cycle = 30%?

After some Googling, I found that every n=(1/duty cycle)th harmonics will be missing in the spectrum of a pulse wave. E.g. a 20% duty cycle will have their 5th and 10th harmonics missing. However, if ...
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2answers
71 views

Building an RSSI map for an indoor positioning system

As I study so far, Indoor positioning mechanisms are built with two approaches: Trilateration, triangulation: Directly calculate/compute position with signal fading/RSII data which mobile device ...
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1answer
88 views

How much difference in net length is ok?

Sorry, but I couldn't find a better title. Consider the following: I have an address/data bus interface. Intended frequency of the D/A bus would be around 10-50MHz. According to the datasheet of the ...
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0answers
25 views

Link integrity test pulse vs carrier signal

Ethernet uses a refinement of ALOHA, known as Carrier Sense Multiple Access (CSMA), which improves performance when there is a higher medium utilisation. When a NIC has data to transmit, the NIC ...
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1answer
62 views

Remove DC offset and rectify

I'm using ACS712 hall effect current sensor to detect presence of current in the power line of a remote device. I don't need exact current value but rather just want to know if it's above certain ...
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1answer
44 views

Distance confusion about Shuncom SZ05-ADV ZigBee module

I ordered this module looking at the datasheet that it has a range of 2000m LOS distance. But now when I test it, I can receive signal from a maximum of 50m distance! It sends 2.4GHz signals. As far I ...
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7answers
305 views

Measuring direction of object (or angle of signal origin)

I am interested in somehow tracking the "compass" direction of a moving object from a reference-station -- in other words, something similar to submarine sonar systems (although I'm unsure how those ...
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2answers
95 views

What is “M” in Hartley's law?

If Hartley's law is: $$ C = 2 B \log_2 M $$ I know this equation is part of calculating the capacity of a channel. I also understand that: \$C\$ is the digital bandwidth, in bits/second \$B\$ is ...
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2answers
83 views

fourier transform for non-stationary signal

I have read that for non-stationary signal we break the signal into smaller segments by applying a window function . My question is how this can help to make the signal has a fixed features or to ...
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1answer
59 views

Space Vector Modulation

Im looking to learn more about this topic so that I can implement it in an amplifier design. I've read around and understand most of the math behind it, but I'm still a little fuzzy on how to ...
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1answer
65 views

Response of a stable second-order transfer function to a unit sine wave input

In the lecture slides from my university it says that: "The response of a stable second-order transfer function to a unit sine wave input is:" ...
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0answers
34 views

Bypass switch for amp

I've just successfully completed a CMOY amp and I'm pleased with the result. However, I want to be able to hear the difference between the original signal and the amplified signal, so I put a switch ...
4
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1answer
49 views

Analog off board connectivity

I have a board that I intend to control with high fidelity differential analog, I'm aiming at one part in 216. I want to connect the two boards with a COTS connector that solves most of the pick-up ...
2
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2answers
160 views

Signal rate, data rate and bandwidth in digital signals

I'm trying to understand the concept of signal rate and the relation between signal (baud) rate and bandwidth of digital signals from a book about data communication. First, the book distinguishes ...
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5answers
200 views

Why does differential signaling send complementary signals instead of just pairing the input and ground voltage?

I'm very new to EE, so please excuse me if this question is bad or has an obvious answer. After reading an overview of differential signalling, it left me wondering: Why does differential signalling ...
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1answer
97 views

Driving “Arcade CGA” monitor safely

I have some arcade machines which I build custom Linux PCs for. They all have 15khz monitors in them so I do some funky Linux stuff to output (what I think is) a correct signal to drive them. This is ...
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3answers
145 views

Driving 60 signals one at a time, in constant sequence

I have an application where I need to turn on/off one of 60 signals one after another in a constant order, ever repeating. (1, 2, 3, ... 59, 60, 1, 2, ...) Only one signal is on at any given time. The ...
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1answer
58 views

How boost a DVB-C signal [closed]

I receive a DVB-C signal from my broadcast TV provider, and I use coaxial cables and some splitters to connect my three televisions to the coaxial wall-socket. Unfortunately I have problems to ...
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2answers
50 views

What is the frequency at which meaningful data can be sent? [closed]

Excuse my poor use of accurate terminology, in advance. Is it possible to hear anything meaningful on a 1Hz signal? Are there any 1Hz signals? What frequencies can you hear natural phenomena? At ...
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4answers
129 views

Baud rate calculation

I have an exam tomorrow and I'm confused on the following question, that may be asked in the exam: One byte data with parity bit by using asynchronous serial transmission with two stop bits. For ...
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2answers
96 views

SNR vs Signal Strength for digital throughput

I'm trying to compare two antennas, A and B for WiFi. A is showing: Signal Strength of -77dBm, but SNR of 9dB. B is showing: ...
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1answer
82 views

Differential signal processing and generation

I am trying to interface to a Mitsubishi central aircon unit. Based upon the manual, the internal units communicate over a differential bus (I hope is TDM). I have a screenshot of the signal: How ...
3
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4answers
305 views

How to prevent PA system from interference of 4G signal

I apologize if this is not the right place to post this. I am working on a small PA system for a weekly gathering. It catches the signal from wireless mics and output it to the speakers. I am pretty ...
2
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3answers
105 views

Wireless EEG electrode design

Currently, all 'wireless' EEG systems acquire signals from electrodes which are wired to an amplifier, a filter, a digitizer and then finally a wireless module. I want to design a system that's ...
0
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1answer
59 views

Measruement of RF Signal strength / phase difference

I would like to measure the signal relative strength and phase difference of two bluetooth(BT) receivers. and I found a chip that will do exactly that, AD8302 ...
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2answers
95 views

Eye diagram test

I am trying to perform a eye diagram test on a device to check its USB performanance. I am using a board "SQIDD" in order to perform this test. The following figure shows my test setup, I am using ...
2
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4answers
229 views

Thermocouple reading different from Commercial Datalogger when using Arduino

A K-type thermocouple is connected to a thermocouple breakout board that outputs 1.2V to 8.8V that covers the entire -260C - 1380 °C of K-type thermocouple. This output is than divided by ...
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1answer
41 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.
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2answers
161 views
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3answers
147 views

What is the deal with resonant frequency?

During the last day or so, I have studied the topic of resonant frequency over a few circuits. Now, I could easily see that every time my circuit operated upon that resonant frequency something ...