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.
0
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3answers
57 views
Can you measure voltage along a wire a multiple points simultaneously?
Basic EE question here. Suppose I have a piece of wire a foot long. Suppose there is some signal (for example a clock signal) going through the wire. Is it possible to simultaneously measure the ...
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0answers
25 views
analog filters- dispersion, ripple and windowing
What is the adventage of using a rectangular window instead of hamming?
Is it necessary to minimize the ripple in the pass band or in the stop band?
If I put a periodic signal through an analog filter,...
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0answers
54 views
Finding UART pins on a PCB header
I have a PCB with some headers exposed. I know for certain that some of those pins are UART connections (RX,TX, Ground). I'm hoping to find RS232 with TTL voltage levels but this is just an assumption....
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votes
1answer
32 views
What is the type of the wifi interference to ZigBee? Multiplicative or additive?
As we all know, the cross technology interference is a critical problem. CTI means that different communication technologies operate on the same spectrum (e.g., 2.4GHz), and this would lead to the ...
1
vote
2answers
63 views
Type J Thermocouple Signal Conditioning to 0-5V
I've been working with signal conditioning, thermocouple out specifically. I'm working with a span of 450 °C, that is, from -50 °C to 400 °C. For those values of temperatures I get, according to the ...
0
votes
1answer
28 views
Generate +2V Offset on a +12VCD Supply line
I have a 12VDC @50mA_Max supply line. I need to inject a +2V 50us offset pulse to the +12VDC line, having an effective +14V for 50us.
I have access to an external power supply, where I can have ...
0
votes
1answer
60 views
“Tagging” Data traveling over serial port?
If I'm reading data from multiple channels (UART) of a microprocessor, but I want it to be continuously read, I imagine the logical thing to do would be to cycle through the channels and output data, ...
0
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1answer
54 views
one-way RF signal diode
Is there a special diode or band pass filter that will only allow RF signal to go though a wire in one direction like a diode does with electricity?
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0answers
58 views
RS 422 signal voltage booster
I have RS422 output signal with 2.6V peak to peak, However after distance 25 meter this signal voltage is attenuated upto 0.8V and receiver is not able to detect signal. Is there any IC for boost this ...
1
vote
1answer
81 views
How do I stop coiled (telephone) wire blocking signal?
This circuit is working just fine if the output signal uses a straight wire, even if it is a very long wire with say a 1K resitor added to the end of it.
However, the signal does not get through when ...
3
votes
1answer
62 views
How can I create two ac signals with a voltage controlled phase offset?
Is there a fairly straightforward analog circuit (resistors, capacitors, transistors, etc) to generate two sine waves of the same frequency and introduce a relative phase offset between them? So I'm ...
1
vote
2answers
58 views
What is a typical value for the gain of a smartphone's Bluetooth (or Wi-Fi) antenna? [closed]
I can't find specific values for transmitter and receiver gain anywhere. Very often the Bluetooth module is together with the Wi-Fi module, so a Wi-Fi antenna gain value will help me as well.
I need ...
0
votes
2answers
91 views
How to read out data from this moisture sensor?
I found a cheap moisture sensor on Ebay that only came with the schematic attached. The moisture can be read with an analog or digital signal.
However, I am wondering how the opamp creates a digital ...
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votes
1answer
72 views
Falling edge detector using BJT
I'm trying to build what is basically an electronic push button switch - something that would switch an led on an off with the same signal . I figured doing this would require a falling edge detector ,...
1
vote
1answer
23 views
Fetch RSS value using Nordic NRF24L01 module and RadioHead library
RadioHead provides a lastRssi() function (http://www.airspayce.com/mikem/arduino/RadioHead/classRHGenericDriver.html#ab04f2ca335d89f5fac1d213c0aea9da2) to fetch the ...
3
votes
2answers
134 views
What is the source of this shape on my USB eye diagram?
I have designed a USB device around an STM32F105. It is USB 2.0 Full Speed CDC device configured as a Virtual COM Port using ST's USB Library. It uses the STM32's built-in PHY, and runs at 12 Mbps.
...
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votes
2answers
82 views
What is the difference between the terms wave, waveform, and signal?
What is the difference between wave, waveform, and signal? Or do they have the same meaning? Can they be used in place of one another?
2
votes
2answers
79 views
Lengthening button press signal
I'm trying to rewire an arcade game, and I need one button (a simple microswitch hooked up to the coin acceptor) to have a longer press than a coin passing by provides. I'm not sure exactly how long ...
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0answers
26 views
Resonant RC Series and deriving equivalent circuit
How is it that this is equivalent? Assuming all transients have died out.
vi = Vcos(omega*t)
The fake input was defined as:
\begin{equation}
v_{cp}^\sim = \frac{V_i}{1+j\omega_1RC} e^{j\omega\\_1t}...
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1answer
95 views
Small signal equivalent circuit BJT question
This circuit is two BJT transistors in so called 'darlington configuration'. I want to analyse this circuit for AC signals (where the capacitors are shorts).
The question is to calculate Delta_V_L/...
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votes
0answers
60 views
making EMG electrodes
For a bionic hand controlled by EMG signal, I need EMG electrodes.
The problem is that I searched everywhere for suitable electrodes but I couldn't find any.
Can you suggest how to build them myself ...
0
votes
0answers
26 views
Simulink how to convert Duty Cycle to reference voltage signals(Uref)
In Simulink I am creating a DC-DC buck converter using Average-model based VSC Universal. But one input of VSC is in Uref. For this case I need to convert Duty Cycle (D) into Uref for Input. Because ...
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2answers
38 views
Wireless 2.4GHz to Bluetooth? [closed]
I've been wondering about this for a while; I have a Wireless 2.4GHz keyboard that requires a USB reciever to catch the signal.
How great would it be though if I could use it on my phone, for ...
0
votes
2answers
69 views
12-bit output to +/- 10v
Suppose we have a signed 12-bit output which is capable of representing both positive and negative numbers, how can this be converted to a +/- 10v signal using DACs, op-amps, etc.
For example, 1100 ...
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votes
2answers
69 views
How do I determine the start and end of the wave?
I am facing a bit of a challenge in trying to understand basic concepts or terms within the signal world.
I have a number of values retrieved from a sampled signal that is generated randomly for no ...
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votes
1answer
77 views
Using an earthed function generator with an earthed oscilloscope and ground loops
I have a function generator and I noticed that its DC GND is internally wired to its earth pin.
Similarly I have an oscilloscope and I noticed that its DC GND is also internally wired to its earth ...
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votes
1answer
33 views
Lock-in amplifier output to spectrum analyzer
In several lock-in amp tutorials and experiments (including at the end of “Physics 111: Low Light Signal Measurements” on Youtube), the lock-in amp X or Y output is applied directly to a spectrum ...
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1answer
59 views
Analog signal vs. Alternating current
I am seeing that both of the analog signal and alternating current is represented by the same graph:
As far as I think I know, an alternating current travels back and forth with gradual changes in ...
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votes
1answer
26 views
Actual procedure used to establish a MW link budget in telecom?
If it possible can someone share with me the actual procedure used (Not the theoretical steps in book !) like in Huawei or others telecom vendor to establish a Microwave Link between to sites
Like ...
3
votes
1answer
57 views
In a Delta-Sigma ADC, does noise shaping bring the noise to the signal's frequency?
I'm trying to understand the Delta-Sigma ADC. It is known that it pushes the quantization noise to be in the higher frequencies (noise shaping). Since I don't quite understand how this works, I ...
0
votes
1answer
52 views
3.3V to 5V logic converter using p-channel mosfet
I am trying to convert a 3.3V logic signal to 5V logic signal. I am using a p-channel MOSFET and I can not get it to send the full 5V signal through. Below is the circuit I am using.
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votes
0answers
27 views
Low pass filter for differential signals
I'm building an adc and amplifier circuit for sensing a differential signal out of a pressure sensor. My plan is to use a circuit very similar to what is seen below:
The total differential output ...
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0answers
30 views
Determining Sampling Rate of Analog Signal from Modulated Signal
I'm studying for a final and have a question.
The image above contains a graph of time and signal duration. I'm used to seeing the PWM/PPM/PCM/etc rather than this type of graph.
Am I correct in ...
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votes
1answer
68 views
Problem with implementation XAPP495 [closed]
I'm working on XAPP495 to show a signal which is throughput of a HDMI signal from my Laptop
I do this steps:
created a new ISE project
added all of the .v files from XAPP495
added dvi_demo.ucf
set ...
2
votes
0answers
83 views
Q: What is the power of this signal
Determinate the power of the discrete signal:
$$x[n] = u[n] + (-1)^n + (\frac{-1}3) ^n * u[n]$$
where: $$u[n] =
\begin{cases}
\ 1, & n \ge 0 \\[2ex]
0, & n \lt 0
\end{cases}$$
The answer ...
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votes
1answer
35 views
generating a 10mVpp signal from computer
I have an input to a system that requires a 10mVpp max signal. I have to use my computer to input it due to constraints out of my control. I am well aware an audio card cannot go down that low.
I ...
2
votes
1answer
63 views
Noise can be Differential or Common!
I have a basic understanding on this topic but i still have some doubts, my text books says Differential means it will have impact on one of the 2 signal nodes. and Common will have a common impact on ...
7
votes
7answers
952 views
Why is one return conductor for each forward conductor in a ribbon cable better than a shared return conductor?
I don't understand why second way of implementing is better than the first one? I have my own basic logic regarding this topic, but i am not confident if what i think is correct! so i was looking ...
0
votes
1answer
34 views
How to evaluate quality of signal?
guys. I'm trying to evalute received signals from a transceiver. I'm a rookie in wireless communication. So I hope that you guys can help me out. I want to make a threshold of received signal so that ...
3
votes
2answers
65 views
Band-pass filter with a given impulse response (Matlab)
I am trying to pass a .wav sound waveform through a band pass filter whose impulse response is given by
\$ h(t)=50u(t) \exp(-10t) \sin(2 \pi 440t), \$
I have imported the file into Matlab as follows:...
8
votes
3answers
581 views
Chokes vs. small capacitors on signal cables
I know that many signal cables (usb camera to computer cables, etc.) have bulky ferrite chokes on them to prevent noise.
Why do they all have ferrites instead of ceramic capacitors? Small ceramics ...
1
vote
0answers
35 views
how to sample and modulate a gps gold code
I am trying to simulate the data transmission of a GPS satellite. Telecommunications is not my field so I am struggling a bit with some concepts. I managed to generate the Gold code of the GPS ...
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2answers
54 views
Fourier Series Coefficients Calculation
Could someone tell me where my calculation is going wrong?
So I integrate $$\int_{-1}^1te^{-jn \pi\ t}\ dt$$ and get
$$\frac{e^{-jn \pi\ }}{-jn \pi\ }\text{+}\frac{e^{-jn \pi\ }}{-(jn \pi\ )^2}\...
-1
votes
1answer
54 views
0
votes
1answer
54 views
Is it possible to measure Spinal Cord electrical activity over skin? [closed]
sorry if this is not the right place to ask this question.
I'd like to know the possibility and reliability of measuring electrical activity of spinal cord (specially the cervical region)
if it's ...
0
votes
0answers
35 views
difference between rising and falling time from the pulse response of transmission line
Attached is output pulse response of a transmission line (s-parameter).
In the high-speed serial link design, we usually see more # of post-cursur ISI than pre-cursor ISI.
One of the main reason is ...
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vote
2answers
66 views
On board signal termination
and thanks for bothering with my problem.
I have a two signals A and B that I want to route using several alternative paths via jumpers on my board. In one of the occasions I need to use the same ...
1
vote
1answer
62 views
How frequency generator in telephone works
I was doing some research, on how telephone works, and I found that when user, click numbers they are converted to frequency and passed to wire. I want to know how the frequency generator work, what ...
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votes
2answers
90 views
Ambilight without computer - µC [closed]
Firstly, sorry for my english. I'm not very confident with this language but i'll try to give my best for you guys :).
So, now i will talk about my main problem.
For my school project, i have to ...
-1
votes
4answers
153 views
What analog circuit i should use to shifting a signal from -5..5v into 0..10v? [duplicate]
I want to output my circuit from -5..5v into 0..10v. My circuit generate -5..5v. What should i do to generate that signal? what analog circuit i should use?
thanks
