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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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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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 ...
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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 ...
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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 ...
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1answer
59 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, ...
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1answer
53 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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57 views

Can the unscrambling of a scrambled analog tv signal be detected remotely? [closed]

In short: Can the unscrambling of a scrambled analog tv signal be detected remotely? Is there a mechanism to detect the unscrambling of a scrambled tv signal? The source of the broadcast is a ...
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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 ...
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1answer
80 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 ...
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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 ...
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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 ...
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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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1answer
70 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 ,...
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1answer
22 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
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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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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?
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2answers
78 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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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 ...
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0answers
25 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 ...
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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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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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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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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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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 ...
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1answer
50 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 ...
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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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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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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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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 ...
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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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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
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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 ...
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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 ...
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1answer
33 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
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2answers
64 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:...
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3answers
578 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 ...
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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}\...
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1answer
54 views

\$e^{i2\pi Nf_snT}=1\$ why?

Why is: \$e^{i2\pi Nf_snT}=1\$ in snippet from book
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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
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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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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 ...
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1answer
61 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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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 ...
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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
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1answer
29 views

Some confusion about differential-ended data acquisition system

I have many transducers which all have single-ended signal outputs. I hook them up to a single-ended DAQ board. A board with 16 single-ended inputs. The DAQ bard is currently set to single-ended ...