# Questions tagged [signal]

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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### Does this digital line-encoding/keying scheme have a name?

"1" is a single low pulse of length T, followed by a single high pulse of length T "0" is a single low pulse of length 2T, followed by a single high pulse of length 2T This is similar to BFSK, ...
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### Signal identification: What serial protocol does my desk use?

Can anybody identify what kind of signalling protocol this is? I'm sampling at 2 MHz. Here's the first falling edge of the signal, with a default UART protocol decoder for reference (8 bits, no parity,...
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### Increase voltage of a 1.6MHz frequency

I have a digital signal with voltage of 3V and frequency of 1.6MHz. How can I increase voltage of this signal to 36V? The signal is generated by PWM feature of esp32. EDIT: I'm trying to use this ...
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### How should fuse selection be made in discrete-time alternating current?

My V(t) signal progresses for hours as 0.75 seconds on,5 seconds off.(Let assume V(t)=I_lamp(t),R_lamp=1 ohm) The general formula for fuse selection at room temperature is: In summary,what should I ...
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### Detect LOW signal in a two-way IO line that's HIGH when idle

I am trying to implement the ISO 7816-3 protocol as can be found in the EMV Co. Book 1 using an ESP32 and MicroPython. However, I noticed that the default state of the I/O line is HIGH, and there's ...
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### Ratio detector FM demodulator

The aim of the exercise is to design a ratio detector FM demodulator circuit. UPDATE: I changed the circuit: This is my transient analysis in output: I found the information about AC analysis and ...
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### Convert complex number to phase shift in simulink

I am currently modelling some dynamic phenomena, combining pure simulink blocks and simscape blocks. I have measurements (real-valued) on which I perform computations with complex-valued matrices, ...
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### Mixed sensitivity controller design

I am defining a controller using the mixed sensitivity approach, and I have the following specifications: a low frequency attenuation of 60 dB a maximum resonance peak of 2 and I have chosen to use ...
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### How to extract the switching noise component for this signal data?

A servo accelerometer when powered by batteries has a clean output, but when used with this SMPS supply its output seems like have switching artifacts from the power supply(the datasheet says its ...
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### Vanishing of Gibbs Phenomenon in MatLab

I was trying to represent a square wave with its Fourier series in Matlab. But as I increased the number of terms in Fourier series expression, the Gibbs phenomenon vanished and the edges of the ...
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### Parasitic Passbands in distributed filters

it is known that if we realize a filter (for instance a low pass filter) by using distributed elements (transmission lines), there will be some parasitic passbands (which moreover show a behaviour ...
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### 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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### Which serial protocol or encoding scheme does this scoreboard use?

I am trying to decode a signal stream coming from a Nevco scoreboard controller: Packets like this are sent every ~2.7 ms. I suspect it is some sort of UART signal because it is on the RX line of a ...
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### Proof that two systems are equivalent

I was wondering if someone could help me with the proper answer for this? Below is the question and my solution. I was hoping for partial points but I don't know what can be marked partially correct ...
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### Triggering a signal on the falling edge of an input, and not re-triggering when it stays low

I have a 555 in monostable mode that will generate a signal from the transition to low from one of it's inputs (as they do). The issue I have is that the trigger will out last the signal by an order ...
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### Button switch input signal reading was higher than VDD value at some point

I was monitoring a signal output from a button during debouncing on my oscilloscope and surprisingly as you can see in the image, the signal peaked at 5.92 volts and then went back to the VDD value ...
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### How do I combine positive and negative pulses into one single signal?

EDIT: I kinda solved the problem. I swapped both diodes polarity and then added an op-amp to amplify the resultant signal. I'm trying to emulate a motorcycle crank pickup signal as shown by CH2 below (...
1 vote
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### RF circuit: How do I calculate the power of signal?

I have the following schematic of a RF circuit with helical antenna of 5 turns which I'm analysing For simplification, I replaced the antenna with an equivalent resistor of 140 Ω as in the below ...
1 vote
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### How to separate Transient and Steady-State Expression from Periodic Summation Response?

Background My question comes from here, it's a response of 1st order LPF RC circuit from an arbitrary periodic input. How to determine the transient response of a circuit to causal periodic inputs? ...
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### Problem with voltage-controlled current source circuit using op-amp with MOSFET at high frequencies

This is a circuit from Mr. Sourav Gupta: The problem is that I want to use this circuit to drive a current using voltage control which is a digital pulse signal in 1T, see picture below: I want to ...
1 vote
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### Unable to measure frequency response of a Wien bridge oscillator with Bode plot

I'm unable to get the Bode plot to work with this Wien bridge oscillator circuit. Is there something wrong with my configuration, or does the Bode plot not work without an external signal source? I ...
1 vote
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### Attenuation and capacity

Does attenuation affect capacity for multiple narrowband signals? For example, assume there exists a 20 MHz channel with two 10 MHz subchannels. The first subchannel has frequency response 2 and the ...
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### How to convolve these two signals?

I tried to convolve these two signals (top image). I’m not sure if I have done it properly. My partial answer (further below) is wrong.
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### Digital input conditioning?

I'm designing a schematic with opto-coupled digital inputs (BNC). For better noise/ground loops immunity/reflections should I add 50 ohm resistors on both input lines, signal(+) and GND, along a ...
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### How do you sketch a signal given by x(t) = A(t/T) for time period 0 to T? Does t/T simply denote that the signal covers entire duration of T?

Does t/T simply mean that the signal has magnitude A over the entire "T" duration? Or does it mean that it covers only a fraction? How will it look? I tried assuming A to be some magnitude ...
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### Relative error of power estimation

I'm reading my teacher code for FFT windowing in Matlab and there is one thing I don't understand. When you run the code at the end it says: ...
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### How to calculate RSSI empirically?

can we calculate RSSI? is RSSI and power received are same? From research papers i found this PL(d; n; o) = PL(d0) + 10nlog10(d/d0) + Xo RSSI=Pt-PL(d). but on the ...
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### How to setup STM32F103C8 encoder triggered output signal

I have a project where I need to read the encoder phase A&B to output the pulse so I can drive a motor, I did some research and saw this picture where it is exactly what I wanted to do: output a ...
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### What's wrong with my experiment to observe harmonics caused by receiver saturation and non-linear behavior?

I've been trying to devise an experiment to produce a third order harmonic in radio receiver that's been saturated, but I'm not seeing the expected results. My understanding of the theory is that when ...
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### Way to mitigate parameter dispersion in NMOS attenuator

I am building an automatic gain control for a subMHz signal, which comes in the 30-120mVpp range, using a NMOS as VCR. At the output, ideally, signal should be 'compressed' around +-Vpeak_detect_th . ...
1 vote
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### opamp single supply output AC (audio) voltage limit

I build non-inverting op amp with single supply voltage cca 9V. The basic scheme is shown in the figure below: How to limit output AC signal if the base DC voltage is at half the supply voltage 4.5 V ...
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### Signal path / configuration help for a PLL for AWG

In our system signal path, there is a clock signal being sent from the FPGA noted as SCLK. This goes to each component not including the MCU. The way I understand this is that the PLL receives the ...
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### Single Fault Pulls up Both AND Gate Inputs

I have a situation where I have 2 inputs to an AND gate coming from 2 sensors (passing through a comparator before). If both signals exceed some predetermined value (let's say 2.5 V for sensor 1, and ...
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### Arduino sensor labels: "s" vs "out"

On many Arduino sensors, there are most likely a port for, gnd, vcc, and signal/s. On some other sensors, I see there is an "out" replacing an "s". This confuses me because "s&...
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### state equation from given signal flow graph

I was solving a question in which I have to write state equations from given signal flow graph ,but I wanted to clear some basic doubts regarding general problem like this I thought it can we solve ...
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### Why do sensors or biosensors use AC excitation signal and not square wave signal?

I have recently started looking into transducers to measure a natural physical phenomena. The sensors I read about, especially electrochemical sensors like interdigital electrodes use a sinusoidal ...
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### Is it possible to transfer a bluetooth signal via something else?

Problem: For example, I have 2 devices communicating with each other via bluetooth. But there is a thick metal wall between these devices and this makes a difficulty between them. To fix it, can I ...
1 vote
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### How to parse this protocol with an arduino?

I'm analyzing a signal from my building's intercom system to my tenant station. Intercom has two wires, +24V/0.27ma, and ground. Every 10 seconds, the system sends a "heartbeat" signal to the tenant ...
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### Need to branch USB data lines... what to do with unused ends?

I have a USB 2.0 low-speed connection design with an unusual constraint. On the host side the D+ and D- lines have a branch, a requirement of the connector and this cannot be changed. On the device ...
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### Zero - IF receiver main limits

I was reading these slides about receivers architectures, and I have some questions about Zero - IF receivers: Precisely: Why is the spectrum around the carrier (i.e. the 2 "side bands") mirrored ...
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### Composite video signal detection problem?

I have an android headunit and I installed a reversing camera to it. The problem is that the headunit does not seem to detect the camera signal if the environment is too bright. It just shows black ...
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