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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What is the key circuitry in a form of high frequency signal generator that means power would be sent and reflected when there's an open load
Ive asked enough questions to explain why when there is an impedance mismatch there is power reflected which from my understanding is because there is a reflection of the waves, and also the cause of ...
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How can I confirm the presence of an HDMI signal with a slow scope?
Per the title, I'm trying to troubleshoot a circuit and confirm if a device is putting out an HDMI signal but I only have access to "slow" (<=200MHz) oscilloscopes.
I don't need to know ...
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How does a PI or L network match impedance even though it does not have a real component?
Let's say I have an IC (ESP8266) with an output impedance of 39+j6 ohms, and I want to connect it to a 50-ohm antenna. The IC has a real (resistive) part of 39 ohms and an imaginary (reactive) part of ...
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How to get the transfer function out of a Bode Curve on a datasheet?
I am trying to find the transfer function of AMC1350 out of its datasheet. I dont have any information about which degree of a lowpass filter or what kind it has. DC gain is 2/5. Cutoff frequency is ...
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The effect of the wavelegth on the receiving power in Friis equation
In the Friis transmission equation,
$$\frac{P_r}{P_t} = G_t G_r \left( \frac{\lambda}{4 \pi d} \right)^2,$$
it seems that if the frequency is halved while the other parameter values are fixed, the ...
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Does signal source of mobile phone, from its 3.5mm headphone jack, act as a current source or as a voltage source?
Even though the audio output of the mobile phone (which we draw through 3.5 mm jack) outputs a signal that's a function of time, at a very short interval of time, this source acts as a dc source of ...
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Can two or more RF noise signals (or noise sources) still be added together if they have been attenuated below the thermal noise floor?
Can two or more RF noise signals (or noise sources) be attenuated below the thermal noise floor, and still add together to be higher than TNF?
If a noise signal experiences path loss or attenuation ...
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Radar received RF signal phase-shifted by 90 to obtain I/Q signals
I am trying to get idea how marine radar works before start any repairing process. And this part confused me, most articles that i saw explain that in mixing stage we obtain I/Q signals using LO ...
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Difference in voltage level using different probes [closed]
I have used an active probe and a passive probe to do the same measurement at the same site. However, the active probe has measured a lower voltage than the passive probe under DC coupling measurement....
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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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Non inverting OP AMP maximum output voltage problem
This is my non inverting OP AMP based amplifier for one of my measuring circuit.
I have 2 queries about this circuit:
With maximum input voltage of 5 V, I'm getting only 3.7 V only. (I know the ...
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Sketching fourier transform after sampling
I'm having trouble understanding how this system is supposed to work. My sketch (all my sketches are for fourier transforms) for \$X_b(jw)\$ are two pyramids centered at 7pi and -7pi with height 1/2. ...
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Signal Processing Question--old school [closed]
I have a signal generator that creates a mostly 8kHz sine wave signal, with a couple quirks. It repeats in a 96ms pattern. Output is 220mV into a 1-20 ohm wire. It is used to provide wire guidance ...
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How is digital data sent over long wires?
I want to have a mental-model for how digital data is sent over wires for basic networking purposes. My current understanding is that on the transmitting side and receiving side, there are ...
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How are PCM signals put onto a wire?
I just want to get a sense of how digital data is physically transmitted over cables using protocols like USB or Ethernet.
I've read that they use PAM signaling (USB4 uses PAM-3, Gigabit Ethernet uses ...
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Is digital signal transmission different from square wave?
I am just getting into signal processing and am having trouble understanding where generating square-waves by means of harmonics is useful.
Digital signal transmission can be achieved by changing ...
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Incremental Encoder problem
I have a problem is that it is not possible to specify the direction of rotation in the encoder. Refer to it as in the attached picture.enter image description here.
The problem with the selection is ...
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Minimize Single Balanced Mixer Insertion Loss
I am self teaching RF via the internet, "Introduction to Radio Frequency Design" by Wes Hayward and the 2005 ARRL handbook. My intended project is a 1 stage IF heterodyne receiver. Not ...
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What component should I use to protect reverse signal for another CAN device?
I am doing some can bus communication using WCMCU-230 and ESP32, I connect two CAN BUS devices with different CAN BUS addresses, so I join the cable directly, and it's working fine with CAN BUS Device-...
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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 (...
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How to generate this signal in LTspice
I would like to generate this signal on LTspice. Does anyone know?
(this pic is plotted from excel and matlab)
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Using op amp to turn AC 55 kHz from 5 Vpp to 30 Vpp
simulate this circuit – Schematic created using CircuitLab
I want to augment a 55 kHz 5 Vpp sine wave using an LM324N op amp.
The potentiometer is so I can easily slide the signal to the desired ...
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A question about scope's channel affecting other
I have the Digilent's USB scope and when I couple different signals to Ch1 And CH2, the channels affect each other. I didn't observe this with another USB scope.
If both are coupled I get the ...
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Which waveform leads the other: A or B?
If you only look at the waveforms A and B below, can you determine which one leads or lags the other?
One person argues that A leads B because the first rising edge of A occurs before the first ...
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Need a suggestion how to convert an analog signal to a digital signal
I am trying to make a speed monitoring system. I want to monitor motor RPM with an IR phototransistor sensor.
I am getting analog values and negative peaks when a sensor flashes on a reflective ...
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Break logic signal irreversible [closed]
I have a PCB which needs a 3,3V logic signal during the start-up of a system. Then this signal needs to be irreversibly broken.
Of course this could be done by flipping a switch, but the PCB isn't ...
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LTI System with Transfer function - Self signal of exponent without complex - question from test
There is an question from test which drives me nuts.
Let there be LTI system with transfer function H(s).
The impulse response exist:
$$\int _{-\infty }^{\infty }\:\left|h\left(t\right)e^{\left(3j+5\...
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Spending money on gold cables [closed]
Recently a friend of mine spent several tens of euros to buy a set of gold connectors to connect to the audio amplifier, justifying this expense on the grounds that they were gold and therefore the ...
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Why isn't this IR NEC signal being accepted by the receiving device?
I'm trying to transmit an IR NEC signal to a portable air conditioning unit. I have the remote control that came with the unit, and it appears to use the NEC IR protocol.
I've setup a receiving ...
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A pull-up resistor increases the low side of a signal, how can I counteract it?
I have an ebike computer that has two inputs that accept square wave signals. The range is 0-5V. One of the inputs has no pull-up/down resistors on it. When I hook up a device producing signal, the ...
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Power supply of isolation amplifers
First time experimenting with a design with isolation amplifiers and I am unsure about the amplifier power supply range I need.
I need to provide isolation to measure a current between 0 and 7.4mA. ...
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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 ...
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Amplifier gain values vary when changing power supply
The amplifier circuit below has a gain of 29000. It means when a sine wave is given in about 10uV, the output will be 290mV. I tested it in circuit-simulation and it was a success with the given ...
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3 electrode EOG system design
I'm trying to design an EOG system based on how the JINS MEME glasses did it. 3 electrodes, two on either side of the nose and one of the nose bridge. This will be battery powered. The expected ...
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Determining the sampling rate / frequency from a graph
I don't understand how the two graphs in the image below are connected. The context is signal processing and sampling rate (+ its relation to bandwidth). I don't know the exact terms to look up. I am ...
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How would you compute Fourier transform of a real world signal where the signal keeps getting updated (not a static one)?
A very naive question: How do we use Fourier transform for real world signals - for which you have the information only up to the present instant (and the present time keeps moving continuously)?
The ...
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I want to know the calculation behind this amplification circuit and then how to amplify the voltage and pk-to-pk of the signal
I want to know the math behind this circuit and how to amplify the voltage and pk-to-pk knowing that:
MCP4725 delivers a value of ~300 Hz (Coded with arduinoIDE and atmeg328p using sine lookUpTable) ...
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How to send voltage when a grounded signal is present?
I'm currently designing an adapter PCB for FAT model PlayStation 2s so that I can use power/eject/LED PCBs and matching disc drives between any PS2 FAT model revisions.
Technical details:
The PS2 ...
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Differential amplifier and modulation
I conncected this differential amplifier circuit:
The input V1 was 50mV,5kHZ and V2 was grounded
When I measured the output VO1, the oscilloscope gave me a weird signal that was not sinusoidal but ...
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USB Type-C sink states
I'm a Digital engineer. I'm trying to understand how to write a testbench to verify the fsm state transitions in USB type C when acting as a sink, sink with accessory support and sink with try_sink ...
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Pulling 5 V signal line down to 0.5 V
I want to pull a 5 V signal line down to 0.5 V via an open-collector NPN BJT.
I intend to implement a simple voltage divider by using a resistor between emitter and ground. The base is driven by a 5 V ...
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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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How to use two or more ultrasonic transducer drivers?
My circuit is below, it has two ultrasonic transducers, transformers and drivers. The transformer is B78416A2232A003, the transducer is MCUSD14A40S09RS-30C, the driver is PGA460-Q1. Digital interface ...
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cannot get the correct signal voltage from the bldc controller output phase
I am currently working on a BLDC (Brushless Direct Current) controller project using Arduino to manage a 48V BLDC motor. The controller utilizes a trapezoidal control method, which involves a six-step ...
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stm32wl55jc adjust adc dma sample rate for microphone
I am using stm32wl55jc1. I want to use accelerometer at 50khz and microphone at 2khz (2048). I am trying to make fft. With pooling adc method, I can do that easily.
I shouldn't blok the cpu so I need ...
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Running multiple ICs with a single crystal
I need to run three AD7779 ADCs using the same clock signal for synchronization. I don't have access to an oscillator which I can use as a master clock, so I was wondering how I could use a single ...
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How to shift level up voltage signal?
I am looking for a circuit to do a level shift for a signal from RL for a DAC0808LCN.
From what I see in the image, this signal has three levels (-100, -200 and -300 mV) and a 10 kHz frequency, but I ...
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Is it possible to simulate with some composition of signals an analog of a function of two variables and then to calculate its gradient?
With the help of an operational amplifier (op amp), a signal can be differentiated, using it in a differentiator mode. Due to that we can calculate an analog of a derivative of a mathematical function ...
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How to determine the signal direction in Altium Schematic?
I have 5 signals as digital input. We can think of them as a simple button. They hook up to PCB via a connector on the card and I want to show them as a port in the Schematic. How can I determine ...
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5V, 50 Ω input single pulse signal to an FPGA
I have a 5 V, 50 Ω input single pulse signal (<1 ms pulse width) going into Trenz TE0711 (operating @3.3 V and 50 MHz clock). Since the input signal is too high of a voltage, I am trying to find a ...
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