Questions tagged [noise]
Noise is an unwanted disturbance in an electrical signal. This tag is for questions about sources of noise, noise types, issues caused by electrical noise, or improving the signal-to-noise ratio of an analog circuit.
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Output noise of integrator op amp
Consider the following circuit (https://www.electronics-tutorials.ws/opamp/opamp_6.html)
I want to compute the output noise of the op amp.
I believe the op-amp noise is given by the quadratic sum of ...
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Is there any reason at all to use a capacitance multiplier for power rails in 2024?
I've seen a few people recommend capacitance multipliers for reducing noise on power rails recently, usually in the context of audio electronics, and I'm left feeling a bit baffled. We've got these ...
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Proper Connection of Safety Polypropylene Capacitors in Power Supplies for Audio Equipment
I'm designing a power supply for an audio system, and I've heard that safety polypropylene capacitors are recommended for filtering high-frequency noise from switching components. I have one of these ...
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Power supply coil whine on video intercom [closed]
I have this video intercom in my home. It's powered by Mean Well APV-12-12.
While the display on the intercom is on, everything is fine. As soon as it goes into “sleep” mode (it stays on, but the ...
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3
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1
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Instrumentation Amplifier noise on noisy power supply
I have some confusion on the circuit I am looking at. In the case we have a very long cable picking up lots of common mode noise from the atmosphere - it has 4 wires, vsup, V1, V2, and GND and we want ...
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Is this design approach for a DC motor H-Bridge correct?
I am designing an H-bridge circuit to drive two linear actuators. The circuit also has low noise differential ADCs that will be measuring strain gauges. I want to isolate the ADCs as much as I can ...
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2
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175
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Dual-555 servo controller: how to "stabilize" without two separate voltage regulators?
I'm trying this circuit, and variations of it, to control a mini servo motor.
The circuit uses two 555 timers to generate a constant-frequency PWM signal with adjustable duty cycle to control the ...
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4
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High frequency noise increasing by current drawn
There are a lot of noise related questions here. Mine may be somewhat different.
I'm using a 24V 2A SMPS power supply bought from market. I've used more than 20 of them.
Some have noiseless output ...
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Do radios need a minimum range to function properly?
I'm going to use some well-known radios (nRF24L01+) to wirelessly read some voltage/current sensor data over little distances on a quad-copter since the drone is quite populated and we don't want to ...
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Mathematical relation of RMS to PK-PK for noise
RMS is root mean square, peak to peak is the difference between peaks of a signal.
In the video and other places, they say the 1 mVRMS = 6.6 mVpk-pk.
The reason is 6.6 standard deviations covers 99% ...
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How to limit the effect of Contactors noise on the electronic circuits?
I have designed an electronic circuit that is used to switch 8 relays in certain circumstances (like 8 times in a minute). Then these relays switch on and off the contactors connected to AC electric ...
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1
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Differences between audio ADCs and general-purpose ADCs
From my limited understanding, audio ADCs, and even decoders, also have 16-24 bit resolution and not-so-low sample rates in comparison to high-resolution, low-noise ADCs.
It's also worth noting that ...
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Why is braid shield more efficient than a foil for low frequency noise? [duplicate]
I know that for lower frequencies the wave length is larger, but what happens to the noise that makes a braid more efficient than foil? Is it the amount of copper that is greater in the braid than in ...
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Why are green pair (or orange pair) wires not adjacent in RJ45 connectors?
For the sake of the discussion, let's talk about T-568B, but this applies to T-568A as well.
I've searched a bit for why the green cables are not adjacent, and the answer was that this reduces ...
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1
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Shot noise converted to digital value
I'm trying to estimate the standard deviation in the final digital value that originates from shot noise only, when using a standard smartphone camera. In high illumination, shot noise is supposed to ...
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How to calculate non systematic ADC error in perfect scenario
I'm using the ADC "ADC121C021" (datasheet) in my design. My question is rather theoretical.
Given a perfect (noise free) reference voltage and input voltage, is it possible to calculate the ...
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LT6268-10 OpAmp Noise
Following on from my previous post , I printed the circuit as below however getting very noisy signal.
what am I doing wrong here?
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1
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Oscilloscope makes board glitch out?
I am baffled. Well and truly flummoxed. I was testing some boards, because a particular receiver component on them had been substituted for one whose readings were really noisy. There was one board ...
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1
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Servo moving to limits randomly
I've seen a very similar question to this but want some extra pair of eyes on my circuit here.
The issue I've encountered is on startup of this script every so often the servos will randomly move to ...
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2
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Is the x-capacitor essential in the circuit below?
hi
I hear a buzzing noise from c1 and L1 in this circuit
C1 used a film capacitor, not an X capacitor
(Film capacitors were used instead of x capacitors because of internal space problems.)
I thought ...
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1
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10 µF and 0.1 µF capacitors not making any difference in filtering out noise
I have two circuits (green and brown) featuring a load cell, HX711, and ESP32-C3:
The HX711 and ESP32-C3 go on top of those round female pin header.
The only difference between them is that one is ...
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2
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What should I make of this spectrum analyzer data?
Here I have two signals that I placed into a spectrum analyzer. Channel 1 (yellow) comes from an avalanche photodiode + TIA circuit that has a 50 Ω output resistor, which is directly connected via BNC ...
3
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2
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398
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Digital-to-analog-converter PCB: Ground plane cut or not?
I'm designing a DAC board and I'm not sure what would be the best thing to do regarding grounding, to minimize noise.
This is the approximate layout I have so far, with the system ground point (also ...
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2
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126
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Caps vs. no caps = the same noise?
This is a setup with an ESP32-C3 and HX711.
In this oscilloscope reading, there is a 10 μF cap and a 0.1 μF cap across the VCC and GND of the HX711 (it makes the load cell readings more stable).
In ...
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2
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89
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Voltage unexpected noise
I'm quite new to the electronic designs so might have made some horrible mistakes in the below circuit. It works as expected but it has a problem.
The voltage at the output has some sort of noise ...
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3
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1
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82
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Custom PCB to make a high-precision, low-current voltage source "fix" drift in a lower-precision, high-current current source
I have the following goal, which I presented in a previous question:
I'm trying to generate a current source which is extremely low drift
but can maintain high current (3A into a few ohms), that ...
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1
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51
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Does LISN eliminate differential mode noise?
Do I understand correctly that this LISN circuit doesn't eliminate differential mode noise? And when I get a spectrum, there are two parts of noise: differential mode (DM) and common mode (CM)?
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Sprinkler controller couples electrical noise between stations, firing wrong solenoid
I've been trying to troubleshoot a Toro DDCWP 4 battery-powered sprinkler controller which started exhibiting strange behavior this summer. This is a basic four-station controller paired with RainBrid ...
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96
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'Strange' behaviour due to DC motor
TLD: How do I minimise noise / electrical disruptions created by a DC motor?
Situation
I would like to control a DC motor through DMX512. Therefore I connected a Max485 chip to an Arduino to receive ...
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50
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Filter for supply voltage of amplifiers
I need to design an ultra low noise amplifier in transimpedance architecture. This is the architecture I have chosen:
In addition to the decoupling capacitors on the supply pin I have also added two ...
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2
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86
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Issues with Audio Amplifier Circuit - No Output Signal with Capacitor, noise
I'm having trouble with an audio amplifier circuit that I designed, and I hope someone can help me figure out what's wrong.
Here's the schematic of my circuit:
Rsig is a variable resistor
The circuit ...
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0
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83
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Persistent ripple at the buck converter output
I developed a half-bridge buck converter, I did all the steps, from the converter calculations, such as accommodating the copper in the appropriate ferrite core, wire gauge diameter, etc., my project ...
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How to work with UART to make communication between stm32 and hmi nextion display in noisy environment?
in an ultrasonic generator project, I am using an STM32F334 microcontroller as the main controller and an HMI Nextion display (model NX8048T070) that includes another STM32 for driving the monitor. I ...
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Noise Figure at the Rx ADC output
I need to measure gain & nf of the Rx at the ADC output. I inject sine wave tone to the Rx input. Then I make a ram dump of the IF ADC output, read it, perform fft and finally get the IF PSD.
My ...
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Power supply issues for poor man's SONOFF
So I have zero electronics education. I've created some devices just following YouTube videos and what I call a bit of common sense. Long story, but basically found that I could purchase D1 Mini's (...
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Ground loop issue with Raspberry Pi and amplifier board
I'm trying to run a Raspberry Pi with a USB audio adaptor into an external amplifier board via 3.5mm, then running out to speakers from the amp.
Right now I'm getting a lot of electronic noise coming ...
2
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3
answers
103
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Can a high-precision, low-current voltage source "fix" drift in a lower-precision, high-current current source?
I'm trying to generate a current source which is extremely low drift but can maintain high current (3A into a few ohms), that should be similar to this expensive high-precision current source.
However,...
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0
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49
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EFT (IEC 61000-4-4:Burst Test) Fail. I used SPI Interface [closed]
I am using TI ADC part# ADS131E08 and STM MCU Part# STM32H7 Series.
#3 channel : Voltage measurement (3phase)
#3 channel : Current measurement (3phase)
#1 chanel : Internal-zero current measurement.
#...
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0
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Question re: layout and grounding of a PCB with SPI-controlled H-bridges and load switches
My question is regarding the layout, and in particular the grounding, of a PCB that has a microcontroller that controls various H-bridge drivers (that will be PWM’d) and load switches via SPI. The ...
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75
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Noise in ADC PIN
for signal conditioning before feeding it to the ADC of a microcontroller, I have the circuit shown in the image below. The 12V comes from an external source, and my goal is to measure this voltage ...
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Periodic Voltage and Current Fluctuations in Autonomous Robot System
I have an autonomous robot system powered by a 24V LiFePO4 battery that has several distributed PCBA's getting their power from the 24V battery, and also having their own on-board DC-DC buck ...
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PCB Power and Ground planes Setup [duplicate]
When designing a 2-layer PCB, I've read that ground planes are good to reduce noise and to provide a stable-ish ground reference when a board isn't connected to a chassis, ground etc.
If I need to ...
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Noise added by an amplifier when deriving Friis's formula
I have been asked to derive the equivalent noise factor for a cascaded system of two amplifiers. Here is the figure of the system (assuming a general configuration where \$ G_1 \$ and \$ G_2 \$ are ...
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1
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Noise in classical quantum transmission
In classical quantum transmission, we introduced a scattering model that includes two components: free projection and collision
Now, in this figure, this model is introduced that when it goes up in ...
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Output Noise of MOSFET with parallel current source
How can I calculate output noise voltage of the given circuit?
Noise contribution of the M1 to output noise current: $$4kT\delta g_{m1}$$
Noise contribution of the RG to output noise current: $$4kTR_G[...
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TDM signals crossing
I'm working on a 2-layer PCB design and trying to do the best I can for signal integrity. I have 2 TDM lines and at a certain point they cross between each other. See image below.
Is this likely to ...
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1
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Proof showing thermal noise of 2 resistors in series behave as a single noisy resistor
For the second part of this question, I came up with two slightly different answers? I believe it's the second one however I am not too sure which one would be the correct one.
First one:
Second one:
...
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89
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Mains hum in TDA7265-based active loudspeaker
The old pair of M-Audio Studiophile AV40 active speakers (one box containing all the amplifier parts and the second is just a passive box) I have have developed a clear low-frequency hum. This hum is ...
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what is the source of this noise when recording to raspberry pi using USB soundcard
I connect aux out from my laptop to USB soundcard mic in and use arecord to record audio. But I am getting noise even recording at CD quality. The nature of the noise is really strange as it seems to ...
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Choosing Y-capacitor value for isolated DC-DC
In an isolated DC-DC converter datasheet (link), the Y-capacitor recommended is 270 pF. How is this value arrived at? And would the intended use of the Y-cap be achieved if a higher value like 1nF is ...
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