The noise tag has no wiki summary.
2
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2answers
64 views
Buck Regulator Running From Car Battery Stability Problems
I'm running this regulator off of a ~12V car battery. I've set it up almost identically to the 'typical application' schematic and layout that the datasheet suggests to generate a 5 V output, ...
2
votes
2answers
99 views
Noise over time
I've installed an audio auxiliary input unit for my car stereo, but I'm encountering a problem. After driving for a few minutes, I start to hear a low pitched "throbbing" sound from my stereo that ...
-2
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1answer
80 views
undervolting processor/mainboard to safely reduce fan speed [closed]
I would like to make my desktop pc less noisier. I do not wish to buy a new cooler, nor fan, nor motherboard. I do not care about decreasing computational performance. The loudest seems to be the ...
1
vote
1answer
46 views
Performance Analysis of PLC Modem
I'm an electronics and communications engineering student undertaking a project regarding the occurrence of Electromagnetic Interference (EMI) in power line communications (PLC).
I would like to ...
3
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2answers
69 views
Reducing noise in mixed-signal audio circuit
I am working on an audio circuit featuring the MOS Technology 6581 SID. The circuit works on a solderless breadboard with acceptable but still quite noticable noise. I am now going to design a PCB, ...
0
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1answer
48 views
What might be the cause of noise in my audio out on Stereo when connecting computer as the “audio in”?
This is from a friend. I wasn't sure of the cause.
Perhaps:
Ground Loop
The wire connecting the computer to stereo needs to be shielded?
I have a question about my stereo. I get a hum through my ...
1
vote
4answers
116 views
Sinusoidal Waveform Induced on Long (~15m) Wire
I have about 72 of the following circuits on my board. The MOSFET and R2 comprise of the output stage and the pull up resistor is my input stage. The long length of wire in-between is the wire under ...
3
votes
1answer
133 views
Generating thermal noise from a resistor
I'd like to create a random number generator based on thermal noise from a resistor, using an opamp to amplify the noise and an inverter to convert the resulting spikes into a digital signal.
Here's ...
3
votes
2answers
124 views
How do i protect analog circuit from relay switching noise?
I'm making a thermocouple based temperature controller. The thermocouple voltage is measured by using cold junction compensation IC LT1025 and precision opamp LT1050.
The measurements are read by ...
3
votes
1answer
109 views
What do you call the dynamic range of a variable gain amp?
Dynamic range is the ratio of the largest signal a system can process to the noise floor of that system.
If the system has variable gain, though, then you could interpret this two ways:
Fixed gain ...
1
vote
2answers
59 views
Crosstalk avoidance on fpc cable
I am re architecting something that works. (laser range finder). This is a cost down excercise.
In the existing system I have separate boards for laser driver and afe. Now I am combining those and ...
1
vote
2answers
79 views
What is the definition of interference vs. noise in radio communication?
Is it defined by the source or by the nature of the waves?
Can one with some instrument make a reading like "In this room we have this level of interference and this level of noise"?
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0answers
59 views
johnson noise potential divider
Quick question - If I have a potential divider with say two 10k resisters - Is the noise that you would measure between the two resisters simply the the Johnson noise of a 20k resister?
On a ...
4
votes
1answer
331 views
How to filter noise from ground?
I have an audio application scenario here. The Idea is to power a device (that later produces sound) with USB.
Unfortunately, I have massive static and what sounds like pink (Brownian) noise on GND. ...
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0answers
45 views
Measure logical circuit average noise?
I design a logical circuit that behave like Digital Clock with alarms. So, i want to measure it's electrical noise, how can i do this ?
Thanks for your advance.
12
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5answers
382 views
Noise reduction strategies in electrophysiology
When recording electrical signals from cells (in a dish or inside a living human or animal body), one major problem is to increase the signal to noise ratio.
These signals are usually in the 10uV ...
1
vote
2answers
150 views
Noise when powering headphones amplifier through USB port
This question is actually connected with this one:
Getting 1.2V from USB
I've successfully connected my FIIO E3 headphones amplifier to USB (so that I don't have to use batteries). But I've notices ...
3
votes
3answers
249 views
Resistor Noise - What it will have effect on, in a circuit?
Reading the article resistor noise and knowing that resistor noise is in the form of Voltage (is that thr right expression?!) leaves me wondering that this generated voltage will have only eefect ...
3
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4answers
481 views
Implementing guard trace/ring in PCB design
I have read here and there some articles about pcb guard trace/ring. But none of them discussed how to correctly implent it. What I could find were some pictures and comparison that cant help me at ...
6
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1answer
293 views
Reducing noise in audio circuit (optical pickup + op amp)
I am building an optical pickup using a photodiode connected to a LM741 op-amp. My circuit is similar to this one:
Except that I've added a passive high-pass filter after the output of the op-amp, ...
4
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2answers
157 views
How to measure/compensate wire's stray capacitance
How should one measure and compensate (If necessary) a wire's stray capacitance in low-level measurements?
Is Guarding applicable here? If so, does it mean having a wire with same signal voltage ...
1
vote
1answer
82 views
Unoccupied SMD and TH pads and noise/interference/capacitance
Imagine a rather noise sensetive application, My question is if there are unoccopied pads for SMD and through-hole are existing on the board and somehow connected to other components through theire ...
0
votes
1answer
225 views
EMF Detector Sensitivity
A fun little project I've been working on is an EMF detector using my recently acquired Arduino. It is based off of the guide at http://www.aaronalai.com/emf-detector, primary differences being my own ...
0
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2answers
110 views
Noisy data line clears up on wiring up multiple output pins of uC to Logic Analyzer
Some people reading my question might be familiar with a string of questions (latest being this one) where I have been asking about how to decode data from an ISM-band ASK/OOK type RF receiver module. ...
0
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1answer
95 views
Very small camera or endoscope like device with minimal electromagnetic noise generation
I need to be able to visually monitor movements of a recording electrode inside an electromagnetically shielded chamber. This is a cylindrical chamber of 1" X 1" and is in absolutely dark environment ...
2
votes
2answers
366 views
STM32F103 ADC Noise
I am new to this forum. I have read the questions and answers in this forum on the similar topics but that one was for STM32F2 CPU. I am using STM32F103 and I have similar problem.
Similar to the ...
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2answers
142 views
Input clock signal with noise
I design a frequency divider in FPGA. It is nothing more than the D flip-flop, which use the inverted output as input. Then on the output of D flip-flop is signal with half-frequency of input CLK ...
1
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1answer
217 views
Simulating noise signals in Multisim
I would like to simulate the effect of noise in a circuit built in Multisim so that I can make better component choices to improve my design. The main source of concern for me is that the circuit will ...
2
votes
1answer
180 views
Reducing noise in elementary audio circuit
I wish to hook up the line-out from a digital piano to a surplus 4 ohm 15w speaker unit. I bought a simple Amplifier module and connected it up.
My plan was to roughly assemble the circuit and, if it ...
6
votes
3answers
712 views
STM32 ADC Noise 2
I have just tested my second design with STM32F2, now it is STM32F207ZFT6, the ADC behaviour is the same as in my first application - strong noise in ADC.
Noise of current input without any ...
2
votes
2answers
205 views
How to correctly simulate this filter?
I am trying to design a low-pass filter for a 24V, DC, 10A power line to suppress EMI, RF interference and noise in a bus. There is no ground(chassis). I am trying to simulate this filter that was ...
3
votes
1answer
293 views
Designing a low-pass filter
I want to design a low pass filter with common-mode choke that has a cutoff frequency of 100 Hz. This is going to be used in a bus 24V DC power system that will deliver 10A to the load. I want to use ...
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vote
3answers
214 views
LM317 Ripple Rejection
I've developed a circuit for my model aircraft, which requires 3.3V @ 100mA. My aircraft uses a 3S LiPoly, which ranges from 9V - 12.6V. When the motor is off, the 3.3V supply is good; very low ...
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2answers
150 views
2 SMPS - Does it make sense?
I am following up on my earlier question. I am trying to build a very clean 5V and 3.3V supplies. I have asked this question and got several very good answers, we designed it and it will come back ...
3
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1answer
66 views
How is Capacity affected by distance?
Shannon's Law says:
$$ C = B* log_2 \left( {1+\frac{S}{N}}\right)$$
where
C is the information-carrying capacity of the channel,
B is the bandwidth,
S is the received signal power, and
N is the ...
1
vote
1answer
87 views
Noise on simple proto
I am trying to evaluate a component (OpAmp) and built this simple circuit. I didn't use a breadboard due to high capacitance and noise, I just soldered stuff over the air thinking this would be low ...
3
votes
1answer
282 views
How use ferrite bead to reducing noise from charge pump?
Old senior design project and in schematic I see he uses ferrite bead and capacitor after charge pump voltage output befor connecting to opamp input
Circuit very simple:
charge pump uses MAX232 to ...
2
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3answers
732 views
Ground loop? Switch mode power supply noise
I have a single 12V supply powering a 12V class D audio amplifier (Tripath TA2020 based, model 'SMSL SA-36') (C) and a very cheap 12V to 5V 2A rated switch mode converter (A). The 5V is used to power ...
3
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2answers
554 views
I2C - Cannot read temperature from TC74 with PIC16F887
The question was:
I want to read temperature from TC74 using I2C module of PIC16F887, however, in Proteus
simulation, I see noises in I2C Debugger Tool's output.
It told me that I had "Spurious SCL ...
2
votes
2answers
235 views
Best way to generate white noise, DC to 1MHz
In this question a zener diode is used to generate white noise, and I've also seen reverse-biased transistor base-emitter junctions for this.
Digitally a Linear Congruential Generator (LCG) can be ...
7
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3answers
352 views
Why use LNAs in a noise generator?
In this Maxim appnote the avalanche noise of a zener diode is amplified by two cascaded LNAs (Low-Noise Amplifiers):
You can guess what my question is: why use low-noise amplifiers if you want ...
0
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2answers
267 views
What is the best way to filter out noise on data line?
I am working on a product that has a controller connected to a device via an 8 conductor cable (an ethernet cable). The cable length varies depending on where the device is installed but the length ...
1
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1answer
129 views
How Johnson measured Johnson-Nyquist noise?
How Mr. Johnson, the one after which Johnson–Nyquist noise was named measured/discovered this phenomena? Details about equipment and method are most welcome.
7
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3answers
310 views
How to measure electrical noise?
Another question I asked about Power Supply Noise pushed me to ask this question.
The background is as follows: I have a design with PD (Photodetector) and Opamp at medium frequency (couple hundred ...
5
votes
3answers
235 views
Need help with eliminating LED-generated noise
I am very new to electronics, to electronics.SE.com and this is my very first project, so bare with me if my question misses some key-information (in such case, just leave a comment and I will try to ...
2
votes
4answers
354 views
Power Supply Noise
What is a good decent power supply noise?
Let me expand, two cases, I have a bench top PSU, I put my scope in AC coupling and look at the ripple it is around 20mV. Is this a good number for a decent ...
3
votes
1answer
88 views
Looking for good articles about reducing crosstalk and other noise in PCB design
I am designing a rather large PCB with straight parallel traces 20cm long carrying CMOS logic at around 100kHz. On top of that I have 8 MOSFETs supplying 5A switching on/off at around 400Hz which a ...
3
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3answers
274 views
How to apply passive PFC on low side of transformer in power supply?
I have a low power power supply, built with a 60Hz 120v/12v 0.3A transformer. It will have an ordinary diode bridge and capacitor filter. What I want to achieve is reduction of current/magnetic field ...
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1answer
93 views
Mismatched Pull Up Resistors
Is it OK to have pull up or pull down resistors which aren't all the same value (if you're running low on components for example)? I can't think of a reason it should affect simple logic circuits.
...
5
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3answers
192 views
How are low-noise transistors different from other?
Yes, I know: they have lower noise levels. What I mean is how is this achieved? And I guess there must be a trade-off as well (otherwise all transistors would be made as low-noise?)
