About issues caused by electrical noise, or improving the Signal/Noise ratio of an analog circuit.

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1answer
35 views

AYTINYx4 - execute other code during analog conversion

I am using an ATTINY44 in my current project. As I need to do some time sensitive switching I would like to avoid any unnecessary delay. To control another device (not time sensitive) I need to read ...
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0answers
48 views

Notes when designing circuits near Noisy Sources (Fluid pumps)

I'm currently designing a data-logger that logs water level of the well ,there is a water pump of unknown specifications that will be near the data-logger but i will not be connected to it in any way, ...
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0answers
27 views

How to remove noise from power adapter

I am making an audio amplifier using an LM2879. I am using the schematic provided in the data sheet. For a starting point, this design works pretty well, although the base cutoff point could be a ...
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4answers
66 views

DC motor causing noise on the power line

I've been building a circuit where I'm controlling a motor using a bluetooth module + phone. I've been having some problems, which mostly are fixed (see topic: previous topic). The main problem I'm ...
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2answers
43 views

Is it possible to filter out noise to a pulse counter when there is no twisting or shielding on a long conductor?

simulate this circuit – Schematic created using CircuitLab I have an application where 400'-450' of 14 AWG solid core cable was buried to connect a flow meter to a shed. I built this ...
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1answer
55 views

Does the physical distance from electrolyc capacitor to inductor matter?

I am designing simple LC circuit (L=470uH, C=1000uF) for 12V / 12A (1 Ohm load): As you can see, I did do some soldering already (without too much or noob thinking). The capacitor and inductor ...
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3answers
39 views

Audio Signal Noise: Understanding & Troubleshooting

Today, I'm wearing a pair of active headphones for a change.. ( Running on 2x AAA batteries ). I've hooked them up to a synth and noticed this really annoying monotone buzz / hum in the background. ...
3
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1answer
49 views

How can any spectral analysis show that Sigma-Delta ADC reduces quantization noise?

Quantization noise refers to the modeling of the difference between an analog signal and its quantized version as an additive noise process. The power of the quantization noise can be calculated by ...
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2answers
79 views

How do you get rid of hum in audio?

I built a circuit for a simple amplifier that can use both bluetooth or a 3.5mm connector. The problem is that I am getting noise when I use the bluetooth module. There is no noise when I use the ...
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1answer
33 views

DC-LVDT Output noise filtering

I am working with the DC-LVDT Omega 620-25 http://www.omega.com/pptst/LD620.html Manual: http://www.omega.com/Manuals/manualpdf/M4345.pdf Specs: http://www.omega.com/pressure/pdf/LD620.pdf I am ...
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0answers
22 views

Short period of noise after audio stops?

I am building an audio amp based on the TPA1517. I added a bluetooth module to it and I noticed that now wired or bluetooth, once the music is paused, there is a few seconds of noise, a pop, and then ...
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0answers
29 views

Arduino input noise control

I have been working on a project to simulate a fire suppression system. Below is a brief theoretical picture of what the project looks like Anyhow, the system is set up into a box, and the system ...
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4answers
127 views

Exact meaning of dB?

I know that when people say that a gain of amplifier is X dB, they mean that 10*log(Pout/Pin). However, How can I interpret it when they say that "noise floor is -120dB"? How can I derive voltage ...
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2answers
71 views

How does Hybrid Ground Works?

The text that is above the figure is from my textbook and i am having difficulty to understand what it is trying to say because it's not in detail!! why only remove high frequency and prevent low ...
0
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1answer
28 views

Cut-off frequencies for common mode and differential mode filter?

Attached is the circuit section for the differential signal amplification. The circuit is comprising of common mode and differential mode filter capacitors.So there will be two different cut-off ...
2
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1answer
62 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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1answer
52 views

reducing the effect of a parasitic capacitor!

According to my text book, the second figure says that the noise current returns to their source without flowing through z1, how is that possible? if the noise returns why doesn't signal/ original ...
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2answers
90 views

Reduce noise in Buck converter:

I'm making a buck converter, this is the circuit I've: The average voltage at the output is ok, but I'm getting lot of noise at all nodes of the circuit: I'm using as a main source a 30V 5A bench ...
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2answers
28 views

Noise source in orcad pspice

I have a certain circuit and I want to see its ac performance when I send in certain noise as a signal. is there some option like noise source similar to sine etc signals in orcad.... I can make my ...
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1answer
50 views

Less noise when not following LED Driver datasheet

I designed a board which uses a LED driver (datasheet). It clearly states, DO NOT connect DIM- to Vin-: However, these are the waveforms I get on Analog DIM pin when they are disconnected, and ...
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1answer
107 views

Noise from stun-gun based butane torch ignition spark is locking up ATmega328 microcontroller

I have a stun gun (http://www.amazon.com/VIPERTEK-VTS-989-Heavy-Rechargeable-Flashlight/dp/B00FPE6UN2) which I am using to create a large 1/2" electrical arc through the air to remotely ignite a ...
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1answer
37 views

Getting rid of electrical noise produced when one touches amplifier and amplifier's dials

I purchased a Lepai LP-2020A+, which is a pretty good little amp for the price, but I've modified it to make it much better and decided it deserved a better casing to look the part, too. So I ...
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1answer
60 views

Switching power supply noise and grounding

So I have a +-15 V and a neutral switching power supply. As far as I can see the outputs are floating. The power supply has no earth connection. Voltage from negative terminal to neutral and to ...
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0answers
46 views

Do I need to worry about FCC emissions when using PWM?

I have a AC-connected (though an adapter) unintentionally radiating device that runs a large DC motor (12v, ~6a continuous) under <10khz PWM control. Naturally, switching this large a motor ...
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0answers
72 views

What LDO has lower noise: AMS1117 or AP2114?

I'm trying to choose a low noise and low cost 500mA to 1A LDO for my VCO project, but i'm having trouble figuring out which of the AMS1117 and AP2114 choices has the lower PSRR noise. Each component ...
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2answers
64 views

How suppress bounce-related turn-on spikes in DC bench power supply?

I'm taking a refining pass on my DC Bench Power Supply design. It generally works quite well on veroboard, so I thought I'd move on to SMD PCBs and refine the design while working out a few of the ...
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3answers
115 views

Protection For This Circuit

This is my theoretical (haven't tested yet) circuit I have designed for a project of mine. Electrics is a new field for me so please raise flags if my circuit has flaws. Assuming the circuit is ...
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2answers
94 views

4-20mA Error vs Distance Relationship [closed]

Is there a relationship between noise error and distance for 4-20mA? This noise error could be expressed as S/N ratio, percent from full range, dynamic range, noise density, resolution, etc. Digital ...
14
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7answers
2k views

Is there any downside to using a larger than needed smoothing capacitor?

I work with low-power DC voltage regulators. I am already aware of the formula to calculate the size of smoothing capacitor(s). This can be an iterative process of testing one size with a scope and ...
2
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3answers
104 views

Mains hum without ground loop

When I hook a device to the monitor input of my digital piano, I get a very noticable 50Hz hum. I understand that the monitor input doesn't have to be particuarly good quality, but it really is ...
3
votes
3answers
179 views

What is the peak - peak voltage of 15mV rms white noise?

I've been experimenting with zener diode based noise sources. I have such a source for which I want to determine the peak to peak noise voltage. I've measured the noise with my trusty multimeter and ...
0
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1answer
23 views

What is the difference in the input from inbuilt microphone and an external microphone amplifier?

I wrote a MATLAB script interfacing my laptop's inbuilt microphone to calculate the dbA levels of noise in my classroom. (un-calibrated, as of now) I want to now use this dbA calculation script on ...
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0answers
46 views

Inverting op amp gain using high value resistors and using oscilloscope measuremnts

I built an inverting op amp circuit as shown in above figure using varying values for Rf and Rin. When I used Rf=10kohm and Rin=100ohm, my measured gain (using national instrument's virtual ...
4
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1answer
71 views

Grounding Scheme for Signal + Power

Background I am working on a project which requires a both digital and analogue signals along with power and biases to be connected between two devices over roughly 1 metre is quite a harsh (magnetic ...
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2answers
50 views

Adding noise to examine a circuit's performance

I am interested in adding noise in two circuits, to examine the filters I designed, and the overall performance of the circuit. I currently have in mind two cases, but I believe in both cases the way ...
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0answers
33 views

Noise appears in image when IC is cold, disappear once getting hotter

We're using ADDI 7004 to convert signal from CCD to image, but one strange thing we observe is that when the board boots from cold, there are a lot of noise on the image, but once the ADC getting ...
1
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1answer
30 views

Why is noise input referred?

Many of the textbooks I have read analyze noise signals. We have a circuit and find the output noise RMS voltage. But there is always the "extra" step of finding the input-referred noise. Why do we ...
0
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1answer
28 views

Signal Switching Advice/Recommendation needed

I need to design a switching circuits for this: A tester device is used to test a controller(lets call it controller A). This controller have both input/ouput(analog and digital for each) which is ...
7
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3answers
85 views

Alkaline battery noise varies with temp

I had an 9V alkaline battery connected to a resistive bridge, that stepped out the voltage to several analog channels. I was testing the analog channels over temperature and when it got below 10C I ...
0
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1answer
47 views

Reading ECU tacho signal with PIC MCU - noise issues

Am trying to read the frequency of a 0-12V square signal generated by a motorbike ECU with a PIC. Range 20Hz-300Hz I'm getting strange intermittent noise on the output of my optoisolator, and wondered ...
0
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2answers
54 views

How to calculate appropriate value for noise-removal capacitor?

I'm still figuring out analog electronics with my waveform generator project. It has a 9V power supply that I split into +/-4.5V rails with an op amp virtual ground (the subject of an earlier ...
1
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1answer
56 views

Weird noise waveform on signal line

I'm doing some electrode recordings and a large noise waveform keeps appearing on the oscilloscope (see pic attached). Interestingly the recording set-up functions just fine with a clearly ...
-3
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1answer
104 views

noise calculation for LM741 [closed]

my circuit is very simple, i want to calculation output when i apply 0 amplitude sine-wave to do circuit from datasheet, ...
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3answers
228 views

How to decrease distortion/noise of LM386 amplifier at max gain and volume?

From my previous question, I've made LM386 amplifier and it works better than LM1458 amplifier. I've added gain and bass boost in my LM386 amplifier. How to decrease distortion/noise of LM386 ...
0
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1answer
64 views

Hum Cancelling Circuit

Consider the following circuit: I was just thinking about how connecting consumer grade unbalanced electronics together has a tendency to generate hum. For example, I have a little mixer that has ...
1
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1answer
63 views

Why the need for capacitive loads?

Pioneer, Kenwood, Sony, Onkyo, Denon you name it, they all have a similar circuit like this: Why they use C1 and C3 for? Thanks
2
votes
1answer
229 views

Triac spurious triggering issue

I have a circuit where I am using triacs to switch home appliances like fan, tube light etc. This is the circuit I am using: (TRIAC1, TRIAC2, TRIAC3 come from arduino GPIO pins) First load is a ...
0
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1answer
27 views

How to 'simulate' an input device?

I made a diy guitar amplifier with two seperate amplifiers. When potentiometer is raised something strange and annoying begins - various whispers, noises and reacts really strange. HOWEVER this never ...
2
votes
1answer
84 views

Spurious triggering in TRIAC due to EFT

I am working on a project to control AC load using TRIAC In normal operation it working complete fine But when a fan regulator specifically step type capacitor regulator is used in vicinty the ...
3
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3answers
793 views

How to clean/remove distortion/noise in my LM1458 Op-Amp?

I've made a LM1458 Op-Amp based on this video. it amplifies the input music but it produces noise and has low volume. How can I remove the noise and how to increase the volume? when i parallel ...