Normally related to EMI (see [tag:emc])

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How to read noise suppression sheet specs?

I am trying to shield a component from GSM850 and GSM900 radiation. When I read the datasheet below, I don't quite understand which parameters I should care most (relative permeability, magnetic ...
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36 views

How to read EMI absorber specs?

I am looking for some EMI absorber to shield a component from GSM 850/900 radiation. Never use one before. From p.2 for the datasheet below, the AB7050 absorber has ~-3.5dB reflection loss and ~80% ...
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2answers
51 views

Shield arduino for electrical interference

I have an Arduino UNO controlling two high voltage relays via a switch. It also reads out a third relay, which is controlled outside of the Arduino. My setup looks like this: With the following ...
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1answer
74 views

Why is an HDMI signal causing interference with Over-The-Air digital television? [closed]

I do not have cable or satellite television so I rely on Over-The-Air digital programming (free) and Internet streaming services to provide entertainment. A couple years ago, I purchased a video card ...
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52 views

Glitches on the SPI Chip Select signal

Observation: I am driving a chip select signal from FPGA through a bidirectional level translator to a PLL chip on my module for the configuring the PLL. I assert a high to low transistion for the ...
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1answer
77 views

Possible reasons for DC fan failure

In my design I have a constant problem with failing 24VDC fans. The fans are used all across the machine, however they fail in only one position, so I excluded faulty fan model as a source of problem. ...
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2answers
56 views

What is the core concept of SINR or SNR model?

As we all know, there is a relationship between SINR or SNR and BER. Specifically, when SINR/SNR is higher, the BER is lower. And there are lots of work on modeling the complex SINR/SNR. SNR ...
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1answer
34 views

What is the type of the wifi interference to ZigBee? Multiplicative or additive?

As we all know, the cross technology interference is a critical problem. CTI means that different communication technologies operate on the same spectrum (e.g., 2.4GHz), and this would lead to the ...
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41 views

Solenoid valve circuit causing scale error in labview

Last night I checked to make sure that my solenoid valves were working by lifting up the float switch that I have in a tank, which controls the solenoid valve circuit. The solenoid valves worked, but ...
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24 views

Can I reduce the interference caused by my phone's body to an rfid tag?

I recently got sick of carrying around a massive fob to get into my condo building, so I opened it up and took out the rfid tag. I then taped the tag to the inside of my phone case, and tested whether ...
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24 views

How to determine the limit to the number of bluetooth masters in a given area?

I am working on concept development for a sensor network and considering scale-up issues. I have found plenty of info on the number of devices a bluetooth master can connect to and I have found a few ...
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1answer
60 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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2answers
89 views

Grounding dc project to clean RF noise

I'm doing a home automation arduino / RFID project and using a 12v DC switch mode power supply to power it. This supply will be plugged in to a wall outlet. The project however will have some ...
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2answers
85 views

How to avoid interferences (antenna effect) in long traces in PCB?

I am working on a PCB layout in which I have a 40cm long traces (bus of 4 traces). This traces will support between 50mA to 100mA and 5V. I want to minimize possible antenna effects that may occur due ...
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1answer
59 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 ...
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2answers
68 views

Minimum separation between antennas in receiving

It's known that there has to be a separation between antennas of same frequency to minimize interference. But this is really necessary when antennas are mostly in reception mode?
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4answers
137 views

Humbucker-style microphone interference cancelling

For a recent experiment, I decided that it would be a good idea to try to add some electric guitar distortion effects to my otherwise Classical flute playing. In order to do this, I attached a small ...
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2answers
48 views

WWVB antenna interferance from AC/DC converter supply

I'm working on a design that uses a WWVB antenna receiver.... The WWVB antenna is a small (~ 1/4" x 4" rod). Size is not a constraint so I could make it much bigger if a I half to. The design is ...
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5answers
117 views

Will the data throughput decrease if the transmitter and receiver are in motion?

What I'm thinking of is a 2 way communication (voice communication) between two systems which are in motion. (like 100 km/h difference) Will the data transmission and reception be disturbed, by how ...
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2answers
84 views

12V vs 5V servo

I am looking to actuate a throttle on an internal combustion engine. I am using a 5V servo driven by an Arduino Mega2560 at the moment. The throttle is very close to the engines alternator and there ...
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1answer
104 views

electronic interference generated by blood? [closed]

Hi so i made a little electrical signal detector that can detect electrical interference/noise(for example putting it near a light or plug makes it squeal). I was messing around with it and noticed it ...
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1answer
174 views

Unusual interference [closed]

I'm experiencing an effect somewhat like GSM frame-rate audio breakthrough in my auditory systems - completely different frequencies but equally wideband. I've noticed it occasionally in the past - ...
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4answers
407 views

Dealing with signal noise over 50 foot communication link

Situation: Connecting a motor controller to an MCU. Motor controller is about 50 feet away from MCU. Connected via a single conduit (buried), containing the following cables: (There is no other ...
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1answer
64 views

Oscillating Amplifier

I am attempting to build the following amplifier The amps used are MAR-8A+'s from minicircuits C1, C2, C3, L1 - while these are available on the board they have not been placed The filters are epcos ...
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1answer
87 views

Crystal grounds and minimal trace distance to leads

Some questions have already been asked about crystals but there's a few competing designs and I have a few "obsessive" type questions on layout. Here's a almost completed layout with a PIC16F ...
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1answer
124 views

How can I use multiple Arduino-read photo resistors without interference between them? [closed]

I'm working on a prototype that utilizes a combination of photo resistors and LEDs to simulate a "tripwire" to detect when a coin falls through a clear tube. When using one tube, one photo resistor, ...
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2answers
45 views

Help with RF interference

I run an animated Christmas light show on the house, and that interferes with my garage door opener whenever the lighting electronics are on. The lights themselves don't have to be on, the problem ...
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66 views

Ballanced BNC cables?

I'm working in an experiment with high voltages and unfortunately a high voltage AC source is affecting the signal in my BNC coaxial cable (which is going into an oscilloscope or some other measuring ...
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1answer
48 views

Do short circuits between transformer windings cause noticeable change in EMF?

I am looking into developing a sensor system to be placed within a transformer. This sensor system in theory, should be able to detect any unprecedented change in EMF within the transformer enclosure. ...
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1answer
290 views

GPS antenna ground plane design considerations and limitations

I have a PCB design which incorporates a GPS unit. I'm looking at refining the PCB, and I'm looking to do away with the long cable length, occupation of space within my enclosure, current consumption,...
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1answer
355 views

GPS consideration for PCB with GSM (interference, setup etc)

I am working on a project which has a GSM and GPS on the same PCB (fairly near each other in an enclosure). Since I am not familiar with GPS I was wondering if any of you could give me some tips on ...
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1answer
79 views

Credit Card Swipe Interference

I am asking a question as a part of library maintenance for electrical equipment. We have installed a POS machine with credit card swipe on the same outlet as a laser scanner (used to check in books)....
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1answer
88 views

Mobile WIFI: how close can mobile devices be placed and still have a functional WIFI connection?

I wish to run a large array (50+) of hacked Android phones as a computing cluster. They will need to be networked so I plan to use their built-in WIFI radios to talk over a single WIFI network. (I ...
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2answers
491 views

Using PC audio to listen to electrical noise on power line?

I have done a bit of research on digital filtering and I was wondering if it would be possible to use the audio hardware of my computer tu listen to the electrical noise on my powerline ? If it is ...
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709 views

2.4GHz Wi-Fi interference between devices in close proximity, even though they're using completely non-overlapping channels?

Is there any known electromagnetic / interference / [no idea] effect which can cause IEEE 802.11 (Wi-Fi) 2.4GHz devices located in very close proximity (one on top of the other) to severly interfere ...
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0answers
106 views

Will the following circuit cause EMI-problems?

I'm trying to get a feel for which circuits will have EMI-problems and which won't. To make things a bit more concrete, I've designed a super-simple LED-blinking circuit using the PIC16F1788 micro-...
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3answers
134 views

Via fences or pickets important parameters for design

What is more important for EMI shielding effectiveness with respect to guard traces and via fences, the width of the copper trace that circles around the area or the distance between the vias to ...
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3answers
77 views

Electrical noise sources in farms

I am designing the data logger of a solar-powered automatic weather station that will be installed in farms. It's used to gather data from environmental sensors (wired) and send it to a host using the ...
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1answer
169 views

Wi-Fi transmitter/receiver in close proximity: Override interference?

I'd like to control a camera via Wi-Fi (zoom, trigger shutter, etc.), and possibly also capture a live video stream. This will be at an event with a huge number of Wi-Fi devices, and connectivity is ...
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3answers
231 views

How does EMI affect a circuit? [closed]

I was designing pcbs and my head engineer told me that if input supply is large then there should be a separate layer for ground and positive supply as this will reduce EMI effects on the nearby ...
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1answer
109 views

GSM module noise

I'm developing an embedded system that uses telit gl865 modem to connect to a server using gprs. I've noticed that the module makes a strange noise when connected. It's the same noise I used to hear ...
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1answer
127 views

Usefulness of line EMI Filter on bench power supply

I have read this pdf file about EMI filters. I'm about to construct a variable bench power supply of 12V/5A. Will there be any usefulness to add an EMI filter to the primary windings of the ...
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1answer
151 views

Two 2.4GHz radio modules (XBee+Bluetooth) on same PCB. How to minimize interference?

I'm designing a PCB with XBee radio module and a bluetooth module (RFDuino SMD with XBee 2mW Radio). Since both of these modules are using 2.4GHz, are there any special consideration about how to ...
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1answer
139 views

Will coiling a mains power electrical cord cause interference?

I am a maker working on a lamp design in which a decorative power cord is wound through the structure, creating a coil down the lamp's main structure. The coils are about 3cm apart and the same in ...
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1answer
171 views

Multiple hall effect sensors in proximity

I'm interested in using a linear Hall effect sensor to measure displacement varying by about 1.5 inches. The idea is I have a piston with a magnet at the end and a Hall sensor at the end of the cavity ...
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2answers
1k views

How to shield for electromagnetic interference (DIY level)?

I am building an optical rotation encoder for my "autonomous robot" (a LED pointing to a photodiode that gets interrupted as the axis rotates). My issue is that at the voltage that I am using the ...
0
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1answer
210 views

5V TTL signals over 4m or so?

Adding input and output capacitors either side of my 5V DC-DC converter doesn't seem to help much, and I'm wondering if some kind of signal interference might be my problem. I'm running signal from a ...
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2answers
75 views

What can be used for impromptu EMF shielding?

I have a robot with a lot of servos in close proximity and a high-current DC motor powering an airsoft gun. The motor is causing electromagnetic interference with the servos, and we need to shield it ...
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2answers
138 views

Does gauge size of a signal wire has an effect to its susseptability to electromagnetic interference?

Let's say you have the option to use a lower gauge wire size (i.e. thicker wire) for a signal wire that happens to be run along power wires. Will it pick up more electromagnetic interference than ...
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2answers
195 views

Sensible standard wiring type for long-range I2C

I'm planning on interfacing with some sensor devices via I2C over a long bus, with devices chained every 2m or so, up to 16m in total. I've seen other questions here referring to this from the "which ...