Questions tagged [shielding]
Questions regarding shielding devices against noise, interference, or ESD. Not to be confused with arduino-shield.
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1answer
67 views
Effects of Neodymium magnets on PCB
I'm currently doing a project that consists of:
Arduino Nano.
Battery.
Buck Boost converter.
GPS module.
TSL2561 light sensor.
BH1750FVI light sensors.
LSM6DS3 Accelerometer.
HDC1080.
MicroSD shield ...
-3
votes
1answer
78 views
how can i attenuate mobile signal completely(maybe 90%) and please suggest me the wall thickness ,as i want to use copper or aluminium [closed]
please help me as i want to make a den for my dog that completely attenuates em waves of phone
1
vote
1answer
53 views
Why is the usb shield always tied to ground (GND pin)?
The shielding on a cable is to avoid interference from the outside world however it is always tied directly to the GND pin. Not inside the cable itself but inside a device. Every single device I take ...
0
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1answer
30 views
Testing the integrity of cable shielding for suitability
I am currently working with an ECG cable, is there a way for me to test the integrity of the shielding of the cable without using it directly on an ECG monitor to check for interference.
4
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2answers
1k views
Long wires causing Raspberry Pi to die?
I've been working on a simple project involving a Raspberry pi and some switches.
I would never thought I would have any problem for something as simple as a switch, but here I am.
The 2 wires from ...
1
vote
1answer
78 views
Why do USB data cables have 5 wires, what is the use of shielding wire?
I have always been curious about the 5th wire(aka shield wire) in USB cables. What is its purpose? Does it anyhow affect charging speed for mobiles or data transfer?
I do know that it carries the ...
1
vote
1answer
107 views
USB shield for analog and digital ground?
I'm new to Mixed-signal design and I'm having trouble deciding how to connect my digital and analog ground. I'm doing a 4 layer design, so I have a split ground plane.
As I understand, since I'm ...
1
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2answers
47 views
Help Shielding RF Anechoic Chamber - FM Stations
a collegue and I acquired a surplus small anechoic chamber (8 ft x 8 ft) for making some pre compliance test measurements, and we're running into the issue of FM Stations being only attenuated around ...
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3answers
99 views
Using shielded audio cable for potentiometer sensor
I'm trying to measure a potentiometer from an Arduino's ADC. The potentiometer has a maximum value of 100k ohms and is located about 1 meter from the Arduino. The potentiometer's wiper is wired to the ...
1
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0answers
44 views
How does the size of a conductor affect a driven voltage?
I'm designing a capacitive sensor which uses an active shield to focus the sensing field. This much works well.
Now, in order to most effectively protect the active signal from noise I'd like the ...
2
votes
1answer
175 views
SD card connector chassis grounding
I have been designing a PCB which includes an SD card connector. As I'm not a PCB designer expert, I was looking for a reference design when I came across with the circuit bellow, extracted from Texas ...
1
vote
2answers
82 views
What does metal to metal bottoming mean?
Some connectors datasheets specify the following:
Metal-to-metal bottoming for maximum EMI shielding under extreme vibration
Reference: Dualok Connectors
I have also encountered the following for ...
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2answers
123 views
Does burying a cable shield it?
TL;DR: Does burying a cable provide shielding? I.e., is a shielded cable in air equivalent to an unshielded cable buried ~ 6 inches in soil?
Long:
I'm a technician at a university. I don't have ...
1
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1answer
225 views
Shielded cable, to ground or not, in amplifier
I have been looking for an answer on the net about this question but not found it fully answered. The topic has been up here a few times (see links below) as well but I find the answers lacking.
My ...
1
vote
1answer
61 views
How to shield a battery powered instrumentation with USB interface?
I would like to ask for advice on shielding the following setup.
I have a measurement target sitting inside a Faraday cage, connected through a shielded cable to a measurement circuit. The cable ...
1
vote
1answer
44 views
dip switch electric shield
I have ordered a Reed Relay with a diode and electric shield, but I am not sure how to connect the shield to the rest of the circuit because I do not know what the shield does and how does it work in ...
1
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3answers
68 views
Is there any sense in carrying assembled enclosed electronics in a static-shielding bag?
Say I have a Raspberry Pi enclosed in a metal case, such as this:
Would it offer any additional level protection if I put it in a static-shielding antistatic bag whenever I carry it around (e.g. ...
3
votes
2answers
80 views
How should I use a static-shielding bag prior to opening, and why?
After grounding the ESD mat and wearing the properly grounded anti-static wrist strap, what is the correct process to take the contents out of the static-shielding bag and take it onto the antistatic ...
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0answers
82 views
Can a grounded static-shielding antistatic bag be used as a circuitry work surface to protect from ESD?
Basically, I have looked around about how to take proper care with respect to ESD and I am quite confused. I know an antistatic bag of any type would not provide additional protection from ESD if used ...
0
votes
1answer
43 views
A question about AC Ground and Shielding
I see this question on EE but reading those I am not sure they answer what I am asking here.
This is the problem. I am designing an audio device that is powered by an external 15VDC adapter. This ...
2
votes
5answers
252 views
Electromagnetic shielding and EMP
I've asked several related questions, but I'm afraid that some of the answers that I received, while great answers, might be skewed because of incorrect assumptions or unclarity in my questions.
The ...
0
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2answers
75 views
Is it easier to attenuate a sine wave or a more complex wave?
All other variables being equal, how does waveform complexity of a plane wave affect shielding effectiveness? Is it easier to attenuate a sine wave or a complex waveform?
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0answers
80 views
Skin effect of copper in a high-strength AC magnetic field
I'm trying to determine the thickness of copper foil required to construct an enclosure that attenuates a very fast-rising, very brief pulse of AC magnetic field at a frequency of 1 MHz and field ...
0
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0answers
63 views
How to calculate attenuation of two layers of RFI shielding material
I'm developing a type of enclosure that provides EMR shielding. It's constructed of two layers of shielding material. I don't have access to professional test equipment, so my dynamic range is ...
0
votes
1answer
75 views
How to build EMF radiation protection [closed]
I've recently started to use my laptop more and more on my lap and I'm worried about exposire to radiation emmited by the laptop.
I keep it at a distance of about 10cm but still...
I was wondering if ...
1
vote
2answers
149 views
What are the limitations of “fake” balanced audio cables?
I have an AV receiver providing amplified outputs and preamp outputs.
The pre-amp outputs are in the form of (unbalanced) RCA jacks. My speakers are amplified and have a balanced input.
I was ...
2
votes
3answers
720 views
Why is a caseless PC not an EMI problem?
As I understand it, the case of a PC is metal so that it can form an EMI enclosure around the electronic parts. My view is reinforced by there being conductive fingerstrips around the mating edges.
...
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4answers
127 views
Blocking cell phone interference on LM386 amp
I built a small amplifier using an LM386 on a protoboard. The problem I have however is that it makes those typical cell phone sounds if my mobile phone is close to it.
Since I want to 3d print an ...
1
vote
2answers
604 views
DMX: What should I do with ground and shield?
I'm currently developing a DMX interface (master interface) with USB and Ethernet connections. The power for my device I'm retrieving from the 5V of the USB connector.
The shield of the USB connector ...
6
votes
2answers
1k views
How can I make a diy anechoic chamber?
I'd like to make a small anechoic box for RF measurements. I need roughly a 30x30x30cm cube of usable space, and I'd like the reflections from the walls to be attenuated by 10dB or more from 100MHz ...
0
votes
1answer
53 views
If I run electrical current through the conductors in a magnetic shield, can It be used to shield stronger magnetic fields?
I'm wondering if running electrical current through a shield amplifies its effect to a significant extent, effectively making it into a shield you can "turn on and off" for stronger magnetic fields ...
1
vote
1answer
36 views
Current Rating of Stepper Shield Ground Wire
I have a 2 phase bipolar stepper motor;
https://catalog.orientalmotor.com/item/all-categories/20mm-pkp-series-2-phase-bipolar-stepper-motors/pkp214d06a-2
Its 4 power wires are wrapped in a shielded ...
0
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3answers
137 views
EMI shielding without shield? [closed]
Hi I sorted of had an epiphany when thinking about EMI shielding a PCB...
If the frequency of the system on a PCB was constant ( lets 20MHz digital system or something) could I take advantage of that ...
5
votes
2answers
497 views
Confusion in grounding shield wires of transducers
There is a 6-wire Wheatstone bridge type load-cell and one of the wire is called shield and it is electrically connected to the metallic case of the load cell as below(I marked that with yellow ...
0
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0answers
74 views
How to check if the isolation room is causing noise in MRI images
The schematic shows how an MRI shielding is supposed to be done. You have (1) the physical room where everything is installed, (2) isolating materials to isolate the main room from the MRI room, and (...
2
votes
1answer
75 views
Which one of these shielded scenarios is correct?
I have a system were both the signal generated and the sensing equipment is sharing the same ground.
Which one of these shield terminations scenarios is correct? (if any). I searched the internet for ...
0
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1answer
87 views
How should I connect a braided shield 2-core cable with a headphone plug with three cores
I'm a beginner in Electronics.
The cable has two cores and a braided shield. What should I do about the ground?
2
votes
1answer
62 views
Unshielded RJ45 connectors on SFTP Cat5e
I have "inherited" an old SFTP Cat5e cable connecting the basement of my house to the upper floor. There seems to be a break on some of the wires (6 and 7) so it won't even function at 100mbps.
I ...
2
votes
1answer
379 views
ungrounded chassis shielding
I'm looking into whether an ungrounded metal box provides good/bad EM shielding.
This thread seems like a definite "good", for reasons of the box acting as a faraday cage : How much shielding does an ...
2
votes
1answer
360 views
Shielded breadboard jumper cable wires
Does it exist a shielded version of 2.54mm pitch breadboard jumper cable wires?
Thin flexible wires, Gauge AWG 24-28. I want use shielded wires for JTAG cable, to reduce electrical noise from ...
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2answers
251 views
How to determine quality of headphone earbuds by spec sheet?
I have been doing some work with cheap headphone earbuds for quite a while now. I was wondering, when buying earbuds in bulk, if there was any way to tell what the sound quality would be before ...
0
votes
1answer
279 views
USB OTG Cable Shielding
I just soldered a USB OTG cable to connect a keyboard (regular USB-A) to a Raspberry Pi Zero (micro-USB).
How to wire the VCC, GND, D- and D+ pins was obvious and the cable works. However both ...
1
vote
1answer
172 views
Cable shielding groundloop
I am trying to connect a encoder to a motor controller which runs very close to the motor that it controls (30+ amps). Due to the risk of high EMI of the motor inducing on the encoder signals, we send ...
7
votes
3answers
645 views
Why does my GPS and Wi-Fi work inside a sealed copper clad box?
I have just finished assembling a Raspberry Pi-based project into a DIY box made from copper clad FR4 PCB, with the edges soldered together and the copper surface connected to ground.
I expected, ...
0
votes
1answer
118 views
Should it be expected that some shielded wire is not good at data transmission?
I have recently purchased a reel of this specification screened wire from RS Components to use in I2C communications, expecting it to be very well suited to purpose. I am running at approximately 400 ...
0
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0answers
140 views
How do I choose a twisted pair shielded cable?
The charging/discharging of a battery (1u to 30 mA) and remote voltage measurement is to be performed over 2 pairs of 2 m cable. In order to reduce picked up common mode noise I intend to use shielded ...
0
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1answer
332 views
Encapsulating an inductor with epoxy and ferrite powder
Say I have some SMD inductors and I'm trying to limit their EMF from the rest of the board, can I simply potty it with epoxy mixed with ferrite powder (or perhaps iron filings), if I make sure the ...
2
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3answers
414 views
Connect signal ground to safety ground?
We are designing a product which has to meet EMC directives. It consists of metal backplate folded into a chasis (the front is open). on the backcover there is a SMPS mounted. and on top of this we ...
3
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2answers
1k views
Should I connect a cable's shield to the ground layer of board when it's isolated from earth?
I have a controller board powered by DC that may or may not be isolated from earth ground. The chassis of the device is non-metallic.
This board connects through a long (30-40m), shielded cable to a ...
2
votes
1answer
48 views
Calculate field strength for shielded isotropic transmitter
How to calculate the field strength of a shielded theoretical isotropic transmitter, if there is a hole in the shield for example.
I am looking for a complex formula that also takes into account the ...
