Questions tagged [shielding]
Questions regarding shielding devices against noise, interference, or ESD. Not to be confused with arduino-shield.
191
questions
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2answers
62 views
How can I reduce noise caused by shift register updates?
I have a couple of designs using 74HC595BQ-Q100,115 shift registers. Some are using the SO-16 package, some the DHVQFN16. Some have five shift registers, some have three. ALL have a significant ...
1
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0answers
65 views
Twisted pair with shield and drain wire
Ive been posed with a problem regarding calculating the characteristic impedance of a shielded twisted pair with a drain wire. While I understand how to calculate this for a "normal" shielded twisted ...
1
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2answers
70 views
Shielding and Ground Loops - RF panel jacks for GPS
I've been working on a design that requires me to pass an RF signal through a conductive panel. I'm using SMA jacks for that purpose as they're readily available and also available in an isolated ...
0
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0answers
31 views
Connecting TVS diodes to a floating shield
I need a little help with shielding for ECG leads.
The design I'm working on has 3 leads, about 60mm in length. We use shielded cable for each lead, which all come to a meeting point at the ...
0
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1answer
72 views
Faraday cage - reducing EMI?
I am curious about the working of a Faraday cage as the shield for EMI in many systems. As far as I studied, it depends on Faraday's and Lenz's laws.
When the electromagnetic waves are incident on ...
0
votes
1answer
55 views
How to use shielded audio cable with micro-fit molex connector?
This is typical shielded audio cable which I’m supposed to use with micro-fit molex connector. The problem with that cable is that the ground cable/the shield is not insulated and I found it very ...
3
votes
0answers
41 views
RFI protection for a stepper motor controller
I'm building a remote tuning device for a magnetic loop antenna. It will use a stepper motor to turn the shaft on the mag loop's variable capacitor. The electronics will consist primarily of a ...
0
votes
1answer
50 views
Grounding and shielding between isolated devices
I have a battery operated micro controller with a hall sensor, mounted on a motorbike. The hall sensor has a shielded cable to counteract spark plug induced EMI. By default, the entire setup is ...
2
votes
3answers
62 views
If a PEC surface completely reflects an EM wave, why doesn't an ungrounded shield work?
I was thinking about shielding and its effectiveness.
An ungrounded shield doesn't work well for either inductive or capacitive coupling.
However, if you think about plane wave theory, a PEC surface ...
0
votes
1answer
76 views
Could shielding (not grounded) affect signal integrity?
I'm trying to shield 6 flat cables that give me some communication issues because I thought that there might be cross-talk or other sources of interference that cause the problem.
The shielding is ...
2
votes
1answer
90 views
Motor / VFD / Protective Earth
I have little experience with AC motors since I'm majoring in Mech.E. My team is setting up an AC motor with a VFD to control the movement of an airfoil inside a metal cage we built. I understand the ...
0
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1answer
83 views
Shield ground to metal body or signal ground?
I have a question about grounding.
I will have two short shielded cables with signal wires inside, located at the top of a tower. The cables have a grounding wire inside shorted to their foil shields ...
4
votes
1answer
151 views
Ground planes disposition in Ethernet connection
I am designing a board that will have sensible analog signals and a processor communicating with the external word via Ethernet and I want to avoid that common mode currents couple into my analog ...
1
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1answer
117 views
Voltage detected across Micro USB cable shielding
I designed a Keyboard PCB using an ATmega32U4 with the data lines wired up to a Micro-USB B Receptacle. Brand: Molex; part number: 1050170001. The USB ground is directly connected to the Micro-USB B ...
0
votes
1answer
103 views
4 pin connector is melting even with 5 volt and 0.1 amp power supply, Why?
I am using a connector as shown:
.
I am using this to connect to my camera, which works at 5 volts and 0.1 Amp. But this connector works only for few days and then the plastic portion of the ...
4
votes
2answers
81 views
Why is shielding effectiveness different for various hole geometries?
I have run into the equation below in various literature/app notes. (example). I have never seen the derivation for such an equation and don't understand why round apertures are more effective at ...
0
votes
3answers
111 views
RS422 Full-Duplex Cable Shielding
I need to interface two PCBs via RS422 (250kbps) in full-duplex mode (4-wire, 2-twisted pairs 100ft cable). This system will operate in a noisy (CNC) industrial environment, ie, industrial controls ...
0
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0answers
291 views
Connecting the Chassis Ground and Signal Ground in my PCB
I have been reading alot of questions on this site to clear my understanding on Chassis, Signal Ground, ...
3
votes
1answer
146 views
Analogue (or digital) signal integrity with multiple sources of noise
tldr: Can I transmit an analog signal through a noisy environment without it being corrupted, or should I use a digital signal instead?
My requirement is to transmit a signal from a MA3 absolute ...
0
votes
2answers
139 views
Should I use shielded RJ45 plug by the computers? [closed]
If I have shielded cables, jacks and plugs and I ground the shielding properly, then should I use shielded plugs at the computer's site too? I mean if I do so, then the shielding will be connected to ...
0
votes
1answer
42 views
ADC wire is picking up noise from cellular antenna [EMC]
I have a 5 wire micro jst cable with a line for ADC readings from an IR sensor that is picking up interference from the cellular antenna of the microcontroller. Will I be able to reduce this noise if ...
0
votes
2answers
424 views
How close to a stepper motor do I need to shield the wires?
I am trying to shield the cabling on my CNC mill. The motors, unfortunately, do not have connectors but instead have wire leads coming out from the motor housing. I can cut those wires about an inch ...
0
votes
2answers
105 views
Strategies to reduce EMF radiation
During a long-term, almost six month long, data acquisition in a proximity of scanning electron microscope I have found a significant source of magnetic field noise, which is altering the results. I ...
0
votes
1answer
246 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
92 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
488 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
votes
1answer
46 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
votes
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
633 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
177 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 ...
3
votes
2answers
56 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 ...
1
vote
3answers
253 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
vote
0answers
45 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
538 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
99 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 ...
1
vote
2answers
135 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 ...
2
votes
2answers
755 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
152 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
70 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
vote
3answers
95 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
231 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 ...
0
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0answers
172 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
62 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 ...
3
votes
4answers
379 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
votes
2answers
95 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?
2
votes
0answers
88 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
votes
1answer
98 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
213 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
2k 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.
...
1
vote
4answers
236 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 ...
