Questions tagged [shielding]

Questions regarding shielding devices against noise, interference, or ESD. Not to be confused with arduino-shield.

31 questions with no upvoted or accepted answers
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75 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 ...
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0answers
91 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 ...
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0answers
2k views

Understand the shielding of a USB device

I have a GPS PCB which has regular USB pinouts (GND, +5V, DATA- and DATA+), but in addition has one stranded wire which is connected to USB type A plug. Marked as "USB connector" on the image: What ...
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0answers
5k views

Shielding effectiveness calculation

From The Basic Principles of Shielding: Apertures, or holes, have SE. The SE of an aperture and ultimately the entire electronic enclosure is determined by the size, shape and number of the apertures....
2
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1answer
297 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 ...
2
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1answer
496 views

Advice for Grounding and Shield Placement

I am working on a board design which includes an ADC and a DAC. The board attaches to the headers of the Mojo V3 Spartan 6 FPGA Dev Board. The ADC has to pick up a quiet signal at the same time as the ...
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0answers
27 views

Advice on Bulk Current Injection Testing

I am having trouble getting a new product I'm working on to pass Bulk Current Injection Testing. I had trouble on the 50mA test at around 30MHz where the Ethernet link was not functional. I have a 6 ...
1
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1answer
64 views

Would there be a significant difference if a metal shield is connected or not to the circuit ground?

Assuming that we have a sensitive electronics that is battery powered, which consist of a very sensitive 32 bit adc is reading a voltage from a chemical reaction and you place it inside a chunky 1 ...
1
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1answer
41 views

Self solder 8-pin din cable

a bit of specific question. I want to build my own cable based on pins stated in the manual of an old camera, so I can capture the video (composite video) and audio signal. Question: Is there ...
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0answers
44 views

Prevent Reception from an Extended Distance (Beyond Design)

I have a magnetic field that is being induced onto a power line by a transmitter, which is following the length of the power line to the receiver. The receiver communicates via a loosely coupled coil ...
1
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1answer
57 views

Decoupling capacitors on opposite side of board when using PCB mount EMI shield

When using a PCB mount EMI shield, can you put decoupling capacitors on the back side of the board? Well of course you can put them there, but will it make the shield essentially useless? Or will ...
1
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2answers
85 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 ...
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0answers
196 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 ...
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0answers
193 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 ...
1
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1answer
53 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 ...
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0answers
167 views

Why compass module is affected by its x,y position, if my phone's compass work in the same environment?

I am using hmc5883L on an autonomus robot. It shall remain in a 1 meter squared area. I have recently discovered that its reading changes up to 20 degrees on different positions even when it is facing ...
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0answers
26 views

Adding Ground or Earth to the shielded cable

I am using 8 core shielded cable to transfer I2C signal along with analog sensor data. We have connected earth to the shied cable, we have option to connect DC ground also. Everywhere I have read ...
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0answers
60 views

Should I (and in what degree) be concerned about EMI/RFI shielding?

I am starting on designing a sort of HAT (like used on the RPi) for the Nvidia Jetson Nano. As I am on my third year of electrical engineering I know little to nothing about EMI and shielding. Should ...
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1answer
49 views

Which side is the shield's drain cable connected and why?

I have 2 PCBAs connected using a shielded cable. The cable is transmitting an SPI signal from master PCBA to the slave at 30MHz. I have previously been advised to shield on the driving circuit (master....
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0answers
58 views

Will a vacuum tank shield against microwaves?

I am working on an experiment that involves 50-250W of microwave radiation. The antenna will be inside a small vacuum chamber (~2ft Dia x 3ft long) with ~1.5" steel walls. There are a handful ...
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1answer
43 views

I/O panel filtering for shielded room

We are looking into setting up a very basic shielded chamber inside a small room at my company to be able to perform some basic relative radiated EMC measurements. We will buy a somewhat cheap ...
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0answers
51 views

Can current absorbed by a shield of a cable be harmful to a human?

I wonder if I should isolate shielding everywhere throughout the system. It is a bit costly because shields are on the outside and tend to touch a bunch of outer metal parts. But then humans can touch ...
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2answers
61 views

How to connect a few shields correctly?

There are several shields on my PCB: shield on CAN-bus, on RS485, on Ethernet, on ENCODER motor signals. How do I correctly connect all these shields? If I use the star topology, which filters should ...
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0answers
60 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 ...
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1answer
93 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 ...
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1answer
74 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 ...
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1answer
54 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 ...
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1answer
53 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.
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213 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 ...
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3answers
55 views

Is better to have holes on different sides of the shield instead of the same side?

I suppose the best is to have no hole on the shield, but that is practially impossible if you have to let cables come out of it. So I read somewhere that having the holes on different sides of the ...
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127 views

Shielding from inductive charging in simple PCB

I am going to design a fairly simple binary LED wrist watch. For a cool feature and a good learning experience I want it to have wireless charging capabilities so I purchased this wireless charging ...