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

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0answers
55 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 ...
0
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2answers
20 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
63 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
86 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
89 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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31 views

LCD Flickering when Shielding is not Connected to Ground

I got myself one of these LC-Displays: http://www.sainsmart.com/sainsmart-hdmi-vga-digital-9-9-inch-1024x600-lcd-driver-board-for-raspberry-pi.html It's a barebone LCD setup with just the components ...
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1answer
35 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
54 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
44 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
66 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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0answers
47 views

Parallel connection between two circuits 15cm apart

I need to connect two PCB that must be 15cm away from each other. I considered an IDC connector with ribbon cable like this http://www.zagipalma.es/images/USBASP/USBASP%2010%20a%206%20Pines%2011.jpg ...
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1answer
40 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
153 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 ...
1
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1answer
65 views

Wireless Panic Alarm

I have made a panic button with a simple circuit with a wireless doorbell button connected wirelessly to the chiming box with the output of that connected to a relay powering a 12v flasher and siren, ...
0
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1answer
105 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
53 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
53 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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0answers
49 views

What would be some solutions to prevent system malfunction after IEC 61180 4 kV and 6 kV tests?

My team of engineers are developing an energy analyser that have to be submitted to the 6 kV transient tests of IEC 61180, Table 1 Line 8 and 4 kV fast transients tests, Table 1 Line 9. When we were ...
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2answers
97 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 ...
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0answers
70 views

HF RFID 13.56MHz Interference from WiFi/BLE 2.45GHz?

If a Wifi/BLE antenna were placed within a multicoil loop antenna for 13.56MHz HF RFID, would there be significant crosstalk/interference?
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1answer
35 views

3 axis magnetometer issue in one axis

I have several 3-axis magnetometers mounted on breadboards, and they all read correctly in the x and z directions. The Y direction is very strange; when turned to read ...
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1answer
118 views

Strange TV Blue Screen issue on switching on any home appliances [closed]

i have recently purchased Android Tv Box CS928 from Chinese site http://www.aliexpress.com/item/CS928-Android-4-4-kitkat-Rk3288-A17-quad-core-2GB-16GB-2-4-5-0Ghz-100M/1939723909.html The Android TV ...
0
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1answer
60 views

Can a rotary incremental encoder, count more steps due to interferences

I have an incremental encoder having differential signals A-NotA, B-NotB I-NotI, that apparently randomly seems to count more impulses. It is possible to have more impulses due to electrical ...
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0answers
83 views

How to shield a USB device from high EMI

What is the best way to keep a USB device from disconnecting when exposed to a high EMI environment, such as when connected to a high voltage power supply under test? For example, in debugging a ...
0
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0answers
75 views

If my WIFI chip has poor performance at 5GHZ, what does that mean to the end user?

I'm testing my WIFI chip, and it has poor performance at 5GHZ. The transmit power I'm measuring is really low. How does this problem manifest to an end user? Will the internet connection be really ...
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4answers
3k views

Wireless Home Automation 2.4GHz versus 433MHz [closed]

Project specifications To make some things clear first(wow that sounds so arrogant): This is an Arduino project This is supposed to be internationally applicable I have experience with 433 MHz ...
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1answer
102 views

Bluetooth Interference with High Pitched Tone

i'm building a portable stereo system and am having some unwanted noise from the bluetooth receiver. the noise is typically a high pitched tone. please see the attachment for my chicken scratch ...
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2answers
74 views

Suppressing interference in a pressure sensor circuit

I just looked over a circuit designed by my predecessor, which is used to interface with a pressure sensor. It works, but I have some doubts about the way the input filtering is done. The simplified ...
2
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1answer
102 views

pH sensor project: trouble with RF interference

I built this pH sensor project on a breadboard and I'm having a big problem. The output on the voltmeter is completely erratic, and I'm pretty sure it's due to RF interference. When I connect the ...
0
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0answers
54 views

How to debug and resolve an antenna interference problem?

We have had a board made that features an interacting processor, chip antenna and GPRS/3G module. We have proved the functionality of the board - it works - but the board is not stable. We have ...
2
votes
1answer
50 views

Atmel and coil close on a board - is interference an issue?

I'm going to build a circuit which uses AVR uC (probably ATmega8 or some ATtiny) and a coil with iron powder ring core. The coil has 330uH and will be working under current of approx. 6A. I'd like to ...
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0answers
129 views

Isolation between GSM and GPS antenna

We are doing a prototype for a gps based tracker. We got a problem in placing the GSM and GPS antenna. Both the GSM and GPS antenna are omni-directional antennas. In forums and application notes, the ...
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1answer
247 views

Microcontroller freezes (or doesn't) when plugged into different outlets in my home

I have an ARM development board (Marvell ARMADA XP CPU) and depending on which plug outlet I plug the system into, the system will freeze up after a few minutes or not. I found that plug outlets in ...
4
votes
1answer
397 views

Multiple nrf24l01, shared power, ripple/interference, DSO screenshot provided

I've got this circuit with 3x atmega328 & nrf24l01+ running off shared power supply, either 2x AA battery or 3v3 reg. It acts as a repeater, and depending on the origin of the message and the ...
1
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1answer
45 views

Reduce Interference in Wireless Mesh Network

I am playing with the idea of mesh network path finding. The goal is that each node can find the most efficient path through other node to a hub. One way I could approach it is by flooding the ...
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1answer
73 views

How do I place a long wire to make the EMI and inductance minimum?

I'm going to measure high current. After seeing that there is not a lot of low valued sensor resistors in the market and the available ones are very expensive, I decided to make my own current sensing ...
0
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0answers
63 views

How much electromagnetic interference/pollution is produced by home power-line network adapters?

How much electromagnetic interference/pollution is produced by home power-line network adapters? How do they compare for example to WiFi routers? They operate on high frequencies to achieve high ...
2
votes
2answers
72 views

Trying to Understand Spurious Sideband Interference (and some causality problems…)

Suppose I have a radio and I intend to transmit a 0.1 µs pulse on a 100 MHz carrier. Fourier theory tells me that this signal will produce some sideband interference resembling a Sinc function. ...
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1answer
118 views

NFC tag interfere with hearing aid device

I want to add NFC tag to hearing aid device for a child to monitor on smartphone (or smatwatch - either carried by children) if the tag is in the range - if not it means that child lost it and I can ...
3
votes
3answers
691 views

50MHz SPI PCB routing, use vias or resistors?

I am trying to route the SPI between MCU and ADC. However, the pin orders between MCU and ADC are not matched, there are crossings. A four-layer board is used.(signal - ground - power - signal) I ...
3
votes
4answers
1k views

How to prevent PA system from interference of 4G signal

I apologize if this is not the right place to post this. I am working on a small PA system for a weekly gathering. It catches the signal from wireless mics and output it to the speakers. I am pretty ...
0
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2answers
613 views

Stepper motor failing. Electrical interference?

Update: This question is already so long, I'm hesitant to add to it but it occurs to me to ask if electrical interference between the stepper motor wires could cause this sort of behavior (motor ...
3
votes
1answer
103 views

Audio oscillator cross-talk on small synth project

I am making a small 9V battery powered synthesizer with a square wave oscillator built around a 40106b Schmitt trigger (reference: http://richdecibels.com/blog/?p=11) and a few other components, one ...
5
votes
1answer
2k views

Permanent magnets near wifi device

Background I have a small circuit that consists of a microcontroller operating on 14Mhz and a wifi module. This circuit is enclosed in a small plastic box. I am considering gluing a few magnets on ...
2
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2answers
184 views

Verifying design that uses guard ring

I had a colleague design a board for pH sensor amplification based on schematic (fig 1)and spec in a paper. The paper recommends using the spec noted in figure 3. It uses a guard ring to reduce ...
6
votes
3answers
222 views

What Regulatory Requirements are Really Necessary for Sale in the USA?

I understand that unless you fall into some specific product categories that are exempt from FCC regulations, electronic products sold in the US are legally required to meet FCC EMC limits. However, ...
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4answers
3k views

How come radio signals don't interfere with each other all the time?

I'm a newbie on wireless technologies and I'm trying to understand how they work. One thing I don't understand is this: How come transmissions from different devices don't interfere with each other ...
3
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1answer
451 views

Why do library book detectors make my headphones buzz?

Whenever I enter or exit a library while wearing headphones (cheaper intra-aural type), I hear loud buzzing as I pass through the book detector gate. I can vaguely speculate at a high level that ...
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1answer
80 views

Can mobile cell stations cause interference in audio circuits near them?

It's a fact that if you put a GSM cell phone near a desktop PC and call it, the phone will interfere with the audio card and cause that noise most of us have heard somewhere. But is it the case with ...
3
votes
3answers
189 views

Are Wi-Fi 'transparent' buildings superior to antennas mounted on the exterior?

Looking in particular at wireless mesh networks in cities - is it advantageous to design a building that does not interfere with Wi-Fi (e.g. out of wood instead of steel and concrete), or would ...