The tag has no wiki summary.

learn more… | top users | synonyms

4
votes
1answer
695 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
votes
2answers
100 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 ...
14
votes
4answers
708 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
votes
1answer
125 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 ...
1
vote
1answer
67 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
85 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 ...
9
votes
1answer
231 views

PCB clearance/keepout area surrounding wireless antenna

Suppose a PCB antenna or chip antenna is integrated onto a board design with a wireless IC, e.g. a Zigbee or Bluetooth module. What are some guidelines regarding clearance/keepout area on the PCB ...
1
vote
2answers
80 views

Radio or TV signal interference

I am curious to know why can not signals of different tv stations mix together while transmitting. I have seen many towers built near each other in mountain areas in my country. If two different ...
0
votes
1answer
115 views

Inductive phone charger mod - doesn't work with battery too close?

I am experiencing a strange issue, likely because I do not fully understand the technology I am trying to make play nice together, but maybe someone here can shed some light on it. I have an HTC Evo ...
2
votes
0answers
93 views

Possible wifi interference with processor

I am building a device that consists of an ordinary WiFi router (WDR4300) as shown here: Which works as a client and scans for networks OK when alone. The problems appear when I add another board ...
0
votes
0answers
114 views

Prevent interference caused by fan

I have several strips of addressable (LPD8806) LEDs hooked up to an Arduino. simulate this circuit – Schematic created using CircuitLab I have noticed that whenever I turn off a fan ...
0
votes
0answers
40 views

Will this RAM bypass interfere with linux's total memory count? [duplicate]

As the patent in this question shows, it may be possible to hijack a computer by bypassing the memory controller. If it's true that it only hijacks part of the RAM at a time, does that mean that it ...
0
votes
1answer
76 views

Should I use Magnet Wire as a conductor in this experiment?

I need to run a few wires from a HMC5883L compass sensor to a micro-controller to process the data. Can I use magnet wire to carry the signals from the sensor to the micro-controller or would the ...
16
votes
5answers
805 views

Why does a simple conductor start to emit EM waves when carrying a signal?

I understand that on circuit board traces with a clock, if the higher harmonics have sufficient power, it results in electromagnetic waves being emitted from the traces which creates EMI. What I don't ...
0
votes
1answer
147 views

Could an aluminum housing and passive cooling interfere with SoC's functioning?

I took the board out of a broken tablet. The SoC on the board gets hot pretty quickly. I thought about fixing the board to an aluminum plate, so that it touches the SoC and disctributes its heat, and ...
1
vote
1answer
148 views

I2C on FFC or IDE cable - interference?

This is a follow-up question on this answer. I need to communicate with I2C over approximately 10cm and I'd like to use an FFC or IDE cable for that. Earlier, I used an FFC cable to link a segment ...
1
vote
1answer
182 views

Bluetooth Interference between piconets

I am developing a device that consists of a base station and several wireless sensor nodes. In application there may be up to 30 of these devices in a laboratory with up to 5 sensor nodes ...
4
votes
2answers
257 views

Why are low frequency channels (10kHz - 200kHz) especially susceptible to interference?

I am working on a system which should communicate with a ~100kHz signal, and read that low frequency channels, e.g 10kHz to 200kHz, are especially susceptible to interference. Why is that? Are they ...
0
votes
2answers
273 views

Computer case causing interference with TV

I've recently changed my computer case to a new, bigger case. However, after I changed this case over, I can no longer watch TV due to interference with the signal. I have removed every output to my ...
12
votes
4answers
1k views

Microcontroller with a long wire for digital input

I have the doorbell button on my house wired into a GHI EMX dev board. The software evaluates the time of day and determines whether or not the doorbell should ring. Side Note: This was ...
0
votes
1answer
172 views

BBQ iginter power surge

I am building a home beer brewing rig that has several electrically actuated components controlled by an Arduino. The typical scheme is Arduino -> Shift Register -> Relay -> Component. One of the ...
1
vote
1answer
245 views

Can my weather station cause interference with my wireless network?

I know my weather station is on 433 MHz and my home Wi-Fi network is on 2.4 GHz and 5 GHz. It's ok so far and everything seems to be fine. But I found many cases on the Internet that cheap stations ...
2
votes
2answers
392 views

Would a digital compass work reliably when installed in a car?

I'm working on a project that needs dead reckoning sensors to combine to GPS readings, and is to be installed under the dashboard of a car. Currently I have an accelerometer and a gyroscope for that. ...
1
vote
1answer
415 views

How close can I place two transformers?

I need to place two of these transformers in a case. How close am I allowed to place them? Can they touch each other (of course, they will be electrically isolated)? Is their orientation with ...
-6
votes
1answer
196 views

Jamming Devices [closed]

Im am thinking about building a low power broadband jamming device to blanket a small area, around 400 sq.ft. I want my frequency range to be from DC to 100 ghz. Would amplifying the outputs of noise ...
10
votes
2answers
700 views

FCC part 15 “must accept interference from other sources”: what does this mean?

I've googled around a bit and here are the interpretations I've found in non-authoritative sources: that the device is unable to filter out interference caused by other certified equipment that if ...
0
votes
1answer
549 views

Could a bad hdmi cable be the cause of 60hz speaker hum?

I was at a friend's house trying to help him get his computer/tv/stereo connected in his new apartment. We had some difficulty getting the tv to acknowledge the video signal. The hdmi source option ...
2
votes
2answers
427 views

Ground induced noise between two connected boards

I have a CNC system that consists of a CNC controller connected to a PC via USB. The controller is in turn connected to a stepper motor driver board. My problem is that some time the turning off/on of ...
2
votes
2answers
345 views

Does RFID interfere with NFC

i have a small question about interference. Do active RFID (860 MHz) interfere with NFC cards (13.56 Mhz) when placed on top of eachother? (NFC above RFID tag for example). Thanks!
1
vote
2answers
3k views

What is the definition of interference vs. noise in radio communication?

Is it defined by the source or by the nature of the waves? Can one with some instrument make a reading like "In this room we have this level of interference and this level of noise"?
8
votes
2answers
919 views

How to build a cheap device to determine where Wi-Fi interference is coming from?

In this post, the ServerFault guys use a fancy tool to map out the WiFi spectrum under normal conditions, with a microwave running, and with a baby monitor on. The baby monitor and microwave cause a ...
5
votes
1answer
785 views

Killing GSM Buzz with Ferrite Beads

I'm trying to rid my speakers of the typical buzz from my iPhone. I get poor reception in my apartment and so it's constantly trying to find a signal, meaning I get a near-constant buzzing when the ...
10
votes
1answer
2k views

How to shield microcontroller from electromagnetic interference

I'm working with high voltage circuit (2.1 kV for defibrillator capacitor testing) and I'm controlling power supply with arduino, reading required information from laptop using serial interface. Most ...
1
vote
2answers
121 views

Will this setup create much audio interference for me?

I'll be installing a ipod adapter kit in my 2004 honda accord, and on the device that connects to my stereo, it includes stereo outputs - red/white - that i can connect with a stereo to 3.5mm cable to ...
16
votes
5answers
5k views

What is causing large oscillations in my DC/DC boost converter? Is this ground bounce or some other effect?

I designed my first PCB for a DC-DC boost converter only to find that it produced very noisy output. The design is based around the MIC2253. Here's a schematic: Although my circuit allows for ...
0
votes
1answer
162 views

Whether RF affects LPG Gas Sensor sensitivity or can it be hazardous, like fire and all?

I want to make a wireless electronic LPG gas leak detection solution. I want to start with any of two sensors MQ2 (How Catalytic Combustible Gas Sensors work?, DataSheet, Another DataSheet, Tech ...
10
votes
4answers
542 views

Why is RS-422 interface interference insensitive?

I am trying to understand differences between RS-232 & RS-485. I just don't grasp what is the core principle behind RS-422 inteference resistance? Is it number of wires (4 instead of 3)? Is it ...
5
votes
1answer
1k views

What should I know about interference between wires in a multi-conductor cable?

I want to use a multi-conductor cable for a few different circuits. What do I need to know about interference between circuits within a multi-conductor cable? Some of the wires will carry stepper ...
5
votes
1answer
2k views

How do I shield my pc-speakers from mobile interference? [closed]

I have a budget (not cheap :P) pc-speaker set from Logitech (2.1) at home which are extremely sensitive to cellsignal interference. My iPhone is about 1m from any part of the set - including the ...
12
votes
6answers
1k views

How to avoid interference in wireless communication?

I am working on wireless communication system. We are using around 10 pairs of transmitter and receivers. We are using atmega16 microcontroller for encoding and decoding by USART ports. Now we are ...
1
vote
1answer
153 views

Electronic compass soft iron distortion

I'm making a small autonomous vehicle, it is about 300x300mm in size. I need to get a heading for the robot. I currently have a CMPS03 compass but am finding that it is highly sensitive to soft iron ...
7
votes
3answers
921 views

Sizing an RC snubber

My fridge is sending bad clacks to my loudspeakers when it turns on/off, I fear for the tweeters. I'd add a snubber/suppressor to the compressor but my notions about RC filters from school are 15 ...
2
votes
1answer
433 views

LC Filter for Phase Control

Can you point me to a good online resource to learn how to understand and design LC filters? The goal is digital forward phase control to dim a light bulb. I've read that the EMI produced by the ...
13
votes
11answers
601 views

Is it possible that the phases of the moon could have an effect on the operation of certain types of electronics?

What type, what could the potential effects be, and why would this happen? EDIT: Yes, I am talking about physics not the supernatural. I figured this would be obvious unless people thought I was ...
2
votes
2answers
570 views

Interference from high voltage power supply (EHT power supply)

In class today our physics teacher was demonstrating how ionic fluids move when a high voltage exists between them. A USB microscope was placed above the test rig, and the image was projected onto the ...
7
votes
10answers
2k views

EMI: CFLs vs Incandescent Lights in Your Lab?

Being a green-oriented treehugger, I've put in all CFL lights in my house. Just as much light for about 1/4 or 1/3 the power. Nice, but flourescent lights put out a lot of EMI. Does this cause ...
4
votes
3answers
1k views

Non-metal cases

This question is really aimed at computer cases, but I suppose it also applies to other PCB cases. Most of the Computer cases I come across are aluminium, or else some other metal; As I understand it ...
7
votes
3answers
188 views

Wire to use with Sensors

I am trying to minimize interference in a sensor project. Can anyone recommend a good shielded wire I can solder into my board?