Questions tagged [interference]
For questions about electromagnetic interference (EMI); see also the [emc] tag.
71
questions with no upvoted or accepted answers
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When are 1:1 baluns worth it?
I am trying to build an antenna to connect to the GOES-16 satellite (downlink at 1690,1MHz, linear polarization) with my SDR. My plans are using a 1m offset parabolic dish with a BiQuad feed, ...
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1
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248
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Weird SWD debug port behaviour
Today I have started to encounter strange problems with SWD debugging.
The debug only works if I keep my finger on the SWD pins. To be more interesting I have the same problem with the boards I was ...
- 2,438
2
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415
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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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54
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Second shift register 74HC595 with wrong outputs
I have a controlling panel at my wall to control which electrical device is active (because I have only a single 10 A phase and running way to often to the breaker).
The principle is easy: read Input ...
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0
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99
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IR receiver somewhow being triggered by cell phone screen?
First time asking a question here.
I am curious why the TSOP4838 ir sensor is acting erratically when my Google Pixel 2's screen is facing it.
As you can see from the schematic, I have a 555 arranged ...
- 13
1
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135
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PH 4502 electrical interference EMI when in aquarium
I'm trying to get a regular ph reading in an aquarium.
The sensor works well when the probe is in a small quantity of water(i.e. a glass) but has large variations in larger water quantities (i.e. ...
- 21
1
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204
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Forward and Backward Crosstalk
I have some basic questions about crosstalk. My reference for this question is this website.
This website introduces crosstalk in this way:
Crosstalk is the unwanted coupling of energy between two or ...
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1
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98
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Separating mains power from data lines
I'm an electronics hobbyist who's learning from wiring stuff together and searching the internet if something doesn't work. Hence my electronics knowledge is very patchy.
I recently found out that ...
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1
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87
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Measure antenna S11 next to another source
I have a dipole antenna designed to work on ~800MHz and 2.44GHz frequency, and a miniVNA Tiny USB device that I can use to measure return loss of the antenna. I connect the antenna directly to the DUT ...
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92
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Bluetooth and Wifi range onboard a boat
On my sailboat the range of wifi and Bluetooth appears to be very much shorter than in my home - I can't figure out why.
ex1:
At home I can stream video with Miracast from my basement to a room ...
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49
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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 ...
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109
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Where to place RF shield
I'd like to put a pump drive circuit similar to the one shown below on the same PCB that has two I2C devices, a GPS module, seven analog signals, an ESP32 MCU transmitting WiFi via a trace antenna, ...
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69
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Using a switching DC-DC converter in high dynamic range current/voltage sensing
I'm thinking of making a power meter circuit which will have a high-side current-sensing amp (LTC6102), a resistive voltage divider for sensing the voltage, a dual op-amp (OPA2365) as a buffer for the ...
- 817
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162
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Electro magnetic interference with Arduino Uno and a portable radio
I'm surprised when I'm working with Arduino Uno, by just sitting beside a portable radio, like when I was powered on both Arduino & Radio and when they are close to each other I got some noise ...
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94
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Trying to find the signal in an AC line
I have a medical office call box/light system that is older probably 20 year old and they moved the main panel that the Drs see to know when there are patients waiting and since they moved it, it is ...
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1
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1
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95
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Digital signal interfering with analog signal and creating false triggers
I am in need of some help/advice.
To start the problem.
I am trying to install a sound player on a model train table. I currently have 8 sound triggers, the switches on four are within 12 inches ...
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263
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Do I need anything between a microcontroller and a basic FM transmitter to cut out EMI?
Below is my circuit of a basic FM transmitter attached to an output pin of the AT89C2051 micro controller. I haven't tested it and I might decide to connect R1 to the NPN collector instead of to VCC. ...
user116345
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158
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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 micro-...
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548
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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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3
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425
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I2C noise from 433MHz transmitter
I have built a little thermostat based on BMP280 temperature sensor over I2C, ESP8266 Lolin v3 and STX882 433Mhz transmitter.
I have not added additional pull-up resistors or decoupling capacitors.
...
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1
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29
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Interference of RF currents with a combiner
I am trying to understand what happens to 2 RF currents flowing in separate planar waveguides (such as microstrip lines), when combined with a power combiner.
More specifically, will they interfere, ...
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0
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84
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How does an integrating receiver work?
I am reading some papers and in one paper, the working of an integrating receiver is mentioned to remove (periodic) interference from the received signal. The paper explains the working as such:
The ...
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66
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Intersymbol interference on PAM Trasmitter
I would like to simulate on Matlab a PAM signal which, travelling on a time-dispersive communication channel, contains intersymbol interference (ISI).
I have 'built' the transmitter by generating:
8-...
- 121
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75
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RF interference on GPIO?
Novice here.
I think I have an RF interference problem with a 3.3v digital device used to control lights via an API over wifi and need some help making sense of it.
I have an esp8266 based device with ...
- 101
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31
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RF noob here, help with antenna extension & noise reduction keywords
I have a design restriction. I have 24-bit adcs on the same circuit as a 4g lte module and "i have been told" that the ~250mw (~24db) of the 4g module interferes with adc measurement , i was ...
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What happens when the attenuation between radios in an RF test bed becomes higher than the RF leakage attenuation of the coax cables?
If I have an RF testbed with radios connected to each other via an attenuation matrix, what happens when that attenuation between radios exceeds the rated attenuation of the braided shield coax cable (...
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117
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Can ferrite beads deal with electromagnetic interference on attached PC peripherals?
This questions is more related to computer + external electromagnetic interference with my PC.
I'm using a PC where one USB 3.2 Gen2 port is occupied with a USB 3.0 USB hub. I'm facing problem with ...
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37
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RF noise filtering chassis or power return?
I need to place some filtering on the IO lines of a DC powered device.
The RF noise is induced or conducted into the chassis of the equipment and also into the interconnecting cables. The frequencies ...
- 171
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83
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Help with the design of a RF PCB transmitter
Edited with previous suggestions
I work for a company that builds (redacted for privacy), and a big company lent us a special GPS anti-jamming device, and I am in charge of implementing and testing ...
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36
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Avoid body interference in a parallel plate capacitor
I'm making a parallel plate capacitor. Each plane is 4"x6" and they are separated at about 1cm.
I am using an LC meter to measure the capacitance, and the results agree with the parallel ...
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71
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Can inductors interfere with a BLDC motor?
I'm working on a student project. It involves running a brushless DC motor with 70uH external unshielded inductors on each phase.
Can the inductors, seeing as they generate a magnetic field, somehow ...
0
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1
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253
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Bluetooth antenna on top of large metal object and other RF questions
I've been doing some research on RF antenna design considerations but haven't really found anything close to the situation my device will be in. I am designing a wireless sensor for my FSAE team that ...
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3
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171
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Relay is switching by touching optocoupler with finger
To switch a 12V relay with a micro controller, I designed ("borrowed") this schematic.
Build the pcb and it works great. But there's a little bug that got me a bit worried. If I touch the ...
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581
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How to stop LED EMI on capacitive touch sensor TTP223
I am trying to make a piece of wood touch sensitive. I have a piece of wood carved with runic letters.
I inserted LED's inside then filled the letters with epoxy resin.
When I touch one I want the ...
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64
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RF line: routing it orthogonal over SPI digital signal lines
SPI will be kept below 1MHz. RF signal is under 434 MHz. Is this crossing fine through the big zero ohm resistor ?
Side question: will the outermost SPI line (it is the chip select one), or any of the ...
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Is it ok to have two stepper motors right next to each other?
Would there be any issues having two nema 23 stepper motors laying right next to each other, facing opposite ways (see image)? 48v, 4amps.
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LTC5599: why are these baseband inputs passed through 49.9 ohms and the capacitor + SPI
I'm designing a radar transceiver board using the LTC5599. In the datasheet for the part, there is a schematic that shows the circuit configuration for the evaluation board. Here is an image of the ...
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0
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66
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Basic shielding practice for simple passive audio project in an enclosure?
I'm a tinkerer but not an electrical engineer. I'm constructing a stereo->mono summing box for my stereo (to listen to Beatles LPs properly, natch). I'm using the design & schematic here for ...
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1
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99
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Correct model for interference from an unterminated transmission line branch
Question about the correct mathematical model for a branched transmission line
Baseline Setup
Waveform generator: Output 10-60MHz sine wave, 8Vp-p, Output impedance 50Ohms
RG58 50Ohm coax: ...
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What's the logic inside the formula for the calculation of the maximal envelope modulation amplitude of two temporal interfering electric fields?
Since my question is a bit elaborate, I will first write some details. Thank you all!
I refer to the study conducted by Nir Grossman et al. (2017) about the use of the temporal interfering stimulation ...
user274494
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66
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Do I2C wires and 120W (12V) power wires close together cause trouble?
I'm a beginner with electronics and I'm building my first solar powered robot. I now have a 50cm long (1.6 feet) small pipe through which I want to put four wires; 2 for the power from the solar ...
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87
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Weird interference when controlling piezoelectric humidifier
I am trying to build an Arduino controlled piezoelectric humidifier. I am using two humidifier modules which have 5V dc operating voltage(they have usb connectors). When I connect one module to my ...
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Will using a relay for triggering remote send interfering signals?
So I have a remote control with a SMD button I want to trigger. To do so, I need to bridge horizontally a pair of the pins, as shown in blue:
However, when testing this, I connected a long (10cm) ...
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161
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Arduino relay module interferece on signal pin (230VAC moror load)
I'm trying to switch a small 230V AC motor using an Arduino Uno, but I'm having same problems due to interference on the relay (so the Arduino itself is not a problem).
Sometimes the module create ...
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177
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Isolated step-down module for powering a Raspberry Pi from a speaker's 12V supply avoiding ground loop and interference
I have an older speaker with an iPod dock that I would like to extend with a Raspberry Pi as a streaming music player. At first, I tried powering the RPi from the dock connector with a Micro USB ...
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Downsides of Extending a USB Bluetooth Antenna?
I found an interesting video about how to extend the range on a USB Bluetooth antenna by resoldering a new antenna in its place: (https://www.youtube.com/watch?v=cwKWOdOHiWY).
I'm planning on using a ...
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100
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How to prevent common ground circuits messing with each other
I made an Arduino based 18650 battery tester that has 4 identical circuits that charge and drain.
Testing one battery at a time gives one set of results which I deem to be correct but testing more ...
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515
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Radio static caused by windscreen wipers
I was driving past a radio station transmitter of the radio station I was listening to. I turned on my windscreen wipers, which caused a noticeable static to be emitted through the speakers for the ...
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Experimenting with a Walkie Talkie
This is one weird bizarre thing which I noticed while I was in the electronics lab.
I had this Power Supply and a walkie talkie similar to this
I have not ventured in RF side yet.
The power supply ...
user220456
0
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162
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Hall effect current sensor and proximity to EMI
I am preparing to layout a PCB. I have an ACS723, that I want to use to sense the current going through a relay. In addition to the relay I have a Meanwell IRM-12-20 to supply ac to dc voltage to the ...
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