Questions tagged [interference]

For questions about electromagnetic interference (EMI); see also the [emc] tag.

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Can two interfering light beams create radio waves?

Two sound frequencies differing in only a few hertz can create ‘beats’ and this has been popularized in music designed to produce ‘binaural beats’. Can two lasers be tuned in a similar fashion so that ...
aquagremlin's user avatar
0 votes
0 answers
29 views

PIR Sensor Interference When RF Transmitting

I have created a small DIY circuit which sends a signal over 433.92Mhz when a PIR sensor is triggered. The circuit consists of 4 modules soldered onto stripboard. Schematic: Components are: 0.71mm ...
Jonas's user avatar
  • 179
0 votes
0 answers
32 views

ESP32 shielding inside an inverter

I am thinking about using an ESP32 as a secondary controller for a 12 V DC to 220 V AC inverter to monitor and control overload, low battery, using relays to switch AC output, etc. The inverter will ...
asim's user avatar
  • 590
2 votes
2 answers
125 views

How can it be possible that I hear people's voices from my computer speaker? [closed]

I searched on the web and found it can apparently be due to truck drivers communicating on citizen's band radio which is around 20 MHz. Apparently this communication may cause interference with the ...
allexj's user avatar
  • 41
2 votes
1 answer
86 views

Mysterious artifacts in my strain gauge data. Can anyone suggest a possible source? [closed]

I'm working on a project where we are collecting timeseries data from multiple strain gauges. We are seeing a strange pattern of artifacts in our data. The artifacts appear as sharp 'spikes' with a ...
pnadeau's user avatar
  • 121
0 votes
1 answer
41 views

Tuned RF circuit: How to minimise interference?

The circuit in Figure 1 is designed to detect an RF signal at f0=40kHz. For information, this will be a portable proximity sensor, worn on a cat's collar, so it has be small and light. The circuit ...
James V Stone's user avatar
0 votes
1 answer
78 views

ESP32 powered over long lines with 230V

I'm planning to put several Ethernet ESP32s with AMS1117 5 V to 3.3 V power converters and SHT31 temperature sensors around my house to report temperatures. They will be connected over Ethernet; power ...
syster's user avatar
  • 3
2 votes
1 answer
43 views

Is there a risk of damaging built in RF components having several Iridium SBD 9603N modems active close to each others?

I use Iridium SBD 9603 N modems in some hardware (oceanographic buoys). I use high gain antenna, typically the setup is based on https://www.sparkfun.com/products/18712 and https://www.sparkfun.com/...
Zorglub29's user avatar
  • 373
1 vote
1 answer
61 views

Unexpected signal at AD620 module output when Vsupply is on

I bought an AD620 instrumentation amplifier module and below is the module schematic. Souurce - https://protosupplies.com/product/ad620-instrumentation-amplifier-module/ A problem shows up when I'm ...
Jack Huang's user avatar
0 votes
0 answers
50 views

Pump motor interference with PIC microcontroller

I am building a fermentation chamber for sourdough which has a heating element and a 5v mini-pump for humidity. Both are controller by a PIC16 microcontroller. Without the pump all is well, but as ...
Elad Lahav's user avatar
0 votes
1 answer
47 views

Precautions when using multiple analog devices on same circuit

I have a KP236N6165XTMA1 5V analog pressure sensor and a SHT31-ARP-B 3.3V analog temperature and humidity sensor on the same circuit, connected to the same ground plane (see v0.2 schematic bellow). ...
Tommy95's user avatar
  • 87
1 vote
1 answer
81 views

Will termination resistors help with USB data line "dead legs"?

I'm designing a USB switch, using small relays to connect a USB peripheral to any one of ten PCs. The USB traces from the peripheral branch out to ten different relays. I anticipate these "dead ...
Sod Almighty's user avatar
  • 1,445
0 votes
1 answer
112 views

Multiple DC/DC or single DC/DC + LDO

My FSAE team and I are developing the electronic boards for the car, like BSPD, TSAL, etc. So far, we use a 24V battery for low voltage system with a single DC/DC 24V to 5V converter for each board, ...
Gigapel's user avatar
  • 61
-1 votes
2 answers
2k views

Power supply makes a static/coil whine noise when the power supply is off and the PC is off

I have noticed that my power supply (PSU) makes a VERY slight coil whine/static noise while it is plugged into the power outlet, regardless of the power status of the PC and the PSU. It sounds no ...
P. Z.'s user avatar
  • 1
1 vote
2 answers
97 views

How can I protect this gate signal trace from EMI?

I'm designing this board which will control current through a coil using an IGBT. The coil is 500 uH and is mounted around 3 cm above the PCB and will handle peaks of 400 A. Because of the close ...
Swiss Gnome's user avatar
3 votes
1 answer
80 views

Stepper Motor Interference from Metal on Frame or Shaft

I'm working on a project with a stepper motor and am running into an odd interference issue related to metal contact with the motor. I'm using a StepperOnline Nema23 2.8A (23HS22-2804S) motor with a ...
Mroctopi's user avatar
0 votes
0 answers
50 views

How to shield a wireless microphone receiver from hdmi cables running under it?

We have some wireless microphones set up with the receivers in a confined space. After adding some HDMI cables (for streaming purposes) we now have an interference problem. While the transmitter is ...
Louis Somers's user avatar
2 votes
2 answers
182 views

Could a device connected to one MCB/phase affect a device on another MCB/phase?

I have a 3-phase 230V residential supply. It's divided among 3 groups of MCBs all powering single phase devices. The problem I'm having is that whenever the air conditioning (single phase) turns on ...
Pavin Joseph's user avatar
0 votes
0 answers
64 views

How to eliminate the VFD noise affecting digital sensor reading?

I have a problem getting correct readings from a 5v digital sensor connected to an Arduino Uno board. I get correct reading until I start the VFD that drives a 3-phase motor. The sensor reading then ...
Shamooooot's user avatar
0 votes
1 answer
147 views

Relay Switching Causing Arduino to Crash when Load Attached to Relay

The title pretty much says it all When we don't have devices attached to the relay (standard 4 relay module board) this doesn't happen. But when there are devices attached this does cause the problem ...
AustinFoss's user avatar
1 vote
0 answers
45 views

Mitigating 2.4GHz interference from 0-5V analog signaling line

I am chasing my tail on a project and cannot seem to find a way out of the hole. I have a small 18mm 40kHz piezo transducer running through a powered precision rectifier+preamp circuit. This tiny ...
Matt001's user avatar
  • 17
0 votes
1 answer
89 views

VFD interference with microcontroller

I’m doing a project that requires the control of a VFD (variable frequency drive) that powers a motor by using a microcontroller to send the signals. When the VFD is powering the motor, there is a lot ...
francesco guerrini's user avatar
2 votes
1 answer
112 views

Treadmill charges electrostatically, creating interferences with my PC [closed]

I have been using a treadmill for around 10 months, then it started causing my PC to detect connection and disconnection of my keyboard. It took me a while to realise that the treadmill was the source ...
Norcino's user avatar
  • 121
0 votes
0 answers
19 views

How to prevent interference between high voltage and brushless dc motors

I am a DIYer without much experience in electronics or electrical. I have a device that has 6 DC brushless motors spinning discs around a cube with plasma inside. The motors are were bought at ...
CanRobbo's user avatar
3 votes
3 answers
332 views

Why is inductive coupling negligible at low frequencies?

I've been reading some papers from the early telephone era. I see a lot of statements thrown around like "crosstalk at low or voice frequencies, where inductive coupling is negligible..." ...
Rydberg's user avatar
  • 253
1 vote
2 answers
140 views

variable speed drive interfering with distant PHEV charger

I am using a generic variable speed drive for a water pump. About 5% of the time that I run it, it stops my BMW 530e PHEV from charging. What is the most likely cause? What measurements can I make to ...
personal_cloud's user avatar
0 votes
1 answer
36 views

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, ...
Nova's user avatar
  • 1
0 votes
4 answers
117 views

Weird component in radio player interferes with FM functionality of the radio itself

I got my hands on an old radio player which has both cassette player and FM/AM functionality. I got constant noises while playing on FM and it turns out to be some weird component on the cassette ...
Harish Aathiyan's user avatar
2 votes
1 answer
137 views

Picking a pi- or T-filter to suppress radiated interference on supply line

Normally when I design suppression filters I use π-filters for data lines and T-filters for supply lines as supplies generally have a lower output impedance than data pins. I now have the situation ...
Remco Poelstra's user avatar
6 votes
2 answers
2k views

USB shielding, device or host side?

I have an SBC with a USB host port, but it is exposed as male header pins rather than a female USB port. I have soldered female headers to a USB cable and have a working but intermittant connection, ...
davegravy's user avatar
  • 359
1 vote
0 answers
78 views

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 ...
AngelOfEffekt's user avatar
0 votes
1 answer
46 views

Would grounded conductors placed on skin prevent signals from reaching a shielded body part?

Here is the scenario: You are in an environment where there are sources of EM signals that your body will pick up as though it were an antenna via capacitive coupling, i.e. what happens with the 50/...
Zacary Wengdom's user avatar
2 votes
1 answer
83 views

Understanding opamp circuit, 13 MHz (interference?) amplification

I have the circuit drawn below soldered to a prototyping board. First, I added a high-pass filter a with cutoff-frequency of 600 kHz, since I would like to receive around 2 MHz. Then the received ...
Mart's user avatar
  • 326
0 votes
1 answer
144 views

Why does EMI from a DC motor lock up my Arduino, while consumer electronics remain unaffected? [closed]

For example: my laptop, while connected to the Arduino over USB, runs just fine, while the Arduino locks up.
kraber94's user avatar
1 vote
1 answer
252 views

Two laser diodes beat frequency

With a single laser diode, the interference pattern of the light with itself gives a beat frequency of zero. Given two laser diodes (same wavelength, same manufacturer), the interference pattern of ...
Julio Otuyama's user avatar
1 vote
1 answer
157 views

Two transformers with common ground (Split supply)

When and where you can have a common ground? In this case between 2 different transformers. The initial goal is to have: One Ground -15 V +15 V +12 V The split 15 volt supply will be used for ...
Lex Geurts's user avatar
0 votes
0 answers
118 views

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 ...
Mart's user avatar
  • 326
0 votes
0 answers
82 views

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-...
KaleM's user avatar
  • 417
11 votes
3 answers
2k views

Why does a 50 Hz, 200 mV sine wave appear sometimes on my portable oscilloscope without a probe connected to anything?

I have a portable oscilloscope, and when I connect just one probe to it, sometimes, moving the probe into the air without connecting it to anything, then I can see (in some of the places of my house) ...
Roger's user avatar
  • 239
2 votes
1 answer
83 views

Special considerations for circuit prototyping near an airport?

I am a hobbyist circuit designer. I recently moved to a home near an airport. I am directly under the flight path, and sometimes planes fly as low as 500-1,000 ft over my house. My circuits are ...
jemalloc's user avatar
  • 720
0 votes
0 answers
162 views

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 ...
Adam Griffiths's user avatar
0 votes
0 answers
34 views

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 ...
Geocheats2's user avatar
0 votes
0 answers
35 views

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 (...
Macuser's user avatar
  • 83
0 votes
1 answer
162 views

Shielded header cables or alternatives for IDC / 2x8 header cables

For my project I currently use 2x8 IDC cables, all of them carrying digital data, like SPI, I2C and TDM (digital audio). As I have tested, I found that these cables bring in loads of noise to the ...
sandeepzgk's user avatar
0 votes
3 answers
534 views

Could multiple transmitters on the same frequency work if phase-locked to GPS? (gedanken)

I've been noodling this concept for a while; it seems to me that if it were actually workable somebody would be doing it already, but I haven't heard of it happening. So where do I go off the rails ...
Crash Gordon's user avatar
  • 1,268
1 vote
1 answer
376 views

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 ...
15 Volts's user avatar
  • 486
0 votes
0 answers
57 views

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 ...
tarmogr's user avatar
  • 181
1 vote
1 answer
291 views

FM radio interference on PCB

I have designed a few PCBs for one of my projects. The PCB is picking up FM radio signals. I can see this as spikes in the spectrum where each radio station is broadcasting. I tried covering the PCB ...
user32335's user avatar
0 votes
2 answers
156 views

Coaxial 75ohm cable parallel to electrical mains 127V AC @ 60Hz

Everywhere we look at, the same recommendation is made: "never run coaxial cable parallel to electrical cables". Well, I get it, but.... I have no other option™. More than that, those cables ...
rslemos's user avatar
  • 121
1 vote
1 answer
155 views

2-stroke engine interferes with Arduino project

I'm currently working on a bicycle project where I have mounted a 25cc 2-stroke (weedeater) engine at the rear of a bicycle. I have also created a speedometer (based on Arduino) which is mounted on ...
Lefteris Garyfalakis's user avatar

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