Questions tagged [interference]
For questions about electromagnetic interference (EMI); see also the [emc] tag.
318
questions
0
votes
1answer
55 views
Running and grounding paired shielded cable thru a connector
I need to run two logic signals around a vehicle, so for good measure, regardless if its overkill or not, I want to use a shielded single pair wire for that job. At one point it should be crimped to ...
0
votes
1answer
74 views
NFC and magnet interference in a concrete piece
Do you know if both NFC and a magnet would work correctly in this scenario?
I´m designing small pieces of concrete (imagine chess pieces) with three layers: magnet inside, NFC tag in the middle, and ...
0
votes
2answers
78 views
Flashing random LEDs when multiple wires fished through hole
I've been building a large, 3D printed dodecahedron infinity mirror. Prior to adding the polycarbonate pentagons with mirror film applied, the LEDs worked perfectly in the frame. Once I fished the ...
-1
votes
2answers
117 views
What can negatively impact a motherboard's / CPU's clock generator / oscillator?
Is it possible for a clock generator / oscillator to be skewed by something from the electrical grid (e.g. to work perfectly fine at place A, and have issues at place B - all reproducible)?
What would ...
0
votes
1answer
64 views
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 ...
1
vote
2answers
35 views
RF interference in high node density 2.4 GHz networks
These days, there are a lot of products that are working on 2.4 GHz RF - mobiles, laptops etc using 2.4 GHz wifi, earphones using BT, home automation products using 2.4 GHz zigbee. Though these ...
0
votes
2answers
56 views
How best to allocate signal wires to 4 twisted pairs that best reduces inteference
I have to transmit digital signals 30meters including power. I am going to use a cat 6 ethernet cable with 4 twisted pairs (8 wires in total). I can already assure that my signal gets to the other end ...
0
votes
3answers
53 views
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 ...
0
votes
1answer
70 views
Desktop screen goes black because of radiowaves from phone?
I hope this is the right community for this phenomenon.
For some weeks my desktop screen went black for some seconds - no warning prompt no nothing - and then came back to life.
I usually change my ...
0
votes
0answers
118 views
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 ...
0
votes
0answers
33 views
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 ...
8
votes
4answers
725 views
Why does analysis indicate that ground lifts do not fix ground loops?
Note: "Ground loop" in this question refers to a ground loop caused by linked magnetic fields. (Sometimes ground loop refers to slightly different scenarios.)
Recently I've been looking into ...
3
votes
1answer
85 views
Oxygen sensor voltage changes when machine is powered on. Interference?
I built an Arduino Uno based control panel for an altitude training machine, which connects to an oxygen sensor. The value is amplified by an instrumentation amp (INA122P) and read into the analog ...
0
votes
3answers
65 views
Better to Opto-Isolate on Sending or Receiving End? Isolating to Avoid EMI
I am working on an art project using some modified bug zapper circuitry to produce loud and bright sparks. I have the circuit working and the sparks are very impressive, but I'm running into a issue ...
2
votes
1answer
60 views
Protecting against static interference/noise for encoder
I have a chassis that is made from box steel beams, they are painted/surfaced. Attached to it is a fiberglass tub which can rotate. Attached to the fibreglass tub are supports and mounts where some ...
0
votes
0answers
135 views
Why does my Ethernet upload speed go to 0 Mbps when connecting an RGB LED strip?
I recently installed the following RGB LED strip on my bedroom's ceiling:
The computer and the lights share the same electrical connection. However, everytime I plug the lights into the wall my ...
2
votes
2answers
125 views
Best configuration for ethernet-as-speaker-wire?
I'm hooking up a couple of small speakers (3w max each) outside, and I have a small run in my house from inside to out that was done with ethernet cable. There's no way I can pull speaker wire through,...
1
vote
1answer
125 views
Power Supply issues with CAN bus
I am currently working on a system using C# for a windows GUI with an Ixxat USB-to-CAN and an STM32F303K8 that runs CANopen, The system itself is running fine I can send and receive messages to and ...
3
votes
2answers
153 views
I2C gets Interference from motors in an Arduino project
I built a small Arduino "robot" on a tracked chassis. The device uses MPU-5060 for direction finding (on a prototype shield) and Adafruit MotorShield v2 to control two 320-type motors. The ...
2
votes
1answer
96 views
SMPS grounding interference ... ground loop maybe?
I am experiencing a weird phenomenon with my class 1, 15 Volt, 1000 watt SMPS with an isolated input and output grounds. The AC input (PE) ground connection has continuity to the SMPS chassis. When ...
0
votes
0answers
51 views
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.
3
votes
3answers
166 views
Decreasing I2C SDA SCL interference
I am setting up a fast I2C communication between a microcontroller (STM32, master) and an FPGA (Zynq-7000, slave). Currently, it won't work correctly because whenever the FPGA pulls down SDA, it ...
2
votes
1answer
75 views
DIY electromagnetic shielding (CNC mill)
I'm building a DIY CNC router. I'm running at a low RPM and only planning on cutting soft materials (wood and under, maybe a PCB).
I'm currently having problems with magnetic interference. When ...
0
votes
1answer
62 views
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 ...
1
vote
0answers
58 views
IR reciever somewhow being triggered by cell phone screen?
First time asking a question here.
I am curious why the TSOP4838 ir sensor is acting eratically when my Google Pixel 2's screen is facing it.
As you can see from the schematic, I have a 555 arranged ...
0
votes
2answers
50 views
Shielding an RF module from noise
I feel like a fool. As seen in the image below, the nRF module is right next to the VIN terminal. When I powered this up, I was able to communicate with the nrf module via SPI but it wouldn't receive ...
0
votes
2answers
153 views
Cross-Talk/Interference between UART Lines on a PCB
I am wondering at what distance UART lines begin to interfere with each other? And can I expect the UART lines below to function properly? The PCB board below has 6 UART lines running alongside one ...
0
votes
0answers
40 views
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 ...
0
votes
1answer
100 views
How to know which radio frequency is free to transmit data over a particular frequency to avoid interference
I found that some radio broadcasting stations transmit data at a particular frequency, and I was told that if I were to transmit my own at that particular frequency that I would interfere with their ...
2
votes
2answers
176 views
Shielding powerful HF EMI
I'm trying to install a plasma cutter on a CNC machine, but the problem is that the cutter uses a high-power HF start to initiate the cutting arc, and this causes horrible interference with my control ...
0
votes
2answers
50 views
Multiple AC-DC power supplies or use DC-DC converters and one power supply?
I have an electrical control box that needs 48v, 12v, and 5v to power stepper motors, sensors, and microcontrollers, respecitvely. All power items will be mounted on a DIN rail right next to each ...
0
votes
1answer
63 views
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: ...
3
votes
1answer
1k views
What types of cables do ferrite beads/chokes have a beneficial effect on?
Ferrite beads prevent electromagnetic interference from affecting a cable. Without fundamentally understanding how EMI works, this is obviously a beneficial effect for the stability and integrity of ...
0
votes
1answer
32 views
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 ...
0
votes
2answers
105 views
Arduino resetting or malfunctioning when controlling 48V DC motors with relay module
I'm building an Arduino controlled crane machine out of old crane machine parts.
The motors in a crane machine are 48V DC and I am controlling them with an H-bridge configuration using an 8 channel ...
0
votes
0answers
55 views
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 ...
0
votes
1answer
49 views
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 ...
1
vote
1answer
107 views
Top layer vs mid layer for high speed ADC signal routing
Assuming we have an analog differential signal trace that we must route from the connector to,say, an ADC (24 bit or 32 bit kind as I don't think lower resolution ones are affected by this.) What we ...
0
votes
0answers
31 views
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) ...
1
vote
1answer
72 views
Nearby jail's signal jammer affecting cellphone and devices using 2.4GHz band
I just rented an apartment that seemed perfect at the first sight.
However, once I moved in, I noticed a lot of instability on my cellphone signal. I found that odd, so I did some research and ...
0
votes
2answers
128 views
Terminating an audio line-in signal when source is disconnected
I've been trying to DIY a home audio setup. We have a pair of speakers in the ceiling of an upper floor (previously installed), and a new TV on the same floor. We wanted the sound of the TV to come ...
0
votes
1answer
59 views
Interference suppression coils for 9V DC adapter for audio equipment
I am about to add voltage regulation to an unregulated 230V AC to 9V 150mA DC adapter, by adding an L7809 voltage regulator and ceramic 0.33µF and 0.1µF capacitors.
I want to use this adapter to power ...
0
votes
1answer
66 views
How to reduce RFID interference
I am using a MFRC522 RFID reader I have read that it's antenna when in close proximity with metals then interference could be generated. What should be the distance between the antenna and the metal ...
1
vote
0answers
65 views
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. ...
3
votes
1answer
82 views
Crosstalk between transmission lines
I was reading these slides about crosstalk between transmission lines. At page 6 there is this circuital model to describe the effect of mutual coupling between these two lines:
My doubt is: why \$I_{...
3
votes
2answers
385 views
ESP8266 noisy input when wires go through power supply
I had made a circuit for an LED strip using an EDP12e. I had also attached two buttons to change between colors on the strip.
To make it compact I inserted the circuit board inside the casing of the ...
1
vote
0answers
123 views
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 ...
0
votes
1answer
99 views
Controlling a Brushed Motor with DC Voltage to Avoid EMI (no speed control needed)
I have a fairly simple project coming up. My task is to design a system which powers and controls a Pan and Tilt positioner for a camera. It has some weird and unavoidable requirements/constraints:
...
10
votes
5answers
1k views
What are some quick, cheap hacks for determining the source of EMI in my house?
TL;DR - Without dumping a bunch of money, is there a quick MacGuyver-y way to help diagnose what's causing the EMI in my house?
Longer -
I have the curse that I'm a little too technical to be helped ...
0
votes
2answers
78 views
How can I create signal interference in a circuit? [closed]
I understand that this is counter intuitive but, as an experiment I want to create interference in a circuit.
I want to expose an AC sinusoidal signal to a second sinusoidal signal. This will cause ...
