Explaining a Strange Phenomenon: EM Field & PC Fan

AI Thread Summary
A user reports experiencing a strange electromagnetic (EM) field phenomenon from a mains-powered PC fan, noting a consistent frequency of 200 Hz at a distance of three feet. The frequency appears synchronized with the mains frequency, and its amplitude fluctuates during power transitions. Discussion points include the possibility of the fan motor having four poles, which could explain the 200 Hz output, and the role of asymmetric distortion in generating this frequency. The conversation also touches on the effects of motor stator saturation and the influence of nearby permanent magnets. Understanding these factors may clarify the unusual EM field behavior.
Ravaner
Messages
134
Reaction score
3
Hello. I need an explanation for a strange phenomenon ... I use a fan (PC type) powered by mains (220 V / 50 Hz in my country). At a distance of about 3', I get a sin EM field (sure it is not by mains cords) at a stable frequency of 200 Hz synchronized on main frequency. Even during power on (acceleration) and power off. During these periods amplitude grows or decreases but frequency is sill 200 Hz. If somone can explain that, thanks by advance ...
 
Engineering news on Phys.org
I wonder if the motor has 4 poles? Maybe that would account for the 200 Hz "back feeding" on the mains.
 
Curious. 200 Hz, being an even order harmonic would require some sort of assymetric distortion. If the stator of the motor simply went into partial saturation on both +/- halves of the current peak, this wouldn't happen. Rectification would cause it...
Is there a permenant manget nearby?
 
Thread 'Weird near-field phenomenon I get in my EM simulation'

Thread 'Weird near-field phenomenon I get in my EM simulation'

I recently made a basic simulation of wire antennas and I am not sure if the near field in my simulation is modeled correctly. One of the things that worry me is the fact that sometimes I see in my simulation "movements" in the near field that seems to be faster than the speed of wave propagation I defined (the speed of light in the simulation). Specifically I see "nodes" of low amplitude in the E field that are quickly "emitted" from the antenna and then slow down as they approach the far...
View full post »

Thread 'EMF (Electromagnetic Field) & EHS (Electromagnetic Hyper Sensitivity)'

Hello dear reader, a brief introduction: Some 4 years ago someone started developing health related issues, apparently due to exposure to RF & ELF related frequencies and/or fields (Magnetic). This is currently becoming known as EHS. (Electromagnetic hypersensitivity is a claimed sensitivity to electromagnetic fields, to which adverse symptoms are attributed.) She experiences a deep burning sensation throughout her entire body, leaving her in pain and exhausted after a pulse has occurred...
View full post »

Similar threads

Query about the time average of an AC power supply
Replies
2
Views
2K
Mystery Solved - Strange Phenomenon on PCB
Replies
4
Views
2K
How to find input signal formula
Replies
11
Views
2K
Explaining Light intensity with EM Field Oscillations?
Replies
7
Views
2K
Studying Preparing for Plasma Physics (Jackson)
Replies
4
Views
3K
Einstein@Home search for periodic gravitational waves in LIGO S4 data
Replies
20
Views
6K
The Embarrassing Simplicity of Light: A New Theory of EM
Replies
1
Views
3K
Medical NeuroQuantology another gem, hiding in plain sight
Replies
6
Views
3K
How bright is the future of Maglev Cars?
Replies
19
Views
11K
Particle / wave duality on a scale of light frequencies.
4
Replies
194
Views
24K

Hot Threads

Recent Insights

Back
Top