EMI, electromagnetic interference, is any electromagnetic disturbance that degrades performance, coupled by conduction along cables, by capacitive or inductive coupling between nearby conductors, or by radiation. Common sources are switching power supplies, motor drives, relay coils, digital clocks and radio transmitters. Cures include filtering, shielding, twisted pairs, ferrite cores and layouts with short, tight current loops.
Every time the welder strikes, the HMI freezes, classic EMI on the comms cable, reroute it away from the welding leads.
Also heard as
- electromagnetic interference
Related terms
EMC
Electromagnetic compatibility: a product neither upsets nearby equipment with its noise nor gets upset by theirs.
Common-mode
Describes signals or noise present equally, in the same phase, on both conductors of a pair relative to ground.
Ground loop
Unintended current path formed when connected equipment is earthed at points of different potential.
Crosstalk
Unwanted coupling of a signal from one conductor or channel into a neighbouring one.