Appendix 4 Countermeasures Against Incorporation of External Noise
A6
Pass the power cord through a commercially available EMI suppression ferrite core and secure the core as
close as possible to the AC power inlet of the unit in order to suppress the incorporation of noise from the
power line.
Suppression is even more effective if you also attach an EMI suppression ferrite core close to the power plug
of the power source.
If a toroidal ferrite core or split ferrite core with a large enough internal diameter is used, the amount of noise
suppression can be increased by passing the power cord through the core several times.
EMI ferrite cores and ferrite beads are commercially available from various specialist manufacturers.
If interference is producing noise in the measurement cables, its influence can
be moderated by the following countermeasure.
Pass the test cables through a commercially available anti-interference ferrite core, and fix it close to the mea-
surement terminals, so as to suppress noise from the measurement cables.
Moreover, if the internal diameter of the ferrite core allows, winding the measurement cables several times
around the ferrite core (as with the power cord as described above) may further reduce the amount of noise.
Attaching an EMI Suppression Ferrite Core to the Power Cord
Appendix4.2 Countermeasures Against Noise from the
measurement Cables
Fitting an anti-interference ferrite core on the measurement cables
Anti-interference ferrite core
To Next Page
Loading...
