Intercom doorbell electromagnetic EMC solution

When the visual intercom system conducts the space (RE) radiation test EN55022 standard, the radiation exceeds the limit and cannot pass the test.It pass the test after the EMI filter process.

Test Data-Before rectification:

Test Data-After rectification:

Solution:

The clock crystal vibration series RU filter performs a narrow-band noise attenuation treatment, reducing its emission intensity.

The broadband noise of the power supply line is suppressed when using EMI power filter.