A Basic Guide To EMC
stands for Electro-Magnetic Compatibility. If you use
your electric toothbrush and the shower radio crackles,
this is an example of two things not being electro-magnetically
compatible, but what is happening?
Electrical noise from
the toothbrush motor is being transmitted through the air
in the same way that signals are transmitted to your TV.
Wires and tracks within the shower radio act as tiny
aerials and pick up this signal which appears as a
crackling sound. To use the correct terminology, the
toothbrush is sending radiated emissions and
the radio has poor radiated immunity.
Another example is when
the washing machine launches into the final spin, wobbly
lines may appear on the monitor of your PC. What is
This time, the electrical
noise is being conducted through the mains.
Again the items are not electro-magnetically compatible,
but this time the problems are conducted
emissions and conducted immunity.
Fortunately, such events
are rare because the European Union insist that all
electrical and electronic goods meet the Electro-Magnetic
Compatibility or EMC standards, one of the many safety
standards associated with CE marking. It can be perceived
that these standards are an inconvenience, but there are
some compelling reasons why electrical equipment needs to
be compliant. For example, it would be unthinkable for a
life-support machine in a hospital to fail because
someone had selected hot chocolate from the
vending machine down the corridor.
Despite many of the
rumours you may have heard, there is nothing mystical or
magical about EMC. At Top Hex, our engineers come across
EMC every day and we will work with you to ensure that
your product is compliant.