Switching load and EMC

at 50 Hz flicker will that scare away mice? the 15 ns rise time will certainly fill the AM band with a 50 Hz buzz if pointed in the direction of the loop. How far away depends on how weak the AM radio signal is. It takes more than this to measure field strengths.

"Normally" one uses a spectrum analyzer and a calibrated antenna (its gain) to
do radiated emissions testing. Ground effect an important component of doing
this. The FCC web site has some recommendations for measuring process.

Conducted again the spectrum analyzer, calibrated for load/line situation you
are working in.

For the novice there are experienced consultants in this area, for measurement and
design recommendations. If I am not mistaken now there are FCC certified consultants
that can do testing for submission and their results (passing specs) taken as passing
by FCC (you need to check out this and its conditions).

When you do the submission and get exam date I recommend you send an engineer to
be in attendance, the FCC can also be helpful there. Or if using consultant EE be present
when work is done. Its an art, EMC and EMI design.

There are some simulators out there, unfortunately in my time not available, so I cannot
comment on their effectiveness.


Regards, Dana.

danadak said:

If I am not mistaken now there are FCC certified consultants
that can do testing for submission and their results (passing specs) taken as passing
by FCC (you need to check out this and its conditions).

When you do the submission and get exam date I recommend you send an engineer to
be in attendance, the FCC can also be helpful there.

Click to expand...

You're rather assuming everyone is in the USA?, that's only one of the countries in the world, and the only one where the FCC has any relevance.

The OP is in the UK, where OFCOM is the relevant authority.

Nigel Goodwin said:

You're rather assuming everyone is in the USA?, that's only one of the countries in the world, and the only one where the FCC has any relevance.

The OP is in the UK, where OFCOM is the relevant authority.

Click to expand...

And you are assuming the only country they will sell in is UK ?

Worlds 1'st or 2'ond largest marketplace ? USA that is.


Sigh.....

Tony Stewart said:

at 50 Hz flicker will that scare away mice? the 15 ns rise time will certainly fill the AM band with a 50 Hz buzz if pointed in the direction of the loop. How far away depends on how weak the AM radio signal is. It takes more than this to measure field strengths.

Click to expand...

Using an AM radio between channels as a spectrum analyzer here would allow me to compare brushed motor handtool noise on products that pass with this product at similar distances for self certification if documented with spectral data for any certified device. For you, it allows you to test out cheap solutions like 1kohm CM chokes at 1MHz or lossy high mu ferrite with many turns of both wires and 100 pF output after torroid CM choke.

Tony Stewart said:

Using an AM radio between channels as a spectrum analyzer here would allow me to compare brushed motor handtool noise on products that pass with this product at similar distances for self certification if documented with spectral data for any certified device. For you, it allows you to test out cheap solutions like 1kohm CM chokes at 1MHz or lossy high mu ferrite with many turns of both wires and 100 pF output after torroid CM choke.

Click to expand...

We also tested in a poor mans Faraday cage. It was companies first venture into TV
games and we were all treading in new waters. We had bets with Atari who said we
could not pass FCC first time, we did, very satisfying .

Regards, Dana.

Flyback, did not realize you are UK based.

Love UK, will be visiting again, soon. Churchill, Montgomery, Queen Elizabeth, some of my heroes.

Visited Churchills home years ago. Read most of his books. Have his speeches on
laptop, I listen to them occasionally. British Museum, and the War museum (Bedlum ?), could
live in them for awhile.

Your Moniker, and postings, leads me to believe you have a lot of expertise in
DC/DC, an area I am lacking in, especially magnetics.


Regards, Dana.