Obviously it is not the logic circuits I am refering to! The front end of the
power supply has many types of scenarios that can cause high (30 MHz)
frequency emissions. To name a few. Switcher pulse risetime and fall-off. As
semiconductors get better adn smaller, their ft also better (to other
In a message dated 98-07-06 20:40:33 EDT, rbus...@es.com writes:
A test house explained to me that the FCC allows either CISPR or FCC
limits/procedures providing that one can determine worst case.
Consequently, you have to test both ways (120 V 60Hz or 230V 50Hz) to
determine which way you
; dwight.hunnic...@vina-tech.com;
emc-p...@ieee.org
Cc: eric.lif...@natinst.com
Subject: RE: Ce versus FCC
That's interesting. The change from 50 to 60 Hz would change some
input
components and that could effect the input impedance and hence the
conducted emissions signature
Your comment below is absolutely true. Manufacturers spend far too much
time and money obtaining certifications for so many countries that have just
minor differences in their standards. One standard for EMC/product safety
is too simple I guess.
Darrell
--
From:
-tech.com; emc-p...@ieee.org
Cc: eric.lif...@natinst.com
Subject:Re: Ce versus FCC
I have encountered certain European agencies requesting that not
only are the
conducted emissions required to be performed at 230V 50Hz but
radiated
emissions
To: dwight.hunnic...@vina-tech.com; emc-p...@ieee.org
Cc: eric.lif...@natinst.com
Subject:Re: Ce versus FCC
I have encountered certain European agencies requesting that not
only are the
conducted emissions required to be performed at 230V 50Hz
Dwight,
While pursuing a TCF route, this was discussed at length with our CB. The
frequency was of secondary concern to the line voltage. We tested with both
frequencies anyway because we can: it made no discernable difference to our
emission or immunity data..
Best regards,
Derek Walton
Thanks, Derek
These are all good examples of problems everyone can relate to.
A good domestic one from a colleague of mine recently was that when he
walked near a bathroom in his house while carrying his (FCC Class B)
laptop computer switched on (- he is a workaholic), and if someone was
bathing
PSTC emc-p...@ieee.org
Cc: eric.lif...@natinst.com eric.lif...@natinst.com
List-Post: emc-pstc@listserv.ieee.org
Date: Monday, July 06, 1998 4:45 PM
Subject: Re: Ce versus FCC
Eric-
You tossed in one line that brings up a parallel question for Europe:
Note that the FCC expects conducted
I have encountered certain European agencies requesting that not only are the
conducted emissions required to be performed at 230V 50Hz but radiated
emissions as well. I agree that for conducted emissions it may make a
difference but I have not seen radiated emissions change when the power source
Eric-
You tossed in one line that brings up a parallel question for Europe:
Note that the FCC expects conducted emissions to be
measured at 115 VAC, 60 Hz.
Has your experience indicated that all Euro EMC directive
(emissions/immunity) testing be conducted at 50Hz? Many local EMC labs
do not
Keith,
with over 18 years in EMC I could go on a long time. Some examples this year
already...
My computer ( FCC Class B ) interferes with my cordless phones, to some degree
on all 10 channels.
My FAX machine ( FCC Class B ) interferes with my TV and some channels of my
cordless phones.
Dear Derek and Brian
If you (or anyone else) have any examples of things that didn't work
well together for reasons of lack of adequate EMC I'd be pleased to
have some details of them. Also of things that didn't work well because
of their electromagnetic environment.
E.g just recently I heard two
Brian,
here is the US the manufacturer has is easy... But many things we buy don't
work well together!
Derek.
Eric
Top answer!
Regards
John Harrington
EMC Group Manager, KTL
Telephone : +44 (0) 1482 801801
Fax : +44 (0) 1482 801806
email : jharring...@ktl.co.uk
To: eric.lif...@natinst.com
Sent: Thursday, July 02, 1998 1:08 PM
To: Brian Harlowe
Cc: emc-p...@ieee.org
Subject: Re: Ce versus FCC
The FCC has the authority to mandate immunity for Part-15 devices, but
has declined
to do so. The exception is for consumer telephones
Hard to do in simple words but:
FCC -- many emissions requirements for digital products; lightning
immunity requirements for telecom (part 68).
EEC EMC Directive -- both emissions an immunity requirements; specifics
depend on the product. Suggest you look at a couple of these web pages
to get
Brian,
Here's the differences in a small nutshell:
FCC CE
Radiated Emissions x x
Conducted Emissions x x
Immunity x
There are differences in frequency and emission
Sorry, George, I beg to differ and to offer my two bits:
47CFR (Oct. 1, 1997) Para. 15.5 (b) states: Operation of an
intentional, unintentional, or incidental radiator is subject to the
conditions that no harmful interference is caused and that INTERFERENCE
MUST BE ACCEPTED that may be caused by
The FCC has the authority to mandate immunity for Part-15 devices, but has
declined
to do so. The exception is for consumer telephones and other telephone
equipment
under FCC Part-68 rules. But in general, noise immunity is practically
unregulated
in the USA.
The FCC expects industry to
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