When choosing transient suppression for power line input to equipment, what
are the choices (MOVs, silicon TVS, glass discharge tubes, others) and what
are the trade-offs? Thank you.
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Mirko,
I happen to have a copy of CISPR 16-1 at hand. Clause 16.6 Open area site
validation procedure reads:
... The deviation between a measured NSA value and the theoretical value shall
not be used as a correction for a measured EUT field strength. This procedure
shall be used only for
That will work, but the electrical length of the tail will change due to
the inductance of the coil you're winding... This method has been used
to produce shorter antenna elements in the HF (3-30MHz) region with some
success; however, shorter antenna elements generally also mean loss rather
Seems to me it can be almost anything -- AM broadcast stations in the US
range from a few hundred watts to 10kW could be much higher (and
probably is) in some contries like Mexico.. I've been out of this
business for a while, but I remember FM and TV broadcast radiation being
listed as
Forwarding for Mike. Jim
Reply Separator
Subject:Re: electronics used in refueling
Author: miksher...@aol.com
List-Post: emc-pstc@listserv.ieee.org
Date: 01/11/00 3:42 PM
In a message dated 1/10/2000 11:06:09 AM Central Standard Time,
try www.jargonbuster.com
Best Regards,
Jerry Roberton
NET Europe Ltd
Jim Bacher wrote:
forwarding for DEWASTHALEE... Jim
Reply Separator
Subject:RE: What is Fire-wire?
Author: PRDEWASTHALEE priyawrat.dewastha...@wipro.com
Date:
Hi,
Yes, you need three or more layers of pre-preg in between the SELV and
MAINS traces.
Ned Devine
Entela, Inc.
Program Manager III
Phone 616 248 9671
Fax 616 574 9752
e-mail ndev...@entela.com
-Original Message-
From: Andrews, Kurt [mailto:kandr...@tracewell.com]
Sent: Tuesday,
Paul,
UL6500 2nd edition requires that decorative parts meet any of the following
flame ratings:
HB, V-2, V-1, V-0, HBF, HF-2, HF-1, HF-0, VTM-2, VTM-1, VTM-0
(Reference Table 13)
I hope this is helpful.
Mat Aschenberg
-Original Message-
From: Paul Smith [mailto:phsm...@excite.co.uk]
David,
You may try http://n5xu.ae.utexas.edu/rfsafety/;.
Barry Ma
Anritsu Company
Morgan Hill, CA
- Original Message -
From: David Monreal
To: emc-p...@majordomo.ieee.org
Sent: Tuesday, January 11, 2000 5:14 AM
Subject: Radiation levels.
Hi all!
Could anyone tell
Ned,
You wrote: For example, you can have SELV over Mains if you have
three or more layers
of pre-preg. You also would not have to do any type or routine
testing.
Does this mean 3 layers in between the SELV and the Mains layers i.e.
Mains-layer of pre-preg-layer of
Hello All,
My company is selling a used HP8568B spectrum analyzer that we no longer need.
It is in excellent condition and we are asking $11K or will consider the best
offer.
If interested, reply directly to Ed Nakauchi at e...@garwoodtestlabs.com
Ed Nakauchi
Director EMI/EMC Consultant
Richard,
You could improve correlation by adjusting chamber antenna factors for a
correlation differences which you can get from NSA measurements one at OATS
the other in the chamber with a fixed antenna height. You could also
determine correlation differences by comparing measured field
David,
Measured 3 to 7 V/m around and inside a building that is within 200-300 feet
of the 10KW AM station's three towers. The towers are phased and the
amplitude you measure will change based upon time of day as the station
changes that phasing.
Amplitude is greatly affected by materials,
The FCC has records of field strength for broadcast stations (at least
AM radio stations) in terms of V/m @ 1km. They're on record at their
web site.
Typical values for the AM radio stations near me range from
200-1000mV/m @ 1km. Due to power levels antenna style, the results
may vary widely.
We have a compact 3 meter semi-anchoic chamber which is not suitable for
official final emissions testing due to its compact size. Nevertheless, we
have found the radiated emission results in the chamber are within +/- 6 dB
of what we find on the OATS. I would like to reduce that difference to
In a previous life in the UK I was involved in this sort of thing
associated with oil rigs.
As I remember the hazards were broken down into 3 groups
1) Equipment continually in contact with the explosive gas
2) Equipment that would come into contact if there was a leak
3) Equipment that was some
The meeting is open to everyone and is free of charge.
Some food and drinks are offered for purchase prior to
the meeting.
visit our website for driving directions.
www.scvemc.org
=
Best Regards
Hans Mellberg
EMC Consultant
__
Do You
According to the BBC transmitter information site
http://www.bbc.co.uk/info/reception/tvpb/index.shtml
the maximum ERP for
1) A TV transmitter is 1000kW (Crystal Palace and others)
2) An FM transmitter is 250kW (Wenvoe and others)
3) A MW/LW transmitter is 500kW (Droitwich)
Transmitters
I don't hve a copy of this standard but hopefully somebody out there will and
might be able to help.
Can I presume that decorative parts of equipment enclosures tested to UL6500
need to meet UL94 HB as a minimum or is there anything less stringent?
I only ask as I'm sure somebody has told me in
Hi,
Be careful. Through insulation does not necessary mean 0.4 mm. It can be
thin sheet material. See UL 1950, Table 6A and IEC 60950, 3rd edition,
Table 2M for requirements for printed wiring boards.
For example, you can have SELV over Mains if you have three or more layers
of per-preg.
Roger,
Most of this problem occurs from the Latin M= 1000
and the Greek K=1000 What came later just confused the issue- is this an
example of a decision
by committee(s) ?
Ralph Cameron
- Original Message -
From: roger.vi...@wwgsolutions.com
To: emc-p...@majordomo.ieee.org
Sent:
David:
The field strength at any given point remote from the antenna system can be
quite variable and depends on power output, antenna pattern, height of antenna
above ground (TV) and whether you're in the near or far field. I've seen
levels of 200V/m 200 ft from a 50Kw broadcast array
Ned and emc-pstc'ers,
After reading the clauses you mentioned it appears that the UL Engineer was
a little off base. You are correct that internal PCB layers can be treated
as distance through insulation. In fact both standards specifically state
that internal PCB layers are done this way (you
The only answer I know is that AM broadcast stations are limited to 50 kW
ERP, while FM broadcasts are limited to 100 kW ERP. I don't know the limit
for broadcast TV, or whether it varies between VHF and UHF stations.
Regardless, you must specify the distance from the transmitting antenna(s)
in
Fellow Listmembers,
I have a question regarding tiger tails used to improve transmission
characterisics of a hand-held transmitter (HHT). The HHT is basically a
dipole, with the chassis as the bottom element. The tiger tail is a
quarter-wave length of wire that connects to the shell of the
The directives can be found at
http://europa.eu.int/comm/dg03/directs/dg3b/newapproa/eurstd/harmstds/reflis
t.html
http://europa.eu.int/comm/dg03/directs/dg3b/newapproa/eurstd/harmstds/refli
st.html
including any amendments.
Richard Woods
--
From: peterh...@aol.com
forwarding for DEWASTHALEE... Jim
Reply Separator
Subject:RE: What is Fire-wire?
Author: PRDEWASTHALEE priyawrat.dewastha...@wipro.com
List-Post: emc-pstc@listserv.ieee.org
Date: 01/11/00 10:00 AM
Hi,
You might like to take a look at this:
Hi all!
Could anyone tell me the radiation levels (V/m) generated by broadcast
antennae? (Radio and TV). I also need the radiation levels for any other
emmitig devices, machinery, GSM antennae, power cables, etc. The more
information the better.
Thanks a lot :-)
David - The V/m guy
The full list of EU legislation in force can be found at:
http://europa.eu.int/eur-lex/en/lif/index.html
Be warned - this is everything the EU currently has in force,
including agricultural, social and other matters. CE marking and
product safety in general only forms a (very) small part of
On a custom luminaire to a ballast we need to use high voltage cables as the
strike voltage is in the region of 4kV albeit for a momentary time whilst the
lamp strikes. IF we used cable rated (individual conductors) for 4kV, what
should we use for a shroud around all the conductors?
I've
Thanks to all who made their comments following my complaint about the misuse of
K for 1000. Maybe a final word about this problem!
The IEC (even more pedantic!) are attempting to fix this by creating a new set
of units for binary multiples (Amendment 2 to IEC International Standard IEC
Hi all!
Could anyone tell me the radiation levels (V/m) generated by broadcast
antennae? (Radio and TV). I also need the radiation levels for any other
emmitig devices, machinery, GSM antennae, etc. The more information the better.
Thanks a lot :-)
David - The V/m guy
attachment: David
Hello All,
For UL (but may be interpreted differently by other agencies), a PWB
investigated to the PWB Component standard is treated as a Component and
there are no additional requirements for internal (ie interlayer) creepages
other than meeting the min. 0.4 mm distance through insulation
Hi Robert,
Try PC World Online for a good primer.
http://www1.pcworld.com/heres_how/article/0,1400,14371,00.html
Regards Matt
Heard of this high speed interface?
Anybody know about it?
Need information, please.
Something about IEEE1394
Is the cable defined *very* well? like
Hello and happy New Year to all,
Could someone let me know where I can obtain the latest revision of various
European directives please? Are they available on www?
Thank you
Peter
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Robert Macy wrote:
Heard of this high speed interface?
Anybody know about it?
Need information, please.
Hello Rob,
FireWire is based on the IEEE 1394 protocol, a high speed (up to 400
Mbps) serial digital interface intended for interconnecting real time
digital video and high speed
Heard of this high speed interface?
Anybody know about it?
Need information, please.
Something about IEEE1394
Is the cable defined *very* well? like CAT-5?
- Robert -
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