I'll second the experience with 85 Volts design target, which can be very
common.
The normal business practice for Japan (at least 8+ years ago) was to turn
off power to an office complex Friday night, turn it back on Monday morning
- this was shown as a huge dip on the distribution network, not
Eastern Japan Voltage 100 Vac @ 50Hz. (Tokyo, Kawasaki, Sapporo, Yokohoma
and Sebdai)
Western Japan Voltage 100 Vac @ 60Hz. (Osaka, Kyoto, Nagoya, Hiroshima)
I also agree with Tania and the brown-out conditions that exist in Japan.
It is my understanding that 90 Vac is quite common,
Mark,
Please pardon my ignorance. I have a silly question.
It seems to me that the purpose of brownout is to save
energy by reducing voltage. Why do you test your power
supply down to 85 Vac at 50/60 Hz at the maximum
specified operating temperature with high humidity
conditions present instead
Barry,
Brownout is a fault condition. Alot of switching supplies operate in a range
of 100 - 240 Vac 50/60 Hz. Supply Manufacturers usually specify operating
temp and humidity conditions. So start by testing the Manufacturers own
specification. 106 Vac already falls into the specified range.
Sorry, I just forgot inputting the subject.
-- Original Text --
From: Bailin Ma@MMDILAB@ACUS, on 11/4/99 1:28 PM:
Scott,
Thank you very much.
Barry
--
From: Lacey,Scott sla...@foxboro.com, Date: Thu, 4 Nov 1999
14:52:57
-0500
Barry,
In a
Disagree. A switched mode power supply (SMPS) will draw more current at low
bus potential to provide constant load output power.
--
From: Bl Ma mbl...@yahoo.com
To: mschm...@xrite.com
Cc: EMC/PS IEEE Group emc-p...@ieee.org
Subject: RE: 90V 47Hz - Is this a realistic combo
Date: Thu,
With regards to the question at end of Macy's e-mail. Count the number of
squares between probe points. Say the probes are 2 apart. If the surface
containing the two points is at least 2 wide, then it only takes one
square, and the resistance measured is numerically equal to the ohms/square.
The recent loss/disaster in space surprises me no longer
-Original Message-
From: Andrews, Kurt [SMTP:kandr...@tracewell.com]
Sent: Thursday, November 04, 1999 10:24 AM
To: pmerguer...@itl.co.il; emc-p...@majordomo.ieee.org
Subject: RE: Fans; m3/h to CFM
Peter,
1ft.
1m^3/ 1 hr * 1hr/60 min * (39.37 in)^3/1m^3 * (1 ft)^3/(12 in)^3 = 0.5886
cubic feet/minute.
Check me out gentlemen. I work for NASA. You don't want your fan crash
landing on Mars!
--
From: pmerguer...@itl.co.il (Peter Merguerian)
To: emc-p...@majordomo.ieee.org
Subject: Fans; m3/h
Note: forwarded message attached.
=
__
Do You Yahoo!?
Bid and sell for free at http://auctions.yahoo.com---BeginMessage---
Check this out quickly and respond!
I am forwarding this because the person who sent it to me is a very
Ken, agreed
-Original Message-
From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Thursday, November 04, 1999 12:49 PM
To: Westin, Amund; 'emc-pstc'
Subject: Re: Emission / Enclosure
My opinion: From 30 - 1000 MHz the material is not as important as the
treatment of seams and
In addition to all this, the hipot tester may not be capable of providing
the current necessary to drive the voltage up to the test level. Example, I
had a product with a power supply that required 54 mA to drive the test
voltage to 1.5kV AC. The tester could only source 39 mA and so would cause
Scott,
Thank you very much.
Barry
--
From: Lacey,Scott sla...@foxboro.com, Date: Thu, 4 Nov 1999
14:52:57
-0500
Barry,
In a switchmode supply, the primary side dc voltage = 1.414 times the rms
value of the ac input. This is then switched (at 100kHz or
Peter and fellow EMC-PSTC members,
It seems I made a major mistake in my calculations in the email I sent out
earlier. I made a mistake in the third line when I said that 1cu.ft./min. =
1.699008 m3/min. Here are the corrected calculations:
1ft. = 0.3048m then 1 cu.ft. = (0.3048m)3 =
My opinion: From 30 - 1000 MHz the material is not as important as the
treatment of seams and apertures.
--
From: Westin, Amund amund.wes...@dnv.com
To: 'emc-pstc' emc-p...@ieee.org
Subject: Emission / Enclosure
Date: Thu, Nov 4, 1999, 6:18 AM
Members,
I looking for persons who
Its not possible to get FCC approval for a Network Interface
transformer...Perhaps an FCC approved DAA could be purchased, but not the
transformer.
While the transformer is a critical component, the whole modem need to be
approved...I believe that the transformer would be listed as a critical
Peter,
1ft. = 0.3048m then 1 cu.ft. = (0.3048m)3 = 0.0283168m3 and
1ft./Sec. also equals 0.3048m/Sec.
so then 1cu.ft./Sec. = 0.0283168m3/Sec.
so then 1cu.ft./min. = (0.0283168m3/Sec.) x (60Sec./min.) = 1.699008
m3/min.
so then 1cu.ft./min. = (1.699008 m3/min.) x (60min./hr.)
Peter,
1 m^3/H = 0.5885778 f^3/m (CFM)
-
Robert L. Mavis
Agency Compliance Coordinator
Engineering Department,
Compliance Engineering Group
Pelco
300 W. Pontiac Way
Clovis, CA 93612
Phone: (559) 292-1981 x2309
Toll Free: (800) 292-1981 x2309
Fax:
Here is one way to make a rough measurement:
Take a coated surface. Take a knife and carve a 3 x 1 plated area on the
surface.
Use a DMM to verify that the isolated rectangular surface is electrically
separate
from the rest of the plating. Cut 2 pieces of copper foil into 1 x 1 square.
Solder
CKC in Mariposa (and other locations) comes to mind (Chris Kendall
Consultants). Chris and Roger McConnell of CKC were involved in the
committee work that generated the D rev to DO-160.
--
From: Campi, Mike mca...@fpc.fujitsu.com
To: 'EMC/PSTC' emc-p...@ieee.org
Subject: DO-160D
Hi Peter,
1 cubic meter per hour = 0.59 cfm
(Determined from 1 m3/1 hour X 1 hour/60 minutes X 35.3 ft3/1 m3)
Rick Cooper
Sr. Project Engineer
MET Laboratories, Inc.
410-354-3323 Ext. 331
http://www.metlabs.com/
-Original Message-
From: pmerguer...@itl.co.il
In my experience with these coatings the choice of material for EMI puposes
doesn't matter that much. Nickel or copper work just fine. I have seen
30db attenuation based on the coating alone. The are some other problems
with safety/reliability, and material selection is important.
Select
Hello There!
Anyone knows how to convert m3 (ie meters cube)/hour to CFM? To serve my
clients better so they can use alternate dc fans, I usually specify in the
UL Reports the use of Recognized fans rated XXX Vdc, max --- A, minimum ---
CFM. However, I just looked up a spec sheet for a dc fan
Some other issues regarding safety - if your product is UL Listed or
Certified the conductive coating will need to be listed in the UL Plastics
Recognized Component Directory as well as the applicator of the conductive
coating and the supplier of the raw plastic material. I had the experience
of
Members,
I looking for persons who have experience in use of aluminum vs.
metallic plastic enclosure. The enclosure is typically 5cm X 10cm.
Which configuration will reduce emission ? Has somebody compared the
configuration in practical tests ?
Best regards
Amund Westin
Det Norske Veritas
*
Hello from Tel Aviv Everyone!
Well, simple question for those machinery experts out there. The standards
requires a 1000 VAC Dielectric Strength Test between Live Hazardous Parts
and Earth. Can a dc potential at 1.414 of this ac potential be applied
instead (ie 1414 Vdc). There are many machines
On 3 Nov 99, at 10:13, Jim Eichner wrote:
Eric: I was referring to the metric.htm file that was attached to one
of the posts in this thread. The file is from Western Tube and is
partially reduced below:
Trade Size Designator Outside DiameterWall Thickness
NPS Metric
Statutory Instrument 1994 No. 1768
The additional terminology of ordinarily intended for domestic use
may have been an unfortunate use of words that have clouded the issue
rather than clarify the definition.
(they only do it to give newsgroups something to talk about)
Certainly the
A small pedantic point here:
Coatings are usually rated in ohms per square which is dimensionless.
Looking at the resistance formula:
R = rho * length / Area = rho * length / ( width * thickness )
Given fixed rho and fixed thickness (of the coating) you can see that you're
left
Hello group,
I strongly suggest changing a version number. As a test house we always
oblige our customers to change their version number on every modification
that justifies TCF changements. Most of the time this is done by adding a
character A-Z or A1-Z9 to cover for many variations, and most
Don:
One thing that hasn't been mentioned so far is that you should place your
room ground stud as close as possible to the powerline filters. If your room
is a modular design (and not double electrically isolated), then the room is
actually an assembly of conductive panels with clamp plates
There are many different types of conductive coatings available. Silver paint
is
very conductive, less than 5 ohms per square inch. But it is not as scratch
resistant
as sheet metal surfaces. Electroless copper / nickel plating is very
conductive and
durable. You can get as low as 1 ohm per
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