Re: modest proposal -> unl at unu.edu
There is already a project running that will address item 1)of the mail shown below: http://www.unl.ias.unu.edu/ As the central concept of this project seems to be about grammar, it will probably not be able to fulfil the requirement of item 2)of the mail shown below. Learning vocabulary is learning facts, that might be done during sleeping (with a tape-machine running under the pillow). Grammar in my opinion is more a concept, a thing of logic. For learning grammar you probably have to be awake. Regards Rene Charton Barry Ma on 03/28/2000 08:07:25 AM Please respond to Barry Ma To: emc-p...@ieee.org cc: "Lou Gnecco" (bcc: Rene Charton/TUV-Twn) Subject: Re: modest proposal Hi Lou, There must be some day in the future, the artificial intelligence has been so well developed that (1) An instant interpreting machine built-in to your PC would automatically transfer any language you input (either typed or voiced) to any languages the other party would like to have. (2) Learning foreign language is a very pleasant process and can be completed in very short period of time even when you are in sleep. ... :-) Best Regards, Barry Ma b...@anritsu.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Ambient Cancellation Device for OATS - Dual Channel Spectrum Analyzer
Hi Cortland, I agree that if you want to get successful cancellation of ambient by mixing an negative ambient signal to the measured signal you need an exact adjustment of amplitude and phase. And here lies the problem. Is there a spectrum analyzer in the market that has two channels, or that makes it possible to couple two analyzers in a way that -- - the oscillators are coupled, and the phase relation can be adjusted - that can perform a substraction of the two IF Amplifier outputs, and feed this signal to the demodulator You say that there are two other methods apart from what CASSPAR suggests. Please can you let me know what the two other methods are. Thanks in advance Kind regards Rene Charton Cortland Richmond <72146@compuserve.com> on 03/24/2000 12:26:55 AM Please respond to Cortland Richmond <72146@compuserve.com> To: Doug , ieee pstc list cc:(bcc: Rene Charton/TUV-Twn) Subject: Re: Ambient Cancellation Device for OATS Basically, one combines the ambient, a signal whose amplitude is not dependent on distance from an EUT, in the correct phase and amplitude, with the signals received by an antenna on the OATS. There are at least three ways (counting CASSPER) this can be done, ranging from the technically sophisticated to the technically ridiculous (but still effective). What you pay for in using a technically sophisticated method is speed of testing and reliability - it is less dependent for its effectiveness on the tech or engineer doing the test. What you pay for simplicity, is awkward and time-consuming set-up which requires much more of a tech or engineer. Plus, regrettably, people are more apt to believe your results if it takes a lot of equipment to achieve them. (sigh) Cortland == Original Message Follows SNIP List-Post: emc-pstc@listserv.ieee.org Date: Wed, 22 Mar 2000 23:38:20 -0800 From: Doug Subject: Re: Ambient Cancellation Device for OATS Reply-To: Doug Perhaps it's because I've never understood ... How exactly does one do ambient cancellation at an OATS? UNSNIP --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Certification of Products and other emerging countries
Dear Charles, REGARDING: ..the emerging countries have been very erratic in the implementation and enforcement of EMC legislation... The emerging countries are quite numerous, can you come up with some actual examples? "Grasso, Charles (Chaz)" on 03/22/2000 02:43:36 AM To: Rene Charton/TUV-Twn@TUV-Twn, Kevin Newland cc: emc-p...@majordomo.ieee.org Subject: RE: Russian Certification of Products and other countries It has been my experience that - with the exception of the EU and Aus/Nz - the emerging countries have been very erratic in the implementation and enforcement of EMC legislation. Rene, I must disagree with your comment regarding scheduled implmentations. Putting incomplete EMC enforcement/legislation in to force on schedule is NOT good planning. Kudos to the EMC Framework - that EMC legislation was advertised and compliance methods available well before the required date. If only it were true universally... -Original Message- From: r...@twn.tuv.com [mailto:r...@twn.tuv.com] Sent: Wednesday, March 15, 2000 5:34 PM To: Kevin Newland Cc: emc-p...@majordomo.ieee.org Subject: Re: Russian Certification of Products and other countries What about Japan, Australia&NewZealand, South Africa, Argentina, Mexico... In many Asian Countries (Taiwan, China, Korea, Hongkong.) rules are just being set up. This implies that there are frequent changes, but not on daily basis. And changes are implemented according to a schedule. Can you show me a similar schedule for the "stock exchange"? If you can, I will change my Job immediately. Rene Charton Kevin Newland on 03/16/2000 06:59:11 AM Please respond to Kevin Newland To: "Maxwell, Chris" , "'EMC-PSTC Internet Forum'" cc:(bcc: Rene Charton/TUV-Twn) Subject: Re: Russian Certification of Products Chris, Just remember that with the exception of Western European countries,USA and Canada, the rest of the world (without being rude) have not really have a solid rule for anything. These countries rules and regulation changes daily (just like stock exchange) without any notice or explanation). This is sadly the real life and we live in it. Thanks Kevin --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Dithered clocks and EMC - BEWARE
I never used SSCG, but following the thread, my humble opinion is the following:
If the interference just comes from the oscillator, it is feasable that the use
of a SSCG will even increase the interference, as the circuit elements inside
the SSCG that create the clock signal will also have a current consumption that
will contribute to the interference emanating from the clock generator.
You will probably get better results from the use of a SSCG, if the interference
not just comes from the oscillator itself, but mainly from the circuits driven
by the SSCG.
-
Keith Hardin (in the mail shown below) wrote:
... The output spectrum is a series of stationary harmonics spaced at 30kHz
apart
To my understanding, SSCG produce a FM modulated clock. I dimly remember that FM
does not produce a series of stationary harmonics spaced at the modulation
frequency, but the harmonics change dependent the modulating signal.
-
I think the SSCG does not fool the QP Detektor, it fools the bandwidth of the
test receiver. The effiencency of fooling depends not only on the modulation
frequency, but also on the frequency offset. In the example, where the use of
the SSCG did not help to reduce interference from the second harmonic, the
frequency offset was probably less than 60kHz ("peak to peak")
-
For analog TV you will minimize the perception of interference on the screen if
the modulation frequency of the SSCG is 39kHz or 55kHz, as these frequencies
have the maximum offset from the line frequency harmonics.
Furthermore, for analog TV the assessment of the level of acceptable
interference is decided by the eye and the brain of the beholder.
In digital TV it is decided by the software on the chip, and that these days is
still inferior to the brain of a beholder.
Where I live, there is no digital TV available. Maybe digital TV is not suitable
for a terrestial air link.
Dipl.-Ing. Rene Charton
Manager
EMC Services
_
TUV Rheinland Taiwan Ltd.
TAIPEI HEAD OFFICE
Spring Plaza Building
14F, No.6, Min Chuan E. Rd., Sec. 3,
Taipei 104, Taiwan, R. O. C.
Tel. (02) 2516 6040 Ext. [ 086 ] e-mail: r...@twn.tuv.com
khar...@lexmark.com on 03/18/2000 03:30:51 AM
Please respond to khar...@lexmark.com
To: emc-p...@ieee.org
cc: m...@california.com, sla...@foxboro.com (bcc: Rene Charton/TUV-Twn)
Subject: RE: Dithered clocks and EMC - BEWARE
Scott,
Sorry to hear about your experience but we have had great success using Spread
Spectrum Clock Generation (SSCG) since 1994 and have shipped many millions of
units.
Most PC's built over the last 2 to 3 years also use this technology.
For back ground information, see http://www.lexmark.com/sscg/ and
http://developer.intel.com/ial/scalableplatforms/sdt.htm. Included in this
information
is what SSCG is and its effects on some other devices. I suggest one read these
references as a basis for further discussions.
Experimental data has clearly shown is that the QP and Peak readings are
exactly the same for SSCG signals (No Fooling). An SSCG output properly
designed will create
a clock that is frequency modulated at ~30kHz. The output spectrum is a series
of
stationary harmonics spaced at 30kHz apart.
Finally, this method will attenuate the clock and system as compared to the same
system
with the modulation turned off. All other EMI reduction techniques will also
reduce emissions further.
Our design philosophy is to bring all good low cost techniques to bare on
reducing the emissions
and SSCG is just one of them.
Keith Hardin
Lexmark International
For the last time this came up, please see the append on the emc-pstc archives
at http://www.rcic.com/ with subject "Clock Oscillator &Re: Spread spectrum
clock oscillator (1) 20-Feb-97 ".
slacey%foxboro@interlock.lexmark.com on 03/17/2000 11:18:46 AM
Please respond to slacey%foxboro@interlock.lexmark.com
To: macy%california@interlock.lexmark.com
cc: emc-pstc%ieee@interlock.lexmark.com (bcc: Keith Hardin/Lex/Lexmark)
Subject: RE: Dithered clocks and EMC - BEWARE
Robert, and the group,
Although I have only limited experience (1 instance) with dithered clocks, I
thought that I might share that experience with the group. I had a product
that was failing radiated emissions at one particular frequency with a
vertical antenna orientation. I tracked the problem down to a particular
cable and circuit card. Use of a near field probe identified the oscillator
package as the source of the emissions (the second harmonic).
The device was located near the card edge, insufficient decoupling, etc. All
the textbook layout errors. A check of the oscillator specifications showed
that it was a standard TTL device with a fanout of 10 inputs. I had already
found some fixes that would reduce emissions, clamp-on ferrites, additional
shielding, etc., but thought it made more sense to reduce the emissions at
the source. I suggested to the design engineer that a lo
Re: Russian Certification of Products and other countries
What about Japan, Australia&NewZealand, South Africa, Argentina, Mexico... In many Asian Countries (Taiwan, China, Korea, Hongkong.) rules are just being set up. This implies that there are frequent changes, but not on daily basis. And changes are implemented according to a schedule. Can you show me a similar schedule for the "stock exchange"? If you can, I will change my Job immediately. Rene Charton Kevin Newland on 03/16/2000 06:59:11 AM Please respond to Kevin Newland To: "Maxwell, Chris" , "'EMC-PSTC Internet Forum'" cc:(bcc: Rene Charton/TUV-Twn) Subject: Re: Russian Certification of Products Chris, Just remember that with the exception of Western European countries,USA and Canada, the rest of the world (without being rude) have not really have a solid rule for anything. These countries rules and regulation changes daily (just like stock exchange) without any notice or explanation). This is sadly the real life and we live in it. Thanks Kevin --- "Maxwell, Chris" wrote: > > Our sales people in Russia have started the process > of "Certifying" our > equipment to sell in Russia. The two agencies that > they are working with > are "Gosstandart" and the "Ministry of > Communication". > > According to them, the certification will consist of > an inspection of all of > our existing Compliance Documentation including > ISO-9000 certification, EMC > Test Data (for the products of interest), Safety > Test Data (for the products > of interest), Environmental Test Data including > heat, frost, moisture, > vibration, and blow (what is that?) along with other > inspections of our > calibration equipment and methods. We are also > being asked to pay for a > trip to the US for 3 people from the Ministry of > Communication and > Gosstandart (6 people total) for 7 days each. > > The total is a staggering $44,000 (either cash or > wire transfer). Note > that all of the actions being performed for this are > "inspections" of > existing documentation, not actual testing. So in > the end, they will > decide to certify our products based upon existing > documentation, testing... > I have never experienced this before. It appears to > be a great deal of > expense for not much substance. Is this typical? > Has anybody else out > there certified products with these agencies? > > By the way, we typically classify our product as > "light industrial test and > measurement equipment" and already have solid > testing and documentation to > to EN 61326-1 (EMC), EN 61010-1 (Safety) and EN > 60825-1 (Laser Safety). > Does this give us any kind of out? > > Chris Maxwell, Design Engineer > GN Nettest Optical Division > 109 N. Genesee St. > Utica, NY 13502 > PH: 315-797-4449 > FAX: 315-797-8024 > EMAIL: chr...@gnlp.com > > > > --- > This message is from the IEEE EMC Society Product > Safety > Technical Committee emc-pstc discussion list. > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Jim Bacher: > jim_bac...@mail.monarch.com > Michael Garretson: > pstc_ad...@garretson.org > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > > > __ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Surge Testing per EN 55024/EN61000-4-5
In the Test-Setup Section, Conditions during Testing of EN 55024 it is said: Test should be made in the most representative mode. To my understanding, in the present days most ITE Equipment and Peripherals comes with a 3-prong plug, i.e. it is grounded. So, if the EUT has external ports intended to be connected to ITE Peripherals , Surge Testing should be done Line to Ground, with the secondary side of the Equipment Grounded, or with a Grounded ITE Peripheral connected. Dipl.-Ing. Rene Charton Manager EMC Services _ TUV Rheinland Taiwan Ltd. TAIPEI HEAD OFFICE Spring Plaza Building 14F, No.6, Min Chuan E. Rd., Sec. 3, Taipei 104, Taiwan, R. O. C. Tel. (02) 2516 6040 Ext. [ 086 ] e-mail: r...@twn.tuv.com Please respond to "Jim Hulbert" To: emc-p...@ieee.org cc:(bcc: Rene Charton/TUV-Twn) Subject: Surge Testing per EN 55024/EN61000-4-5 Colleagues, EN 55024 calls for surge pulses to be applied line-to-line and line-to-earth on the AC mains port and line-to-ground on signal and telecommunications ports that connect directly to outdoor cables. However, if my EUT is encased in plastic covers and has no direct earth ground connection (class 2 power supply), is the line-to-line test on the AC mains the only surge test that I need to apply? It seems to me that performing a line-to-earth test on either the AC mains port or on signal/telecommunications ports is not warranted since the basic standard EN 61000-4-5 does not specify placing the EUT over a reference ground plane. With no reference ground plane and no direct ground connection how can a test be applied with respect to ground? Jim Hulbert Pitney Bowes - This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list adminstrators: Jim Bacher: jim_bac...@mail.monarch.com, or Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Common Mode or Differential Mode
EN 55 022:1998, in the Appendix shows ISNs which suppress the differential mode and give you the common mode only. Does someone know where to buy such ISNs, but in the LISN version? Thanks in advance Rene Charton - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: EN 60 950 and Denmark-> conv. class I into class II
One thing that might be a problem is if the heat sink of the primary switching transistor is grounded. Then it might be difficult to reinforced isolate the primary switching transistor as changing the isolation material will also influence the heat conducting properties and thus the life span of the transistor. Rich Nute on 09/29/99 04:50:43 AM Please respond to Rich Nute To: pe...@itl.co.il cc: b...@anritsu.com, emc-p...@majordomo.ieee.org, jo...@exchange.scotland.ncr.com (bcc: Rene Charton/TUV-Twn) Subject: Re: Re: EN 60 950 and Denmark Hi Peter: > This is the exact deviation which I was referring to. One of my > clients states that a distributor wishes the product to be safe for > those establishments where earthing cannot be relied upon. Does > this mean to provide double or reinforced insulation from hazardous > live parts to earth? This may be a pain killer if the power supply is > Apporved for Class I. Not necessarily. Today's designs of SMPS are typically double or reinforced insulated. Even if certified as Class I, you have the option of evaluating it for double- or reinforced-insulation and declaring it as complying with double- or reinforced-insulation for use in Denmark (and other Nordic countries where grounded outlets may not be present in the electrical installation). There are two insulations that must be considered: primary-to-secondary primary-to-ground 1. Primary-to-secondary. In a typical SMPS, there are three such insulations that must be considered: transformer opto-isolator PWB spacings Typical SMPS transformers are double-insulated. It is very inefficient for a SMPS transformer to employ a grounded shield. If the certifier did a good job, he will have ascertained that the solid insulation, the through-air insulation, and the surface insulations meet the respective double-insulation requirements. In my experience, most SMPS transformers do meet these requirements. Opto-isolators are almost always rated as double- or reinforced-insulation. Most PWB spacings are those for double-insulation. If not, the secondary circuit and conductors must be grounded as if they were protective conductors. So, I believe you will find that most PWB spacings are sufficient for double-insulation. 2. Primary-to-ground. In a typical SMPS, there are two insulations that must be considered: PWB assembly and the metal chassis PWB spacings across Y capacitors and similar spacings Here is where you are likely to find spacings only sufficient for Class I. Most power supply vendors will likely balk if you should require Class II construction between the circuits and ground. But, you can easily get around MOST of the spacings by interposing a solid insulating sheet between the circuits and the grounded parts (e.g., chassis). You can get around the Y capacitor spacings by asking for double-insulated spacings on the PWB conductors. Its really not too difficult. Its really easy if you spec your power supply as double-insulated primary-to-ground and primary- to-secondary. Almost zero cost. By the way, we find that the weakest insulation in such designs is the Y-cap lead spacing on the PWB. We experience arcs in the range of 4-5 kV, well above the required 3 kV! We do this on all of our products. We KNOW our products will be used in situations without ground. So, we require our power supply vendors to provide double-insulation as well as grounding. Best regards, Rich - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: explanation of ESD events with coins in baggie.
It was 20 years ago, and now I live in a house without central heating and cable TV , so I can not reproduct that effect. But I remember for sure that the distortion similar to that which you get from spark plugs of internal combustion engines, about half a TV scan line long and repeating itself about every 3 to 5 scan lines. --- - - To: Rene Charton/TUV-Twn cc: 102630.1...@compuserve.com, emc-p...@majordomo.ieee.org Subject: Re: explanation of ESD events with coins in baggie. Rene, That is an interesting phenomenon! If you could give me a more detailed description of the TV "distortion" and "black lines" I might be able to explain at least what was happening inside the TV set (I worked many years in TV R & D). This in turn might help others to explain what ESD or EMI effect it was! For example: Are you referring to picture geometric distortion, color distortion (or was it B/W?), interference "flashes", loss of vertical or horizontal synchronization etc! Also were the "black lines" random, diagonal or what spacing etc? Also "many years ago" TV's in different countries might react differently, so where were you and about what year did you see this? Tony - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: explanation of ESD events with coins in baggie.
I remember a similar effect. Many years ago, when I was a student, in my room I had a TV set with a simple loop antenna. 2 meters away from the antenna was the radiator of the central heating of that house. On seams of the elements of that radiator the paint had come off. Below the paint the metal was slightly oxidized with a black colour. When I took a scewdriver and rubbed the metal blade along that seam the TV picture would become distorted with some black lines. I always wondered why, and in fact still do. Rene Charton - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
