RE: EMC-related safety issues

[Ehler, Kyle]

In Kansas there are no emissions laws or annual inspections.
The entire state gets a full air change every 10 minutes -so why bother?
We also benefit from no mandated vehicle inspections -ever.  The only
thing that does get a check is the odometer and VIN, but only when a title
transfer occurs.  The state is more interested in indentity than safety
of the machines the public chooses to play caroms with. 

IIRC, California and many states have an amendment to their respective 
emissions law that states that once a car is more than XX years old, 
they are considered 'antique' and exempt from the law.
The threshold ranges from 20 to 30 years, depending on state/county.

Another point of trivia is that a fresh oil change and new air filter 
prior to having your vehicle smog tested will improve the emissions 
results.  At one time there was available OTC a fuel additive that one 
could deploy to further skew the results in your favor.

Kyle Ehler
'73 and
'76 914 2.0 'Euro' antiques

-Original Message-
From: Pettit, Ghery [mailto:ghery.pet...@intel.com]
Sent: Friday, January 04, 2002 10:28 AM
To: 'James, Chris'; 'Ken Javor'; Doug McKean; EMC-PSTC Discussion Group
Subject: RE: EMC-related safety issues



Chris,

Annual inspections of motor vehicles are done on a state by state basis,
rather than as a national requirement in the U.S.  Automobiles are
registered at the state level, so the federal government doesn't get
involved.  Some states have annual inspections, others don't.  Likewise,
smog inspections are at a state or lower level.  California cars get
smogged.  Here in Washington it depends on what county you live in.  If air
quality in your county is good enough, you don't have to have your car
smogged.  If not, you get to pay more for the privilege of having a car.  I
live in a county where I don't have to deal with the fight.

BTW, a trick I learned when I lived in California is that you stand a much
better chance of passing the smog test if the engine is well warmed up when
you arrive at the inspection station.  Take it for what it's worth.

Be thankful that we don't have to have annual inspections on our cars to the
extent that one does on an airplane...  $$$

Ghery Pettit
Intel


-Original Message-
From: James, Chris [mailto:c...@dolby.co.uk]
Sent: Friday, January 04, 2002 1:02 AM
To: 'Ken Javor'; Doug McKean; EMC-PSTC Discussion Group
Subject: RE: EMC-related safety issues



Sorry disagree about turn and brake lights not being in the same class.
Their very failure is often the reason for very serious accidents. I have
long wished that all car manufacturers had to by law fit bulb failure
warning devices to cars (but what happens when that fails).

In the UK it is an offence to drive a vehicle with defective lights,
(although many do). It is the driver's (not owner's) obligation to be
satisfied the vehicle they are driving is fit to be on the road irespective
of whether it passed it's MOT the previous day.

The UK mandatory annual vehicle inspection (MOT) for vehicles over 3 years
old, covers seat belts, brake efficiency on a rolling road, mirrors,
windshield cracks (a 20mm, 3/4inch crack in the wrong place will fail a
vehicle), tyres, wheel bearings, gaiters, steering components, structural
body condition, lights, smog emissions, etcI don't
believe airbags are tested but guess it will come, along with the inevitable
hike in price.

I'm surprised the US does not have a similar Federal requirement - with all
the vehicles this is a cash cow waiting to be milked.


Chris

-Original Message-
From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: 04 January 2002 02:40
To: Doug McKean; EMC-PSTC Discussion Group
Subject: Re: EMC-related safety issues



A signal light is easily replaceable in terms of time and money.  Most 
people don't use them (well, in good old Huntsville, AL, anyway, where a
favorite bumper sticker reads, "Turn signals, not just for smart people
anymore").  Failure of a light is not in the same class as an airbag
deploying at the wrong time or not deploying, or ditto for brakes.

--
>From: "Doug McKean" 
>To: "EMC-PSTC Discussion Group" 
>Subject: Re: EMC-related safety issues
>Date: Thu, Jan 3, 2002, 7:00 PM
>

>
> Point taken Ken, but consider signal lights.  They're
> essentially safety devices and they're supposed to
> be maintained on cars which have been transferred
> amongst several owners and are decades old.
> Same idea with windshields, I guess also.
>
> - Doug McKean
>
>
> ---
> This message is from the IEEE EMC Society Product Safety
> Technical Committee emc-pstc discussion list.
>
> Visit our web site at:  http://www.ewh.ieee.org/soc/emcs/pstc/
>
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>   

RE: Enclosed OATS facilities---detour

[Ehler, Kyle]

I have the 'dome' (well, my employer does).
Actually, it is an 8 meter dia. radome, white fiberglass throughout.
With door, HVAC and rotating floor that serves as ground plane.
We pipe in fibre optics for PC host to EUT control from a receiver 
shelter located 50 meters perpendicular to the elipse.
It is part of our $5M facility.

It looks like a giant golfball sitting on a large, grounded, concrete pad.
-not the sort of place to be in a raging electrical storm...

If we could simplify the RE emissions data collection, it would
truly be a golden opportunity.  Worthy of the expense to upgrade.
Would this serve as a really large, spherical GTEM or more like a
spherical magnetic field antenna, with the EUT on the INSIDE?

Food for patents...

Kyle Ehler  
 
Assistant Design Engineer
LSI Logic Corporation
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8889



-Original Message-
From: Chris Maxwell [mailto:chris.maxw...@nettest.com]
Sent: Wednesday, December 12, 2001 2:46 PM
To: geor...@lexmark.com; Patrick Lawler
Cc: EMC-PSTC
Subject: RE: Enclosed OATS facilities---detour



H,

This conductive layer of snow reminds me of a daydream/ thought
experiment that I had for measuring emissions... 

What if you put a DUT inside a chamber that looked like a hemisphere.
The chamber would be hollow (otherwise, how would the DUT get in).  The
chamber "skin" would be a sandwich with a thin layer of absorber on the
inside and a good conductor (conductor 1) then a dielectric then another
good conductor (conductor 2) on the outside.  

Why these layers?

The inner layer would offer just enough attenuation to reduce
reflections, while letting some energy get to the conductor 1 behind it.

The conductor 1 layer would effectively be a "integrating measurement
antenna" which  picks up and integrates all emissions from the DUT.

The dielectric layer would insulate conductor 1 from conductor 2.
(maybe this layer would need to be RF absorbant as well, not sure).

The conductor 2 layer would be grounded all the way around and would
serve to block ambients.

What would happen?

Would conductor 1 capacitively couple to the DUT such that a simple
swept RF voltage measurement between the DUT and conductor 1 would show
the total interference produced by the DUT?

Who's with me?  Let's go to K-mart and get:

A large dome tent.
About 50 square yards of tin foil
Some Tokin flexible ferrite stuff **
A DUT.
An RF voltmeter/spectrum analyzer and a stub cable. **

**probably not available at K-mart...maybe Wal-Mart?

Might make a fun experiment, or maybe give the neighbors the idea that
you're building an escape pod to the mother ship.

Any immediate pitfalls that can be foreseen by the collective gurus?

Chris Maxwell | Design Engineer - Optical Division
email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797
8024

NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA
web www.nettest.com | tel +1 315 797 4449 | 



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RE: CFR 21 Sec. 11

[Ehler, Kyle]

Thank You everyone!!

I found quite a bit of information on this subject 
and it was determined that our products are compliant.
This is more of a OS and System Administrator file and
network security issue than hardware integrity.
I think I caused a completion on the sale of 1.5 TB of 
disk storage products.
Not bad for a few minutes work.

Thanks again,
Kyle Ehler  KCØIQE
<mailto:kyle.eh...@lsil.com>
Assistant Design Engineer
LSI Logic Storage Systems Div.
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8321


-Original Message-
From: richwo...@tycoint.com [mailto:richwo...@tycoint.com]
Sent: Thursday, December 13, 2001 1:10 PM
To: keh...@lsil.com
Subject: RE: CFR 21 Sec. 11


The CFRs are online at
http://www.access.gpo.gov/nara/cfr/cfr-table-search.html


-Original Message-
From: Ehler, Kyle [mailto:keh...@lsil.com]
Sent: Thursday, December 13, 2001 11:02 AM
To: 'PSTC list'
Subject: CFR 21 Sec. 11


Could someone explain to me or point in the right direction 
for what CFR 21 Section 11 requirements in a product (such as 
a disk storage system) for it to be compliant. 
I think this is about records and electronic signature authentication 
and has something to do with the FDA (CPG 7153.17).  It would seem to be 
more of an application feature than a hardware requirement? 
We are caught ignorant on this one and I dont have 
a copy of the CFR 21, much less CPG 7153.17 (?!).  
We have found some info, but our layman understanding doesnt 
answer the question of what/how to comply. 
Anybody? 
Respectfully, 
Kyle Ehler  
<mailto:kyle.eh...@lsil.com> 
Assistant Design Engineer 
LSI Logic Storage Systems Div. 
3718 N. Rock Road 
U.S.A.  Wichita, Kansas  67226 
Ph. 316 636 8657 
Fax 316 636 8321 

CFR 21 Sec. 11

[Ehler, Kyle]

Could someone explain to me or point in the right direction
for what CFR 21 Section 11 requirements in a product (such as
a disk storage system) for it to be compliant.

I think this is about records and electronic signature authentication
and has something to do with the FDA (CPG 7153.17).  It would seem to be
more of an application feature than a hardware requirement?

We are caught ignorant on this one and I dont have
a copy of the CFR 21, much less CPG 7153.17 (?!).  
We have found some info, but our layman understanding doesnt 
answer the question of what/how to comply.

Anybody?

Respectfully,

Kyle Ehler  
 
Assistant Design Engineer
LSI Logic Storage Systems Div.
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8321

RE: Sometimes product safety just isn't enough

[Ehler, Kyle]

That looked like one of those old 'Mall' hand drills with the metal body.
They were known for excessive AC current leakage.  Dont ask how I know...
Yowwp!
At least the guy's eyes will be in good condition for organ donation..
Kyle


-Original Message-
From: Robert Johnson [mailto:john...@itesafety.com]
Sent: Wednesday, December 12, 2001 12:28 PM
To: emc-p...@majordomo.ieee.org
Subject: Sometimes product safety just isn't enough


I couldn't help passing on this reference to a bit of unforeseeable misuse.
 
http://electrical-contractor.net/ubb/Forum4/HTML/48.html
 
Bob Johnson
 

RE: GTEM for full compliance testing?

[Ehler, Kyle]

Since I have no experience with GTEMs just yet, I was wondering
if it was necessary to re-orient the EUT or the transducer to 
'see' emissions, particularly those at Ghz that tend to be beam-like
and may require careful alignment to acquire the peak value.
Kyle Ehler  
 
LSI Logic Corporation



-Original Message-
From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Sent: Wednesday, December 12, 2001 3:31 AM
To: emc-p...@majordomo.ieee.org
Subject: Re: GTEM for full compliance testing?



I read in !emc-pstc that John Woodgate  wrote (in
) about 'GTEM for full compliance
testing?', on Thu, 6 Dec 2001:
>I read in !emc-pstc that Gelfand, David 
>wrote (in ) about 'GTEM
>for full compliance testing?', on Thu, 6 Dec 2001:
>>I imagine this has probably been discussed at length before.  Can full
>>compliance, emissions to FCC Part 15/ 55022  and rf radiated immunity to
>>55024/61000-4-3 be tested in a GTEM cell?  
>
>Not to 55024/61000-4-3. A new section, 61000-4-20, will be published
>next year and ***when/if it is called up in product standards such as
>55024*** it will be possible to use GTEM cells for full compliance.

The CDV is now issued, as a CISPR/A document.
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk

After swimming across the Hellespont, I felt like a Hero. 

---

RE: need to identify an SMT fuse's manufacturer marking

[Ehler, Kyle]

Chet, et al;
In the back of Volume 3 of the UL Recognized Component 'yellow books' there
is a large 'List of Company Identifications' section that has logos for
hundreds of companies.  They are listed in alphabetic order (somewhat).
Raychem, Bourns and another vendor make these 'PTC' resettable fuse.
Happy Hunting,
Kyle Ehler  KCØIQE
 
Assistant Design Engineer
LSI Logic Storage Systems Div.
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8321



-Original Message-
From: Summers, Chet [mailto:csumm...@pelco.com]
Sent: Thursday, December 06, 2001 3:22 PM
To: Emc-Pstc (E-mail)
Subject: need to identify an SMT fuse's manufacturer marking



Hello Group, a colleague has asked me to identify the mfg marking stamped on
a metal surface mount fuse.  Looks like a small "V" with another inverted
"V" placed directly on top in "interlocking" fashion.  The UL rep has asked
us to identify this manufacturer.  The fuse is installed on a purchased PCB.
The symbol seems familiar, but I cannot place it.

Also, the engineer charged with identifying this part says he used to know a
website where someone had compiled a useful list of manufacturer's component
logos/symbols.  Any guidance would be much appreciated!

Chet w/Pelco 
 
















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RE: Mains Cords in the UK and the fuse rating

[Ehler, Kyle]

I agree provided there is no earthing conductor.
I thought the 2 meter cord length happens to meet earth fault requirements
as many cords are 3 conductor and the 60950 standard specifies the ground 
conductor resistance to be less than 0.1 ohms as verified by test.
kyle

-Original Message-
From: Rich Nute [mailto:ri...@sdd.hp.com]
Sent: Friday, November 30, 2001 6:39 PM
To: j...@jmwa.demon.co.uk
Cc: emc-p...@majordomo.ieee.org
Subject: Re: Mains Cords in the UK and the fuse rating




So, the 2-meter length restriction (0.092 ohms) 
appears not to be in consideration of the short-
circuit current.  It appears that a 0.75 sq mm
cord could be 20 meters in length (0.92 ohms) and 
still operate the overcurrent device.


Best regards,
Rich

RE: Revised EMC standards and CE Declarations.

[Ehler, Kyle]

I saw a kid use his bassoon like a Louisville Slugger once.
The competition for first chair was vicious in the woodwind section...

I played the cornet.  A really old silver plated one.
Funny thing was it always had a terrible hall-filling halitosis.
-maybe that is why the conductor was always picking on me.
I tried everything...listerine, toothpaste, WD-40, even PGA..
kyle

-Original Message-
From: Aschenberg, Mat [mailto:matt.aschenb...@echostar.com]
Sent: Thursday, November 29, 2001 11:15 AM
To: 'Pettit, Ghery'; 'John Woodgate'; 'emc-p...@majordomo.ieee.org'
Subject: RE: Revised EMC standards and CE Declarations.

I wonder how many of the engineers on here have been or currently musicians.
I play clarinet and saxiphone. 
I figure the bastard that invented the saxaphone made it out of metal
because they were always burning the bassoons. 


> -Original Message-
> From: Pettit, Ghery [SMTP:ghery.pet...@intel.com]
> Sent: Thursday, November 29, 2001 9:34 AM
> To:   Pettit, Ghery; 'John Woodgate'; 'emc-p...@majordomo.ieee.org'
> Subject:  RE: Revised EMC standards and CE Declarations.
> 
> 
> Oh, and as long as we're picking on instruments in the orchestra...
> 
> Do you know the difference between a Violin and a Viola?
> .
> .
> The Viola burns longer.  ;)
> 
> -Original Message-
> From: Pettit, Ghery 
> Sent: Thursday, November 29, 2001 8:14 AM
> To: 'John Woodgate'; emc-p...@majordomo.ieee.org
> Subject: RE: Revised EMC standards and CE Declarations.
> 
> 
> John,
> 
> That quote refers to the Oboe, not the Bassoon.
> 
> Ghery 
> former Bassoonist ;)
> 
> -Original Message-
> From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
> Sent: Wednesday, November 28, 2001 12:15 PM
> To: emc-p...@majordomo.ieee.org
> Subject: Re: Revised EMC standards and CE Declarations.
> 
> 
> 
> I read in !emc-pstc that Pettit, Ghery  wrote
> (in ) about 'Revised
> EMC standards and CE Declarations.', on Wed, 28 Nov 2001:
> >Hey, John.  I resemble that remark.  I'm not complaining, just pointing
> out
> >a practical result of 89/336/EEC. ;)
> 
> It's an ill wind that blows nobody any good.
> 
> The Directive is thus unlike a bassoon, which is an ill woodwind that
> nobody blows good. (;-)
> -- 
> Regards, John Woodgate, OOO - Own Opinions Only.
> http://www.jmwa.demon.co.uk
> 
> After swimming across the Hellespont, I felt like a Hero. 
> 
> ---

RE: Quality Assurance and Product Approvals

[Ehler, Kyle]

Maybe this problem is even more insidious:
Ask your HR department if they have a "Radford Benchmark Salary Survey" 
Job Description -for the work you do.
(or equivalent to AON Consulting/Radford Associates service) 

I became aware some months ago that in some parts of the industry do not
have 
a job description for the product safety functionary!!
Maybe RBSS is unique in this, or my case is unusual, but the 
closest they could come for me was job code 8284 "Software Technician 4".
Beyond the 'specialist' level...there should be an 'esoteric level'..
heh, heh
-obviously this is not close-  So I've been listing what it is that I do.
I'm up to 4 pages so far...

Kyle
MOO!

RE: Reliability recommended books

[Ehler, Kyle]

Try this:
http://www.google.com/search?q=MTBF&btnG=Google+Search

Google is my favorite search engine.  No rubbish.
Regards,
kyle

RE: Methods & Equipment; Surge & Dips

[Ehler, Kyle]

True, but did KT have this equipment 4yrs ago?
Does anyone you know of rent this equipment?
 
We also have a Schaffner tap switcher, but it eats itself under heavy loads.
Is the KT stuff more robust under heavy startup loads?
The Pacific Power equipment I use has never broke down.  Worth the weight
just for that...
kyle

-Original Message-
From: Mike Hopkins [mailto:mhopk...@thermokeytek.com]
Sent: Tuesday, November 20, 2001 2:47 PM
To: 'Ehler, Kyle'; 'wmf...@aol.com'; emc-p...@ieee.org
Subject: RE: Methods & Equipment; Surge & Dips


Seems to me this is the hard way to do it. 
KeyTek has a product that is a tap switcher for the required levels and will
pass the in-rush currents required. It's a much smaller package.
 
Also, other manufacturers have systems that are basically software
controlled switches -- bring in the AC levels you require via a variac or
some other transformer and simply switch between them
 
Mike Hopkins

-Original Message-
From: Ehler, Kyle [mailto:keh...@lsil.com]
Sent: Tuesday, November 20, 2001 1:19 PM
To: 'wmf...@aol.com'; emc-p...@ieee.org
Subject: RE: Methods & Equipment; Surge & Dips



Hi William, 
I dont know about renting equipment for the tests. 
You can probably find it. 

For the -4-11 (dip/dropout) test; 
Depending on your load, your site wiring has to be up to snuff. 
The power sources for doing the dip and dropout test are hefty stuff. 
My lab uses a three-phase powered source to deliver a max of 16A into a
single phase capacitive (SMPS) load. 
I have a Pacific Power 140 TMX and an AMX 390.  The 140 does
flicker/harmonics and can do dip/dropout within its output limits (about 10A
inrush).  Any loads beyond a 10A inrush gets dip/dropout tested by the 390.
The 140 is totally pc controlled but can be programmed through the front
panel.  It is a handy doer.

The 390 is the heavy (up to 20A inrush) and I program it through the front
panel for the desired dips and dropouts. 
There are some models that are computer attached (RS232 or IEEE488) and you
execute software programmed routines for the test.

Mitigation?  Most EUT's can easily withstand half and single cycle drop,
many can take a little more (up to 5 cycles) before going seriously anemic.
Same is true for sags if the mains are wide range input.  If you fail, you
reselect the product's power supply, or beef up the input bulk capacitance
(assuming SMPS type) or adjust the monitoring circuitry (i.e. remote sense,
power good signal) for slower response and/or higher threshold.

For the -4-5 (surge) test; 
We use a schaffner NSG 650 attached to a pc running the schaffner surge
software.  The surges are delivered to the EUT through a CDN 110 coupler.
The cross coupling changes are manual jumpers.

We also have a Haefely Psurge 4010 and 32.1 coupling filter for heavy loads.
The cross coupling changes are automatic. 
The EUT supply cord length has to be no longer than .8M to the surge
generator.  
This test series can damage your EUT, so you might want to do this test
last. 
Mitigation of failures takes on a myriad of possibilities.  Wiring length,
TVSS absorber capacity, etc.  It is hard to say without knowing more about
your product.

Do you also need to do the -4-4 (EFT) test? 

All this test gear is large and heavy, particularly the power sources and
stepping xformers. 

Perhaps someone else can elucidate on exceptions to Class A rules? 

I gotta go, 
Happy Hunting, 
Kyle Ehler  KCØIQE 
< mailto:kyle.eh...@lsil.com <mailto:kyle.eh...@lsil.com> > 
Assistant Design Engineer 
LSI Logic Storage Systems Div. 
3718 N. Rock Road 
U.S.A.  Wichita, Kansas  67226 
Ph. 316 636 8657 
Fax 316 636 8321 




-Original Message- 
From: wmf...@aol.com [ mailto:wmf...@aol.com <mailto:wmf...@aol.com> ] 
Sent: Monday, November 19, 2001 10:29 AM 
To: emc-p...@ieee.org 
Subject: Methods & Equipment; Surge & Dips 



Esteemed listmembers, 

In gearing-up for testing under the auspices of EN61326:97, I'm trying to
understand two immunity tests: EN61000-4-5 (surge immy) and -4-11 (dips
immy). Is there test equipment one can rent to conduct these tests? What
sort of mitigation steps are typical. Is anyone aware of any exceptions for
this testing under ClassA rules?

Thanks in advance... 
Wm Flanigan 
Standards Engineer 
Ameritherm Inc 


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 Ric

RE: Methods & Equipment; Surge & Dips

[Ehler, Kyle]

Hi William,
I dont know about renting equipment for the tests.
You can probably find it.

For the -4-11 (dip/dropout) test;
Depending on your load, your site wiring has to be up to snuff.
The power sources for doing the dip and dropout test are hefty stuff.
My lab uses a three-phase powered source to deliver a max of 16A into a
single phase capacitive (SMPS) load.
I have a Pacific Power 140 TMX and an AMX 390.  The 140 does
flicker/harmonics and can do dip/dropout within its output limits (about 10A
inrush).  Any loads beyond a 10A inrush gets dip/dropout tested by the 390.
The 140 is totally pc controlled but can be programmed through the front
panel.  It is a handy doer.
The 390 is the heavy (up to 20A inrush) and I program it through the front
panel for the desired dips and dropouts.
There are some models that are computer attached (RS232 or IEEE488) and you
execute software programmed routines for the test.

Mitigation?  Most EUT's can easily withstand half and single cycle drop,
many can take a little more (up to 5 cycles) before going seriously anemic.
Same is true for sags if the mains are wide range input.  If you fail, you
reselect the product's power supply, or beef up the input bulk capacitance
(assuming SMPS type) or adjust the monitoring circuitry (i.e. remote sense,
power good signal) for slower response and/or higher threshold.

For the -4-5 (surge) test;
We use a schaffner NSG 650 attached to a pc running the schaffner surge
software.  The surges are delivered to the EUT through a CDN 110 coupler.
The cross coupling changes are manual jumpers.
We also have a Haefely Psurge 4010 and 32.1 coupling filter for heavy loads.
The cross coupling changes are automatic.
The EUT supply cord length has to be no longer than .8M to the surge
generator. 
This test series can damage your EUT, so you might want to do this test
last.
Mitigation of failures takes on a myriad of possibilities.  Wiring length,
TVSS absorber capacity, etc.  It is hard to say without knowing more about
your product.

Do you also need to do the -4-4 (EFT) test?

All this test gear is large and heavy, particularly the power sources and
stepping xformers.

Perhaps someone else can elucidate on exceptions to Class A rules?

I gotta go,
Happy Hunting,
Kyle Ehler  KCØIQE
 
Assistant Design Engineer
LSI Logic Storage Systems Div.
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8321




-Original Message-
From: wmf...@aol.com [mailto:wmf...@aol.com]
Sent: Monday, November 19, 2001 10:29 AM
To: emc-p...@ieee.org
Subject: Methods & Equipment; Surge & Dips



Esteemed listmembers,

In gearing-up for testing under the auspices of EN61326:97, I'm trying to
understand two immunity tests: EN61000-4-5 (surge immy) and -4-11 (dips
immy). Is there test equipment one can rent to conduct these tests? What
sort of mitigation steps are typical. Is anyone aware of any exceptions for
this testing under ClassA rules?

Thanks in advance... 
Wm Flanigan
Standards Engineer
Ameritherm Inc


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RE: Quality Assurance and product approvals

[Ehler, Kyle]

You are all making some excellent points.
It would seem that many of us share commonality.  Perhaps that is one of the
underlying purposes of the quality organizations.  When followed, the
effects are positive and things move correctly, and in synch, but when
exceptions are present...
In my case, the compliance group and the engineering group are one.  This
obviously has good and bad implications.
 
Brian makes an excellent point that has at times caused my hackles to raise
more than once...the independence (or lack thereof) between the compliance
department and the engineering department.  In the company documents filed
by two of these quality agencies, i.e.  ISO 900x, A2LA, TUV or COMPASS,
there is a clause that specifically mentions the requirement for this
independence.  Or, is it more of a 'suggestion'?
 
There does not however, seem to be an audit check for departmental
independence.  I recently have become an ISO auditor, and I am uncertain
there is, UNLESS I want to take it upon myself to press the issue.  Since I
work in the department, I cannot be assigned the task of auditing it, but I
could express my concerns with the person assigned the audit of the
EMC/Safety/Design engineering department.  Hmm...
 
I dont recall where these clauses are, but the purpose behind them is to
express the importance of functional isolation between the interests of the
two groups.  In our case, this causes a disastrous effect on scheduling and
allocation of resources because the conflicts are quick to rise and there is
a weak attempt to resist.  At times, we find ourselves pulled in two
directions simultaneously.  The 'Janus'..?
 
All the planning, procedures and methods in the world cannot overcome this
conflict if no one is willing to meet the challenge and push the issue.
(as in our case)  My poor boss has been subdued...and our compliance group
is eternaly the whipping boy.  I see the problem, but I am ineffective at
fighting off the 800Lb gorilla's because they do not believe a lab
rat...could read, think and speak.  Ah, but I can AUDIT, or cause focus by
another auditor...that would attract the attention of the QA folks (who seem
to be beyond reproach).
 
In the end, the quality of our output is in the hands of the lab rats who,
take it upon themselves to ensure the letter of the standards are adhered to
despite the conflict associated with the work.  That makes it a thankless
job, with little if any, appreciation.  Ha!! what's that you say...you want
a medal?  -for driving up COSTS and delaying product release!!!  If it
were'nt for the beaurocracy...you would not have a job.

[Ehler, Kyle] 
(my words)
 
 -Original Message-
From: Brian McAuliffe [mailto:bally...@iolfree.ie]
Sent: Tuesday, November 20, 2001 4:36 AM
To: 'EMC-PSTC Discussion Group'
Subject: RE: Quality Assurance and product approvals



I think the point raised by Gary re: where the Compliance group fits into
the organisation structure is more important than procedures/process,
although I disagree with him about where that should be. Let me explain. 
 
Having a good working relationship with Engineering is indeed critical,
however from my experience I believe it essential for the Compliance group
to be organisationally independent of Engineering. If not, then there are
always conflicts of interest when allocating the (usually limited)
Compliance resources between:
 
Engineering - there are 4 design reviews this week and preparation required
for a safety pre-compliance test next week;
Operations  - the agency auditor is visiting next week and there is some
prep needed;
Sales/Marketing - the Russian approval is expiring in 2 weeks and you need
to re-apply, prepare doc pack, 
etc.
 
How do you prioritise without getting slack from at least one functional
head ?? Obviously if the Compliance group is actually a group and not just 1
or 2 persons, then with a good understanding of the roles amongst the group
members the above does not really pose a problem. However I do NOT believe
this is the case, particularly in the current climate of lay-offs, with us
Compliance folk are becoming less essential.
 
Unless the role of the Compliance group is very narrow and involves only
support of one function (which I doubt), I feel that an independent
Compliance group is essential. It should be functionally independent to any
other group and reporting to the MD, or, reporting to the QA
Director/Manager. This will mean you can realistically argue for adequate
resouces to do a professional job for all those groups requiring your
services. You will have somebody independent at the right level in the
organisation supporting the Compliance group - essential when $$$ are
involved. Let's face it, no R&D Manager is going to approve headcount for a
2nd Compliance Engineer whose primary function is to do audits of the
production facility to ensure critical components are controlled as they
should, and, t

RE: Define Continuous DC Voltage

[Ehler, Kyle]

I knew someone was going to ask this..
A few years back, I was attending a UL 1950 seminar in Minneapolis.
One of the presenters (a fellow named 'Bahra') happened to mention 
that UL has a specification for the 'electric chair'.

The operating current was quoted by him to not exceed 70ma.

I jotted down this figure, but unfortunately the voltage and clause 
was not mentioned, and I was hesitant to ask.  The topic at the
time was AC electric shock.  In my copy of the slide presentation 
(slide 25), I noted the effects: (for AC electric shock, verbatim, 
with figures added as quoted)

-perception   .05 to .5ma
-reaction 2 to 5ma
-inability to let-go  5 to 20ma
-ventricular fibrillation 20ma +
-cell damage  20 to 70ma
-burn hazard(high frequency)

No voltages or frequency were specified..

btw,
I lived in Portland, Or. in the 70's and had a friend that
worked at the Tek Wilsonville plant.  He had the most amazing
set of tools...I think I kinda bonded with him.
Now, I have even more tools than he did..


Kyle Ehler  KCOIQE
 
Assistant Design Engineer
LSI Logic Storage Systems Div.
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8321



-Original Message-
From: Dan Kinney (A) [mailto:dan.kin...@heapg.com]
Sent: Tuesday, November 13, 2001 3:56 PM
To: Rich Nute; gkerv...@eu-link.com
Cc: jrbar...@lexmark.com; emc-p...@majordomo.ieee.org
Subject: RE: Define Continuous DC Voltage



Does anyone know what voltage is used in electric chairs?  Just Curious.
Dan Kinney
Horner APG
Indianapolis

> -Original Message-
> From: Rich Nute [SMTP:ri...@sdd.hp.com]
> Sent: Tuesday, November 13, 2001 2:08 PM
> To:   gkerv...@eu-link.com
> Cc:   jrbar...@lexmark.com; emc-p...@majordomo.ieee.org
> Subject:  Re: Define Continuous DC Voltage
> 
> 
> 
> 
> 
> Hi Gregg:
> 
> 
> >   There was also a very good (but short) article by Tektronix in the
> 70's
> >   called The Lethal Current.
> >   
> >   It concluded that currents between 100 mA and 3 Amps were more lethal
> that
> >   currents of more than 3 Amps because those high currents tended to
> 'restart'
> >   the heart.
> 
> Hmm.  Having been the manager of product safety at Tektronix in 
> the '70's, I don't recall such an article.  At least not by that
> name.
> 
> Electric energy causes various injuries to the body depending 
> on the magnitude of the energy.  Only two of the injuries can 
> lead to a fatality.
> 
> The two injuries are fibrillation of the heart, and overheating 
> of internal organs, especially the liver.
> 
> Fibrillation is caused by ac current in the range of 50 mA to
> 500 mA (external connections) where the current pathway through 
> the body includes the chest (and the heart).  Above 500 mA, 
> fibrillation is not a likely consequence.  (And, I believe I
> am correct in asserting that dc cannot cause fibrillation.)
> 
> Overheating of internal organs is a function of power dissipated
> in the body, where the body impedance can be taken as 1000 ohms.
> The power required depends on the time of contact.  Electric
> utility linemen are subject to such injury.  Consider 1 ampere
> through 1000 ohms is 1000 watts!  (The electric chair kills by
> over-heating the internal organs, not by fibrillation.)
> 
> So, Gregg's statement that there is both a lower and upper limit 
> for fibrillation is correct (although I do not agree with Gregg's 
> values).
> 
> 
> Best regards,
> Rich
> 
> 

RE: RF Immunity Testing to 50V

[Ehler, Kyle]

Please, oh please! let Ed Price have the job.
-ANYTHING to keep Ed out his Santa suit Ho, HO, HOing around the malls.. :)
He beat me to it last year.  I NEED the spare income this year.
heh heh,
kyle

-Original Message-
From: lfresea...@aol.com [mailto:lfresea...@aol.com]
Sent: Tuesday, November 13, 2001 12:30 PM
To: ed.pr...@cubic.com; harr...@dscltd.com; emc-p...@ieee.org
Subject: Re: RF Immunity Testing to 50V



Hi Kevin,

we too can achieve high fields, currently about 80 v/m is our limit. Again, 
you may want to talk more offline

Best regards,

Derek.

RE: Metrics cost at 1991

[Ehler, Kyle]

John,
Oh now you have hit the nail on the head!!
-or should I say..spot on dear chap! :)

We have had a few folks trained in safety/EMC (me inclusive), but we have
exactly 
one engineer that actually does work very hard to measure, study and
understand why 
our products are so leaky at the end of the design cycle.  
Then he single handedly fixes them.  Sometimes taking months to accomplish
this.
He listens to me, and sometimes he uses my quip of an idea.

Unfortunately, management that would enforce directives have NOT been
trained.

I dont need to espouse on the virtues of this approach, do I?

My employer has the unique luxury of a well equipped lab exclusively 
at the engineering department's disposal.  This provides an artificial
environment where competitive disadvantage is minimal. -or is it?

The purpose of my assigned green belt project is to determine these
attributes
and to supposedly develop procedures that will reduce costs.  As you
astutely
point out, and I agree, the efficient approach is to attack EMC problems at
the source
but mgmt sees this as peripheral to the problem of accurately scheduling
resources 
to keep the lab folks occupied.  For this project and for the moment, I must

ignore the King's nudity. =8-0

These are, to be certain, my mutinous words and not those of my employer.

heh heh, Robert, the Vituperous...
I like that.

kyle

-Original Message-
From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Sent: Monday, November 05, 2001 3:43 PM
To: emc-p...@majordomo.ieee.org
Subject: Re: Metrics cost at 1991



I read in !emc-pstc that Ehler, Kyle  wrote (in
<95fbd8b0830ed511b7720002a51363f102905...@exw-ks.ks.lsil.com>) about
'Metrics cost at 1991', on Mon, 5 Nov 2001:
>Naturally, the project dictated to me is to attempt an analysis of the EMC
>compliance process used here.
>This will be an attempt to apply structured analysis procedures in efforts
>to better understand and apply changes in personnel and/or test/scheduling
>procedures to shorten cycle time and perhaps reduce costs.
>
>We seem to spend 15% of lab resources in actual compliance work and 85% in
>troubleshooting to get compliant.

I get the impression that your company is not training its design
engineers to think of EMC (and safety) right up front at the design
stage. Or maybe it tells them to do that but doesn't train them in how
to do it. NO way should you be troubleshooting to the extent you quote.

My audio design team were told that THEY were responsible for their
product's safety; they could discuss freely with the compliance team in
advance of submitting the product for test, and they had free access to
the safety standard, BUT the product MUST NOT FAIL at first submission.
It worked very well, except on one product, where we had one unit (out
of about 200 000 product units that we shipped) with a screw through the
mains lead - a hazard that everyone had missed.
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk

Eat mink and be dreary!

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RE: (was blank, now Alternate construction strategies)

[Ehler, Kyle]

Hi Andrew,
I have generically dealt with motherboard alternates and other pesky stuff
as well.
Nearly all motherboards I have seen employ a non-rechargeable primary type
lithium cell for CMOS backup, and all I have seen use a keyed receptacle
that prevents polarity reversal, along with a label or a bit of text in the
owner's manual on warnings and battery replacement.

The MFR's know about these requirements and enable their integrating
customers to gain certification by including these features in their
product's design.  They may or may not engage in the services of a safety
agency to gain formal certification, because this drives up the cost of
their product.  Its sort of a game they play with us...some Asian power
supply mfr's do this too.

For MB's that have no UL file number on them (that would indicate the pwb
and it's myriad of circuits are compliant to the 60950 standard. -primarily,
overload of user accessible connectors and flame rating of the PWB material)
you can perform the tests to produce data that indicates compliance.
(assuming you are a client test data certified lab)  Most MB's I have seen
have a UL or vendor logo marking on the board to indicate flame rating.  I
have, more than once, been forced to perform the battery charge protection
circuitry fault tests, but not on motherboards.
hmm,mm the aroma of roasting FR-4 and chip resistors in the morning...

You can save yourself some grief by selecting a MB that has a UL file number
on it and specifying that in your description.
Some agency engineers are skeptical of Asian products and demand test data.
Again, it depends on the confidence level you have with your agency folks.
I try to cultivate good relations with them.  It makes my life easier.

I like this replaceable secondary lithium battery backed CMOS memory IC that
ST makes.  It is UL recognized -no testing required.  We use a lot of those.

btw, cecil's email bounced, I think because any text in the 'subject' field
makes the server barf.
kyle



-Original Message-
From: acar...@uk.xyratex.com [mailto:acar...@uk.xyratex.com]
Sent: Wednesday, November 07, 2001 11:04 AM
To: Ehler, Kyle
Cc: 'cecil.gitt...@kodak.com'; 'EMC and Safety list'
Subject: Re: (was blank, now Alternate construction strategies)


Kyle 
That is exactly the same strategy we take when selling products with
integrated PCs. Specify a max power consumption and aim for using a Listed
PC. If not, spec the PSU and try keep everything generic. 
But wanted to high light that changing a mother board can be a little bit
more involved. The BIOS will require a lithium power source, and the
agencies will want to know specific battery details and the charge
protection circuit. 
  
Andrew Carson - Product Safety Engineer, Xyratex, UK 
Phone: +44 (0)23 9249 6855 Fax: +44 (0)23 9249 6014 

  
"Ehler, Kyle" wrote: 
  
Hi Cecil! 
>From a product safety point of view it depends on how extensive the
'upgrade' is and how you have worded your product construction descriptions
and 'critical component list'.  In this biz, it matters to some degree that
my lab is ISO 9001, COMPASS and a UL Client Test Data Program (CTDP)
participant.  These credentials support the fact that I can be trusted to
use impeccable judgment in evaluating the hazard impact to my listed
products as they evolve. 
For example, in most of the ITE products I support, we may uprate the disk
drive to a larger capacity, or the controller interface to a higher speed
processor, or a different vendor fan.  I spec these as a component with a
maximum current draw.  Provided the alternate components fit within these
specifications, the task simplifies to filing a change request with the
agencies and providing certificates for the alternate components.  Depending
on the item being alternately listed, you may have to provide test data (as
would be the case with a new power supply with vastly different ratings). 
In your case, I would attempt to describe the computer as a listed component
with a maximum power consumption.  When that pc goes end of life, just spec
another as alternate, but select a pc that is at or below your previous
descriptions. 
To the product safety agencies, these are simple SELV changes and the
underwriting agencies are not overly concerned in the hazards these pose.  I
describe such components generically if possible to allow substitution, but
they must always bear some level of agency recognition (UL listed or
recognized component, and/or TUV/VDE marked) that guarantees that the
alternate construction components have been evaluated for hazards. 
>From the EMC point of view, you must fully test to verify compliance and
file the data.  There is no easy way around it. 
Regards, 
Kyle Ehler  KCOIQE 
<mailto:kyle.eh...@lsil.com> 
Assistant Design Engineer 
LSI Logic Storage Systems Div. 
3718 N. Rock Road 
U.S.A.  Wichita, Ka

RE: (was blank, now Alternate construction strategies)

[Ehler, Kyle]

Hi Cecil!

>From a product safety point of view it depends on how extensive the
'upgrade' is and how you have worded your product construction descriptions
and 'critical component list'.  In this biz, it matters to some degree that
my lab is ISO 9001, COMPASS and a UL Client Test Data Program (CTDP)
participant.  These credentials support the fact that I can be trusted to
use impeccable judgment in evaluating the hazard impact to my listed
products as they evolve.

For example, in most of the ITE products I support, we may uprate the disk
drive to a larger capacity, or the controller interface to a higher speed
processor, or a different vendor fan.  I spec these as a component with a
maximum current draw.  Provided the alternate components fit within these
specifications, the task simplifies to filing a change request with the
agencies and providing certificates for the alternate components.  Depending
on the item being alternately listed, you may have to provide test data (as
would be the case with a new power supply with vastly different ratings).

In your case, I would attempt to describe the computer as a listed component
with a maximum power consumption.  When that pc goes end of life, just spec
another as alternate, but select a pc that is at or below your previous
descriptions.

To the product safety agencies, these are simple SELV changes and the
underwriting agencies are not overly concerned in the hazards these pose.  I
describe such components generically if possible to allow substitution, but
they must always bear some level of agency recognition (UL listed or
recognized component, and/or TUV/VDE marked) that guarantees that the
alternate construction components have been evaluated for hazards.

>From the EMC point of view, you must fully test to verify compliance and
file the data.  There is no easy way around it.

Regards,
Kyle Ehler  KCOIQE
 
Assistant Design Engineer
LSI Logic Storage Systems Div.
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8321




-Original Message-
From: cecil.gitt...@kodak.com [mailto:cecil.gitt...@kodak.com]
Sent: Tuesday, November 06, 2001 4:42 PM
To: emc-p...@majordomo.ieee.org
Subject: 



From: Cecil A. Gittens

Hi Folk,

 I have a computer that supports a Color Proofing System.
Since any given computer have life cycle of 4 to 6 months.
My question is there any way to avoid rectification testing of the computer
with each upgrade.

Regards

Cecil


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RE: Metrics cost at 1991

[Ehler, Kyle]

Richard, et al
This sounds like a Six Sigma project.
Having just completed my 'green belt' training, I have been assigned a
project to complete my certification as a Six Sigma green (horn) belt.  This
is a *huge* undertaking for me..

Naturally, the project dictated to me is to attempt an analysis of the EMC
compliance process used here.
This will be an attempt to apply structured analysis procedures in efforts
to better understand and apply changes in personnel and/or test/scheduling
procedures to shorten cycle time and perhaps reduce costs.

We seem to spend 15% of lab resources in actual compliance work and 85% in
troubleshooting to get compliant.
Accuracy in resource scheduling has proven to be as easy as nailing jelly to
a tree..

I saw your list and immediatly recognized its similarity to mine.  This work
starts and ends with confounding metrics.
>From your list I see that you have 'Defects Per Unit' (DPU), but nothing
about Opportunities For Error (OFE) that occurs with gaining compliance for
new products.  I think this would be the key to unraveling the mystery.
I see that you apply DPU as EMC failures, but I was thinking of DPU as
failures in meeting schedule.  Is this too weird?

Any thoughts on how to calculate OFE on a new product that is bound to be
rife with opportunities due to the use of latest technology such as for
example, 2+ Gbps fibre channel and its accomodating -new- mechanical
packaging?

For your engineering types, the concept of determining opportunities for
compliance failure may be alien to them.
It is for ours.
I am skeptical that these guys could tell me anything meaningful until they
get their training.  -but I keep an open mind.

On major item I picked up in my SS training was the myriad of ways the
metrics can be charted and considered.

Best Regards,

Kyle Ehler  KCØIQE

Assistant Design Engineer
LSI Logic Storage Systems Div.
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8321


-Original Message-
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of
wo...@sensormatic.com
Sent: Thursday, November 01, 2001 3:20 PM
To: emc-p...@majordomo.ieee.org
Subject: Metrics



My management is asking each engineering group to devise and apply metrics
to our department operations. I have struggled for a couple of years to
devise meaningful metrics as applied to EMC and product safety compliance
testing and certification , but with little success. Some ideas have been:

*   % of received products that are found to be fully compliant without
design changes
*   elapsed test and certification time
*   defects per unit (for example, number of fixes required to be safety
compliant)
*   hours of actual test time vs.standard test time

What metrics are you using and how well are they working?

Richard Woods
Sensormatic Electronics

RE: EMC test table construction plans

[Ehler, Kyle]

In our OATS dome, we use a pair of large antistatic plastic Rubbermaid 
wheeled carts with a sheet of plywood laid across the tops.
A tabletop host pc is set on that.
How's that effecting the measurements?  
Should these effects be part of the 'uncertainty'?

Kyle Ehler  KCØIQE
 
Assistant Design Engineer
LSI Logic Storage Systems Div.
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8321



-Original Message-
From: umbdenst...@sensormatic.com [mailto:umbdenst...@sensormatic.com]
Sent: Thursday, November 01, 2001 4:12 PM
To: doug.pow...@aei.com; emc-p...@ieee.org; davi...@ece.umr.edu
Subject: RE: EMC test table construction plans



David,

On a similar note I had heard that an EUT shelter might demonstrate a 6 dB
variation between wet and dry conditions, or dirty vs. clean (pressure
cleaned) condition.  

Did the papers comment on wood properties?  Perhaps identifying soft wood
vs. hard wood, minerals absorbed during growth, wet vs. dry, or other
"conditioning" situations?

I have only seen a handful of labs, but they all had wooden tables (defacto
standard for the times -- past?).  I wonder if the standards were written
around the convention of wooden tables?

You've raised an interesting issue.

Best regards,

Don Umbdenstock
Sensormatic

> --
> From: Pommerenke, David[SMTP:davi...@ece.umr.edu]
> Reply To: Pommerenke, David
> Sent: Thursday, November 01, 2001 4:15 PM
> To:   'POWELL, DOUG'; EMC-PSTC (E-mail)
> Subject:  RE: EMC test table construction plans
> 
> 
> Doug,
> 
> For emissions and immunity you should not use any wood in the table. It
> will
> significantly (+/-2 dB up to 1 GHz for emissions , more above, +/-10 dB
> for
> immunity up to 1 GHz) change the test result. My experience has shown that
> Styrofoam is basicly the best material. There are a couple of published
> papers on this issue. As surface material the following worked out fine:
> 
>   - Foamed PVC (rather stiff, low dielectric constant due to the foamed
> nature), maybe 4 mm thick.
> 
>   - PE sheet, maybe 2 mm thick.
> 
> David Pommerenke
> 
> 
> 
> -Original Message-
> From: POWELL, DOUG [mailto:doug.pow...@aei.com]
> Sent: Thursday, November 01, 2001 11:38 AM
> To: EMC-PSTC (E-mail)
> Subject: EMC test table construction plans
> 
> 
> 
> Hello all,
> 
> I plan to construct my own insulated EMC test table for a 5 meter chamber.
> Seems simple enough to do and I could easily come up with something.  I
> thought I might first ask for input from those of you in the discussion
> group who have experience or maybe even construction plans.  Here are some
> features I want:
> 
> 1) I will be testing products that weight up to 200 Lbs (91 kg).
> 
> 2) I want to minimize metalic fastners.
> 
> 3) I would like to make it a pivoting table (not motorized).
> 
> 4) Height is 80 cm.
> 
> 5) The surface should be replacable if it gets badly worn or scarred.  I'm
> thinking of using hardboard.
> 
> 6) Suggestions on length & width?
> 
> -doug
> 
> ---
> Douglas E. Powell, Compliance Engineer
> Advanced Energy Industries, Inc.
> Mail stop: 203024
> 1626 Sharp Point Drive
> Ft. Collins, CO 80525
> 
> 970.407.6410 (phone)
> 970-407.5410 (fax)
> mailto:doug.pow...@aei.com
> ---
> 

Wiring flame ratings

[Ehler, Kyle]

If I may ask a back to basics question.

The country specific agency flame ratings for insulated 
wiring seem to not be harmonized.  Some materials such 
as limited current (signal) interconnect wiring are marked 
as VW-1 while others are marked with FT-1,2,3,4 or CL-2.
VW nomenclature is a UL rating for wiring, while FT-x is a 
Canadian rating and test method, and CL2 is a NEC rating.
Have I left any out? (;^)

Is there such a thing as a cross reference table that 
indicates which is equivalent (and per application?) ?  
For example, FT4 = VW-1 = CL2 for vert./horiz. raceway?

Inquiring minds...

Kyle Ehler  KCOIQE
 
Assistant Design Engineer
LSI Logic Storage Systems Div.
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8321

RE: Thin Insulation (Electrical) Material

[Ehler, Kyle]

I like a material called 'Formex GK' polypropylene because is is not
hygroscopic like nomex and has acceptable flame rating.  I dont know if they
offer it in clear.
Model GK-17BK comes in a 24 inch by 1000 foot roll and is 0.017" thick black
sheet.  UL listed CCN: QMFZ2 file # E121855
Try: ITW Fastex, Div. of Illinois Tool Works, inc. U.S.A. 847-299-

Cheers,

Kyle Ehler  KCOIQE
 
Assistant Design Engineer
LSI Logic Storage Systems Div.
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8321



-Original Message-
From: Enci [mailto:e...@cinepower.com]
Sent: Wednesday, September 26, 2001 10:16 AM
To: emc-p...@majordomo.ieee.org
Subject: Thin Insulation (Electrical) Material



Hi,

I am looking for source/names/information on thin electrical insulation
material - preferrably in the UK please. 

I have a small metal housing, which needs additional insulation.

My first prototype used polyester tape, as used for transformer windings.
Tape is not an ideal solution due to the size of the area to be covered.

So far I have come up with:

Nomex Aramid Paper  (RS cat. no:) 349-9712
Phenolic Fabric  (RS cat no:) 374-395


Ideally I would like to use a clear plastic film, but have yet to find any.

Any suggestions appreciated.
Thank you.


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RE: Steel ball for impact tests

[Ehler, Kyle]

What about calibration?
Is a trailer ball NIST traceable? =:P
As a 'CTDP' participant I have to maintain a cal list on all instruments I
use in the course of my tests and include it with any test reports I ship to
agencies.

I had to get my certified 'sphere' calibrated recently.  -Not that it
changes much or is easily adjustable.
It was not cheap for this paperwork turn on 'ol ironhead'.

If'n you purchase a new sphere, you get a nice cal cert along with it.
I would venture that your time making and cal'ing/correcting a trailer ball
to spec and getting it cert is just as expensive.
Regards,
Kyle Ehler  KCOIQE
 
Assistant Design Engineer
LSI Logic Storage Systems Div.
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8321


-Original Message-
From: Dan Irish - Sun BOS Hardware [mailto:dan.ir...@sun.com]
Sent: Monday, September 24, 2001 10:22 AM
To: emc-p...@majordomo.ieee.org
Subject: RE: Steel ball for impact tests



The cheapest way to go is to get a 2" trailer ball from
WalMart and cut off the flange and threads with a
hacksaw or Sawzall. File to a spherical shape.
Drill and tap a hole for an eye bolt that
can be installed for the pendulum test.

About $10 US?

Dan

> From: "JENKINS, JEFF" 
> To: "'Jon Jones'" , "Emc-Pstc (E-mail)" 

> Subject: RE: Steel ball for impact tests
> Date: Mon, 24 Sep 2001 08:33:20 -0600
> MIME-Version: 1.0
> X-Resent-To: Multiple Recipients 
> X-Listname: emc-pstc
> X-Info: Help requests to  emc-pstc-requ...@majordomo.ieee.org
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> X-Moderator-Address: emc-pstc-appro...@majordomo.ieee.org
> 
> 
> Try:
> 
> Ergonomics, Inc.
> 1-800-862-0102
> ask for Eric George
> e...@ergonomicsusa.com
> www.ergonomicsusa.com
> 
> Regards,
> 
> Jeff Jenkins
> Advanced Energy Industries, Inc.
> Fort Collins, CO
> 
> 
> -Original Message-
> From: Jon Jones [mailto:jon.jo...@ascom.co.uk]
> Sent: Monday, September 24, 2001 7:00 AM
> To: Emc-Pstc (E-mail)
> Subject: Steel ball for impact tests
> 
> 
> 
> 
> Can anyone detail a manufacturer / supplier who can supply the steel ball
> for impact tests as per EN60950:2000 clause 4.2.5.  (50mm diameter, 500g)
> 
> Thanks in advance,
> 
> 
> Jon Jones
> 
> 
> 
> 
> ---
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RE: EMI sniffer goggles

[Ehler, Kyle]

Hi Tim,
Welcome to the fray..
There is in existence a sheet material that exhibits these properties
however, the flux sensitivity may not be sufficient for practical use 
with EMI work.  I suspect it is for intense near field only.
Here's a link: http://www.wondermagnet.com/dev/magnet34.html

Has anybody experienced this material?

-kyle

-Original Message-
From: Wan Juang Foo [mailto:f...@np.edu.sg]
Sent: Tuesday, August 07, 2001 8:28 PM
To: EMC-PSTC Discussion Group
Subject: Re: EMI sniffer goggles




I suppose that can be achieve with some class of liquid crystals embedded
in a polymer medium.  The problem is that is the representation in the near
field or just a plane (cross section).

I will prefer a none intrusive gas or vapour that will 'glow' at different
field intensity and colour, very much like a corona or  aurora.  :-)  Now
we can have a glass tank 'gas chamber' within an anechoic chamber to
evaluate the field strengths in 3D.  Then the argument will be that there
will be different gasses for different frequent frequency ranges ;-)  Just
think about the possible effect on the environment.

Dreams comes true when we want them to...


Tim Foo,
(or just call me 'Tim')
   E-mail:  f...@np.edu.sg
ECE, School of Engineering,
http://www.np.edu.sg/ece/  Tel: + 65 460 6143
Ngee Ann Polytechnic,  Fax: + 65 467 1730
535 Clementi Road,
Singapore 599489



 

RE: EMSCAN (was TV nostalgia/EMI sniffer goggle)

[Ehler, Kyle]

I mini-evaluated an EMSCAN about 4 years ago.  Cute tool!
At the time, this little gem utilized a planar array of 1,024 microantennae,
coupled to an RF processor and pc.
The radiation display is a user-variable-interpolation color map (spectral
or spatial), but a bit imprecise in X-Y location, and forget about the Z
plane.  You could see a circuit trace acting as an emitter, but you have to
be diligent in comparing the pwb layout with the schematic and the tool's
radiation profile report.  It was also a bit slow.  That might have changed
since then.
Here's a link:  http://www.emscan.com/product/prodline.html

I could not sell our pcb design engineers on the tool -not even for use as a
prescanner.  Now our mechanical folks are having a dickens of a time
containing 2Gbps fibre channel harmonics after the pcb design is done.
Thanks for the job security. 

The biggest problem with this weapon was the absolute need for close
proximity and repeatable indexing.  This severely affects the accuracy and
repeatability of the results, making before/after comparisons questionable.

For many of us, placing an operating pwb on a planar surface for scanning
presents a major challenge.
I dont know about you, but we have a backplane that the pwb plugs into, then
of course there is cabling, power supplies and cooling to worry about.  Not
to mention the CRU canisters for each module.  Then it needs to be
functional.

I witnessed differences in emission profile that were highly sensitive to
operating modes of the firmware loops and application software.  It is
extremely difficult if not impossible to do an accurate comparison of a bare
board to an assembled and completely functioning EUT.  So you are forced to
scan a bare board rather than a fully configured and functioning system.
For our purposes (debugging the EMI containment) this was of no
practicality.  Back to sniffer loops and horns..

On the other hand, one of the proper ways to design for compliance is to
design for containment of the emissions at the [board level] source.  This
is where the practicality of the EMSCAN comes into play.  I found the tool's
virtue for scanning the solder side of the board (close proximity)
excellent, but for the component side (which is where most of the radiation
sources and fixes would occur) the proximity was poor, grossly affecting the
location and precision of the readings.

btw I dont work for, or have any connection with, EMSCAN.
kyle

-Original Message-
From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Monday, August 06, 2001 5:58 PM
To: John Woodgate; emc-p...@majordomo.ieee.org
Subject: Re: TV nostalgia



You could use an array of very short dipoles or small loops and gain in 
resolution by giving up efficiency, meaning that the viewer would have to be
near the source.  Although I have no detailed knowledge of it, I expect this
is the principle behind the devices upon which you lay an operating PCB and
the device maps hot spots.  But clearly you will never get optical or IR
viewer resolutions.

--
>From: John Woodgate 
>To: emc-p...@majordomo.ieee.org
>Subject: Re: TV nostalgia
>Date: Mon, Aug 6, 2001, 12:28 PM
>

>
> <95fbd8b0830ed511b7720002a51363f1319...@exw-ks.ks.lsil.com>, Ehler, Kyle
>  inimitably wrote:
>>Doug has touched on what I think would be a great tool for the
>>EMI hunter...but rather than a 'sniffer', a 'goggle' similar
>>to what Geordi wears that facilitates the direct viewing of EM
radiation.
>>
>>Ideally, the device would allow adjustable band 'viewing' of the
radiation
>>frequency, intensity, polarity and propagation pattern(s).
>
> Yes, it sounds much more attractive than a sniffer, which would produce
> BAD smells around some equipment. And it isn't technically unfeasible.
> The problem is the poor resolution, even a microwave frequencies, due to
> the wavelength of the emission. At 150 kHz, the wavelength is 2 km, so
> only very BIG things are visible.
> --
> Regards, John Woodgate, OOO - Own Opinions Only.
http://www.jmwa.demon.co.uk
> This message and its contents are not confidential, privileged or
protected
> by law. Access is only authorised by the intended recipient - this means
YOU!
> The contents may be disclosed to, or used by, anyone and stored or copied
in
> any medium. If you are not the intended recipient, please advise the
sender
> yesterday at the latest.
>
> ---
> This message is from the IEEE EMC Society Product Safety
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>
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RE: ESD - time between successive discharges

[Ehler, Kyle]

No John, I'm not referring to you. (or anyone else in particular)  I dont
know you well enough -yet..
I'm just spaking on how we do the job of ensuring that our products meet the
standards.

We take this work very seriously and I agree with you that the CE mark is
not a quality mark, but in our case it nearly becomes one when the
customer's expectation of our products is to meet (or exceed) the presently
applied Directives.  We back the CE mark with a detailed test report.  In a
number of cases, the customer performs follow up testing.  On rare
occasions, the customer is followup testing to more stringent or severe
levels and this is where agressive adherence to the Directives, along with
painfully acquired margins, pays off in spades.  On very rare occasions a
test lab challenges our data, in which case we re-examine and submit or
challenge, depending on the issue.

I'm a second party and cannot take direct credit for the lab's work, but I
can say that I advocate doing the right thing.  Even when it creates a great
deal of discomfort for our engineers and reasonably increases our costs.  As
a result, our engineers have at best a rancorous respect for our tiny
department.

I need to state that our lab is a combined EMC and Safety lab.  That it is
part of LSI Logic Storage Systems Division, that we are not independent of
the company, and that we do no external testing or contracting.

Also, what I say here are merely my opinions and are not necessarily those
of LSI.


Take Care,

Kyle Ehler  KCOIQE
<mailto:kyle.eh...@lsil.com> 
Product Safety Engineer / EMC Specialist
LSI Logic Storage Systems Division
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8321



-Original Message-
From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Sent: Tuesday, August 07, 2001 1:37 AM
To: emc-p...@majordomo.ieee.org
Subject: Re: ESD - time between successive discharges



<95fbd8b0830ed511b7720002a51363f1319...@exw-ks.ks.lsil.com>, Ehler, Kyle
 inimitably wrote:
>I suppose what I am alluring to 

You aren't alluring to me, sailor!(;-)

>is debugging for quality, but then, isnt the
>purpose of compliance testing to 'test to fail' rather than test to pass?

No, it isn't, if you mean 'compliance with EU Directives'. To suggest
that it is creates an open invitation to militant test-houses to go
looking for trouble, and you can be pretty sure that some of them are
ingenious enough to find it in every case.

[snip]
>
>For example, as an OEM (to a few of you out there) and direct mfr. we want
>to be as thorough as possible because we want to make a quality product and
>when we put "CE" on it, we mean it. 

The CE mark is absolutely NOT to be regarded as a quality mark. Thus
spake the European Commission itself.

You are welcome to institute whatever product-quality verification
programs you wish, but please keep their consideration separate from
issues concerning compliance with EU Directives.
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk

This message and its contents are not confidential, privileged or protected 
by law. Access is only authorised by the intended recipient - this means
YOU! 
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any medium. If you are not the intended recipient, please advise the sender 
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RE: TV nostalgia

[Ehler, Kyle]

True, but if the display range and bandwidth was tunable, and shown in 3-D
chroma (similar to thermal imagers) rather than time domain -the emissions
would make sense to the wearer.  After all, even modern spectrum analyzers
cannot show full bandwidth without compromising adjustments.

-k


-Original Message-
From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Sent: Monday, August 06, 2001 12:29 PM
To: emc-p...@majordomo.ieee.org
Subject: Re: TV nostalgia



<95fbd8b0830ed511b7720002a51363f1319...@exw-ks.ks.lsil.com>, Ehler, Kyle
 inimitably wrote:
>Doug has touched on what I think would be a great tool for the 
>EMI hunter...but rather than a 'sniffer', a 'goggle' similar 
>to what Geordi wears that facilitates the direct viewing of EM
radiation. 
>
>Ideally, the device would allow adjustable band 'viewing' of the
radiation 
>frequency, intensity, polarity and propagation pattern(s). 

Yes, it sounds much more attractive than a sniffer, which would produce
BAD smells around some equipment. And it isn't technically unfeasible.
The problem is the poor resolution, even a microwave frequencies, due to
the wavelength of the emission. At 150 kHz, the wavelength is 2 km, so
only very BIG things are visible.
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk

This message and its contents are not confidential, privileged or protected 
by law. Access is only authorised by the intended recipient - this means
YOU! 
The contents may be disclosed to, or used by, anyone and stored or copied in
any medium. If you are not the intended recipient, please advise the sender 
yesterday at the latest.

RE: ESD - time between successive discharges

[Ehler, Kyle]

I've been following this thread about ESD testing and the PPS debate.
I would like to inject my point of view on the subject.

So far most of what I have read addresses the need for speed.
This is great for the test lab/house; to be able to slam through the process
in a quest to get it done quick for the sake of process throughput, but for
the purpose of determining if an EUT is immune to a pulse stimuli with
respect to possible entry points, I remain skeptical.

I suppose what I am alluring to is debugging for quality, but then, isnt the
purpose of compliance testing to 'test to fail' rather than test to pass?
This may depend on the lab itself.  With the PPS issue, I submit that from
at least the quality point of view it may depend on the type of product you
are testing and the functional test program that the EUT is operating.

For example, as an OEM (to a few of you out there) and direct mfr. we want
to be as thorough as possible because we want to make a quality product and
when we put "CE" on it, we mean it.  We do not want our customer to find a
problem with our products during their followup testing (not everyone
retests a CE marked product).  To ensure quality, we test our cabinet
products for a full day or two in the ESD lab (much more if it fails).  Many
times we have student interns who do this, but sometimes our experienced lab
techs do the job.  Nevertheless, ESD testing (particularly on our disk
arrays) is done very slowly because a rack mount version EUT can be loaded
with up to 154 disk drives ranging in capacity from 9 to 180Gb while using a
transfer block size ranging from 512 bytes to 256Kb.  The result is massive
overhead to response.

The exercise program for a device such as this (we call it smash/hammer)
performs a chained series of write/read/verify operations.  The tasking
packets may be buffered through a storage attached network (SAN) director
and thus the operations can be lengthy and/or latent in the outcome
reporting in the error daemon.  The only way for our test personnel to
determine if a failure has occurred is to monitor the screen of the EUT's
host pc to visually verify no errors have occured before proceeding to the
next zap.  This can take seconds to minutes after a stimuli is applied.
If such ESD testing were performed too rapidly, the operator can overlook a
failure, and its location.  There may be dozens of stimuli injection points
to be tested and thus the relative location on the EUT where the failure
event occurred can be overlooked.

Fortunately, the standard has provision for variety..

Thank-You,

Kyle Ehler  KCOIQE
 
Assistant Design Engineer
LSI Logic Corporation
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8321

RE: TV nostalgia

[Ehler, Kyle]

Doug has touched on what I think would be a great tool for the
EMI hunter...but rather than a 'sniffer', a 'goggle' similar
to what Geordi wears that facilitates the direct viewing of EM radiation.

Ideally, the device would allow adjustable band 'viewing' of the radiation
frequency, intensity, polarity and propagation pattern(s).

A rig like this could add a pc for compliance recognition/cataloging 
and perhaps someday eliminate the need for OATS, TEM cells and other
investigatinve methods.  The system could also harass on a per sample
basis in situ mfg. product.

-kyle, KC0IQE


-Original Message-
From: Doug McKean [mailto:dmck...@corp.auspex.com]
Sent: Friday, August 03, 2001 8:40 PM
To: EMC-PSTC Discussion Group
Subject: Re: TV nostalgia



Now, if we could just train ourselves to sniff out some of
those pesky EMI problems ...

- Doug McKean

RE: TV nostalgia

[Ehler, Kyle]

Which reminds me of other oddball video contraptions.
A few years back I had to dispose of a Heathkit GR-2000 25" TV w/onscreen
digital clock option.
Alas, it worked great, but the digital matrix tuner did not like CATV (ch.
2-13 only).
Its entire chassis was copper plated steel.  All pcb's were 94V0 and,
typical of Heath products,
documented more than thoroughly.  Very well made!
kyle

-Original Message-
From: Ralph Cameron [mailto:ral...@igs.net]
Sent: Friday, August 03, 2001 2:41 PM
To: Ehler, Kyle; 'Rich Nute'; 'EMC and Safety list'
Subject: Re: TV nostalgia


And lest we forget the Hallicrafters electrostatic deflection systems. You
could sure get a poke off those. 
 
Ralph Cameron
 

- Original Message - 
From: Ehler, Kyle <mailto:keh...@lsil.com>  
To: 'Rich Nute' <mailto:ri...@sdd.hp.com>  ; 'EMC and Safety list'
<mailto:emc-p...@majordomo.ieee.org>  
Sent: Friday, August 03, 2001 9:23 AM
Subject: RE: TV nostalgia


My experience was with the Packard-Bell transistorized models. 
I think the aversion I have was prejudiced by the fellow 
who mentored me.  I had little reason to doubt, but then 
the sets I worked on, had a callback history that may have 
been created by my mentor. 
-kyle 

-Original Message- 
From: Rich Nute [ mailto:ri...@sdd.hp.com <mailto:ri...@sdd.hp.com> ] 
Sent: Thursday, August 02, 2001 5:36 PM 
To: emc-p...@majordomo.ieee.org <mailto:emc-p...@majordomo.ieee.org>  
Subject: TV nostalgia 






Okay... more nostalgia and a bit on safety 
back in those days... so that we don't stray 
too far from the subject matter of this 
forum. 

My first TV was a Motorola 7-inch round in 
a Bakelite cabinet.  The speaker was the 
same size as the CRT. 

My second was the famous RCA 10-inch round 
chassis with 32 tubes.  I could pull out 
15 tubes and still have a usable picture. 

Kyle mentions Packard Bell, which I considered 
a straight-forward, good product.  It used the 
Standard Coil turret tuner. 

The one that won my respect was Muntz TV. 
It was CHEAP!  When you looked inside the 
chassis, there was nothing there compared to 
the other TVs.  They really knew how to take 
the cost out of the TV!  Amazingly enough, 
its picture was among the best, and its 
reliability was indeed the best -- no parts 
to go bad!  The company was owned by "Mad 
Man Muntz," the classic Los Angeles used 
car dealer. 

In the mid-fifties, GE came out with a 
transformerless 17-inch TV.  One side of 
the power line was tied to the chassis 
(2-wire plug back in those days).  The 
only protection was the plastic knob on 
the shafts of the various controls.  When 
servicing this TV, you quickly learned 
never to touch the chassis! 

The power supply was a simple full-wave 
rectified power line.  The tube heaters 
were connected in a series-parallel 
arrangement. 

These sets were the initiation of UL's 
investigation into antenna coupling 
capacitors.  These capacitors provided 
the isolation between the TV antenna 
terminals and the mains voltage. 

TV sets of those days consumed between 
400 and 600 watts.  When they were turned 
on, the cold filaments were a very low 
impedance, so the turn-on current was 
very high.  The off-on switch was often 
mounted on the back of the volume control.  
Eventually, the contact resistance of the 
switch would grow to the point where the 
I**2*R power would melt the solder and 
the power wires would come loose.  It was 
common to have a customer report that his 
TV was dead, and it was due to the lack 
of a good connection to the switch. 

At one company, we had metal bat-handle 
toggles blow out of the switch due to the 
cold filament load. 

Out of this experience, UL developed the 
requirements for the TV-rated switch, 
which had specially-designed contacts 
that would not overheat when used in a 
TV or similar application. 


Best regards, 
Rich 







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Conference Hall," 

RE: TV nostalgia

[Ehler, Kyle]

If they were'nt 'hand wired' who/what would have wired the chassis?
robots? chimpanzees?
Its funny how the public is led to believe that accepted status quo
is somehow better than an emerging technology, but then as Jack
points out, paper/phenolic was the best the technology had to offer
at acceptable cost until a better understanding of the applications 
caused the development of improved standards, materials, and processes.

Cheers,
Kyle
LSI Logic Inc.

-Original Message-
From: Cook, Jack [mailto:jack.c...@cax.usa.xerox.com]
Sent: Thursday, August 02, 2001 2:51 PM
To: 'Rich Nute'
Cc: emc-p...@majordomo.ieee.org
Subject: RE: Creepage dist. for more than 1000V ?



Rich,

Not really "absurd" given the quality of some of the board construction &
materials I saw in those early days.  For one thing, the materials did not
suffer heat well for very long (paper/phenolic?) - remember they were still
using tubes or later a mix of tubes & semi's.  I also worked in TV shops
during school and can remember thoroughly cooked PCB materials.

Regards,
Jack
Xerox EMC

-Original Message-
From: Rich Nute [mailto:ri...@sdd.hp.com]
Sent: Thursday, August 02, 2001 10:45 AM
To: emc-p...@majordomo.ieee.org
Subject: Re: Creepage dist. for more than 1000V ?






Hi Terry:


>   I don't recall the Sony but do recall the Philco and that Zenith held
out with the `hand wired' chassis.

Now that you mention it... I do indeed
recall that campaign.  But, I did not --
then -- realize the context.

Today, looking back, that campaign was
really quite absurd!  But it worked!


Best regards,
Rich



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RE: Creepage dist. for more than 1000V ?

[Ehler, Kyle]

I seem to recall seeing a couple of these.
By this time the 8080 processor was around and many things
were newly introduced, including silicon diodes.
I remember exchanging a few HV rectifier tubes with diode
equivalents.  Imagine confused packaging of semiconductors
in a form factor that bridges the tube to transistor age.
-kyle

-Original Message-
From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Sent: Friday, August 03, 2001 1:15 AM
To: emc-p...@majordomo.ieee.org
Subject: Re: Creepage dist. for more than 1000V ?



<95fbd8b0830ed511b7720002a51363f1319...@exw-ks.ks.lsil.com>, Ehler, Kyle
 inimitably wrote:
>Ah yes, the blissful aroma of hot tubes, ozone and fried
flybacks..those 
>were the days.. 
Didn't you have selenium rectifiers, too.? Inhaling selenium dioxide in
small amounts can be good for throat infections, but don't overdose!
-- 
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk

This message and its contents are not confidential, privileged or protected 
by law. Access is only authorised by the intended recipient - this means
YOU! 
The contents may be disclosed to, or used by, anyone and stored or copied in
any medium. If you are not the intended recipient, please advise the sender 
yesterday at the latest.

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RE: TV nostalgia

[Ehler, Kyle]

My experience was with the Packard-Bell transistorized models.
I think the aversion I have was prejudiced by the fellow
who mentored me.  I had little reason to doubt, but then
the sets I worked on, had a callback history that may have
been created by my mentor.
-kyle

-Original Message-
From: Rich Nute [mailto:ri...@sdd.hp.com]
Sent: Thursday, August 02, 2001 5:36 PM
To: emc-p...@majordomo.ieee.org
Subject: TV nostalgia






Okay... more nostalgia and a bit on safety
back in those days... so that we don't stray
too far from the subject matter of this
forum.

My first TV was a Motorola 7-inch round in
a Bakelite cabinet.  The speaker was the
same size as the CRT.

My second was the famous RCA 10-inch round
chassis with 32 tubes.  I could pull out
15 tubes and still have a usable picture.

Kyle mentions Packard Bell, which I considered
a straight-forward, good product.  It used the
Standard Coil turret tuner.

The one that won my respect was Muntz TV.
It was CHEAP!  When you looked inside the
chassis, there was nothing there compared to
the other TVs.  They really knew how to take
the cost out of the TV!  Amazingly enough,
its picture was among the best, and its 
reliability was indeed the best -- no parts
to go bad!  The company was owned by "Mad
Man Muntz," the classic Los Angeles used 
car dealer.

In the mid-fifties, GE came out with a 
transformerless 17-inch TV.  One side of
the power line was tied to the chassis
(2-wire plug back in those days).  The
only protection was the plastic knob on
the shafts of the various controls.  When
servicing this TV, you quickly learned
never to touch the chassis!

The power supply was a simple full-wave 
rectified power line.  The tube heaters 
were connected in a series-parallel 
arrangement.

These sets were the initiation of UL's 
investigation into antenna coupling
capacitors.  These capacitors provided 
the isolation between the TV antenna 
terminals and the mains voltage.

TV sets of those days consumed between 
400 and 600 watts.  When they were turned 
on, the cold filaments were a very low 
impedance, so the turn-on current was 
very high.  The off-on switch was often 
mounted on the back of the volume control.  
Eventually, the contact resistance of the 
switch would grow to the point where the 
I**2*R power would melt the solder and 
the power wires would come loose.  It was 
common to have a customer report that his 
TV was dead, and it was due to the lack 
of a good connection to the switch.

At one company, we had metal bat-handle
toggles blow out of the switch due to the
cold filament load.

Out of this experience, UL developed the
requirements for the TV-rated switch,
which had specially-designed contacts 
that would not overheat when used in a
TV or similar application.


Best regards,
Rich







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RE: Creepage dist. for more than 1000V ?

[Ehler, Kyle]

Ah, you guys have about 10/15 years on me...
I remember the Motorola Quasar 'works in a drawer'.  When they didnt work,
they were hard to fix..
Zenith had the motto 'the quality goes in before the name goes on'.  They
really were pretty good.
RCA had the best chassis, but the grounds always rattled loose on the
corners of the "pcb's".  I was a genius at fixing these with a soldering gun
-customers loved me, much to the disdain of the shop's $39.95 bench fee...
ROUND CRT's (kinescope) 'nuff said.
Curtis Mathis was a rebadged RCA chassis in a nice, expensive wood box (I
cant recall the RCA chassis #...'105'?)
I really hated those 'combo' sets with stereo -->500lbs!! eight feet long
and always in the basement w/fried flyback..
The worst TV's in North America were the 'packard-bell' ilk...that great
tradition carried on in their pc's..
Admiral's were ok -as long as you didnt twiddle out the ferrite core
thingy's...
dog hair + vacuum tubes = fuzz w/glass bumps.  dim bulbs..stinky tv..pops
and snaps.
crt 'brighteners' -sorry, but your pix toob is kaput, now..its just a BIG
radio w/4 channels..
Globar resistor, or at least a shadow of where it WAS..

Ah yes, the blissful aroma of hot tubes, ozone and fried flybacks..those
were the days..

I was sooo good that I retired after 10 months..
-kyle  =:)

-Original Message-
From: Rich Nute [mailto:ri...@sdd.hp.com]
Sent: Thursday, August 02, 2001 12:45 PM
To: emc-p...@majordomo.ieee.org
Subject: Re: Creepage dist. for more than 1000V ?






Hi Terry:


>   I don't recall the Sony but do recall the Philco and that Zenith held
out with the `hand wired' chassis.

Now that you mention it... I do indeed
recall that campaign.  But, I did not --
then -- realize the context.

Today, looking back, that campaign was
really quite absurd!  But it worked!


Best regards,
Rich



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RE: Mains fusing

[Ehler, Kyle]

Thank You so much Rich, Patricia, Mike, Jim, Ed, et al;

Please do continue to contribute your wisdom to this forum.

I spoke with my LES engineer and good friend at UL.  [a good friend at UL is
a handy thing!]
Someday I should expound on the usefulness of proper care and feeding of
your agency engineer..

In our discussions, I pointed out the grey area in 1950 2.6.2 & 2.7.4 [B]
related to the conditions 
of applicability (PAG), and that this modular product is deployed in a rack
mount environment 
where the mains cord is terminated in a polarized coupler (and disconnect
device) making it nearly 
impossible to reverse the mains.
In addition, the rack mount cabinet provides mains distribution to this
module through 
double side breakers.  I built my case on these two items and believe I can
get an approval
upon review.

I'm told the remaining problem with this UPS is it fails 61000-4-5 in our
lab, although it 
passes 801-5, and that it also fails conducted emissions when using QP->Avg
techniques.
I could be in for engineering a fire enclosure to contain wiring, coupler,
filter, suppressor, 
and while in the area, a double side breaker -and of course, the attendant
investigative redo.

Normally, this would be good reason for vendor rejection, or at least a
public drubbing in this
forum, but we are committed for the short term to use this vendor's product
and I cannot afford
to risk any relationships -for now.  The decision was never mine to make.  
And now we are in a familiar loop where the lab is used to re-engineer a
vendor's product 
that is CE marked.  Doh!!

Statue today, pigeon yesterday...

Thanks again,
kyle

my words, my opinions/mania...etc.
 



-Original Message-
From: Rich Nute [mailto:ri...@sdd.hp.com]
Sent: Wednesday, August 01, 2001 4:30 PM
To: keh...@lsil.com
Cc: emc-p...@majordomo.ieee.org
Subject: Re: Mains fusing





Hi Kyle:


>   I have a new product that includes an off the shelf UPS that is rated
for
>   230V ac operation and has an internal single pole circuit breaker on the
>   mains inlet.  We want to target this product world-wide.  The UPS
presently
>   is CB and certified to EN60950 european only.  For North America we want
it
>   to have UL1950, and to obtain this, UL is demanding the breaker be
double
>   pole.

This is an unusual situation.

On the one hand, the UPS, with single-pole overcurrent
protection, has a CB to EN 60950 for use in Europe where
most mains supply plug configurations are non-polar.
There is no control that the overcurrent protection will 
be in the live conductor.

On the other hand, the UPS, with single-pole overcurrent
protection, is denied UL certification for use in the
North America where UL requires polarization of both
the UPS overcurrent protection and the mains supply plug 
configuration.  There is a reasonable control that the 
overcurrent protection will be in the live conductor.

There is indeed something wrong with this picture.

My guess is that the certification engineer is invoking
Table 1, Case B (UL 1950, 3rd).  (As someone had already
suggested, you should verify this with your certification
engineer.)  Probably, this is because he knows that you 
are marketing your product worldwide.

Since you have a CB, you are qualified for Case B 
independent of your UL certification.  You should point
this out to your certification engineer.

I would ask UL to investigate the product under Case A.
UL can, at its discretion, investigate products to
specific provisions of their standard.  UL can invoke
paragraph D of the UL foreword to the standard.  You
can even ask UL to so note this construction in the
UL report. 

In my experience, these proposals should get you around
this situation.

If you are still unable to use the single-pole overcurrent
protection, I would go to another NRTL.


Good luck, and best regards,
Rich

RE: Mains fusing

[Ehler, Kyle]

Guys-n-Gals,
Thanks for sharing your knowledge!
Please dont worry about educating me here in the forum.

I have UL1950 3rd ed. 7/1995, but it has no clause 3.4.6.
I do have BSI 50091 :1993, I have the CB for this UPS and skimming/recall
seeing the UL 1448 (?) but I'm short on time to read and digest this week.
(Time for annual CTDP lab inspection, -oh joy!)

kyle

 
-Original Message-
From: Ehler, Kyle [mailto:keh...@lsil.com]
Sent: Wednesday, August 01, 2001 6:59 AM
To: 'EMC and Safety list'
Subject: Mains fusing



Greetings, 

I have a new product that includes an off the shelf UPS that is rated for
230V ac operation and has an internal single pole circuit breaker on the
mains inlet.  We want to target this product world-wide.  The UPS presently
is CB and certified to EN60950 european only.  For North America we want it
to have UL1950, and to obtain this, UL is demanding the breaker be double
pole.

Many of our existing products (including this new product) employ SMPS type
power supplies that are fused on the line side only, yet they are certified
to EN60950, UL1950 and CB.  How can these products be acceptable yet another
cannot?

Am I missing something? 
I'm confused. (no pun intended  :) 

Kyle 

Mains fusing

[Ehler, Kyle]

Greetings,

I have a new product that includes an off the shelf UPS that is rated for
230V ac operation and has an internal single pole circuit breaker on the
mains inlet.  We want to target this product world-wide.  The UPS presently
is CB and certified to EN60950 european only.  For North America we want it
to have UL1950, and to obtain this, UL is demanding the breaker be double
pole.
Many of our existing products (including this new product) employ SMPS type
power supplies that are fused on the line side only, yet they are certified
to EN60950, UL1950 and CB.  How can these products be acceptable yet another
cannot?

Am I missing something?
I'm confused. (no pun intended  :)

Kyle

RE: New standards -404 error

[Ehler, Kyle]

This link:
http://europa.eu.int/comm/dg03/directs/dg3b/newapproa/eurstd/harmstds/reflis
 
Produces a '404' for me.
I get as far as http://europa.eu.int/comm/dg03/directs/dg3b/
 before the pages are unavailable.

Thanks,
Kyle 


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RE: Gel-Cells in IT equipment

[Ehler, Kyle]

Thanks to those who responded.  I'm still stuck...and feeling a bit dumb
about posting this.

The UL investigator working this ITE product is insisting on application of
a standard for these batteries beyond IEC 60950.
I posed the question of which standard he is applying my product's batteries
to and he supplied me with a list of 31 standards ranging from IEC 60050-481
to IEC 61434 with none marked in particular.  This product is intended for
stationary computer room environments and SOHO, not aircraft, traction,
starters or ships.  Since these cells are lead-acid and valve regulated, the
nearest standard that might apply is IEC 60896-2 (batteries - stationary,
lead-acid - General requirements and methods of test) but I do not have this
standard.  Can anyone give me a clue what this is or what to expect?  Do I
really need it?

Same vein:
This product uses a hardware optical communication through class one laser
devices, which meet IEC 60825, my feeble mind can understand the why's
behind this standard as it applies to my product, but where would I look to
understand what would apply to a CB'd product using lead-acid, valve
regulated standby batteries?

Kyle 



>I have a sticky situation that I want to share with you for
opinions on
>either how to negotiate this with UL, or select a different battery
vendor
>to satisfy the agency.
>
>We make an ITE product that uses a couple of 6V 7.7Ah sealed gel
cells as a
>battery backup (BBU) for buffer memory in a disk array controller.
The
>batteries are fault protected from the charging circuits with a
resettable
>fuse (polyswitch).
>The BBU is an all steel box that fits into the fire enclosure of
the product
>-which is all steel as well.  The BBU could almost serve as a fire
enclosure
>in itself, but I don't claim it as such.
>The batteries are a listed component (BASS2), but the Mfr. does not
certify
>the flame rating of the battery.  These are part numbered with an
'FR' for
>flame resistant which implies a better flame rating (V0 in the
resin
>listing) yet remains vague because proving the flame rating
requires a lot
>code traceback to the vendor of the battery case parts.  The
batteries are
>not marked for flame rating or UL Recognized Component but in my
description
>I list them as V0 rated.  Have I gone wrong with that?
>
>I want to obtain CB for this product by either TUV or UL and UL is
asking
>for a 'European Certificate' for this domestic U.S. made battery.
There
>never has been a 'European Certificate' for this battery and I
doubt there
>ever will be.  As an interesting side-note, we have TUV Rheinland
doing the
>CB for this product in parallel, and they have not asked for any
certs for
>these batteries.
>
>The dilemma I am faced with is that if I cannot produce a 'European
>Certificate' for these batteries, we may be forced to re-select a
vendor.
>My question is; do I have any negotiating room to reason the UL
investigator
>out of his concern for this application?  What tactical approach
(if any)
>would work?
>On the other hand, we have been using this same battery in another
nearly
>identical product that has had CB for several years.  The
difference being
>that the investigator on this new product has changed from previous
years
>and he has a bit more zeal in the performance of his job.  I am
hesitant to
>start a big stink because it might stir the other product into this
and then
>I've got two products in limbo while we scramble to adjust.
>
>Any pearls of wisdom deeply appreciated.
>
>Kyle Ehler  kyle.eh...@lsil.com


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Permanence of marking test.

[Ehler, Kyle]

I'm sorry to plague the list with such a mundane query, but I am forced to
perform the UL1950 '1.7.15 Permanence of Marking' test using HEXANE as the
test solvent.  I cannot find a local source willing to sell less than
55Gal
0.5L would probably last me ten years.

Anybody know of a source?
Kyle Ehler  kyle.eh...@lsil.com   
Assistant Design Engineer
LSI Logic Corporation
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8889
Fax 316 636 8315

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Home-Made RF probes.

[Ehler, Kyle]

Greetings,
15 years ago I was doing some work at SWRI in San Antonio where I watched an
EMC tech construct two RF probes from small diameter copper jacket hardline
(semi-flex coax?).  These probes resemble a kid's toy soap bubble loop, but
they work wonderfully well for non-contact source investigation of radiated
emissions ranging into the Ghz region.  Our lab still uses these for debug
work to this day, but now they are a bit worn and I suspect they will need
replacing.  Trouble is, I'm fuzzy on their construction details.  Below,
please peruse the steps I recall and offer any corrections or improvements.
I have attached a couple .jpg's for clarity (hope I didn't stretch the
rules).

-For the high resolution probe (see photos):
1)  Start with 6 to 8" length of 0.0625 copper jacketed solid conductor
hardline for 0.5" diameter probe.

2)  Remove 0.125" of jacket and insulation from one end.

3)  Roll-form stripped end of coax into 0.5" diameter loop with exposed
center conductor and jacket touching probe shaft  jacket.

4)  Solder center conductor of loop to jacket first, then outer jacket
of coax end to jacket of probe shaft.

5)  With a sharp knife (X-Acto) cut a 0.010" concentric ring out of the
jacket at the apogee from the probe shaft, exposing the center conductor,
but not cutting it (ok to leave foam insulation intact).

6)  At other (handle) end of probe shaft, affix a female BNC (or SMA?)
connector (your choice?) and carefully solder fillet 360' of connector to
jacket.

7)  Dip finished probe twice into 'Plasti-Dip' of your choice colour.
Let cure in between coats and before use.

-For a low resolution probe:
Substitute 0.125" hardline in 1) above.
Form loop into 2" diameter in 3) above.

The small loop and a wideband preamp is really good for non-invasive
pinpointing the source of radiation (chip, trace, xtal, etc.).

 <>  <> 

Kyle 
<><>

RE: Coatings for Ferrite Tiles?

[Ehler, Kyle]

Hi Scott,
I applied 1" bead board (styrofoam) in 4X8 sheets.  After many trials with
double sided carpet tape, foam tape, silicone rubber compound (RTV), etc. I
found that 'Liquid Nails -Project' (latex based -non solvent) applied with a
caulk gun to reliably hold the panels in place.  I used a 2" dollop in each
corner and one in the center of each panel.  This was fairly cheap and quick
to apply, but getting 40+ sheets of foam into the back of a pickup and then
into the facility (on a breezy Kansas day) quite a challenge.  These panels
easily break, but patching them isnt too bad if you can catch and retrieve
the bits...downwind 1Km.

Not only does it aid with the light level, but it also damps the acoustic
chatter and just feels warmer..

N'yuck, n'yuck,
Kyle 

-Original Message-
From:   Lacey,Scott [SMTP:sla...@foxboro.com]
Sent:   Friday, October 01, 1999 1:26 PM
To: 'emc-p...@ieee.org'
Subject:Coatings for Ferrite Tiles?


To the group,

Can anyone recommend a paint or other (light colored) coating that
can be
applied over ferrite tiles?
The lighting in the bat cave (shield room) is rather grim. It can be
very
difficult to see when working inside of a cabinet. Photos of test
setups
would also look better if there were less contrast with the
background.

Scott Lacey

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Warning label sizing.

[Ehler, Kyle]

Greetings,
We have been lucky in the past, but with the real estate crunch that comes
with smaller products, its getting more difficult to find space to apply a
warning label.
For example, a 'Class 1 Laser Product'.
Just how tiny can the text/graphics in a label be and still comply?

Kyle 

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Creating a reference library -which standards?

[Ehler, Kyle]

As John, Scott and Nick have stirred (RE: IEC 60990 Vs IEC 60950), I just
happen to be in need of specifying which standards to purchase in effort to
have a comprehensive up-to-date reference library.  It's that budget
time...but I don't want to run up a huge bill with standards we may not
need.  I know it was said that keeping the 60950 standard a minimal size was
desirable, but in retrospect, the myriad of documents needed to support
compliance work adds up to a whopping stack.

We manufacture ITE products (disk storage boxes, storage array controllers
and an intelligent server hub).  None of which connect to the POTS or are a
medical device.  We are based in the U.S.A. and desire to ship domestic and
worldwide.
We would want to apply an optional matrix of the UL, CUL, TUV, CE, GS and
C-Tick marks to our product ID labels which would span the worldwide
compliance standards for EMC and Product Safety.

We currently use UL 1950 3rd edition and a CB scheme with EU country
deviations for safety, and EN/IEC standards for EMC to penetrate the foreign
markets, but at times, get surprised.  I could list here what standards we
do have and their vintage, but for those out there who have similar dilemma,
perhaps a clean start would be best.

If the collective would be so kind and willing to advise which standards
would suit -or perhaps we all could pitch in and formulate some sort of
tabular method for choosing what you need based on what/where you
manufacture and what/where your customer's demand in the way of compliance,
this would be a start.

I don't know, maybe I'm just trying to nail jelly to a tree...

Thanks anyway,

 Kyle Ehler  kyle.eh...@lsil.com   
Assistant Design Engineer
LSI Logic Corporation
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8889
Fax 316 636 8315

-Original Message-
From:   Nick Williams [SMTP:n...@conformance.co.uk]
Sent:   Tuesday, September 28, 1999 2:50 AM
To: emc-p...@majordomo.ieee.org
Subject:Re: IEC 60990 Vs IEC 60950


Very little to do with the topc in the header I'm afraid, but...

This post raises a point which has concerned me for some time, and
which
I'd be interested in opinions from other sources on.

It is my impression (and it is only an impression - I have made no
attempt
to gather objective evidence) that it is increasingly common for new
standards to be issued,  and existing standards to be modified, with
certain tests removed from the standard itself and replaced with a
cross
reference to another harmonised or IEC standard.

This seems to be particularly true of mechanical tests (e.g.
vibration,
drop test, enclosure access).

Standards writers would doubtless argue that this makes good sense
because
it make updating these specialist requirements easier, and it
standardises
(!) the requirements between different documents.

Personally, it's a practice which annoys me and I think it is bad
standard
making. I say this on two grounds:

1. Few things annoy me more in relation to standards than spending a
shed
load of money on an enormous document which is supposed to be a
comprehensive set of requirements and then discovering I have to
spend a
load more money to buy subsidiary standards in order to find out
what the
requirements of the main standard really are. It's difficult not to
conclude that this is profiteering by the standards publishing
bodies.

2. When you get a test certificate for an appliance which has been
tested
to (say) BSEN60950:1992 it would be nice to think you could tell
exactly
what requirements have been applied to the product. However, if one
has to
know which version of the subsidiary standards have been applied,
the
process quickly becomes a nightmare.

60950 may be a bad choce to illustrate this phenomenon - I'm not
very
familiar with it, although I know lots of other people on this list
are.
The problem is particularly prevalent in machinery standards, but it
is
also creeping into the main electrical safety standards (e.g.
EN60204 and
60335).

Personally I can see no reason not to give the full requirements of
the
subsidiary standard in the main standard, and to cross reference the
subsidiary standard as well. That way, when you buy the main
standard you
get a completely comprehensive set of requirements, but if you want
to see
what might develop you can look at how the subsidiary standards have
been
changed since the main standard was last issued.

I'd be interested in commends from others on this topic - especially
anyone
on the list who is closely involved in standards writing. Maybe if
enough
people agree wit

RE: help (plastics marking)

[Ehler, Kyle]

I'm probably mistaken, but it would seem that just having the plastic
material marked on the parts would not be enough proof because of the chance
of mis-marking.  Have I missed something here?  This just seems too easy.

I presently use a system of lot marking codes with a simple one-page
document that is shipped with each batch of parts from the vendor.  The
document has the name of the vendor's QA person in signature and the
relevant lot numbers for each shipment from the factory and the exact
plastic material name and/or number with the UL 94xxx flame rating.  All I
do then for the inspector, is pull the recent shipment tracking sheet from
our receiving/inspection department as filed under the part number and let
him/her witness the document and a few of the marked parts from the bin on
the assembly line...

There should be a caveat here:
Many times a plastic part is used as a subassembly into a finished part.
The problem with this system is that tracing back a part number for a
finished part may not lead one into the subassembly part(s) so a disconnect
will occur making it difficult and time consuming to trace some parts to the
source unless you maintain a listing of parent part numbers and drawings for
inclusion to finished assemblies.  This also means you must keep the list
current as engineering/manufacturing changes.
-blech!

I have wanted to switch to a system similar to what Pryor uses, but with
dozens of individual parts, this will easily become an arduous task for me
and I'm not sure if it is acceptable anyway.  If I'm gonna go to all that
effort I'm also going to combine the markings to include a plastic material
name/number, flame rating and the chasing arrows (recycling) mark.  This
would satisfy the UL inspector, the 'greenies' and life's end recyclers.  I
know for a fact that IBM uses a system such as this now along with the
'recognized component' mark, but it seems to me that this mark would lend
the credibility to make such a system acceptable...am I expecting too much?

Btw, Hello Pryor !!

Kyle Ehler  kyle.eh...@lsil.com   
Assistant Design Engineer
LSI Logic Corporation (formerly NCR, AT&T GIS and Hyundai)
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8889
Fax 316 636 8315

-Original Message-
From:   PRYOR  MCGINNIS [SMTP:c...@prodigy.net]
Sent:   Saturday, September 18, 1999 9:43 AM
To: Price, Ed; emc-p...@ieee.org
Subject:Re: help


I have experienced good results by requesting the Part/Component
molder to
mold the plastic identification in the part/component.

Pryor McGinnis
c...@prodigy.net

-Original Message-
From: Price, Ed 
To: 'emc-p...@ieee.org' 
Date: Friday, September 17, 1999 11:04 PM
Subject: FW: help


>
>Posted for  john.linst...@gefgreenville.ge.com
>
>
>
>
>
>
>
>

>:-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-)
>Ed Price
>ed.pr...@cubic.com
>Electromagnetic Compatibility Lab
>Cubic Defense Systems
>San Diego, CA.  USA
>619-505-2780 (Voice)
>619-505-1502 (Fax)
>Military & Avionics EMC Services Is Our Specialty
>Shake-Bake-Shock - Metrology - Reliability Analysis

>:-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-)
>
>> -Original Message-
>> From: Linstrom, John  (IndSys, GEFanuc, CDI)
>> [SMTP:john.linst...@gefgreenville.ge.com]
>> Sent: Friday, September 17, 1999 2:44 PM
>> To: 'Price, Ed'
>> Subject: RE: help
>>
>>
>> My question: we have a UL mark on a box we build. One of the
requirements
>> that the auditors check is flammability of materials. 2 parts
give us
>> trouble - a molded bezel and a plex screen. Both are materials
purchased
>> elsewhere by our fabricators. UL says either assemble a 'paper
trail'
that
>> shows continuous control of the materials, or use a 'recognized
>> fabricator' (read buck$) to make our parts. Neither fab. house is
>> recognized or wants to be.  UL is VERY evasive about the required
>> documents for the 'trail'. Any one have this experience - and
succeed?
>> Thanks-
>>
>> John Linstrom
>> Computer Dynamics
>> PH 864.281.7768 x266
>> FX  864.675.0106
>> john.linst...@cdynamics.com
>>
>>
>
>-
>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
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>jim_bac...@mona

RE: Ground Bond Testers - Continued

[Ehler, Kyle]

-Original Message-
From:   Brian At Work [SMTP:bkundew...@qtm.net]
Sent:   Monday, September 13, 1999 9:26 AM
To: emc-p...@ieee.org
Subject:Ground Bond Testers - Continued


Thanks to everyone for your replies.

Using step down transformers, variacs, and current clamps work well
for
performing the Ground Bond test here in our safety lab with trained
personnel, but this is not an acceptable procedure for less trained
production line personnel.

Kyle emits:

This is a problem everyone has to deal with.  The best approach is
an up-to-date shop floor procedure and the use of a sprinkling of 'master
technicians' who deputize those who are competent to understand and perform
the tests and train others.  A procedure for the tests and a start of day
procedure to maintain confidence in the production test equipment is a must
and  to keep the vigil, a per unit checklist with a strong suggestion to
consult the master techs if a question or unusual occurrence should arise..

The lack of a commercial Ground Bond Tester that will achieve high
current
has me wondering if other manufacturers of high current equipment is
performing 100% production line Ground Bond tests.  Am I missing
something
here?  Does this test not need to be done outside the safety lab?
Am I
foolishly looking for a easy, safe, production line solution for
high
current ground bond testers?

Thanks,
Brian


Kyle emits:

This depends on your agreement with the target agency.  We use UL
under listing "NWGQ" and thus in their "Section General" -Section 2.0
Requirements For Factory Tests, therein lies the text of the methods for
manufacture.  Chances are you are tied to a %100 production line test of
both hipot and ground bond on each unit.  See section 2.1.1.1 for specifics.

There is however, a clause in 2.1.2.1 Test Equipment -that states
 "Any suitable continuity indicating device (such as an ohmmeter,
a battery and buzzer combination, or the like) may be used to determine
compliance with the Grounding Continuity Test requirements.  Commercial
ground continuity testers that pass a current through the grounding path may
also be used to determine compliance with the same requirements." 

Clause 2.1.3 and beyond go into detail of the methods of the
testing.  Acceptability is based on simple continuity between the conductive
parts specified.

Hmm, we presently do %100 test of ground bond and hipot at a full
minute each...I'll have to report to my superiors that a ground bond test
for 1 minute is not required.   Hey!! I just larned something!!  Can I have
a bonus now??  -nope...

Kyle

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RE: Ground Bond Testers

[Ehler, Kyle]

Hi,

As sensitive as some agencies are about test instruments and calibration,
using a rogue current source to do this test would seem to require some
level of traceability for the instruments used?  We maintain an updated list
of all lab instruments and calibration affectivity as used and include this
list when we submit test data (we are an in-house test lab w/COMPASS CTDP
with UL/TUV as target agencies).  Unless one uses a calibrated instrument to
check an uncalibrated 'reference instrument' prior to use, how can it be
expected to perform in a repeatable manner acceptable to the target agency?

I suppose an AC 'buzzbox' welder could be used as a current source, but
these are not terribly well regulated, voltage or current-wise, and getting
a repeatable setting may be difficult depending on design.

Pardon me if I made a dumb noise...

Kyle 
(basically a super-tech with an 'assistant something-or-rather' title tacked
on)

-Original Message-
From:   Brian At Work [SMTP:bkundew...@qtm.net]
Sent:   Friday, September 10, 1999 3:48 PM
To: IEEE Group
Subject:Ground Bond Testers

Hello Everyone,
 
If I have a product that is rated 40 amps at 230V~, I assume I will
have to perform Ground Bond Testing at Twice the Rated current per EN61010-1
section 6.5.1.2 which would be 80 amps.  I have checked by regular sources
and have only found testers that goes to around 30 amps.  
 
Can anyone send me a source to purchase a Ground Bond Tester that
goes up to maybe 100 amps?  
 
If such a device does not exist, can anyone give me their
recommendations on how to best perform this test?
 
Thank you and best regards,
Brian Kunde

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Insulation resistance

[Ehler, Kyle]

I just received an amended CB report for a product we make and I was
reviewing it and see that a 'fail' verdict was given for a deviation + test
in Sub-Clause 5.3.101 of the Japanese deviation to IEC 950.  A remark of
"Not evaluated as part of this investigation" also appears.  The text of the
Deviation + Test reads: "Add: The insulation resistance shall comply with
the requirements of Clauses 16.3 of IEC Publication 335-1 (1976) Second
Edition."

I use UL1950 2nd and 3Rd ed. and I cannot find this 5.3.101 reference in the
latest copy of the standard, much less IEC Pub 335-1.  If a customer put me
on the spot for this, I might need to test for it... Can someone educate me
on this?

Thank You.

Kyle Ehler  kyle.eh...@lsil.com   
Assistant Design Engineer
LSI Logic Corporation


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RE: ground bond test

[Ehler, Kyle]

Interesting how the this forum hits on my concerns.

I recently had a new product witnessed by a UL engineer from NorthbrooK.  He
wanted to see the ground bond test performed and so I ran the test for two
minutes at 30A and 6Vac.  When he saw this, he demanded the test be run at
12Vac which is beyond the capability of the tester.  Is there any
requirement to run this at 12V?  The test described in UL 1950 3rd edition
2.5.11 states "The test voltage does not exceed 12V" and current of [25 or
30 A] depending on CSA or UL (we certify to both).

As an aside, the engineer was new to ITE, having previously been in the
'hazardous locations' segment of the Engineering Services department.

Kyle 

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RE: Temperature Measuring of Magnetic Components

[Ehler, Kyle]

Hi Kamran,

I've run into this problem myself.  Usually, it is because the test
conditions you use are different from what the vendor is using.  They may be
loading the EUT to full capacity and/or using a thermocouple attachment
method different from yours.  In the case where your product's configuration
is not identical to the vendor, you can expect some discrepancy.  Compliance
agencies such as UL understand that your conditions of applicability are
different from the vendor's and thus your data will be unique.

If you wish to minimize the discrepancy, load the EUT to maximum rating and
use a similar probing scheme as the vendor.  
In some cases,  magnetic flux can be so great that it induces an undesirable
EMF and reading error in which case you might have to run the EUT until
thermal equilibrium occurs then, cut power and take a measurement sweep
immediately afterward.

UL for example, demands that the thermocouple probe be attached to the
windings of the coil -with the thermocouple junction in direct contact with
the wiring and NOT through core, ferrite or tape insulation (if the
conductors are coated there is no need to remove the coating).  I was just
audited a couple weeks ago for COMPASS FUS and was reminded that the use of
cyanoacrylate glue or thermal conductive epoxy to attach a thermocouple to a
coil was entirely acceptable.

Here's a  tip in using thermocouples:  It is best to force the junction
wires of the thermocouple to fuse into a single point and to avoid using a
junction made of twisted bare wires (which forms several thermocouple
contact junctions and can cause errors).  In the fabrication of the
junction, I use a microtorch to fuse type 'J' thermocouples.  Twist the
wires together, but clip the excess off and leave enough that when you hit
it with the torch a 'ball' fuses from the wires and consumes all the twists.

This takes a little practice but works much better than using a zapper to
'arc' weld thin 30 to 36ga. wires (IMHO).  I then check each channel for
accuracy before attachment and test.  On most thermocouple types the red
wires are negative polarity, white is positive.  The thinner the wires, the
better ease in accessing tight spots and getting a good contact.


Kyle Ehler  kyle.eh...@lsil.com   
Assistant Design Engineer
LSI Logic Corporation
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8889
Fax 316 636 8315

-Original Message-
From:   Kamran Mohajer [SMTP:kmoha...@cisco.com]
Sent:   Tuesday, August 24, 1999 4:50 PM
To: emc-p...@ieee.org
Subject:Temperature Measuring of Magnetic Components


Hello EMC-PSTCers,

I wonder if anyone knows of the method of measuring temperature
limits on magnetic components.  I happen to get involved in this and found
that my results are different than the vendors result by as much as 10-15
degrees on measuring on a same magnetic component.  Even applying the
thermocouple to different location on a coil seems to give you different
results.  Is there a method that I should be following to measure
temperature with thermocouples methods, not change of resistance, on
magnetic parts such as transformers, coils, etc.? 

Thanks,

 


***
Kamran Mohajer
DSL Compliance Lead
Cisco Systems, Inc.
Phone(408)-525-6121
Fax(408)527-0495
kmoha...@cisco.com


***

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RE: Egon Varju, where are you? (EN60950)

[Ehler, Kyle]

Hi Egon,
Gee, I'm glad the list found you.  I was really worried for a moment...  ;)

I checked out the CENELEC decision website and found it to indeed be missing
the EN60950.  Could I infer from this that there have been NO
decisions...nyet!  The site looks like it could use some tender loving care.

I would be interested in a copy of what you have.  (I'm trying to live in
60950-land)
EMC work is OK, but I don't care to sit behind or inside a hot winded
machine all day (or three!) jolting the ESD out of it.

Also, the threads about U.S. national standards was rather interesting.  As
you can see from my handle, I am not an engineer although I am pretty much
forced to work, associate and think [act?] like one.  (but not spell,
grammar or paid like one..)  =:)

I've been reading some of these references in the CFR and NEC and I think it
is funny that REAL engineers look at this material and get bedeviled trying
to pin down an exact answer to a specific question.  Small wonder that there
is so much work and so little time.

-back to 'lurk' mode...

Please and Thanks,

Kyle Ehler  kyle.eh...@lsil.com   
Assistant Design Engineer
[PSE]  
LSI Logic Corporation
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8889
Fax 316 636 8315

--Never play 'leapfrog' with a Unicorn.  -murphy

-Original Message-
From:   Egon H. Varju [SMTP:e...@varju.bc.ca]
Sent:   Thursday, August 19, 1999 11:50 AM
To: b...@lyons.demon.co.uk; EMC-PSTC
Subject:Re: Egon Vargu, where are you?


Hi Bill,

No, I haven't disappeared.  As desirable as the thought may seem,
it's not 
that easy to get rid of me.
:-)

Regarding the "Cenelec's List of Decisions," yes, I have cancelled
my home 
page.  Wasn't really using it (too busy with my day job), so it was
a bit 
of a waste of money.

In another message on this thread, Art Michael points to a URL that
has 
some of these decisions.  I took a quick look, but it doesn't seem
to 
include EN 60950.  If anybody wants a copy of the one I made up, I
will be 
glad to send a copy by e-mail.  Alternatively, if anybody wants to
post 
this on an easily accessible web site, they are welcome to do so (We
need a 
volunteer here.  Art?).  Just make sure the entire document is
posted, 
including my disclaimer.

Cheers,
Egon :-)

At 12:54 AM 19/08/1999 , you wrote:

>Friends,
>
>As you may know, I maintain the sci.engr.electrical.compliance
(SEEC)
>FAQ.  I was recently alerted by Richard Steele

>that the link in section 2.4 "Cenelec's List of Decisions"
>http://www.varju.bc.ca/standards/ no longer exists.
>
>On further checking, I found that Egon Vargu's home page at
>http://www.varju.bc.ca was missing and the link took me to a
Californian
>web hosting service's home page.  Also, an attempt to email him at
> failed with "unrouteable mail domain
vargu.bc.ca".
>
>I have briefly tried searching the CENELEC website www.cenelec.be
but
>didn't find the "List of Decisions" there although it may well be.
>
>So,
>
>1.  Egon Vargu, where are you?  Or alternatively, does any reader
of
> EMC-PSTC or SEEC have a current email address or URL for him?
>
>2.  Can anyone point me to an alternative URL for the CENELEC "List
of
> Decisions"?
>
>Thanks and regards,
>
>Bill.
>
>--
>Bill Lyons - b...@lyons.demon.co.uk / w.ly...@ieee.org
>  Maintainer of the s.e.e.c FAQ - archived at:
>  HTML:
http://world.std.com/~techbook/compliance_faq.html
>  ASCII: http://www.lyons.demon.co.uk/seecfaq1.txt,
seecfaq2.txt

__

Egon H. Varju, PEng
E.H. Varju & Associates Ltd.
North Vancouver, Canada

Tel:   1 604 985 5710
Fax:  1 604 273 5815

E-mail:  e...@varju.bc.ca
__

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RE: PC Power Supply w/ PFC

[Ehler, Kyle]

John,
When you find one, post the vendor here on the list.
-we looked for one also, but with ATX wiring, and could not find one that
had international compliance.  The vendor is Sunpower model SAP 6300P.  It
is CE marked and specifically marked with 'passes harmonics' and standard,
but there is no international compliance markings (or UL).  The vendor is
aware of the harmonics issue.  I don't have a model number for the straight
pc version supply.  I have tested this supply and I can tell you it is much
cleaner than the non-pfc counterpart.

Since I had to probe this supply with thermocouples for the heating test, I
examined the innards and saw that the PFC circuitry is actually a module and
is more of an optional upgrade.  The case of the supply was not intended for
this upgrade, but the circuit board of the supply did have a connector where
the PFC module wiring was connected.  The mounting of the module was a bit
ad hoc.  Interestingly, the vendor offered to upgrade the other supplies we
had on hand in the lab.

Kyle


 
-Original Message-
From:   John Radomski [SMTP:john_radom...@inter-tel.com]
Sent:   Tuesday, August 17, 1999 12:34 PM
To: emc-p...@majordomo.ieee.org
Subject:PC Power Supply w/ PFC


We are looking for a supplier of 300 Watt PS2, PC power supplies
that have PFC
(Power Correction Factor).
Here is the spec:

It must comply with: EN 60950 (safety approval required), EN
50082-1, EN
61000-3-2/3, CISPR 22 (or EN 55022).

REQUIRED RATED INPUT: 220-240VAC, 50-60Hz, 3.5A (auto ranging power
supplies
with input ratings from
 100VAC, are
accepted)

OUTPUT: +5VDC  30A; -5VDC  0.5A; +12VDC  12A; -12VDC  0.5A

John Radomski
Compliance Engineer
Inter-Tel Integrated Systems,
Chandler, Arizona, USA
john_radom...@inter-tel.com




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RE: cost effective EMC facility

[Ehler, Kyle]

My lab is just 90Km from the world's largest salt mine (Cary Salt,
Hutchinson Kansas, U.S.A.).
The mine is 0.9Km underground.  We send our records there for permanent
archival.
-I'll suggest this to my superiors as a possible OATS relocation site.
[yeah, right!!]
Imagine: negligible RF and acoustic ambients (other than your lab
instruments and computers), constant temperature and humidity.
Kyle 


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RE: cost effective EMC facility

[Ehler, Kyle]

Is this an oxymoron?
I sometimes wish we had a GTEM, but our anechoic screen room has just
started to be used for pre-compliance testing and troubleshooting.  The
workstation consists of a Braden CFC (3000 cu.ft Compact Ferrite Chamber),
AR FM2000 isotropic probe, AR 1Kw log periodic, AR 25W1000M7 amp, HP 8648B,
HP 8564E, Rhode & Schwarz ESCS30 and a PC w/labview /HP applications.  With
this rig we can perform both RF emissions pre-scan, troubleshooting and
susceptibility up to the host level.  

For PCB's alone I suggest an EMSCAN or an EPS 3000 tablet based scanner.
The EMSCAN rather sucked because of repeatability, but the EPS 3000 might be
much better because it couples a CCD imager with the RF scanner to provide
visual grids of the PCB's spatial profile.  Problem is, with either you
still need a screen room to prevent ambients from washing out your data.
And then you have to wrangle with hosts, card extenders, cable toss, etc..
At the time, the EMSCAN was less than $50K and I don't know how much the EPS
3000 is going for.  The CFC approach came in at around $400K or so (I built
the turntable for it to $ave) but the bottom line is this work is always
expensive in both hardware and headcount.  It depends on how far you need to
go and how badly management wants it...
Kyle Ehler  kyle.eh...@lsil.com   
Assistant Design Engineer
LSI Logic 


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RE: NSA (wrangling with ground screens)

[Ehler, Kyle]

Hi Richard,
I've been tasked with maintaining the ground screen on our OATS and what
worked best for me on galvanized screen (aka hardware cloth) was a tub of
fresh acid flux, such as that found in plumbing stores, and a 300 watt
soldering iron with a wide tip.  I don't recommend using a torch because it
causes more oxidation than can be tolerated -it makes it more difficult for
the solder to wet the joint.  You can use a torch with a soldering
attachment, but a bare flame just wont do...  A very important detail is to
pre-clean the seam area of the mesh by brushing on  muriatic acid straight
from the jug (no scrubbing needed), but be sparing with this stuff because
it will dissolve concrete if too much is present.  We don't have a source of
water near our site, but if possible you can rinse the acid away after
soldering.  After applying the acid, then brush on the flux and then heat
and solder.

It does not matter how old the mesh is as long as the galvanized coating is
still intact (your site does have galvanized steel mesh, I assume, but the
same is true for brass).  I brush on a lot of the flux and heat the joints
with the iron while feeding the solder in.  The flux is like wax in cold
temps and turns to liquid at warmer temperatures and flows/coats the seam.
Since we do electronics, I have used ordinary rosin flux cored solder (in
other words, electronic grade solder) and soldered with that.  Bar solder
could be used if you have enough heat and flux.   Mixing of the fluxes does
not matter as the acid flux is more aggressive and will overcome rosin flux
on the substrate to be soldered.  The key is clean parts and heat.  Lots of
heat will ensure a thorough penetration and secure joint both electrically
and mechanically.  The screen wire is steel or brass and can take the heat,
but some of the mesh might try to separate.  Use clamps or weights to hold
it in position while working.  In some cases you can build up a mold from
wood and pour molten solder in and let it cool.  Originally, our screen was
made up this way and after 12 years in the Kansas weather, holds up very
well.

In high traffic areas or in areas that have worn through, I have had to
overlay a new section of mesh as a patch and solder around the periphery to
restore the grounds.  The trick here is stretching the patch and mesh so
that you do not get a bubble effect.  That is a bit dicey, but can be done
with help from extra hands while soldering in the patch.  In many cases, I
have had to use a 'tacking' method where I solder small spots spaced at
intervals to get the mesh fixed in place then follow up with a second pass
where I fill in between the tack spots.  Hey, any job worth doing is worth
doing well, I figure.  

Attaching the screen to ground posts is another trick.  We like to use
copper grounding rods with brass clamps and a short bit of heavy tinned
copper braid to connect from the clamp to the screen.  Then heap on the
solder to attach the clamp to the braid and the braid to the screen.  This
takes a lot of heat.

I like to do this sort of work in the morning before it gets too hot.  I
work with the sun to my back and while wearing leather gloves and a pair of
knee pads.  Even a slight breeze will blow away your heat and your solder
flow penetration will suffer.  In some cases I have had to erect a temporary
windbreak.

Good luck.
Kyle Ehler  kyle.eh...@lsil.com   
Assistant Design Engineer (and rusty Porsche restorer)
LSI Logic Storage Systems Division
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8889
Fax 316 636 8315


-Original Message-
From:   WOODS, RICHARD [SMTP:wo...@sensormatic.com]
Sent:   Wednesday, July 28, 1999 3:16 PM
To: 'emc-pstc'
Subject:NSA


After completing an exhaustive set of diagnostics, we suspect a
problem with
ground screen solder joints near our table.  We suspect that many of
these
joints were not properly heated and/or that flux was not used.
Someone other
than my team finished this portion of the pad before we fired them
for
incompetent work. So now we are faced with soldering a five year old
galvanized screen. One thought is that we will have to use a wire
brush to
remove the dirt and oxide. The second thought is that a flux (rosin,
acid,
other?) may be sufficient.  The third idea, and the least
acceptable, is to
start over with a new screen. What are your recommendations?

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This message is coming from 

Harmonics (EN 61000-3-2) testing of EUT's > 1KW

[Ehler, Kyle]

Hello,
I've just come across an ITE product that fails power line harmonics (EN
61000-3-2).
Naturally, the engineer in charge is nervous about it and wants to know if
there is any way around the requirement to pass.
If memory serves, the standard does not actually go into effect until
1/1/2001 is this correct?  What exposure remains?

Given that, some of our more picky customers may demand it soon.  At which
time we will pursue a power supply with PFC.  We already have identified a
candidate, but it has UL certification and no other.  We have learned that
an off the shelf item without full global compliance is a direct invite for
investigation and redesign to gain compliance -at our expense. Globally
accepted supplies are a must in our business. 

I was reading in Compliance Engineering (March/April '98 pp. 33) that some
discussion has been made concerning the operating class of EUT's to date.
There are four classes (A through D) which categorize products as to power
phases used, consumption character, and intended use.  The limitations of
Class D excludes EUT's with power ratings higher than 600 watts which would
leave an undefined region for testing of such products exceeding this
figure.  The article mentions a "Class E" as professional equipment, but no
limits were expressed but maybe I am confused. 

This product consumes in single phase 1.3KW or more depending on
configuration.  It is made up of a mix of smaller modules that independently
meet all applicable standards including harmonics.  The majority of the
modules employ PFC and therefore are tolerant of stacking into a cabinet
such as this and still comply.  Then we add a couple non-PFC modules, that
by themselves are compliant, and now the harmonics fail in two or three of
the odds.  Swapping of power supplies (cherry picking) shows a range of
failures from 1 to 200 ma over the limit (in class D req'mts) depending on
harmonic.

The next question I would pose:  Is this a non-issue because the EUT is
unclassified ("professional equipment") and therefore exempt?

Thank-You,

Kyle Ehler  kyle.eh...@lsil.com   
Assistant Design Engineer
LSI Logic Storage Systems Division
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8889
Fax 316 636 8315


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RE: Source for Attenuators

[Ehler, Kyle]

Hi Brian,
Those sound like 5 or 10 watt Pasternack prices...they 
are better than HP, but still higher than what we stumbled
into at some of the HAM radio crowd's cache of stuff.  
I'm assuming you want 50 ohm 'N' connector types.  
Check out this guy: 
Gaylen Pearson WB0W  (WBzeroW)
P.O. box 8547
Saint Joseph, Mo. U.S.A. 64508
816 364 2691
800 626 0834
w...@ibm.net   
www.wb0w.com

Don't you just love NSA?  Another one of those 
'builds character' attributes of the black art...
Kyle Ehler  kyle.eh...@lsil.com   
Ass. [of] Design Engineer
LSI Logic Storage Systems Division
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8889
Fax 316 636 8315


-Original Message-
From:   Brian At Work [SMTP:bkundew...@qtm.net]
Sent:   Thursday, July 22, 1999 3:51 PM
To: IEEE Group
Subject:Source for Attenuaters

Hello group,
 
I need to order some attenuaters for NSA: 3db, 6db, and 10db.  I
looked up a few sources and almost had a heart attack.  I'm getting quotes
of $120US per. These are for 10 watt, DC-18Ghz parts. Is there a more common
part (less power and bandwidth) that would be less expensive?
 
If you have a source for these parts that are better in price please
let me know.
 
I hate to bother all 800 members with this question but us "small
labs" have to watch our budgets.
 
Thanks to all.
Brian

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RE: Record Retention

[Ehler, Kyle]

Hi Scott,
A while back I inquired with TUV, UL and FCC about this very subject.
UL and TUV is pretty loose about manufacturer's recordkeeping of production
run information, but product safety test data and related filing information
is expected to be retained for at least seven years after last production
date according to Kevin Hyland (x42652), the RROP for ITE records at the
Northbrook office of UL (847 272 8800).  For factory records, the point is
fairly moot as long as a FUS program is in place with quarterly inspections
conducted which include dielectric and ground bond procedures on %100 of
production and test equipment start of day checks. 
The FCC wants records maintained the same period or longer, but since the
two are closely related to agency compliance, archiving both EMC and Safety
data in one place is just good business practice.  Our lab is in process of
getting all but originals into electronic form and packing it onto CD-Roms.
A dollar a CD-R is a lot less than a zip disk...
Incidentally, UL still maintains records from their first inception.  They
reportedly have product records over 100 years old.

I was investigating this on a proactive basis in efforts to prod our factory
into keeping more detailed records.  The data could be useful in tracking
break-ins of changes to the manufacturing process in event of a call-back.
This would make the task of tracing thousands of products in the field as
simple as associating the serial number list with the customer shipping
list.
The effort was like pushing a rope uphill -I failed anyway.
Kyle Ehler  kyle.eh...@lsil.com   
Ass. Design Engineer
LSI Logic Storage Systems Division
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8889
Fax 316 636 8315

Kyle Ehler  kyle.eh...@lsil.com   
Design Engineer
LSI Logic Storage Systems Division
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8889
Fax 316 636 8315


-Original Message-
From:   Scott Douglas [SMTP:s_doug...@ecrm.com]
Sent:   Thursday, July 22, 1999 8:35 AM
To: 'EMC-PSTC'
Subject:Record Retention


I have a question about record retention.

We make ITE which incorporates lasers and certify to LVD, EMC
directives. 
We do not create a TCF specifically. We do have outside lab test
reports 
for safety and for EMC. We also have the usual parts lists and CAD
drawings 
for fabrication and assembly along with test procedures. We do
record all 
production tests required for each product shipped.

What documents do we need to keep and how long do we need to keep
them?

We keep the form where we record production tests required for
compliance 
(hipot, ground continuity, laser safety, etc.) for ten years. What 
engineering drawings, parts lists, test procedures, etc. do we need
to keep 
and for how long? Can anyone point me to a specific reference that
requires 
this?

Thank you in advance for your comments.

Scott
s_doug...@ecrm.com


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RE: Computer classification in EN61000-3-3

[Ehler, Kyle]

I tend to agree with Gary that disk drives do not heft a big load change and
cause flicker.  I have repeatable lab test proof of this on an ITE product
we make that has ten disk drives (each ranging in capacity from 9 to
50Gbytes).  I have run flicker test while the box is running a program we
call 'smash and hammer' which causes a lot of disk activity.  This product
always passes the flicker test and uses a redundant pair of hefty switch
mode power supplies.  On the other hand, first turn-on of this product does
produce a large changing load on spinup but the test is not performed until
the EUT is running normally.

Based on my experiences, I would say that these types of devices could be
exempted from the test, but many times our end customers demand that these
and a raft of other tests are run as a matter of routine.  In my case, I can
run both flicker and harmonics from the same workstation and complete the
task in less than one half day.  
One never argues with the customer whomever they may be.
Kyle Ehler  kyle.eh...@lsil.com   
Assistant Design Engineer
LSI Logic Storage Systems Division
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8889
Fax 316 636 8315


-Original Message-
From:   Gary McInturff [SMTP:gmcintu...@packetengines.com]
Sent:   Wednesday, July 21, 1999 3:53 PM
To: 'David Gelfand'; emc-p...@majordomo.ieee.org
Subject:RE: Computer classification in EN61000-3-3


IMO - 
Section A. List some test parameters on a variety of
equipment:
Photocopiers, Hairdryers or portable tools, etc and may cause
voltage spikes
when turned on. The test limits describe the acceptable amount of
voltage
drop as 3 or 4% depending( steady state and max relative voltage
change).
There is a time limit imposed as well, but sort of a rule of thumb
if your
equipment is suddenly demanding a lot of power that could cause the
overhead
lights to flicker (this flicker isn't always perceivable on a
onsy-twosy
basis) you probably need to comply to these limits.
This isn't video flicker etc or switch mode power supply
stuff. I
don't foresee a lot of ITE equipment falling into this category. The
occasionally firing of the disk drives etc shouldn't be drawing this
kind of
power.
I have my asbestos underwear on just in case I'm wrong;
somebody
will let me know.
Gary

.
-Original Message-
From:   David Gelfand [SMTP:gelf...@memotec.com]
Sent:   Wednesday, July 21, 1999 10:27 AM
To: emc-p...@majordomo.ieee.org
Subject:Re: Computer classification in EN61000-3-3


Bonjour Benoit et al,

EN 61000-3-3 section 6.1 states:  "Tests shall not be made
on
equipment
which is unlikely to produce significant voltage
fluctuations or
flicker."
How do you interpret the phrase?

David.

David Gelfand P.Eng
Approvals Group Leader
Memotec Communications Inc.
Montreal Canada

-Original Message-
From: Benoit Nadeau 
To: emc-p...@majordomo.ieee.org

Date: Wednesday, July 21, 1999 12:36 PM
Subject: Computer classification in EN61000-3-3


>
>Bonjour de Montreal,
>
>After a careful reading of EN61000-3-3, we tried to
identify the
testing
>conditions for computer devices and peripherals. Appendix A
of the
standard
>details the conditions for various household equipments.
>
>In section A.11 they specify that the test condition for
consumer
>electronic devices is to measure only the dmax (maximum 4%
of
voltage
>variation).
>
>Are computer and peripheral considered as consumer
electronic
device ?
>
>If it is the case, then we don't need a flikermeter to meet
the
EN61000-3-3.
>
>Any comments ?
>
>
>
>


>--
>Benoit Nadeau, ing. M.ing. (P.Eng., M.Eng)
>Gerant du Groupe Conformite (Conformity Group Manager)
>Matrox 


>--
>
>1055, boul. St-Regis
>Dorval (

Product Safety -Australia and UL1950 ITE

[Ehler, Kyle]

Greetings.

This is my first post here.  I do both EMC testing and product safety, but
primarily product safety testing and filings through Underwriter's
Laboratories acting as both reviewer and submitter [Technical Administrator]
in a two-person safety department.

Reason I present here before you is a bit of a problem I am having with UL
concerning an obscure requirement.  I am wondering if UL is singling me out
over an issue that has to do with the Australian/New Zealand specification
for "DC Component from AC Equipment".  Specifically this is AS/NZS 3260:1993
appendix 3 (pp 366-67) or IEC 60950 appendix 3.

I have an AC powered ITE product that uses two switch mode power supplies
output connected in current sharing redundancy with AC input full wave
rectification i.e. 'balanced input' design that I have certificates for but
in which do not specify compliance with the appendix 3 criteria.  Lab tests
show these to comply with the 5ma limit for DC neutral leakage but readings
are extremely fluctuating and difficult to pin down, but compared to other
power supplies that do have certification, reads within limits.

The problem is I supply UL with schematics that prove the supply has AC
input full wave rectification (balanced input according to the spec and
therefore exempt from testing) yet they are demanding test data.  Up to that
point, I was using a Voltech PM3000A power analyzer for all consumption
related measurements including DC component (harmonic zero).  When I
submitted test measurement data, UL rejected it claiming (correctly) that
the meter used had insufficient specs to perform the measurement according
to the appendix 3 spec for test equipment.  (Voltech had no idea what the
PM3000A's series rejection ratio was until I inquired and had them perform
cal lab tests to determine the figure -which was dismal at best)
Since then, I have acquired a Fluke 8842A DMM (with 85dB NMRR) and attempted
measurements but these readings are so wildly fluctuating that I would have
to tally and average the data manually (or through GPIB) -which would
destroy the accuracy of the measurements taken by a 5.5 digit meter!!
Incidentally, the difference in accuracy (or believable numbers) between the
Fluke and Voltech is nearly the same.  I favor the Voltech with its 'data
dump' feature straight to printed copy -very handy.

Ok, so now I've got more questions than UL Northbrook or Melville can
answer...I ask them how to accurately take measurements of a fluctuating
phenomenon and they answer me with something to the effect that their QAS
department is negotiating with Australia's counterpart in efforts to gain
better understanding.  Meanwhile, I've got a product that has been waiting
since December '98 to gain full CB for the AS/NZS market.

In contrast, I have taken measurements using both Voltech and Fluke meters
of all our products and found one product that seems to fail the measurement
but has certified compliance to appendix 3 through a New Zealand NRTL.  When
I asked the failing product's power supply vendor what test instrument they
used to submit data they reported 'Voltech PM3000A' so I know they are not
being honest.  When I talk with the lab in New Zealand they claim 'balanced
input' design and therefore no test needed, which UL has accepted.

Is anybody else having a ride with UL like this?
-I'm dipped in hogwash here...
how 'dat for openers?
Kyle Ehler  kyle.eh...@lsil.com   
Assistant Design Engineer
LSI Logic Storage Systems Division
3718 N. Rock Road
U.S.A.  Wichita, Kansas  67226
Ph. 316 636 8657
Fax 316 636 8889
Fax 316 636 8315


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