MIL & JEDEC static warning label examples at:

http://www.staticcontrol.com/staticlabels.asp

-----Original Message-----
From: Alex McNeil [mailto:[email protected]]
Sent: 25 October 2001 15:05
To: '[email protected]'
Subject: EFT Failures..Solved!+ ESD symbol question



Hi Group,

The problem was an oversensitive Display driver. Replacing this driver
solved my problem.

It was diagnosed by:
1.      Was the problem due to conductive or radiated or both? By using the
DC lead, made a small loop, as my noise source with EFT test running, I
noticed the problem occurring near the display circuitry. The fault was
actually a Display lock whereas I thought it was a keyboard lock (same
symptons). I then attached my large ferrite core to the DC cable, several
turns, and repeated the test. No problems. I assumed from this that radiated
was the problem.
2.      What was actually picking up the noise and was the fault the display
driver? I assumed the cable connected to my display was picking up this
noise and conductively passing it on to the display driver. I could not
bypass the problem using caps, functionality started to play up a bit
depending on my value of capacitor. It was at this time I noticed that we
were using an unfamiliar driver manufacturer! I went to the stores and found
the proper part, fitted it and BINGO it now passes up to 3KV!!!!

I am relatively new to this forum. but I think it a good idea if we all
share our problems and diagnostics. I am sure this would be a great help to
many of us!!

However, for my next question?

I want to place a "Static Sensitive Area" symbol on my product molding,
avoiding words, as it will be a worldwide product. The suymbol will be
explained in the user guide.

Q. Is there a worldwide symbol to denote a "Static Sensitive Area" or a
European one and another North American one or.... I would need the .bmp
file if possible?

Kind Regards
Alex McNeil
Principal Engineer
Tel: +44 (0)131 479 8375
Fax: +44 (0)131 479 8321
email: [email protected]

                 -----Original Message-----
                From:   Alex McNeil  
                Sent:   Tuesday, October 23, 2001 9:44 AM
                To:     '[email protected]'
                Subject:        EFT Failures..Update!


                Hi Group,

                THANKS for your very much appreciated responses!! I was in
panic mode!!

                I thought it would be appropriate to let you know the
status.

                My product is a small all plastic enclosure Point if Sale
(POS) Class III terminal. It has an external SMPS, Class II, no earth,
supplying SELV, 12Vdc 1.5A to my product. The power supply works OK with
some of our other products, for EMC. The problem is with my product.

                I solved the problem at the test house by wrapping a few
turns of the DC PSU cable through a "Large" Ferrite Clamp at the Product
input (it did not work so well at the PSU I/P nor O/P). The fix cannot be
considered final due to obvious reasons.

                I am now at my Lab, now the serious diagnostics begin. I
have been trying various "quick fixes" to no avail i.e. Caps, TVS, MOV etc.

                If you have any further comments feel free to email me.

                THANKS again to all those who responded with their thoughts.
I can tell you they were wide and varied just as you would expect to trying
to resolve an EMC problem over the NET!!

                Best Regards
                [email protected]








                         -----Original Message-----
                        From:   Alex McNeil  
                        Sent:   22 October 2001 11:23
                        To:     [email protected]
                        Subject:        EFT Failures..Help!

                        Hi Guys,

                        I am at an EMC test centre today and tomorrow.
Unfortunately, my product failed EFT testing on the AC power port at 1KV.
This is for various combinations of Line, Neutral and Earth (L, N, E, LN,
LE, NE and LNE)

                        My product is Class II, no Earth. It is supplied by
an external power supply. This supplies SELV to my product. The power supply
manufacturer has stated that his power supply meets EN61000-4-4 for 2KV and
has emailed me this report to verify this.

                        Has anyone got a quick solution to my problem so
that I can implement here at the EMC test house?

                        Kind Regards
                        Alex McNeil
                        Principal Engineer
                        Tel: +44 (0)131 479 8375
                        Fax: +44 (0)131 479 8321
                        email: [email protected]
                        

-------------------------------------------
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/

To cancel your subscription, send mail to:
     [email protected]
with the single line:
     unsubscribe emc-pstc

For help, send mail to the list administrators:
     Michael Garretson:        [email protected]
     Dave Heald                [email protected]

For policy questions, send mail to:
     Richard Nute:           [email protected]
     Jim Bacher:             [email protected]

All emc-pstc postings are archived and searchable on the web at:
    No longer online until our new server is brought online and the old
messages are imported into the new server.

-------------------------------------------
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/

To cancel your subscription, send mail to:
     [email protected]
with the single line:
     unsubscribe emc-pstc

For help, send mail to the list administrators:
     Michael Garretson:        [email protected]
     Dave Heald                [email protected]

For policy questions, send mail to:
     Richard Nute:           [email protected]
     Jim Bacher:             [email protected]

All emc-pstc postings are archived and searchable on the web at:
    No longer online until our new server is brought online and the old 
messages are imported into the new server.

Reply via email to