Pat Lawler posted:
>> If a product is rated for 100-240Vac operation, this means test levels
like 40Vac for 100ms (100Vac/50Hz nominal input, 60% dip for 5 cycles). The
performance criteria makes this especially difficult - "The system shall
provide essential performance". <<
Do not forget that,
Hi Hans,
I bought mine directly from the RTCA (downloaded) at:
http://www.rtca.org/onlinecart/allproducts.cfm
Take care sir,
Brent DeWitt
From: owner-emc-p...@majordomo.ieee.org
[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of hansm
Sent: Thursday, April 29, 2004 10:48 AM
To: EMC-PS
Maybe some of the Product Safety folks could correct me if I'm wrong, but I
believe the nameplate must be as high or higher than any actual operating
condition. If this is the case, then I would say that the conservative
approach would be to use the nameplate rating. I have always used the term
"
Andy,
I ran another simulation. This time with a collinear array 1/4
wavelength above a reflecting plane (perfect ground). Very similar I
think to the antenna you described to me. The collinear is 0.6 meters
long. I classify this as an aperture antenna. I would have gone to a 1
meter length but t
It seems there are two definitions of the near/far field transition. The
definition "an area where the ultimate pattern is not fully formed" appears to
apply to my simulation out to a few meters, which is over 100 wavelengths. But
the region where the induction fields exist (the definition I usuall
Correction in the last formula. To remind you, this is the "pillbox"
antenna having a length of 1 meter and a height of 0.07 meter. The
frequency is 9000 kmc (or GHz if you like).
From: drcuthbert
Sent: Thursday, April 29, 2004 4:57 PM
To: 'Price, Andrew P (UK Basildon)'; IEEE EMC-PSTC E-mail F
Our IT Services group sent around a cryptic e-mail
indicating that one of our facilities lost 4 cards in their
PBX, due to "Telephone and Energy cables mixed by a truck."
The inference is that a utility service person performing
service on street level boxes caused the problem. The
precise mecha
I used to deal with this type of testing/approvals for previous
companies/employers and some would use the 'rating' label and not do the test
based on the 'rating' label. Other companies would assess the power level from
actual measurements and test or not test accordingly. In my opinion the
measur
For class A equipment, harmonic limits are not specified for equipment with a
rated power of 75W or less. What is meant by "rated" power? Is this the power
level that is actually measured during the test or the rating as shown on the
product's data plate?
Jim Hulbert
Pitney Bowes
For a "typical" 250W SMPS, I guestimate that the bus cap(s) will contain
approx 145 j. I can think of several single fault conditions that would make
my product safety Type Tests much more fun and spectacular ...
But note that, for voltage dips and short interruptions according to
61000-4-11, IEC
Hi Pat:
> If a product is rated for 100-240Vac operation, this
> means test levels like 40Vac for 100ms (100Vac/50Hz
> nominal input, 60% dip for 5 cycles). The performance
> criteria makes this especially difficult - "The system
> shall provide essential performance".
>
>
You are indeed correect Ken: I shouldn't reply until my 2nd cup of
Starbucks kicks in
Cheers,
Derek.
Ken Javor wrote on 4/29/2004, 12:30 PM:
> lambda/2 pi is only for a tuned dipole-like antenna. 2D^2/lambda is the
> proper expression for a high gain aperture antenna, which is
> defini
lambda/2 pi is only for a tuned dipole-like antenna. 2D^2/lambda is the
proper expression for a high gain aperture antenna, which is definitely what
the original post was about.
> From: "Derek Walton"
> Organization: L F Research
> Reply-To: "Derek Walton"
> Date: Thu, 29 Apr 2004 10:40:15 -050
EN60601-1-2:2001 (EMC requirements for general medical devices) requires
various voltage dip tests at the extremes of the rated input voltage range.
If a product is rated for 100-240Vac operation, this means test levels like
40Vac for 100ms (100Vac/50Hz nominal input, 60% dip for 5 cycles). The
pe
A start-up company in South San Jose, CA. has an opening for a NEBS/EMC
contract position with possiblity of becoming permanent.
The company makes datacom and wireless devices.
If interested, please send your resume to walest...@yahoo.com. I will be
forwarding resumes to them on May 6.
Wale.
Thanks in advance for your help and leads.
Hans Mellberg
Engineering Manager
BACL, a TCB and an EU CAB
230 Commercial Street
Sunnyvale CA 94085 USA
408-732-9162 x38
408-732-9164 fax
Classically I've used Lambda over two Pi.
But I guess it's worth considdering that there is near field, transition
region, and far field.
Thoughts?
drcuthb...@micron.com wrote on 4/29/2004, 9:08 AM:
>
> What should our definition of near/far field be? My somewhat arbitrary
> definition
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What should our definition of near/far field be? My somewhat arbitrary
definition for this case is where the fall-off in the E-field deviates
by 1 dB from 20LOG(D/d). A better definition might be some deviation in
the 377 ratio of E-to-H. I think I can mimic a dish by properly phasing
many dipoles
Andrew Price wrote:
>> I just couldn't believe that the boundary would be at 67 mteres. <<
You might find even harder to believe how far away the "near field" might
extend for an electric lantern's 5 or 6 cm dish.
Cortland
This message is from the IEEE EMC Society Product Safety
Technical Com
Dave and all,
That is a wire antenna. The far field is based on a different criteria.
:-)
Tim Foo
drcuthb...@micron.com wrote on 27/04/2004 11:44 PM
> I ran a NEC simulation to make some sense of this.
> This is too big of a reflector for NEC to handle
> so I made a large rhombic. The rh
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