Don't ask me where I got this, but ...
An electrically dangerous fence is defined in most countries
by the energy that the fence can deliver to a 500 ohm load
in a second. The IEC is something like 8 joules from fence
energizers. Canada and the UK is something like 5 Joules.
The fence must
Hi Folks
Sorry to be late in replying on this one - and not really trying to
disagree - but I think you will find that the 125% rule is a "North
American" convention and also followed by countries which use similar
installation practice (i.e. that have plugs with quite small blades/pins!).
The s
Hi all,
When abnormal tests are performed against clause 5.3 of IEC 60950 3rd ed, do
we have to measured the SELV voltage to be sure they are in the limits as
defined in case of first default.
I never seen reports where it's done, but I've performed tests where these
voltage were outside the SELV
Reminds me of when my son (now 25) was very young. We were visiting
relatives in California who used electric fences to keep the cattle where
they belonged. We were sitting around talking when my son came into the
house with eyes as big as saucers to report that "the fence shook me!". It
took a
>>Now I just need to get the Z meter.<<
For one, you might try an MFJ 259B. Covers 1.6-170 Mhz with some degree of
accuracy -- though certainly NOT lab quality! -- and can be had for as low
as $220 or so, new, if you can bargain with the seller. I've found mine
useful even where I DO have access
Hi Folks
I once (about 12 years ago) had the dubious priviledge of being the Comittee
Secretary for the UK BSI standards committee dealing with these beasts at
British & International levels!
This question was never asked (that was probably before my time!) but it was
my impression that these ha
And I would add that the energy can be considered as shown in another clause
of '1010. If your stored charge is below a certain combination of voltage
and charge, then the energy level - despite the voltage - isn't a hazard.
Eric Lifsey
---
This message
Hello Group,
Has anyone got a brief document that outlines how to design PCB to have a
better EMC/EMI performance? I basically need to give some basic guideline to
our PCB guy . I know some of it myself. Things such as separation of high
frequency from low frequency, good ground plane, etc. An
Hi Dave,
Test Db variant 1 test cycle has a period of 24 hours.
Regards,
Kurt
David Heald wrote:
Greetings all,
Does anyone know the time length of the condensation cycles in IEC
60068-2-30 (EN 300 019 states that the condensation test lasts 2 cycles and
references 60068-2-30 as the test met
Something's bothering me about this discussion.
It's not what people have said that I disagree.
Maybe it's to be put in the FWIW department,
1MV breaks down 1 meter of air @ STP.
It then follows that 1KV breaks down 1 mm of air.
So, that's 1mm AIR/1KV.
FR4 has a dielectric factor of about
Brent,
Try this:
Put two 3-foot pieces of your material at some convenient spacing. Using a
Z meter, find the quarter-wavelength frequency, where the impedance will be
zero (open stub), around 82 MHz. When you've found THAT, measure the
impedance at HALF this frequency. The reactive impedance o
Everything in the LVD is designed to prevent electric shock. Electric fencers
are specifically designed to give electric shocks. I guess that is why fencers
would be outside the scope.
I don't know the state of electric fences today. Thirty five years ago, there
were several types. One type was
Greetings all,
Does anyone know the time length of the condensation cycles in IEC
60068-2-30 (EN 300 019 states that the condensation test lasts 2 cycles and
references 60068-2-30 as the test method).
Thanks in advance!
Dave Heald
---
This message is f
Hi
I've been asked why electric fence controllers are "outside the scope" of
the LVD.
I don't know much about them and assume its because they generate voltages
exceeding the LVD upper limit.
Is my assumption correct?
Many thanks
Stuart Miller
---
This m
Hi Brent,
I had the same problem when I designed mine. By using square stock,
which is great for building a log-p, I was not able to get the
impedance necessary to make it look 50 ohms at the driving end(but
close enough to keep the VSWR < 2:1). I was also trying to push the
limits on gain and
For general electro-medical equipment see EN-60601-1, clause 15; 'limitaton
of voltage +/or energy'
- specifies restrictions on voltage beteween supply pins, and supply pins
and enclosure, after removal of plug from mains supply (<60V after 1sec),
tested under least favourable conditions. (No te
16 matches
Mail list logo
