Hello from San Diego:
EN 60950 A11 invokes EN 60825-1, laser safety.
EN 60825-1 was amended to include ALL LEDs, not
just laser LEDs or coherent light. Some folks
feel this was a major political snafu of the
committee, but the committee has not admitted
such and is attempting to save face. There is
some justification for including general LEDs
because some of the new automobile tail-light
LEDs can be bright enough to cause damage when
viewed closely.
EN 60825-1 establishes emission classes, from
Class I upwards. Class I is the lowest emission
class; therefore ALL LEDs are at least Class I.
Fortunately, product labelling is optional when
the emissions are Class I, provided Class I is
declared in documents accompanying the product.
Emission class is determined under normal
conditions and under fault conditions. So, if
the circuit has a resistor in series with the LED,
the resistor is shorted during the emission
measurement. If the LED opens, then it is Class I
under fault conditions.
Emission measurement is not easy, requires some
very specialized optical measuring equipment, and
requires some careful calculations. The calculations
required by the standard are not easy to interpret
and apply.
The most difficult (and expensive) measurement is
that of source size.
Some certification houses are ignoring A11, and
some are invoking A11. My experience with one
certification house was disastrous, as they did
not have the necessary equipment to measure the
emissions and neither did we. (I don't know of any
cert house that has the necessary test equipment!)
We were sent to yet another organization for some
of the testing. They would not certify the product
unless they had emission test results. These were
front panel LEDs! It became so onerous and expensive,
that I withdrew the product and went to another
organization. Later, they told me that they accept
front panel LEDs without test!
We ignore EN 60825-1 measurements, but we declare
compliance. Our certification houses likewise
ignore EN 60825-1 measurements. If they don't, I
request no measurements and ask that they so state
in the CB Report.
Most LED manufacturers are not aware that EN 60825-1
applies to LEDs. If you ask for emission data, you
will find the ignorance.
Best regards,
Rich
-------------------------------------------------------------
Richard Nute Product Safety Engineer
Hewlett-Packard Company Product Regulations Group
AiO Division Tel : +1 619 655 3329
16399 West Bernardo Drive FAX : +1 619 655 4979
San Diego, California 92127 e-mail: [email protected]
-------------------------------------------------------------
---------
This message is coming from the emc-pstc discussion list.
To cancel your subscription, send mail to [email protected]
with the single line: "unsubscribe emc-pstc" (without the
quotes). For help, send mail to [email protected],
[email protected], [email protected], or
[email protected] (the list administrators).
