Page 25 - SPARKS APRIL 2013 1-28 LOW RES
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ELECTRICAL NEWS
april
2013
25
lighting
THE infrared Oslon black SFH 4725S is a
secret agent in many ways. Not only does
its light have a wavelength of only 940
nanometers, making it virtually invisible to
the human eye, but its black package reflects
almost no ambient light.
Together with its high optical output of
almost one watt, this infrared LED fromOsram
Opto Semiconductors is the ideal light source
for covert surveillance says Dr Jörg Heerlein,
head of product marketing for industrial
infrared components.
“Concealed security systems – such as
those installed in banks, on machinery and
at border controls – need to be designed
so that they are unobtrusive. This is a major
challenge for infrared illumination in such
applications because the 850 nanometer
(nm) LEDs that are most often used appear
as weak dots of red light especially in
dark environments.
“The solution is to switch to a wavelength
of 940 nm, which the human eye is 130 times
less likely to notice. Camera sensors however
can easily detect this invisible
Radiation, says Heerlein.
“The Oslon black SFH 4725S from Osram
Opto Semiconductors is the ideal compo-
nent for such applications. This compact
infrared LED provides 940 nm light with the
high optical output of 980 milliwatts from
an operating current of 1A. Behind this high
performance lies the Nanostack technology
in which Osram has succeeded in providing
two emission centres in one chip, almost
doubling the light output.
“The SFH 4725S achieves a radiant inten-
sity of 450mW/sr at an emission angle of
90° and provides excellent illumination over
the area being monitored. Radiant intensity
(measured in milliwatts per steradiant) in-
dicates the light output within a solid angle
segment and therefore defines the intensity
of the light beam,”he explains.
“The black package ensures that the
component is completely concealed behind
the camera lens. The 940 nm SFH 4725S is a
further addition to our Oslon black series for
the security sector, which already includes
850 nm versions with standard and Nanos-
tack chips,”says Heerlein.
Picture: Osram.
High performance IR LED for discreet
security applications
“In the compact class the Oslon is currently
one of the most powerful versions for both
visible and infrared illumination,”he adds.
Measuring only 3.85 x 3.85 x 2.29mm, the
infrared Oslon components are among the
smallest IREDs with around 1Woptical power.
“Users with experience in construct-
ing visible lighting units can transfer their
know-how and their processes directly to the
infrared Oslon,”adds Dr Heerlein.
The market is also full of lenses that design-
ers can use to shape the beam from the IRED
to meet their specific requirements.
Technical data for IROslon black SFH 4725S:
•
Dimensions (3.85 x 3.85 x 2.29) mm
•
Wavelength 940 nm
•
Optical output 980 mW at 1 A
•
Radiant intensity 450mW/sr at 1A
•
Beam angle +/-45°
Enquiries: (011) 207-5600
THE ninth Illumination Engineering Society of
South Africa (IESSA) Annual Congress and AGMwill
be held at the Indaba Hotel in Fourways, Gauteng
from 12 to 15 May.
The theme of the congress will be‘Freedom
in Lighting’.
The IESSA council invites those interested in
presenting papers to submit synopses of nomore
than one page to Mark Greenhill, email
Daniel Kasper at
.
For more information on the conference, contact
Clive Beeton (chairperson) on 082 461 3157.
IESSA congress to be
held in May
