LED Luminaries

LED news and insight from our technology editor Steve Bush, who has been messing with LED lighting for more years than he would care to remember.

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IBM builds blue LEDs on graphene

IBM builds blue LEDs on graphene

IBM has shown graphene can be used as a non-stick layer between silicon carbide wafers and epitaxial GaN – allowing the expensive SiC wafer to be used multiple times.

The graphene layer (which it self is epitaxially grown) stays with the SiC – like teflon on frying pan – so the wafer…

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Lumileds adds mid-power arrays and strips

Lumileds adds mid-power arrays and strips

Lumileds has added rigid large-area (55x280mm) arrays and flexible lighting strips to its portfolio – based around 3535 mid-power LEDs.

There is more information on the main Electronics Weekly website…

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Cree's surface-mount CoB alternative

Cree's surface-mount CoB alternative

MH-B is a 4.4W (37V 120mA) 5x5mm lighting LED from Cree.

The idea is that it can replace a whole bunch of single die medium power LEDs, and still be assembled by pick-and-place.

Output is around 500 lm (80CRI, 3,000K), and colour temperatures from 2…

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Just because you can do it, it doesn't make up-lighting right

I can understand why airplanes have tiny LED up-lighters to indicate escape routes, and I can understand up-lighters being used for wall washing, and for under-lighting architectural features and foliage.

What I can’t understand is why anyone puts bright collimated LED sources facing up in normal…

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Just when you thought there was nothing new in optics

Just when you thought there was nothing new in optics

Ledil has shortened a collimator for CoBs by some cunning Fresnel-like compression.

Called Winnie and for CoBs up to 21mm source diameter, it is only 19mm thick for beams from +/-8° to +/-14°, depending on source size.

Even with the unusual light intake, not much has been lost in…

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IR LED emits up to 4.5W at 850nm or 940nm

IR LED emits up to 4.5W at 850nm or 940nm

Up to 4.5W at 850 or 940nm is available for security lighing now LED Engin has put four dual-junction die in its 7x7mm LZ4 package.

It has also released a single die LZ1 (4.4×4.4mm) version, and a single-junction four die version.

For more information, take…

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Verbatim bulb scores 'best buy' at Which?

Verbatim bulb scores 'best buy' at Which?

Verbatim, once a floppy disc company, is now an LED bulb maker. And it has won a ‘best buy’ rating at consumer organisation Which?

Which? is impressive because its reviewers don’t just guess, it has its own test labs. It awards percentages to each item on test based on…

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Osram achives IR LED high

Osram achives IR LED high

Osram has pushed up the power of its 850nm Oslon Black leds, upping output to 800mW from 630mW in the ‘A’ suffix version of its SFH 4715.

This is a 90° led intended for security illumination. For feeding narrow-beam reflector optics, there is also a 150° SFH 4716A.

For…

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Silicone Lenses for COB LEDs

Silicone Lenses for COB LEDs

   Khatod has introduced silicone lenses for CoB arrays, called SIO3.

The material has been chosen for its: sustained transparency over years, resistance to yellowing, UV-resistance, optical efficiency, lack of birefringence, temperature resistance (-40 to 150°C, 200°C peak), and flexible at low temperatures.

Designed for streetlights, depending on…

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Seoul omni light engine for A19 bulbs

Seoul omni light engine for A19 bulbs

Seoul Semiconductor has announced an led module for A19 light bulbs that uses two recently-announced products: Acrich MJT 2525 series LEDs and Acrich3 mains-voltage driver chip – Acrich is the firms brand for higher-voltage products that allow direct-off-mains operation with only a few devices, and without…

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Nichia argues for novel mid-power led encapsulation

Nichia argues for novel mid-power led encapsulation

Nichia has published a white paper discussing encapsulation materials for reliable mid-power leds.

It is quite detailed, and includes Nichia’s critisism of polyphthalamide (PPA – its benzine rings photo-degrade).

The firm’s replacement is decribed as ‘thermoset composite and inorganic materials’, in some sort of matrix, it appears…

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Cavers and miners will be happy

Cavers and miners will be happy

Cavers and miners will be happy, as Ledil has made a collimator especially for them.

Called Crystal, beams down to +/-1.5° are possible.

There are two products: Crystal-RS and Crystal-Mine.

“According to mining head lamp specifications Crystal-Mine has 10% added illumination over the cut-off area…

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