Emerging from the technically sophisticated world of electronics, power LEDs could take a huge bite out of the multi-billion-dollar lighting industry. But only if the vast luminaire industry, expert in metal pressing, plastic moulding and screw assembly, is offered an easy route into a world of surface-mount soldering, beam forming and heat sinking.
Prompted partly by the LED manufacturers, a number of connector firms are tackling the issue themselves and offering assemblies that electrically, optically and thermally interface LEDs to flat aluminium surfaces in ways that suit both sides of the technology divide.
Molex teamed up with LED maker Bridgelux to produce a two-part system called Helieon, announced last month.
The connector is a two-part bayonet type which allows manufacturers, and perhaps consumers, to change LEDs much like light bulbs are swapped.
One part is an annulus (see photo), with a large circular hole in the middle, which is attached by screws to a flat aluminium surface in the luminaire.
This base has two contacts to provide power to the LED module.
Up to 12 contact positions have been provided for future expansion.
"There are two bays with six positions each. One bay is for constant current drivers outside the module, the other is envisioned for putting the driver inside the module," Mike Picini, v-p of lighting products at Molex, told EW.
The part is delivered with wire tails for screw, crimp, or insulation displacement termination elsewhere in the luminaire.
The second part of Helieon is analogous to the bayonet part of a light bulb in that it is permanently bonded to its light source - in this case an LED module from Bridgelux, complete with optics.
When the two parts are twisted together, the contacts mate and a compliant heat pad on the rear of the LED module is squashed onto the aluminium surface.
The thermal pad also provides the slight springing required to operate the bayonet detent.
Helieon from Molex and Bridgelux
Philips is thought to have a similar system to Helieon in the pipeline, dubbed Fortimo Twist, or Twistable, as does a firm called Journee Lighting, which was bought in November by that other lighting giant GE.
For a year or so, German lighting parts maker BJB has been touting a somewhat different two-part system that, while not allowing consumer LED changing, is based around that favourite among LED mounts: the 20mm hexagonal "star" board.
Star boards were invented by Lumileds in the early days of power LEDs as an easy way for engineers to get to grips with the new technology, and they have become a de facto standard where any manufacturer's LED has to be screw- or glue-mounted.
There are also two parts to a BJB LED connector.
The first is a collar with two screw holes that physically and thermally attaches the star board to the luminaire. Underneath the collar are two conductive pads which pressure-connect to the solder pads on the star as it is screwed down. The pads terminate in push-wire terminals - beloved of luminaire assemblers - on the outside of the collar.
The second part is a lens holder - BJB has teamed up with UK lens maker Carclo for optics - which retains the lens and snaps onto the collar to provide optical alignment.
As with the Molex, Philips and GE designs, all parts can be assembled, wired and changed with fingers or, at most, with a screwdriver.
BJB's LED connector system for luminaire makers