TECHNOLOGY REVIEW
But suppliers have also created LED-specific connectors, often as custom components for particular styles of lamp. Avnet Abacus’ Alan Jermyn, VP of Product
Marketing, says that the most important factor is to ensure that the specific application drives the specification. “We offer connectors from Amphenol, AVX, FCI, Hirose, Molex, Samtec and TE Connectivity that will overcome most of the challenges of LED lighting interconnect. The vast majority of applications can be satisfied with standard connectors, or customised cable assemblies created from these parts,” he says. “But a lighting specific part may be right for a certain situation: for instance, if the requirement is extreme ease of assembly.”
OUTDOOR, STAGE AND STUDIO – RUGGED AND RELIABLE One area in which LEDs are already well established is in stage and studio lighting. Lighting designers value their greater flexibility in creating special effects whilst eliminating the problems caused by excessive heat and high power consumption of conventional lamps. The challenge in these applications is often
to combine rugged construction with ease of assembly and high mating, demating tolerance. A minimum of IP65/67 rating is essential, as is a degree of strain relief within the physical design of the connector to counter the risks of everyday use. A system such as Amphenol’s ‘Ecomate’ circular connectors is a good fit for such requirements. Having been originally developed for use in plant construction and machine building, this is a good example of a product type being re-purposed for lighting applications. The connectors have rugged, moulded
housings and they are designed for quick assembly and come with a screwed cable gland, clamping ring, and combined strain relief and mounting gasket as well as offering the necessary IP65/67 rating.
Figure 1: Ecomate circular connectors are particularly suitable for stage and studio lighting, indoors or outdoors
Architectural lighting is another application that has seen a high adoption of LED lighting.
In
these applications the connector often needs to withstand even more extreme conditions, for instance total water immersion and wide ambient temperature variations, Amphenol LTWs outdoor waterproof connectors are a good fit and another example of a connector developed originally for military and aerospace applications but being repurposed for LED lighting.
LIGHTING SPECIFIC CONNECTORS OFFER SPECIAL FEATURES
Where LEDs need to be fitted into an existing standard form factor, a lighting-specific connector can be the right option. AVX’s 9159, 9175, 9176 and 9177 series wire-to-board connectors and the industry leading 9608 & 9609 series of board-to-board connectors are designed for low power DC-DC interconnect in such applications. The 9608 & 9609 parts are specifically designed for LED applications and offer a 1.4mm mating height, the lowest in the industry. This low mating height matches the height of an SMD LED and as such the connector can be positioned very close to the LED without causing a shadow. The 9159 is also particularly suitable for end-to-end stacking of boards in LED lighting strips where their low 3mm height and 5.5mm overall mated length enable the production of very compact lighting products. The connectors, with contacts rated at 125 VAC at 5 Amps, are available in 2-pin to 6-pin versions, accommodate wires sizes from 22-24 AWG and require no special tools for installation. They feature a locking clip for greater reliability. Also specifically designed for LED
applications, the Hirose DF59 (Figure 5) is a multifunctional system with a mated profile of just 2.5mm. Available in wire-to-board and board-to-board versions, only one type of receptacle is needed, irrespective of whether the cable plug or board mount plug is used, reducing the number of components needed. The 2- to 6-position connectors have an overall size of 8mm x 9mm, preventing the formation of large shadows in LED lighting strips. While form factor is often an absolute
constraint in lighting applications, so too is the need to maintain safety standards. In particular, where mains power is used, the designer will need to be aware of creepage (insulation distance along a surface) and clearance (insulation distance through air) standards.
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Like many connector ranges, the Hirose DF59 (Figure 3) is available in a 2mm or 4mm pitch to accommodate these requirements.
Figure 3: Hirose DF59 connectors have a low profile of just 2.5mm
The need for quick and easy assembly is often a major focus in the lighting market: this is a major benefit of many of the LED-specific connector systems developed by TE Connectivity. Solderless interconnect systems can be particularly useful in driving down the cost of creating LED emitter and module assemblies by accelerating and de-skilling the task. The company’s SMIZ series solderless LED sockets, designed for use with Sharp Mini Zenigata LEDs, allow the direct attachment of the LEDs to a heat sink using two standard M2 screws. The two-piece connector assembly has poke-in wire termination for 24 AWG wires. Integral locating features position the LED accurately into the socket during the assembly process. This is just one example of the company’s solderless LED socket solutions for specific LEDs.
Figure 4: TE Connectivity’s Poke-In
connectors can eliminate soldering when assembling lighting modules or fixtures
Similarly, TE Connectivity’s Poke-In wire connectors (Figure 4) are now widely used in LED lighting fixtures where ease of assembly is paramount. They come in 1- or 2-pole, through- hole or SMT versions and each contact is rated at 250 VAC, 5 A. They accept wire sizes up to 0.8mm.
continues p 8 > focus magazine - issue 12
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