Bench Talk

Back off the road after another road trip.

I returned home and pull into my driveway. Immediately, my eyes focus on my overgrown lawn, growing as a result of all the rain and sunshine that has taken place this summer where I live.

The next day, I head to the garage in the blistering 38°C (100°F) North Texas heat. The lawn mower fires, and I am out restoring order to the lawn.

When I arrive to the front of the house, next to my garage, I notice a vine has grown all the way up a window sill to a height of three meters (9.8ft). I go to work and pull it down, thinking to myself, “Wow, how did that grow so fast? That was not there like that the last time I cut the grass.”

This fast-growing vine made me think of the English fairy tale, Jack and the Beanstalk. The young lad, Jack, sold his family’s prized cow for a pile of beans. His mom scolded him for being so foolish and the beans were thrown out the window. To Jack’s amazement, the beans sprouted into a giant beanstalk during the night, and Jack climbed up it to go on and have a great, golden adventure.

At present, the world population is about 7.5 billion people. In the not too distant future, the world’s population will exceed 10 billion people with an expected 8 billion of them living in urban areas. One idea being explored to feed all these mouths is to grow plants and foods through vertical farming within urban areas. And—like Jack's beanstalk—this idea is only growing bigger and bigger.

Much of the arable land is in use and being developed, so a vertical approach makes sense because it lowers the demand to find new arable lands, which are hard and expensive to come by. LED lighting technology is spurring innovative approaches to farming, allowing crops to be grown without direct sunlight in self-contained, environment-controlled, and monitored buildings. Leading LED suppliers, including Cree LED, Lumileds, and OSRAM Opto Semiconductors, are developing horticulture-specific wavelength LEDs. Employing recent wavelength specific enhancements to the color of light illuminating crops, technology is enabling natural ways to use artificial lighting illumination to increase the growth of plants.

LEDs used for vertical farming indoor illumination must be high-efficiency and low-cost. Another important consideration is that they are dependent on the most innovative and reliable interconnect products. Likewise, any connection system that simplifies the tangled beanstalk-like plethora of LED lighting connections associated with the myriad of illumination, power, and sensing requirements involved with vertical farming will, like Jack’s great adventure, surely be a design engineer’s dream come true. Molex is lighting the way with simplicity, flexibility, and innovation. Molex is the recognized leader in providing sealed and unsealed interconnect solutions, wire and cable assemblies, and thermal management expertise for a range of lighting segments.

Two innovative products they have developed that can find their home in vertical farming applications are their new line of Molex’s Lite-Trap^TM and Mini Lite-Trap^TM SMT wire-to-board connectors (Figure 1). These products enable engineers to avoid the tangled beanstalk of LED lighting connections.

Figure 1: Molex Lite-Trap^TM and Mini Lite-Trap^TM SMT Wire-to-Board Connector System, Push-Button Type. (Source: Molex)

 The Lite-Trap connector system is similar to Molex’s Wire Trap connectors and also similar to certain competitive “Poke-In” style versions. A stripped wire is inserted into the connector and pushes open a gate-style terminal that “captures” the wire. To unmate, a button-style lever on the housing top is pushed down to allow the wire to be disengaged. With a profile height of just 4.20mm (0.165in), Molex’s wire-removable Lite-Trap connector offers lower wire insertion force than similar types. It also offers a latch that is easy for operators to engage and disengage, even without the use of a tool. These features combine to offer easy field assembly and removal if needed for trained or untrained operators. Other features of the Lite-Trap connector include a housing design that accepts more Molex insulation-length range than competitive designs. This provides more stable wire seating for electrical contact assurance. The dual-contact, wire-trap clamp design provides further mating assurance.

The Mini LiteTrap™ offers profile heights down to 2.65mm (0.104in) , easy wire removal, low wire insertion, and high wire retention forces for thin LED lighting-module applications. Their ultra-thin profile prevents shadowing in LED lighting applications and saves about seventy percent of overall space when compared to the original Lite-Trap model. The connectors employ an easy-to-use latch that can be opened or closed even without the use of a tool. The Lite-Trap's housing design enables the use of a wider insulation-length range than similar products. This coupled with a dual-contact, wire-trap design provides very stable wire seating and electrical contact assurance.

Large beanstalks may no longer be a thing found only in fairy tales. Vertical farming is coming to the city and with it our ability to grow a variety of plants, including beans. For design engineers working on illuminating beans and other crops, their clear desire is for the horticulturist to worry about tangled beanstalks and for the design engineer to have clear, simple, untangled reliable LED lighting connections in their quest for a magical one-bean solution.