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"Micro-Track" Miniature Lighting Apparatus electrical contact issues

Gentlemen;
I happened on an exchange between finishing.com and a chap who was developing a fishing device that would indicate a strike and the issue of contact oxidation in low voltage applications was discussed. I'm at the stage of developing prduct for a patented low voltage lighting system and contact oxidation is one of my main concerns.

In a brief description, two conductor runs of fine copper braid (34 gauge typical) are housed on alternate sides of a plastic track. A ball on the bottom of a low voltage lamp has left and right hemispherical conductors that make contact with the braided cables. It works by simply snapping the ball into the track and aiming the lamp in any direction while still making contact with the braided conductors.
I anticipate that the flexible braid will provide numerous points of contact on the ball conductor as it conforms somewhat to the surface, but I'm of course concerned about oxidation on it as well as on the copper ball contacts. In your previous on-line response, you had first mentioned gold plating for the fishing strike indicator but suggested he could probably get away with "electroless nickel.

I would like to know more about this finish and if this would be the plating material of choice for my application as well? I presume gold might be superior, but expect it would add immense cost to the fine braided wire. Cost will be an important issue This is a 12 or 24 VAC (or DC) track-lighting application and as such will likely be up for years and years. Additionally, a very good solution to the oxidation issue might open up the possibility of a damp location listing. Any suggestions in any direction regarding this application would be greatly appreciated.

Scott Usher
Product designer - Teaneck, NJ, United States
May 29, 2008

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Hi, Scott. Electroless nickel will almost surely prove excellent for this application. If you look at the charging contacts on cordless phones, DC converters, earphone and other small audio and video cables, you will see that it is ubiquitous.

Electroless nickel tarnishes, but "not much". So it is not adequate for very low voltage and low level signals, like many digital signals, for which gold plating is required; but for a "power" application like this it should be excellent. It also has very good wear resistance. Talk to a local plating shop.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
May 28, 2008