Sunday, September 8, 2013

A Miniature IDC (Insulation Displacement Connector) In-Line Switch Installation

These things are neat.

Those tiny prongs connect to insulated wire by piercing and shoving aside the insulation, hence 'insulation displacement'.

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I just finished an in-line switch installation on an articulated lamp, and that reminded me that I have another, very similar situation in the shop. The lamp at my wood lathe is fitted with an in-line switch that's subbing for the lamp's original rotary switch that bit the dust long ago. As with the previous lamp, the switch is installed just below the base of the lamp -- a counter-intuitive, clumsy place for a lamp's switch to be.

And as with the previous lamp, I'd like to relocate the switch to very near the head of the lamp -- a much more convenient place for the switch. And since I happen to have a very compact switch on hand, I should be able to make quite a tidy job of it. There's a complication, though; the wiring there is not the usual 18AWG zip cord, it's two individual wires with tougher insulation on them. It will be interesting to see if I can make this work. Here's a view of the wiring material I need to install the switch on.

What I'll do is I'll warm up the wire with a heat gun just before I assemble the switch. That should give me a reasonable chance of success with this.

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Installation of these switches is greatly aided and simplified by the design of the cover portion. You cut the conductor to be acted on by the switch, then lay the wires into their respective channels in the cover, like so.

Assemble the two halves, tighten the screw and it's done. The sharp little prongs pierce the cut wire's insulation to contact the copper inside, and there you are.

It works.

Note that you may want to take the switch wheel's rotation orientation into account before assembling the switch. In this case, I wanted the upper side of the wheel to have to rotate toward the lamp head. I had to mind that before committing to assembling the switch.

For a finishing touch, I gave the switch a shot of WD-40. Switches and WD-40 get along famously together.

I'll leave the other switch in place, and always on for now. Once I'm certain that there's nothing flaky about this switch's operation, I'll delete the other switch and have it for a spare.

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