Monday, April 9, 2012

StacoSwitch loveliness

I wish to tell you about the StacoSwitch line of mil-spec iluminated pushbutton switches, especially the 4N (like 44-, 45-, 49-, etc.) product line. Kindly peruse heavily processed, lousy phone-cam photograph:

stacoswitch-asplode.jpg

These wonders of the cold war era occasionally turn up at surplus outlets and on eBay. They are just slightly obsolete, which is the only reason they're becoming affordable to hobbyists like me and you.

They originally used tiny incandescent lamps (T1-3/4 sub-midget flange base), but there are now affordable LED replacements for these. Grainger (!) has 'em for under $2, so you know we can get 'em somewhere else for under a buck if we look.

Now then, the switch itself. It's usually found in a 4PDT configuration, although 3PDT is also available. That's a fair bit of contacts (control voltages only) but you could also link it to logic to make it a single-event device. It's a Push-Push toggle between the two states.

There are four back-light lamps inside, each of which is individually addressable. A baffle (the white plastic bit with the cross shape) can optionally isolate the light from the bulbs in various ways (ie; two different colors of illumination behind 'Retry' & 'Recycle' seen in the photo). Originally the colors were done with fancy gel cutouts as seen in the photo, today we can use colored LEDs. There's a little rubber gasket around the lamps which prevents their light from going anywhere the baffle (which comes in various configurations) doesn't permit. Changing lamps is a snap right from the front panel, but once you swap them for LED's, you'll never have to pull it out again - except to show your friends how utterly cool these are.

The "off state" appearance can be modified with frosted layers of plastic behind or in front of the printed logo, causing it to disappear when not illuminated, or just making the nice white no-color background you see below, when the colored lamps behind are off.

Note that this entire assembly or explosion of parts to the right of the switch body itself (which stays fixed in the panel) comes out as a single module from the front. A small poker tool is helpful on some models to cause the module to pop forward a bit, then you can pull it out. Fingernails or gorilla strength are not necessary. These things are less finicky than they look, and not difficult to work with, if treated with respect. They are VERY well made. These things go in AWACS and submarines, 'k?

They mount in a 3/4" square hole, but that hole does have to be precise- the clamp behind is thin sheet metal, but the method makes for easy install in any panel thickness up to 1/4" or more. You can probably see the possibilities. Oh, the front-most panel - the part you push on with your finger - is tempered glass I think. It's very scratch resistant. It's got little mortices cut in its edges. These things fit together like watch parts. I picked up a bricked-together panel of eight for near nothing, and I have a few others. I'll be getting more (mostly for choice of light baffles) when the time comes because I have a panel in mind that could use these.

Okay sure, dot-matrix display, daylight-readable pushbutton switches also exist which are far, far sexier than a StacoSwitch. But those are a few c-notes each, whereas these are $6.66 in sets of 3, unused: http://www.electronicsurplus.com/item/2079/ (first hit I came across, just don't get 'em from Surplus Sales of Nevada, those people are sniffing glue, I can't imagine who their wealthy customer base is)

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