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Stupid Case Tricks

A project log for TritiLED

Multi-year always-on LED replacements for gaseous tritium light sources

Ted YapoTed Yapo 01/08/2018 at 19:362 Comments

Here's a quick rundown on what I have learned from playing with the case:

TritiLEDs Sink

I had hoped they would float, but I guess that would make the case larger.  This one stayed under water for a day with no leakage.  It was sealed with a 25x1mm o-ring.  The fit isn't very good, though, and I'm going to try to find some better ones.

Spare Battery

You can fit a spare battery in the bottom of the case:

The "5g" jars are a little too deep, and there's just enough space for a spare CR2032.  For 10-year run-times, a spare cell probably isn't too interesting, but for a bright 1- or 2-year marker, having a spare cell right in the case could be handy.

Magnets!

Like lasers, magnets make everything more interesting.  Here, I glued a cheap 18mm ceramic magnet to the bottom of a case with a dab of epoxy:

The ceramic magnet isn't very strong, but holds the light OK.  A strong neodymium magnet will hold it without glue, just from being attracted to the coin cell through the case.  The best solution is probably glue+neodymium, but then you might have trouble extracting the PCB to replace the battery.

Discussions

Nikos wrote 01/08/2018 at 23:48 point

Great idea to use an O-ring! I was wondering if something flatter might work better, similar to the internal seal on a coke bottle-cap.

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Ted Yapo wrote 01/09/2018 at 00:13 point

I agree.  You could probably punch some from rubber sheet stock with pieces of brass tube, if you could find the right diameters.

You might even be able to find some flat ones commercially.  The 25x1mm ones were cheap, but I wouldn't recommend them: the fit just isn't right.

https://www.amazon.com/uxcell-100Pcs-Nitrile-Sealing-Grommets/dp/B01N0DUK90/ref=sr_1_1?ie=UTF8&qid=1515456684&sr=8-1&keywords=25x1mm+o-ring

Now that I look more closely, there appears to be a wide variety available.  I'll order a few more sizes to find one that fits well.

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