Pocket Burglar Alarm

Step 10 Insulating

We are about to put a lot of small electronics into a metal box, which is a short circuiting nightmare.

Cationary Tale: Don't be tempted to start protecting and insulating things before the circuit is complete. I was insulating as I went along, slapping epoxy on everything. I tested the device before sending it, and it didn't work. TBH it would have been faster to start from scratch (there was a short circuit which was buried between the main and sensor boards, under about an inch of epoxy) But I eventually found the offending connection, severed it and rerouted the connection.

So leave this step till last!


Battery Board: flip the board over and file down the space in between the battery contacts as much as possible (don't go too far or you will break the connections)

This gives more space for the batteries (you may notice my lighter doesn't quite close)

I then pasted a thin layer of epoxy(clear nail varnish may allow you to get a thinner layer) over the back of the battery board. Otherwise the batteries will short out against all the other components.

Main/Sensor Board: with a small file go round all the edges removing any unnecessarily large solder lumps which may scrape against the edge.

Then go over these edges with epoxy / nail varnish to make sure they won't short.
You could cover the whole of these board but this is probably unnecessary)

Now that the circuit is finished don't be afraid to put epoxy on any vulnerable connections, especially put a lot on the ends of the wires that go across the hinge, these will be constantly bent about and are in danger of breaking.


Lighter Case: the batteries will come into contact with the lighter lid, so I covered the majority of the lid in pva glue, I used this instead of epoxy because I was able to paint it on and get a nice thin layer.