In the Potting electronics thread you can follow my progress creating mignons à vitrine, but that is mostly waiting and occasionally checking the results of the curing. I think I’m nearing the point where I can reliably encapsulate whole batches of small electronic circuits in epoxy resin, so now my attention turns to soldering together such circuits.
As discussed here in the Potting electronics thread, I mistakenly ordered some surface mount transistors a week or two ago, and as their really small size matches my needs well I think I’ll try incorporating them into a suitable circuit.
The initial mignon I have in mind is one from Bela Salt. I’m posting here a blowup of the trigger input of that schematic under the GNU Public Licence version 2. Copyright belongs to Rebel Technology dated 2018 and a full copy can be downloaded and used under the same licence from github at:
The trigger output is also shown but I intend to work on the input first, then move to the output afterwards in a separate mignon. My main concern will be to fit the circuit into the space, which is about 20ml. Maybe I should also consider surface mount resistors. A ceramic 100nF capacitor will also be placed across the +3.3V and 0V power rails within the mignon.
I’ll test it in chapeau form, which is a small box with a mini breadboard on top. This will give me a chance to measure the quiescent current and heat dissipation, which are important considerations for this construction technique.
Here’s a picture of my chapeau. It’s a small box (boîte) with a separate lid. A small breadboard on the lid makes it easy to configure and test.
