A better illuminated loupe for inspecting circuit boards.
I bought this loupe for inspecting circuit boards, because of its built in LEDs. But there is a risk of depleting the coin cell batteries if it is left on, so I wanted to fit a rechargeable power source. I began by attempting to modify the existing circuitry, but it is extremely difficult to solder to the existing circuit board, due to it being surrounded by a welded plastic shell.
So I removed the existing circuitry and LEDs entirely and created a ring-light that fits underneath the existing lens retaining ring.
You will need some way of limiting the current draw to no more than about 200mA. Either fit a resistor in series with the battery, or stay tuned for my auto-off control circuit.
The circuit needs up to twelve surface mount Light-Emitting Diodes (LED) in size 0603. I used six normal LEDs (LCSC part C965808) and six side-emitting type (LCSC part C273618.
You can upload the gerbers.zip file to JLCPCB to have this made, or use the mill_gerbers.zip to cut your own on a CNC mill.
You can find instructions for the milling process here.
Soon. .