Hi, guys,
does anybody have experience with battery-free amplifiers that are installed in an acoustic guitar to pick up the sound from the guitar and transfer it to an amplifying system? Such devices use large capacity (like, 1.5F) capacitors instead of batteries.
I have got a MiSi device, and it has some kind of interesting component (indicated with a red arrow in the picture). It is only about 3 mm in size. I popped off the cover, to see what is inside. Two pictures are included (with different focus points). Does anybody know what is it? Thank you.