Some of my early Projects
I found the corresponding "hardware" in a dusty box in our attic:
First: my first Swatch prototype composed with components of the pharmacy of Guido's father. It did not yet work properly. Second: the fully functional and portable Sun-Swatch - everlasting, without mechanical movement or batteries. It can be easily aligned with the built-in compass and level.
First: the prototype of the first microphone I designed and used. It is still functional, although the sound quality is not up to modern standards. Second: the backside: two carbon electodes - taken from a worn battery. The space between the cellophane membrane and the electrodes is filled with carbon powder produced by crunching the electrodes of another battery. A grid of some additional wire-electrodes boost the response of the system.