Bench thermometer (CB20501E)

With an ultra-low consumption, this circuit can be powered by solar cells. The circuit is from a 1991 documentation.

Transistor flasher (CB9785E)
This circuit has a very traditional configuration that can be found elsewhere on the site. R2 and...
Microphone preamplifier (CB9311E)
Found with variations on this site, this circuit was taken from an American documentation from the...
Battery Charger (CB4974E)
This charger for a maximum current of 15 A was obtained from an American 80's schematics. The triac must...