This Japanese radio is from the 60s, presenting excellent sensitivity and an output power of 100mW with 6 V power from ordinary batteries. The circuit is of the superheterodyne type.
This two-tone buzzer can be powered by a solar panel. The circuit is from a 1991 documentation. The...
This blocking oscillator was found in a publication from the 50's. The coils determine the...
The TPA3100D2 integrated circuit from Texas Instruments (www.ti.com) consists of an efficient...