Found in an old Popular Electronics this circuit appears in other variations on this site and in this section. It uses a 7-segment common anode LED display as an indicator.
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...