This circuit was found in a 1999 publication. Its purpose is to flash two LEDs according to the sound of an equipment and to randomly flash three LEDs at a controlled frequency
This circuit is from 1987 documentation. The original project was carried out with the tape...
This traditional crystal radio circuit, but which has a modern version with diode, was found in an...
This VCA was found in the July 1988 issue of Radio Electronics magazine. It uses an OTA op amp and...