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 passive tuned circuit was found in a 90s Popular Electronics. The coils must be according to the...
This circuit is suggested by Motorola and is based on the well-known 723, integrated voltage...
This circuit appears in other versions in this same section of the website and in other sections with...