This circuit is valid for other comparators of the same series. In this case, a lamp is excited, but an LED can be used in series with a resistor or other load. The transistor admits equivalent.
Obtained from an English publication, this circuit actually needs a current limiting resistor,...
This 2003 circuit serves to digitally show the intensity of a sound captured by a microphone....
Suggested by a Popular Electronics from the 90s, this circuit uses a buzzer to indicate the...