This regulator with current boost and short circuit protection was found in the LM2931 manual that is used in this case. The integrated circuit is not very common today.
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...