This PA or Public Address amplifier with a few watts of power was found in the March 1986 Radio Electronics magazine. It uses two LM380 ICs in bridge mode for higher power.
We found this circuit in a 1977 publication for radio amateurs. It serves to test general purpose...
This circuit is from a 1998 Poptronics. The circuit triggers a buzzer after a certain time, waking...
This circuit for electronic voltmeter was found in a publication by Gernsback from 1960. The...