Using the LM358 from Texas Instruments, this circuit uses LED indicators and can be powered with voltages of 5V or according to the analyzed logic.
This well-known siren configuration using complementary transistors is from a 1980s documentation. The...
This circuit was found in an old American magazine and could make use of more modern components...
This circuit is from the Philips integrated circuits manual of 1990. It is intended for magnetic...