This simple TTL siren was found in a 1980s Electronics Today International. The power supply is 5 V and the integrated circuit can be the 7400.
The existence of field effect transistors at the input of the integrated circuit (operational...
This circuit generates a siren sound. It was found in the April 1969 Radio Electronics magazine. The...
Suggested by Siliconix in documentation from the 90s, this circuit can present gains of digitally...