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 circuit is from an Electronics Hobbyst Handbook from the 90s, being valid for panels of the...
This circuit can generate signals from 80 to 800 Hz with an amplitude of 0.3 V. We find it in a...
This circuit is from an American publication from the 60's. The power is on the order of 600 mW....