NE556

A popular variant of the well-known NE555 timer IC is the NE556, which contains two timers. With this IC, you can build a simple siren. This siren alternates between two tones, similar to old police car sirens, while also flashing a blue and a red LED. You can test the circuit in Tinkercad: 👉 https://www.tinkercad.com/things/lsxjw2LzvA7-police-siren … Read more