This is a simple circuit which produces a sound similar to the police siren and is built using NE555 Timer. Two 555 timers act as an astable multivibrator. Here is the simple circuit designed to ...
The 555 timer IC is an integrated circuit (chip) which is used in a variety of timer, delay, pulse generation, and oscillator applications. 555 Signals and Pinout (8 pin DIP) Figure below shows the ...
[R-B] designed a 555 timer circuit to scan a keypad. Keypads are common interfaces for small projects and require row and column scanning by a microcontroller. [R-B’s] setup allows you to reduce the ...