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 ...

A PWM circuit works by making a square wave with a variable on-to-off ratio; the average ‘on’ time may be varied from zero to 100%. In this manner, a variable amount of power is transferred to the ...

From simple buzzers to an Atari Punk Console, the simple 555 timer chip is the foundation of a whole lot of interesting lo-fi synth projects perfect for beginners. [Steven] put together a great ...