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 multivibrator circuit has become a default choice of many hobbyists and even professionals in the past 50 years. Its pair of equations for frequency and duty cycle easily gives ...

This article is part of the 2022 April 1st series in the Humor topic within our Series Library. The ubiquitous 1971 digital miracle—the 555 Timer—is important, replete with 25 transistors, 15 ...