555 timer

The 555 timer IC was designed in 1970 by Hans Camenzind. There are hundreds of applications for the 555. The 556 is two independent timers in the same package.

Operating modes

 * Astable multivibrator, (free-running) mode – operates as an oscillator for uses such as tone generation, pulse generation, clock signal.
 * Monostable multivibrator, (one-shot) mode – functions as a one-shot pulse generator. Applications include switch debouncing and pulse-width modulation.
 * Bistable multivibrator, (flip-flop) mode – operates as an SR flip-flop. Uses include debounced latched switches.
 * Schmitt trigger, (inverter) mode – operates as a logic gate to convert a noisy input into a clean digital output.

Projects

 * Atari Punk Console
 * Thomas Henry 555 VCO
 * The VCO-555 by Thomas Henry, Electro-music.com Forum, Aug 2012
 * An easy AD envelope generator by Thomas Henry, Electro-music.com Forum, Dec 2018