The function of the 555 timer is mainly determined by two comparators. The output voltage of the them controls the state of the RS flip-flop and the discharge tube. It also contains 3 working states.

In these days of cheap microcontrollers, it is hard to remember there was a time when timing things took real circuitry. Even today, for some applications it is hard to beat the ubiquitous 555 timer ...

Over at Tiny Transistor labs, [Robo] took it upon himself to reproduce the classic 555 timer in discrete transistor form. For bonus points, he also managed to put it in a package that’s the same basic ...

The circuit was designed sensitive enough to trigger and activate the alarm upon sensing wetness, moisture or dampness on its probes. 555 Timer – an 8-pin electronic device used in several mixtures of ...

A designer and a senior engineer analyze a low-cost alternative for solid-state general-purpose impact sensing uses a standard piezoelectric device (PZT) an a 555 timer. When the piezoelectric device ...