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 low pulse on this pin (below 1/3 of VCC) sets the internal flip-flop and makes the output go HIGH. When the voltage on this pin reaches 2/3 of VCC, it resets the flip-flop, and the output goes LOW.

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.

LED chaser lights (or) sequential LED flasher circuit on a breadboard using 555 timer + 4017 IC and a few other components. The LED’s chasing rate can be adjusted using a potentiometer in place of 47K ...