and [learnelectronics] has a video showing the three major modes you typically see with the 555: astable, bistable, and monostable. The 555 is really only a few comparators, a voltage divider ...

Even better, they used a 555 to do it! The circuit is a simple monostable 555 circuit with an active low output. It’s triggered by the indicator signal. When the indicator is on, the circuit ...