LED strip dimmer (circa 2019) uses a 555 timer, because what else would you use? This year is the 50th anniversary of the original design. Back in 1971 [Hans Camenzind] combined 23 transistors ...

the circuit pays homage to the original 8-pin DIP form of the 555. The video below shows the design and build process as well as testing of all the common modes of operation for the timer chip.