This is a small size led flasher built with the 555 timer IC that is powered from 2 x 1.5V batteries. The circuit can be used as a flashing metronome, dark room timer, memo-reminder or other similar ...

It’s a freeform circuit that synthesizes sound using 555 timers ... in the form of a RGB LED. One with a self-contained circuit to cycle through various colors and blinking patterns.

When the input is 1.25 V and the LEDs are connected, the voltage pulse level will be 23V. The LED driver uses a CMOS 555 timer since it operated with low voltages and can work for about 190 hours when ...

Finding that his recently purchased LED Christmas lights defaulted to an ... and created his two alternating 500 Hz square waves with a 555 timer and a 74HC74D dual flip-flop.